JP3808041B2 - Railway roadbed construction method using asphalt-based structural materials - Google Patents

Description

【００７８】
また、上記の結果を、横軸に経過時間（単位：分）をとり、縦軸に圧縮強度（単位：ＭＰａ）をとって示したものが図４（Ａ）である。図４（Ａ）において、曲線Ａ３は実施例Ａの配合のアスファルト系構造材料の場合を、曲線Ｂ３は実施例Ｂの配合のアスファルト系構造材料の場合を、曲線Ｃ３は従来のアスファルトのみの填充材の場合を、それぞれ示している。これらの数値や図からわかるように、仮にアスファルト系構造材料の強度規格値σ_Bとして０．１ＭＰａを採用すると、従来のアスファルトのみの填充材の場合には、６０分すなわち１時間経過後の時点では、強度規格値σ_Bの６０％であり、初期強度が低く、道床填充に用いた場合には道床沈下防止性能が不足していることを示している。これに対し、実施例Ａ，Ｂは、いずれの場合も、１時間経過後の時点では、強度規格値σ_Bを上まわっており、初期強度が高く、道床填充に用いた場合、十分な道床沈下防止性能を有することがわかる。特に、実施例Ｂの場合には、１時間経過時点の圧縮強度が０．２１ＭＰａと強度規格値σ_Bの２倍以上の値に達している。これは、マイカ粉末によるアスファルトの補強がかなり有効であるとも考えられる。
【００７９】
次に、実施例Ａ，Ｂのアスファルト系構造材料、及び上記と同様の配合のアスファルトのみの填充材について、上記と同様の試験体を作成し、ＪＩＳ Ｒ ２２２６に規定する試験方法に準じて圧縮強度を測定した。最終強度に達した後の各雰囲気温度における圧縮強度の値を以下に示す。下記の測定結果において、温度の単位は°Ｃであり、圧縮強度の値の単位はＭＰａである。

【００８０】
また、上記の結果を、横軸に雰囲気温度（単位：°Ｃ）をとり、縦軸に圧縮強度（単位：ＭＰａ）をとって示したものが図４（Ｂ）である。図４（Ｂ）において、曲線Ａ４は実施例Ａの配合のアスファルト系構造材料の場合を、曲線Ｂ４は実施例Ｂの配合のアスファルト系構造材料の場合を、曲線Ｃ４は従来のアスファルトのみの填充材の場合を、それぞれ示している。これらの数値や図からわかるように、この場合にも、仮にアスファルト系構造材料の強度規格値σ_Bとして０．１ＭＰａを採用すると、従来のアスファルトのみの填充材の場合には、もとになる最終強度自体が低いうえに高温になると圧縮強度の低下度合が大きく、６０°Ｃにおける圧縮強度は０．１５ＭＰａしかなく、７０〜８０°Ｃ程度になると圧縮強度が強度規格値σ_Bを下まわる可能性があり、直射日光にさらされる盛夏期には道床沈下防止性能が確保されないおそれがあることを示している。これに対し、実施例Ａ，Ｂのアスファルト系構造材料は、いずれの場合も、最終強度及び強度低下率のいずれにおいても余裕があることがわかる。特に、実施例Ｂの場合には、６０°Ｃにおける圧縮強度は０．４ＭＰａもあり、圧縮強度が強度規格値σ_Bを下まわる温度は１５０°Ｃ以上と考えられ、盛夏期等においても圧縮強度が強度規格値σ_Bを下まわるおそれはなく、つねに十分な道床沈下防止性能が確保され得ることを示している。
【００８１】
上記した各実施例Ａ，Ｂの配合のアスファルト系構造材料については、さらに、鉄道道床に対し試験施工を行なった。すなわち、基材であるブローンアスファルト及びプレパウダーアスファルトの混成物に繊維、粉末、添加材等を第１温度（例えば１２０〜１８５°Ｃ）で混合し、その混成物を、第１温度よりも高温な第２温度（例えば２２０〜２６０°Ｃ程度）まで加熱し、填充材を流動状態とした。次に、この流動物を鉄道道床形状に敷設した骨材の上から散布したところ、填充材は骨材間に滑らかに流入し、骨材の最深部まで効率良く填充させることができた。その後、道床最上部からアスファルト系構造材料が溢れてきた状態で填充材散布を停止し、放置冷却した。その後、冷却によりアスファルト系構造材料は硬化し、約１時間経過後には所定の強度を発現した。この結果から、注入後短時間経過後での列車走行開始が要求される鉄道の営業線においても、上記のアスファルト系構造材料は十分使用可能であることがわかる。
【００８２】
なお、本発明は、上記各実施形態に限定されるものではない。上記各実施形態及び各実施例は、例示であり、本発明の特許請求の範囲に記載された技術的思想と実質的に同一な構成を有し、同様な作用効果を奏するものは、いかなるものであっても本発明の技術的範囲に包含される。
【００８３】
例えば、上記各実施形態においては、骨材として、かこう岩、安山岩、硬質砂岩等からなる稜角の多い砕石、あるいは細粒分の比較的少ない粒度分布（例えば粒径が１５〜７５ｍｍ程度）の砕石を例に挙げて説明したが、本発明はこれには限定されず、他の種類の骨材、例えば他の材質の天然岩石を砕いた砕石、砂利、石炭ガラ、高炉スラグ、セラミックス等の人工材料による人工骨材などであってもよく、また粒度分布も他の粒度であってもよく、稜角の少ないもの、あるいは稜角のない玉石状の骨材であってもよい。
【００８４】
また、上記各実施形態においては、アスファルト系構造材料として、アスファルトに繊維を適宜の割合で混合したもの（第１実施形態）、アスファルトに粉末を適宜の割合で混合したもの（第２実施形態）、アスファルトに繊維と流動化材をそれぞれ適宜の割合で混合したもの（第３実施形態）、アスファルトに繊維と粘弾性化材をそれぞれ適宜の割合で混合したもの（第４実施形態）を例に挙げて説明したが、本発明はこれには限定されず、他の構成のアスファルト系構造材料、例えば、第１実施形態の混成物（アスファルトに繊維を適宜の割合で混合したもの）に粉末、流動化材、粘弾性化材のいずれか又はこれらの適宜の組み合わせを適宜の割合で混合してもよいし、第２実施形態の混成物（アスファルトに粉末を適宜の割合で混合したもの）に繊維、流動化材、粘弾性化材のいずれか又はこれらの適宜の組み合わせを適宜の割合で混合してもよい。
【００８５】
例えば、アスファルトに混合して強度向上等に寄与させる粉末については、上述したもののほか、石灰岩（石灰石）の粉末も有効である。石灰岩の主成分は炭酸カルシウム（ＣａＣＯ₃）である。また、消石灰（水酸化カルシウム：Ｃａ（ＯＨ）₂）の粉末、酸化カルシウム（ＣａＯ）の粉末も有効である。これらは、いずれもカルシウム分を含んでいる。一般に、ポルトランドセメント等のセメントに水と砂や砕石等の骨材を混合すると、セメントと水が水和反応を行い、セメントの水和反応生成物が骨材どうしを強固に固結させることにより強度の高いコンクリートとなる。この際、セメントの水和反応生成物の主たるものは、カルシウム塩（カルシウムケイ酸化物）である。したがって、アスファルトにカルシウム分を含んだ物質の粉末を混合させた場合は、コンクリートの場合と類似した生成物により強度向上が図られるものと考えられる。これらの材料は、カルシウム系材料に相当している。
【００８６】
また、アスファルトに混入させる繊維又は粉末としては、珪砂等のシリカ（二酸化ケイ素：ＳｉＯ₂）、アルミナ（Ａｌ₂Ｏ₃）、マグネシア（ＭｇＯ）、ジルコニア（ＺｒＯ₂）、ムライト（３Ａｌ₂Ｏ₃・２ＳｉＯ₂）、チタン酸アルミニウム（Ａｌ₂ＴｉＯ₅又はＡｌ₂Ｏ₃・ＴｉＯ₃）、ＬＡＳ（Ｌｉ₂Ｏ−Ａｌ₂Ｏ₃−ＳｉＯ₂）、コーディエライト又はＭＡＳ（２ＭｇＯ・２Ａｌ₂Ｏ₃・５ＳｉＯ₂）、窒化ホウ素（ＢＮ）、窒化アルミニウム（ＡｌＮ）、窒化ケイ素（ＳｉＮ）、炭化ケイ素（ＳｉＣ）等についても、強度向上に有効である。これらは、セラミックスの主成分であり、アスファルト中に混合された場合は、セラミックスと類似した生成物により強度向上が図られるものと考えられる。これらの材料は、セラミックス系材料に相当している。
【００８７】
また、アスファルトに混入させる粉末としては、石英、長石類やフッ石類についても、強度向上に有効である。石英は、二酸化ケイ素（ＳｉＯ₂）を主成分とする。長石類は、正長石（Ｋ〔ＡｌＳｉ₃Ｏ₈〕）、曹長石（Ｎ〔ＡｌＳｉ₃Ｏ₈〕）、灰長石（Ｃａ〔Ａｌ₂Ｓｉ₂Ｏ₈〕）を含む鉱物である。また、フッ石類は、方フッ石（Ｎａ〔ＡｌＳｉ₂Ｏ₆〕・Ｈ₂Ｏ）、輝フッ石（Ｃａ₂〔Ａｌ₄Ｓｉ₁₄Ｏ₃₆〕・１２Ｈ₂Ｏ）を含む鉱物である。一般に、長石類やフッ石類は、岩石の成分である。したがって、アスファルトに長石類やフッ石類の粉末を混合させた場合は、岩石等の場合と類似した生成物により強度向上が図られるものと考えられる。
また、上記と同様の理由から、アスファルトに混入させる粉末としては、岩石や砂を粉砕して生成した石粉等も強度向上に有効である。
これらの材料は、岩石鉱物系材料に相当している。
【００８８】
また、アスファルトに混入させる粉末としては、カオリン系粘土、陶石、タルクについても、強度向上に有効である。カオリン系粘土は、カオリナイト（Ａｌ₂Ｓｉ₂Ｏ₅（ＯＨ）₄）やハロイサイト（Ａｌ₂Ｓｉ₂Ｏ₅（ＯＨ）₄・２Ｈ₂Ｏ）などのカオリン鉱物を主成分とする粘土である。また、陶石は、セリサイトを主成分とし、石英を含む材料である。また、タルクは、含水マグネシウムケイ酸塩鉱物である。一般に、カオリン系粘土、陶石、タルク等は、焼成により固化し陶磁材料や耐火材料となる。したがって、アスファルトにカオリン系粘土、陶石、タルク等の粉末を混合させた場合は、陶磁器等の場合と類似した生成物により強度向上が図られるものと考えられる。これらの材料は、陶磁系材料に相当している。
【００８９】
また、アスファルトの強度向上を目的として混入させる繊維又は粉末としては、上述したようにガラスも有効である。ガラスは、一般には、ケイ酸塩又は硼酸塩若しくは燐酸塩と塩基性酸化物を混合溶融し非晶質状態で固化させたものである。例えば、シリカ（二酸化ケイ素：ＳｉＯ₂）と炭酸ナトリウム（Ｎａ₂ＣＯ₃）と炭酸カルシウム（ＣａＣＯ₃）を混合溶融させ急速冷却させたソーダ石灰ガラス等が知られている。陶磁器における釉薬や、七宝細工等の硬質成分はガラス質である。したがって、アスファルトにガラス質物質の粉末を混合させた場合は、ガラスや陶磁器等の場合と類似した生成物により強度向上が図られるものと考えられる。これらの材料は、ガラス系材料に相当している。
【００９０】
また、アスファルトに混入させる粉末としては、上述したように雲母（マイカ）も有効である。雲母は、フィロケイ酸塩鉱物であり、天然に産出する白雲母（マスコバイト：ＫＡｌ₂（Ｓｉ₃Ａｌ）Ｏ₁₀（ＯＨ）₂）、ソーダ雲母（パラゴナイト：ＮａＡｌ₂（Ｓｉ₃Ａｌ）Ｏ₁₀（ＯＨ）₂）、金雲母（フロゴパイト：ＫＭｇ₃（Ｓｉ₃Ａｌ）Ｏ₁₀（ＯＨ）₂）、黒雲母（バイオタイト：Ｋ（Ｍｇ，Ｆｅ）₃（Ｓｉ₃Ａｌ）Ｏ₁₀（ＯＨ）₂）が含まれる。また、金雲母のＯＨ基のかわりにフッ素（Ｆ）が入ったフッ素金雲母が工業的に製造されており、合成マイカと呼ばれている。これらのマイカは、ガラスの脆性を改善しガラスの性質を有しながら機械加工も可能としたマイカ結晶化ガラス等の材料として用いられている。したがって、アスファルトにマイカの粉末を混合させた場合は、マイカセラミックス等の場合と類似した生成物により脆性の改善、すなわち粘弾性向上が図られ、かつ、アスファルト単体に比べ最終強度も向上するものと考えられる。したがって、これらのマイカは、小径混入部材としても、粘弾性化材としても使用可能である。また上記の各マイカは、マイカ系材料に相当している。
【００９１】
上記した炭酸カルシウム、水酸化カルシウム、二酸化ケイ素、ガラス等の粉末は、アスファルトに比較して比重が相対的に大きい（以下、これらの粉末を「大比重粉末」という。）。このため、これらを単独でアスファルト中に混入させると、粉末分がアスファルト底部に沈澱し、アスファルト分と粉末分との材料分離が発生する場合がある。このような材料分離が生じると、アスファルトの強度向上等は図れない。一方、マイカ粉末は、アスファルトに比較して比重が相対的に小さいため、アスファルト中に混入させた場合、粉末分がアスファルト中に長時間浮遊し、アスファルト分と粉末分との材料分離が発生することが少ない。このことを利用し、上記した炭酸カルシウム等の大比重粉末をアスファルト中に混入させる際に、マイカ粉末も混入させると、アスファルト中に浮遊するマイカ粉末が大比重粉末の沈澱を防止するように作用する。この場合、大比重粉末とマイカ粉末の配分比率が、ほぼ１：１のときに、大比重粉末の沈澱防止効果が最も良好であった。また、マイカ粉末は、上記したようにアスファルトの粘弾性改良効果も有するので、アスファルトの性質改良の観点から好ましい。さらに、マイカ粉末は、大比重粉末に比べ、価格的にも低廉であり、アスファルト系構造材料の低廉化にも有効である。
【００９２】
また、上記した第２実施形態の説明においては、アスファルト中での分散性能等の点から見た粉末の直径として、１０〜１００μｍ程度の値を例に挙げて説明したが、上記した岩石の粉砕粉末等をも考慮すると、粉末の直径の範囲は、１０μｍ〜１ｍｍ程度まで許容可能である。
【００９３】
また、上記した第２実施形態の説明においては、強度の点から見た粉末の混合割合の上限値は、重量パーセントでアスファルト系構造材料全体に対し３０％程度の値を例に挙げて説明したが、上記した大比重粉末をアスファルト中に混合することをも考慮すると、この上限値は重量パーセントでアスファルト系構造材料全体に対し５０％程度まで許容可能である。
【００９４】
また、上記した第３実施形態の説明においては、流動化されたアスファルト系構造材料の流動性を高めるための流動化材として、非晶質ポリオレフィン系合成樹脂を例に挙げて説明したが、本発明のアスファルト系構造材料における流動化材はこれには限定されない。一般に、熱可塑性樹脂は、上記の流動化材として使用可能である。熱可塑性樹脂は、常温では固体であるが、加熱すると軟化し、さらに加熱すると溶融して流動状態となる合成樹脂である。このため、アスファルト系構造材料中に混入させれば、アスファルト系構造材料の流動状態においては、熱可塑性樹脂も流動状態となり、アスファルト系構造材料の流動性を高めると考えられる。熱可塑性樹脂には、上記したポリエチレン、ポリプロピレン等のほか、ポリ塩化ビニル、ポリ塩化酢酸ビニル、ポリ塩化ビニリデン、ポリ酢酸ビニル、ポリビニルアルコール、ポリビニルホルマール、ポリビニルブチラール、ポリビニルアセタール、エチレン酢酸ビニル共重合樹脂（ＥＶＡ樹脂）、ポリスチレン、ＡＢＳ樹脂、ＡＳ樹脂、フッ素樹脂、ポリメチルペンテン、ポリスルフォン、ポリアミド、ポリアミドイミド、ポリエーテルイミド、スチレン系共重合樹脂、ポリカーボネート、ポリメタクリル酸メチル、ポリウレタン、セルロースアセテート、その他のセルロース系樹脂、ポリエチレンテレフタレート、ポリブチレンテレフタレート、ポリフェニレンエーテル、ポリフェニレンオキサイド、ポリフェニレンスルファイド、シリコン樹脂、ポリスルフォン、ポリエーテルスルフォン、ポリアリレート、ポリイミド、ポリアリルエーテル、ポリエーテルエーテルケトン、ポリブチレン、ＡＣＳ樹脂、ＡＳＡ樹脂、ＭＢＳ樹脂等が含まれる。
【００９５】
本発明のアスファルト系構造材料における流動化材としては、さらに他の物質も使用可能である。一般に、アスファルト乳化剤は、加熱アスファルトの流動性の向上に有効である。このアスファルト乳化剤は、アニオン系乳化剤、カチオン系乳化剤、ノニオン系乳化剤に分類され、アスファルトを微粒子として乳化させるための物質であり、このアスファルト乳化性能が加熱時のアスファルトの流動化向上に寄与すると考えられる。
アニオン系乳化剤としては、ロジン、リグニン、トールオイル等の木材製品の副産物のカルボン酸又はスルフォン酸のアルカリ金属塩、脂肪酸や高級アルコール硫酸エステル又はアルキルベンゼンスルフォン酸等のアルカリ金属塩などが挙げられる。ロジンは、松の樹脂から抽出される粗製テレビン油を蒸留することにより得られる黄色から褐色の半透明の物質であり、アビチエン酸、パラストリン酸等を主成分とする。リグニンは、セルロースとともに植物の木質部を形成する無色から褐色の物質であり、紙パルプの亜硫酸溶液から得られる。トールオイル（トール油）は、ロジン、脂肪酸、ステロール、高分子量のアルコール等からなる黄色から黒色の樹脂状物質であり、木材パルプ製造時の廃液から得られる。
カチオン系乳化剤としては、牛脂や椰子油を原料とする脂肪酸誘導体のアミン（ジアミン、トリアミン、イミダゾリン等）の塩酸塩又は酢酸塩が挙げられる。
【００９６】
また、上記の流動化材を使用すれば、同一温度ではアスファルトの流動性を高めることができる。したがって、流動化材を用いれば、同程度の流動性を得るのに必要な加熱温度（第１温度）を低下させることができる。
【００９７】
また、本発明のアスファルト系構造材料に熱硬化性樹脂を混合すれば、固化後のアスファルト系構造材料の強度は向上すると考えられる。一般に、熱硬化性樹脂は、加熱すると硬化する合成樹脂である。このため、アスファルト系構造材料中に混入させれば、アスファルト系構造材料の硬度の向上に寄与すると考えられる。熱硬化性樹脂には、フェノール樹脂、ユリア樹脂、メラミン樹脂、キシレン樹脂、ジアリルフタレート樹脂、フタル酸樹脂、不飽和ポリエステル、エポキシ樹脂、フラン樹脂、ベンゾグアナミン樹脂、熱硬化ポリブタジエン等が含まれる。
また、熱可塑性樹脂の場合も、冷却後は固化するため、固化後のアスファルト系構造材料の強度は向上すると考えられる。したがって、一般に、合成樹脂（プラスチックス）は、アスファルト系構造材料の強度向上に有効である。
【００９８】
また、上記した実施形態においては、アスファルト内に混合する部材として、繊維と粉末とを例に挙げて説明したが、本発明はこれには限定されず、一般に、小径の混入部材であれば、形状はどのようなものであってもよく、粉末よりも粒径の大きい粒子状であってもよい。また、この小径混入部材は、金属材料のように、溶融アスファルト内においてもアスファルトと融合せず混合状態を保持し得る部材であってもよい。この場合には、固化後のアスファルト系構造材料内においては、混合された小径部材は、アスファルト内に分散されており、アスファルト内に融合して消失しているわけではないため、「混合物」ということができる。一方、本発明における小径混入部材は、合成樹脂のように、高温の溶融アスファルト内においては、アスファルトと融合し、純粋のアスファルトとは異なる組成のアスファルト系物質を生成するような部材であってもよい。この場合には、固化後のアスファルト系構造材料内においては、混合された小径部材は、アスファルト内に融合して消失しており、新たな物質を合成しているため、「合成物」ということができる。上記記載における「混成物」は、混合物と合成物の２つの概念を併せた概念を表現する用語として用いられたものである。
また、上記記載における「改質材」は、流動化材と粘弾性化材の概念を含む上位概念を表現する用語として用いられたものであり、流動状態又は硬化後の混成物の性質を改良する物質に相当している。
【００９９】
また、上記各実施形態においては、アスファルト系構造材料を骨材の填充材として用いた構造物として、鉄道用道床を例に挙げて説明したが、本発明はこれには限定されず、他の種類の構造物、例えば道路における床状部、ふ頭やその他の港湾構造物における床状部、滑走路やエプロン等の空港構造物における床状部、埋立地における床状部、建築物における床状部、又は農業用構造物における床状部などであってもよい。
【０１００】
また、本発明に係るアスファルト系構造材料は、骨材を床状に敷設して予め形成した被填充体に流動状態で流し込んでアスファルト系構造材料填充構造物を施工する填充工法以外に、他のアスファルト系構造物の施工に利用することも可能である。例えば、本発明に係るアスファルト系構造材料と、砂や砕石等の骨材とを混合して、アスファルト骨材混成物を作り、これを敷きならして締め固めることにより、層状の構造を形成することもできる。
本発明に係るアスファルト系構造材料は、アスファルトに繊維又は粉末等が混合されており、いわゆる天然アスファルトに類似した組成を有し、硬くかつ耐摩耗性が高いという性質を有している。
したがって、本発明に係るアスファルト系構造材料は、新設道路建設用舗装材料、既設道路舗装のひび割れ，穴等の補修用材料、又は橋りょう上のジョイント部分の舗装の補修用材料、あるいは橋りょう等における段差部のすり付け用材料としても利用可能である。
このように、天然アスファルト類似の材料として使用する場合には、耐摩耗性能をさらに向上させるため、粒径が１〜５ｍｍ程度の粒子状の天然砕石、人工砕石、砂等を混合するとよい。
【０１０１】
また、本発明に係るアスファルト系構造材料を用いた他の施工方法も可能である。例えば、アスファルトを第１温度（繊維等の混合素材の撹拌が可能となる温度）まで加熱して撹拌可能な粘度とした後、このアスファルトに、所定の強度と所定の耐熱性とアスファルト中での所定の分散性能を有する材料からなる繊維、粉末のいずれか又はこれらの適宜の組合わせを適宜の割合で混入させ撹拌して混成物を生成したのち、これを冷却して硬化させ、破砕して塊状にし、その後、骨材間への填充、骨材との混合等の施工時に、現場等において、この塊状材を第１温度よりも高温な第２温度（骨材等への填充が可能な流動状態となる温度）まで加熱して流動化させて使用する方法が挙げられる。
【０１０２】
【発明の効果】
以上説明したように、本発明によれば、１２０〜１８５゜Ｃまで加熱されたアスファルトに、強度を高める小径混入部材と、流動性を高める流動化材を混入させ撹拌して混成物を生成した後、混成物を２２０〜２６０゜Ｃまで加熱し流動化させて骨材間の間隙に填充させるようにしたので、アスファルト単体の場合よりも初期強度、最終強度及び填充性が改善され、骨材からなる鉄道道床の沈下を有効に防止することができ、かつ工事費用も低廉な価格に抑えることができる。
【図面の簡単な説明】
【図１】本発明の一実施形態であるアスファルト系構造材料の強度に関する特性を示す概念図である。
【図２】本発明の他の実施形態であるアスファルト填充工法の構成を示す概念図である。
【図３】図２に示すアスファルト填充工法により施工された軌道構造の例を示す図である。
【図４】本発明の実施例であるアスファルト系構造材料の強度に関する特性を示す図である。
【符号の説明】
１ アスファルト填充装置
２ アスファルト加熱混合部
３ アスファルト移送部
４ アスファルト系構造材料流動物
５ 道床
６ 枠板
７ 路盤
８ まくらぎ
９ レール
２１ 加熱容器
２２ モータ
２３ 撹拌羽根
３１ モータ
３２ ポンプ
３３，３４ 移送管路
４１〜４３ アスファルト系構造材料硬化物
５１ 骨材
５２ 舗装部
５３，５４ 未填充部[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for constructing a railway roadbed using an asphalt structural material in which the asphalt structural material is filled between the aggregates of the railway roadbed and hardened.
[0002]
[Prior art]
Conventionally, the roadbed track in railways has been constructed by laying crushed stone (aggregate) made of granite, andesite, hard sandstone, etc. on the roadbed to form a roadbed, on which sleepers are juxtaposed. It was configured by fastening two rails on the frame. Of the above, the roadbed is
(1) It is possible to distribute the load applied from the traveling railway vehicle via the rails and sleepers over a wide area, and to reduce the impact and vibration caused by the train and transmit it to the roadbed. (2) Train to give elasticity to the track (3) Easy to adjust and change the track without changing the roadbed structure (4) Advantages such as simple structure and low construction cost Was. On the other hand, since the roadbed gradually sinks due to repeated train loads, maintenance work to maintain the roadbed height, roadbed shape, etc. is indispensable, which requires considerable maintenance costs. There was a problem.
[0003]
The roadbed sinks due to the train running because the roadbed crushed stone has a relatively small particle size distribution (for example, the particle size is about 15 to 75 mm). This is because a process (consolidation process) that gradually falls into the gap existing between the crushed stone and the lower crushed stone occurs. After that, the crushed stone under the sleeper moves sideways (side flow process) due to train vibration. This is because it occurs. Therefore, as one measure for preventing the subsidence of the road bed, it is conceivable to prevent the movement by filling the gaps between the crushed stones with some material and fixing the crushed stones. Thus, if the subsidence of the roadbed can be suppressed, the maintenance cost of the railway in the case of the roadbed track can be reduced.
[0004]
For this reason, “asphalt filling method (for example, see Patent Document 1)” in which heated asphalt is injected between the crushed stones and cured, “mortar filling method” in which cement mortar is injected between the crushed stones and cured, A road bed improvement method such as a “resin filling method” in which a curable resin such as polyester or epoxy is injected and cured between them has been considered and attempted.
[0005]
[Patent Document 1]
Japanese Patent Laid-Open No. 9-25605 (page 1-6, FIG. 1)
[0006]
[Problems to be solved by the invention]
However, the asphalt filling method of the conventional road bed improvement method described above is good in terms of elasticity required for the road bed, and the construction cost is lower than the resin filling method, but has the following disadvantages: .
[0007]
First, asphalt is not inferior to other fillers in its final strength after hardening (hereinafter referred to as “final strength”), but it is heated to soften it to the extent that it can be poured between crushed stones. After being injected, it takes a considerable amount of time to be injected into the bed and cured by cooling to develop a predetermined strength, and the initial strength after injection (hereinafter referred to as “initial strength”) is low. It is done. On the other hand, on railroad tracks that have already started operations (hereinafter referred to as “business lines”), work such as road bed improvement is performed during the time period during which trains do not travel ( It is often done at night) or at night, and it is required to complete the work in a short time, and it is often required to start train travel in about an hour after the asphalt injection. However, as described above, since the initial strength of asphalt is not so high, the force for fixing the crushed stone is weak after a time of about 1 hour after the injection, and the performance for preventing the settlement of the bed is often insufficient.
In addition, asphalt tends to soften naturally when the ambient temperature becomes high, and there is a possibility that the performance for preventing the settlement of the roadbed is lowered in summer.
[0008]
In the case of the mortar filling method, it is considered that the strength is higher than that of asphalt, and satisfactory results were obtained in terms of prevention of subsidence. There was a possibility of cracking in winter.
[0009]
In the case of the resin filling method, the strength is considered to be higher than that of asphalt, and satisfactory results were obtained in terms of road subsidence prevention performance. However, the construction cost is high, especially for railways with a long construction extension distance. However, there was a problem that the whole construction cost became very expensive.
[0010]
The present invention has been made to solve the above-described problems, and the problem to be solved by the present invention is that the initial strength is high, the settlement of the railroad bed can be effectively prevented, and the construction cost is low. The object is to provide a method for constructing a railway roadbed using asphalt-based structural materials.
[0011]
[Means for Solving the Problems]
In order to solve the above problems, a method for constructing a railway roadbed using the asphalt-based structural material according to claim 1 of the present invention is as follows.
A step of heating the asphalt to 120 to 185 ° C., and then mixing a small-diameter mixing member for increasing the strength and a fluidizing material for increasing the fluidity into the asphalt and stirring to produce a composite;
Next, the composite is heated to 220 to 260 ° C. and melted to produce a fluid asphalt-based structural material;
Next, the asphalt-based structure material having a step of filling the fluidized asphalt-based structural material into the gap between the aggregates from the side of the sleeper to just above the roadbed among the aggregates of the railroad bed, and then hardening by cooling. A method for constructing a railway roadbed using materials,
As the small diameter mixed member,
It consists of a metal material, ceramic material, rock mineral material, carbon, glass material, synthetic resin, plant material, or animal material, and has a length of 1 to 10 mm and a diameter of 0.01 ~ 1mm short diameter fiber,
Alternatively, it is made of a metal material, calcium-based material, ceramic-based material, rock mineral-based material, ceramic-based material, carbon, glass-based material, mica-based material, or synthetic resin, and has a diameter of 10 to 100 μm. While fine powder is used, the weight ratio to the entire asphalt-based structural material is 30% or less,
As the fluidizing material, an amorphous polyolefin-based resin and an anionic asphalt emulsifier are used, and the weight ratio with respect to the entire asphalt-based structural material is 5% or less.
[0012]
In addition, the construction method of the railway roadbed using the asphalt-based structural material according to claim 2 of the present invention,
A step of heating the asphalt to 120 to 185 ° C., and then mixing a small-diameter mixing member for increasing the strength and a fluidizing material for increasing the fluidity into the asphalt and stirring to produce a composite;
Next, the composite is heated to 220 to 260 ° C. and melted to produce a fluid asphalt-based structural material;
Next, the asphalt-based structure material having a step of filling the fluidized asphalt-based structural material into the gap between the aggregates from the side of the sleeper to just above the roadbed among the aggregates of the railroad bed, and then hardening by cooling. A method for constructing a railway roadbed using materials,
As the small diameter mixed member,
It consists of a metal material, ceramic material, rock mineral material, carbon, glass material, synthetic resin, plant material, or animal material, and has a length of 1 to 10 mm and a diameter of 0.01 ~ 1mm short diameter fiber,
Alternatively, it is made of a metal material, calcium-based material, ceramic-based material, rock mineral-based material, ceramic-based material, carbon, glass-based material, mica-based material, or synthetic resin, and has a diameter of 10 to 100 μm. While fine powder is used, the weight ratio to the entire asphalt-based structural material is 30% or less,
As the fluidizing material, an anionic asphalt emulsifier is used, and the weight ratio to the entire asphalt-based structural material is 5% or less.
[0013]
In addition, the construction method of the railway roadbed using the asphalt-based structural material according to claim 3 of the present invention,
In the construction method of the railway roadbed using the asphalt-based structural material according to claim 1 or 2,
When the small-diameter mixed member has conductivity, the weight ratio with respect to the entire asphalt-based structural material is set to 5% or less.
[0014]
In addition, a method for constructing a railway roadbed using the asphalt-based structural material according to claim 4 of the present invention,
In the construction method of the railway roadbed using the asphalt-based structural material according to claim 1,
The amorphous polyolefin-based resin is an amorphous or rubber-like resin-like substance produced by polymerization of an olefin that is an unsaturated hydrocarbon having one carbon-carbon double bond, and includes polyethylene, Or polypropylene or polybutene.
[0015]
In addition, the construction method of the railway roadbed using the asphalt-based structural material according to claim 5 of the present invention,
In the construction method of the railway roadbed using the asphalt-based structural material according to claim 1 or 2,
The anionic asphalt emulsifier is a rosin obtained by distilling crude turpentine oil extracted from a pine resin, or a lignin forming a woody part of a plant, or a carboxylic acid of tall oil containing the rosin, a fatty acid, a sterol, and a polymer alcohol. It contains an alkali metal salt of an acid or sulfonic acid, a fatty acid or a higher alcohol sulfate, or an alkali metal salt of an alkylbenzene sulfonic acid.
[0016]
Moreover, the construction method of the railway roadbed using the asphalt-based structural material according to claim 6 of the present invention,
A step of heating the asphalt to 120 to 185 ° C., and then mixing a small-diameter mixing member for increasing the strength and a fluidizing material for increasing the fluidity into the asphalt and stirring to produce a composite;
Next, the composite is heated to 220 to 260 ° C. and melted to produce a fluid asphalt-based structural material;
Next, the asphalt-based structural material in the fluidized state is filled with a gap between aggregates from the side of the sleeper to the lower part of the sleeper among the aggregates of the railway bed, and then cured by cooling;
Next, a method for constructing a railway roadbed using an asphalt-based structural material having a step of paving the side surface of the roadbed,
As the small diameter mixed member,
It consists of a metal material, ceramic material, rock mineral material, carbon, glass material, synthetic resin, plant material, or animal material, and has a length of 1 to 10 mm and a diameter of 0.01 ~ 1mm short diameter fiber,
Alternatively, it is made of a metal material, calcium-based material, ceramic-based material, rock mineral-based material, ceramic-based material, carbon, glass-based material, mica-based material, or synthetic resin, and has a diameter of 10 to 100 μm. While fine powder is used, the weight ratio to the entire asphalt-based structural material is 30% or less,
As the fluidizing material, an amorphous polyolefin-based resin and an anionic asphalt emulsifier are used, and the weight ratio with respect to the entire asphalt-based structural material is 5% or less.
[0017]
Moreover, the construction method of the railway roadbed using the asphalt-based structural material according to claim 7 of the present invention,
A step of heating the asphalt to 120 to 185 ° C., and then mixing a small-diameter mixing member for increasing the strength and a fluidizing material for increasing the fluidity into the asphalt and stirring to produce a composite;
Next, the composite is heated to 220 to 260 ° C. and melted to produce a fluid asphalt-based structural material;
Next, the asphalt-based structural material in the fluidized state is filled with a gap between aggregates from the side of the sleeper to the lower part of the sleeper among the aggregates of the railway bed, and then cured by cooling;
Next, a method for constructing a railway roadbed using an asphalt-based structural material having a step of paving the side surface of the roadbed,
As the small diameter mixed member,
It consists of a metal material, ceramic material, rock mineral material, carbon, glass material, synthetic resin, plant material, or animal material, and has a length of 1 to 10 mm and a diameter of 0.01 ~ 1mm short diameter fiber,
Alternatively, it is made of a metal material, calcium-based material, ceramic-based material, rock mineral-based material, ceramic-based material, carbon, glass-based material, mica-based material, or synthetic resin, and has a diameter of 10 to 100 μm. While fine powder is used, the weight ratio to the entire asphalt-based structural material is 30% or less,
As the fluidizing material, an anionic asphalt emulsifier is used, and the weight ratio to the entire asphalt-based structural material is 5% or less.
[0018]
Moreover, the construction method of the railway roadbed using the asphalt-based structural material according to claim 8 of the present invention,
In the construction method of the railway roadbed using the asphalt-based structural material according to claim 6 or 7,
When the small-diameter mixed member has conductivity, the weight ratio with respect to the entire asphalt-based structural material is set to 5% or less.
[0019]
Moreover, the construction method of the railway roadbed using the asphalt-based structural material according to claim 9 of the present invention,
In the construction method of the railway roadbed using the asphalt-based structural material according to claim 6,
The amorphous polyolefin-based resin is an amorphous or rubber-like resin-like substance produced by polymerization of an olefin that is an unsaturated hydrocarbon having one carbon-carbon double bond, and includes polyethylene, Or polypropylene or polybutene.
[0020]
In addition, a method for constructing a railway roadbed using the asphalt-based structural material according to claim 10 of the present invention,
In the construction method of the railway roadbed using the asphalt-based structural material according to claim 6 or 7,
The anionic asphalt emulsifier is a rosin obtained by distilling crude turpentine oil extracted from a pine resin, or a lignin forming a woody part of a plant, or a carboxylic acid of tall oil containing the rosin, a fatty acid, a sterol, and a polymer alcohol. It contains an alkali metal salt of an acid or sulfonic acid, a fatty acid or a higher alcohol sulfate, or an alkali metal salt of an alkylbenzene sulfonic acid.
[0021]
Moreover, the construction method of the railway roadbed using the asphalt-based structural material according to claim 11 of the present invention is as follows.
A step of heating the asphalt to 120 to 185 ° C., and then mixing a small-diameter mixing member for increasing the strength and a fluidizing material for increasing the fluidity into the asphalt and stirring to produce a composite;
Next, the composite is heated to 220 to 260 ° C. and melted to produce a fluid asphalt-based structural material;
Next, the asphalt-based structural material in the fluidized state has a step of filling the gap between the aggregates from directly below the sleeper to directly above the roadbed among the aggregates of the railroad bed, and then hardening by cooling. A method for constructing a railway roadbed using
As the small diameter mixed member,
It consists of a metal material, ceramic material, rock mineral material, carbon, glass material, synthetic resin, plant material, or animal material, and has a length of 1 to 10 mm and a diameter of 0.01 ~ 1mm short diameter fiber,
Alternatively, it is made of a metal material, calcium-based material, ceramic-based material, rock mineral-based material, ceramic-based material, carbon, glass-based material, mica-based material, or synthetic resin, and has a diameter of 10 to 100 μm. While fine powder is used, the weight ratio to the entire asphalt-based structural material is 30% or less,
As the fluidizing material, an amorphous polyolefin-based resin and an anionic asphalt emulsifier are used, and the weight ratio with respect to the entire asphalt-based structural material is 5% or less.
[0022]
Moreover, the construction method of the railway roadbed using the asphalt-based structural material according to claim 12 of the present invention,
A step of heating the asphalt to 120 to 185 ° C., and then mixing a small-diameter mixing member for increasing the strength and a fluidizing material for increasing the fluidity into the asphalt and stirring to produce a composite;
Next, the composite is heated to 220 to 260 ° C. and melted to produce a fluid asphalt-based structural material;
Next, the asphalt-based structural material in the fluidized state has a step of filling the gap between the aggregates from directly below the sleeper to directly above the roadbed among the aggregates of the railroad bed, and then hardening by cooling. A method for constructing a railway roadbed using
As the small diameter mixed member,
It consists of a metal material, ceramic material, rock mineral material, carbon, glass material, synthetic resin, plant material, or animal material, and has a length of 1 to 10 mm and a diameter of 0.01 ~ 1mm short diameter fiber,
Alternatively, it is made of a metal material, calcium-based material, ceramic-based material, rock mineral-based material, ceramic-based material, carbon, glass-based material, mica-based material, or synthetic resin, and has a diameter of 10 to 100 μm. While fine powder is used, the weight ratio to the entire asphalt-based structural material is 30% or less,
As the fluidizing material, an anionic asphalt emulsifier is used, and the weight ratio to the entire asphalt-based structural material is 5% or less.
[0023]
Further, a method for constructing a railway roadbed using the asphalt-based structural material according to claim 13 of the present invention,
In the construction method of the railway roadbed using the asphalt-based structural material according to claim 11 or 12,
When the small-diameter mixed member has conductivity, the weight ratio with respect to the entire asphalt-based structural material is set to 5% or less.
[0024]
Moreover, the construction method of the railway roadbed using the asphalt-based structural material according to claim 14 of the present invention,
In the construction method of the railway roadbed using the asphalt-based structural material according to claim 11,
The amorphous polyolefin-based resin is an amorphous or rubber-like resin-like substance produced by polymerization of an olefin that is an unsaturated hydrocarbon having one carbon-carbon double bond, and includes polyethylene, Or polypropylene or polybutene.
[0025]
In addition, a method for constructing a railway roadbed using the asphalt-based structural material according to claim 15 of the present invention,
In the construction method of the railway roadbed using the asphalt-based structural material according to claim 11 or 12,
The anionic asphalt emulsifier is a rosin obtained by distilling crude turpentine oil extracted from a pine resin, or a lignin forming a woody part of a plant, or a carboxylic acid of tall oil containing the rosin, a fatty acid, a sterol, and a polymer alcohol. It contains an alkali metal salt of an acid or sulfonic acid, a fatty acid or a higher alcohol sulfate, or an alkali metal salt of an alkylbenzene sulfonic acid.
[0026]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail.
[0027]
(1) First Embodiment As a first embodiment of the present invention, an asphalt-based structural material in which asphalt is used as a base material and fibers are mixed therewith can be mentioned. This is by dispersing and mixing fibers in asphalt to form a kind of composite material with asphalt as a base material and fiber as a reinforcing member, and the strength of the entire composite after curing, for example, compressive strength, bending strength, While improving an elasticity modulus etc., viscoelasticity is provided to the whole composite after hardening, and toughness fracture strength is improved. However, if the strength of each of the asphalt and the fiber is high and the fibers are not uniformly dispersed and mixed in the asphalt, the strength improvement cannot be exhibited. For this reason, predetermined quality, conditions, etc. are requested | required of both asphalt as a base material and the fiber as a reinforcement member.
[0028]
First, asphalt itself, which is a base material, is required to have high strength after curing and to be hard, so that a material having a low penetration and a high softening point is preferable. For example, the penetration is preferably about 0 to 50, and the softening point is preferably about 60 or more.
[0029]
Here, the penetration is a specified temperature (for example, 25 ° C.), a specified load (for example, 100 grams), and a specified penetration time (for example, 5 seconds) according to the test method specified in JIS K 2207. This is a value obtained by penetrating a predetermined shape of the needle into the asphalt and representing the penetration depth in units of 1/10 mm. Generally, the smaller the penetration value, the harder the asphalt.
[0030]
The softening point refers to a steel ball with a mass of 3.5 grams placed on the asphalt filled inside the specified metal ring according to the test method specified in JIS K 2207, and heated continuously. In this case, it is a value expressed by the temperature (° C) when the asphalt drops by 25 mm due to the weight of the steel ball, and is an index showing the consistency of the asphalt under the specified conditions. Generally, the value of the softening point The higher the value, the harder the asphalt.
[0031]
Moreover, as a kind of asphalt, straight asphalt is mentioned among the petroleum asphalts for paving. In addition, blown asphalt or semi-blown asphalt subjected to an operation called “blowing” in which air is blown into straight asphalt at a high temperature to cause dehydrogenative polycondensation to be polymerized can be used. The blown asphalt, semi-blown asphalt, and the like are improved in low temperature sensitivity as compared with straight asphalt, and the viscosity at 60 ° C. is also improved. In addition to straight asphalt, blown asphalt, and semi-blown asphalt alone, these may be mixed as appropriate, or pre-powder asphalt, natural asphalt, modified asphalt, or the like may be mixed therein.
[0032]
Next, the fiber is required to have high material strength, particularly tensile strength. Further, since the fibers are put into asphalt heated to a predetermined first temperature (for example, about 120 to 185 ° C.) in order to soften the mixture to such an extent that stirring and mixing are possible, at least the first temperature is altered. Heat resistance that does not cause melting is necessary. Further, after being mixed in the heated asphalt, it is necessary to have a performance (hereinafter referred to as “dispersion performance”) of maintaining a substantially uniform dispersion state without causing precipitation or floating in the heated asphalt in a viscous state. It is desirable that the length, diameter, specific gravity and the like be within a certain range.
[0033]
For example, the material of the fiber is preferably a metal material such as soft iron, steel, or aluminum, a ceramic material such as carbide or nitride, a rock mineral material such as quartz, carbon, or a glass material. If the above conditions are satisfied, synthetic resin materials such as ABS resin and aramid resin (aromatic polyamide resin), plant fibers such as hemp, animal fibers, and the like can be used. Moreover, as a dimension of a fiber, for example, a short small diameter fiber having a length of about 1 to 10 mm and a diameter of about 0.01 to 1 mm is preferable.
[0034]
Moreover, a predetermined restriction can be considered for the mixing ratio of the fibers to the entire asphalt-based structural material. First, when viewed from the strength of the entire hybrid, it is considered that the strength of the entire hybrid increases as the mixing amount increases while the mixing amount of the fiber is small. It is considered that the strength reaches the maximum, and beyond that value, the strength of the entire composite decreases. This is because, when the mixing ratio of the fibers is low, the fibers function as a reinforcing member, whereas when the mixing ratio exceeds a certain value, it is considered that the fibers are in the same state as the base material. Therefore, from the viewpoint of the strength of the hybrid, it is considered that there is a predetermined upper limit for the fiber mixing rate. The upper limit is, for example, about 30% by weight with respect to the entire asphalt-based structural material.
[0035]
In addition, when this asphalt-based structural material is used as a filler for railway roadbeds, restrictions on the mixing ratio of fibers can be considered from another viewpoint. That is, in a railroad, signal current is applied to each of the rails, and a short circuit of these currents causes a signal failure or the like. Therefore, the roadbed that may contact the lower surface of the rail is electrically predetermined. It is required to have a degree of insulation. Therefore, when the fiber mixed with asphalt is formed of a conductive material such as metal, the fiber mixing ratio is lower than a value that can maintain the insulation required between the rails. Need to be. That is, when used for a railway roadbed, it is considered that there is a predetermined upper limit for the mixing ratio of conductive fibers from the viewpoint of electrical insulation. The upper limit is, for example, about 5% by weight with respect to the entire asphalt-based structural material.
[0036]
In addition, asphalt softens to the extent that it can be stirred by heating to the first temperature as described above, but the viscosity is too high to fill between aggregates such as crushed stone. Therefore, in order to use it as a filler for aggregates, it is necessary to further make the asphalt into a fluid state. For this reason, the hybrid obtained by mixing fibers in asphalt is heated to a second temperature (for example, about 220 to 260 ° C.) higher than the first temperature, thereby bringing the hybrid into a molten state. In this way, if the asphalt / fiber mixture is reheated to the second temperature, the mixture becomes a fluid state, so that the mixture flows smoothly between the aggregates, and the aggregate deepest is efficiently obtained. Can be filled.
[0037]
When fibers are mixed in asphalt as described above, the strength is improved as compared with curve C1 in the case of a single asphalt, as shown by curve A1 in FIG. In FIG. 1A, in the case of the conventional asphalt alone (strength curve C1), the value at the time of 1 hour after the injection is below the standard value σ _{B of the} strength required for the filler, In the case of the asphalt-based structural material of the present embodiment (intensity curve A1), the value at the time when 1 hour has elapsed after injection exceeds the strength standard value σ _B. Thereby, in the case of the asphalt-based structural material of the present embodiment, it can be seen that not only the final strength but also the initial strength is improved. Therefore, when the road bed is filled, it is considered that even when a short time has elapsed after injection, the road bed subsidence prevention performance is sufficiently exhibited as in the case of the mortar filling method and the resin filling method. As the above-mentioned strength standard value σ _B of the asphalt-based structural material, for example, there is one in which 0.1 MPa is specified as a value when used for a railway roadbed.
[0038]
In the case of the present embodiment, as shown by a curve A2 in FIG. 1B, compared to the curve C2 in the case of a single asphalt, the strength is reduced at a high temperature and a predetermined strength can be maintained. In FIG. 1 (B), when the atmospheric temperature of the conventional asphalt alone (intensity curve C2) is 60 ° C. or higher, the strength standard value σ _B falls below a certain temperature, whereas the asphalt of the present embodiment In the case of a system structural material (strength curve A2), the strength does not decrease much even when the ambient temperature is 60 ° C. or higher, and does not fall below the strength standard value σ _B in the actual use environment. As a result, in the case of the asphalt-based structural material of the present embodiment, it is considered that even in the summer, the road bed subsidence prevention performance is exhibited as much as in the case of the mortar filling method and the resin filling method.
[0039]
(2) Second Embodiment In addition to the first embodiment described above, what is described below is also effective as the second embodiment of the present invention.
This is an asphalt-based structural material produced by mixing asphalt with a powder. This is because the powder is dispersed and mixed in the asphalt as described above to form a kind of composite material in which the asphalt is a base material and the powder is a reinforcing member. The strength as a whole is further improved. The powder also has viscoelasticity so as not to lose flexibility even when the asphalt-based structural material is in a low temperature state after curing, and also has a function of preventing “cracking” from occurring at a low temperature. However, in terms of strength and function, the powder as the reinforcing member is required to have predetermined quality and conditions.
[0040]
This powder is required to have a high material strength. Further, since the powder is put into asphalt heated to a first temperature (for example, about 120 to 185 ° C.) for softening to such an extent that stirring and mixing are possible, at least at this first temperature, Heat resistance that does not cause dissolution is necessary. In addition, after mixing in heated asphalt, it is necessary to have a dispersion performance that maintains a substantially uniform dispersion state without causing precipitation or levitation in the heated asphalt in a viscous state, and its diameter, specific gravity, roughness It is desirable that the powder is within a certain range.
[0041]
For example, powder materials include metal materials such as soft iron, steel, and aluminum, ceramic materials such as carbide and nitride, rock mineral materials such as quartz, inorganic scales such as mica, and carbon (graphite) ), Glass-based materials and the like are suitable. In addition, a synthetic resin material such as an ABS resin can be used as long as the above conditions are satisfied. For example, a fine powder having a diameter of about 10 to 100 μm.
[0042]
In the same manner as in the case of the fibers described above, the powder mixing ratio with respect to the entire asphalt-based structural material also has a predetermined upper limit for the mixing ratio of the powder from the viewpoint of the strength of the entire composite and the electrical insulation degree. it is conceivable that. The upper limit value of the mixing ratio of the powder from the viewpoint of strength is, for example, about 30% by weight with respect to the entire asphalt-based structural material. Moreover, the upper limit of the mixing ratio of the conductive powder from the viewpoint of electrical insulation is, for example, about 5% by weight with respect to the entire asphalt-based structural material.
[0043]
Moreover, about the point which heats the composite which mixed asphalt and powder to 2nd temperature (for example, about 220-260 degreeC) higher than 1st temperature, and fills an aggregate with a composite in a molten state, This is the same as in the case of the first embodiment described above.
[0044]
In addition, in the case of a short time after injection or in a high-temperature atmosphere, the point of exhibiting sufficient subsidence prevention performance as in the case of the mortar filling method or the resin filling method is the same as in the case of the first embodiment described above. It is the same.
[0045]
(3) Third Embodiment In addition to the first and second embodiments described above, what is described below is also effective as a third embodiment of the present invention.
This is an asphalt-based structural material obtained by further mixing a fluidizing material with the composite of asphalt and fibers, which is the asphalt-based structural material of the first embodiment described above. This is to improve the filling performance by improving the fluidity of the entire composite in the fluid state by further mixing the fluidizing material as a modifier in the asphalt mixed with the fibers. . However, the fluidizing material is required to have predetermined quality, conditions, and the like in view of its function and the like.
[0046]
The fluidizing material further increases the fluidity of the entire mixed material melted in the heated asphalt and turned into a fluid state, particularly the asphalt itself in a low temperature range (for example, about the first temperature), and is used as a filler. It is necessary to have a function of further improving the filling performance. It is also necessary to have a high affinity with other mixing elements in the asphalt and to have a function of assisting dispersion mixing and fluidization of the other mixing elements in the asphalt. For example, an amorphous polyolefin resin is suitable as such a fluidizing material.
[0047]
The olefin generally refers to an unsaturated hydrocarbon having one carbon-carbon double bond and high reactivity, and includes, for example, ethylene, propylene, butylene and the like. Polyolefin refers to a resinous substance produced by polymerization of olefin, and includes, for example, polyethylene produced from ethylene, polypropylene produced from propylene, polybutene produced from butylene, and the like. Amorphous means amorphous or rubbery. Accordingly, the amorphous polyolefin-based resin is a synthetic resin containing an amorphous or rubbery polyolefin. Moreover, you may combine not only these single-piece | units but a suitable thing in a suitable ratio.
[0048]
Moreover, in the case of this amorphous polyolefin resin, it is a modifier mixed to improve the properties of asphalt, and the mixing ratio with respect to the entire asphalt structural material is considered to have an upper limit. For example, the weight percentage is about 5% with respect to the entire asphalt-based structural material.
[0049]
In addition, a composite obtained by mixing asphalt, fiber, and amorphous polyolefin resin is heated to a second temperature (for example, about 220 to 260 ° C.) higher than the first temperature, and the composite is melted to form an aggregate. The points to be filled are the same as in the first and second embodiments. In addition, even in a short time after injection, or even in a high temperature atmosphere, the point of exhibiting sufficient subsidence prevention performance as in the case of the mortar filling method and the resin filling method is also the same as in the first and second embodiments described above. Same as the case. The amorphous polyolefin-based resin may be mixed in advance with asphalt as a base material (premix method), or may be added simultaneously when fibers or powders are mixed into asphalt (plant mix). method).
[0050]
(4) Fourth Embodiment In addition to the first to third embodiments described above, what is described below is also effective as the fourth embodiment of the present invention.
This is an asphalt-based structural material in which a viscoelastic material is further mixed with the composite of asphalt and fibers, which is the asphalt-based structural material of the first embodiment described above. This is to improve the viscoelasticity of the composite after curing by further mixing a viscoelasticizing material as a modifying material in the asphalt mixed with fibers, and to make it highly tough. However, from the viewpoint of function and the like, the viscoelastic material is required to have predetermined quality and conditions.
[0051]
Viscoelastic material is a function that melts in heated asphalt, gives viscoelasticity to the entire composite after curing, and prevents "cracking" even when the asphalt-based structural material becomes low temperature after curing. It is necessary to have. For example, a rubber-based resin is suitable as such a viscoelastic material.
[0052]
Examples of the rubber resin include resins containing styrene butadiene rubber (SBR), natural rubber (NR), chloroprene rubber (CR), and the like. Moreover, you may combine not only these single-piece | units but a suitable thing in a suitable ratio.
[0053]
Moreover, in the case of this rubber-type resin, it is a modifier mixed in order to improve the property of asphalt, and it is thought that the mixing ratio with respect to the whole asphalt-type structural material naturally has an upper limit. For example, the weight percentage is about 5% with respect to the entire asphalt-based structural material.
[0054]
Moreover, the composite material which mixed asphalt, a fiber, and rubber-type resin is heated to 2nd temperature (for example, about 220-260 degreeC) higher than 1st temperature, and a composite material is made into a molten state and is filled with aggregate. About a point, it is the same as that of the case of the above-mentioned 1st-3rd embodiment. And also about the point of exhibiting sufficient subsidence prevention performance as in the case of a mortar filling method or a resin filling method even at a short time after injection or in a high temperature atmosphere, the above-described first to third embodiments are also provided. Same as the case. The rubber-based resin may be mixed in advance with the asphalt of the base material (premix method), or may be added at the same time when fibers, powders, amorphous polyolefin-based resins, etc. are mixed with the asphalt. Also good (plant mix method).
[0055]
(5) Fifth Embodiment Next, an asphalt filling method according to a fifth embodiment of the present invention will be described in detail with reference to the drawings.
FIG. 2 is a conceptual diagram showing the configuration of an asphalt filling device used in the asphalt filling method according to the fifth embodiment of the present invention. As shown in the figure, the asphalt filling device 1 includes an asphalt heating and mixing unit 2 and an asphalt transfer unit 3.
[0056]
The asphalt heating and mixing unit 2 includes a heating container 21, a motor 22, and a stirring blade 23. Asphalt materials such as blown asphalt and pre-powder asphalt are put into the heating container 21. The heating container 21 is provided with a heater (not shown) such as an electric heater, and the charged material can be heated. Further, a stirring blade 23 is provided in the heating container 21, and the stirring blade 23 is configured to be rotationally driven by a motor 22.
[0057]
The asphalt transfer unit 3 includes a pump 32 and transfer pipes 33 and 34, and the transfer pipe 33 is inserted into the asphalt material in the heating container 21. The pump 32 is configured to be driven by a motor 31.
[0058]
Further, the road bed 5 which is a filling material is preliminarily formed in a floor shape in which an aggregate 51 such as crushed stone is laid on the roadbed 7 and the cross-sectional shape thereof forms a substantially trapezoidal shape. A frame plate 6 is provided at the lowermost end of the slope of the roadbed 5. Assume that the aggregate 51 has the same material, shape, and particle size as conventional crushed stone for railway roadbeds.
[0059]
With the above configuration, the asphalt material is heated to a first temperature (for example, 120 to 185 ° C.) to soften the asphalt material to be a viscous material having a stirrable viscosity, and then the fibers described above. , One of powder, amorphous polyolefin-based resin, or rubber-based resin or an appropriate combination is put into the heating container 21 by a predetermined amount, and is uniformly stirred by the rotation of the stirring blade 23 to soften them. The mixed asphalt material is dispersed and mixed (first step).
[0060]
Next, the above hybrid is heated to a second temperature (for example, 220 to 260 ° C.) higher than the first temperature. When heated to this second temperature, the above hybrid is in a molten state, the viscosity is lowered, and as shown by 4 in the figure, it is in a fluid state (hereinafter referred to as “asphalt-based structural material fluid”). (Second step).
[0061]
Next, the motor 31 is operated, the asphalt-based structural material fluid 4 is sucked from the heating container 21 through the transfer pipe 33, sent out by the pump 32, and sprayed and poured from above the road bed 5 through the transfer pipe 34. Since the asphalt-based structural material fluid 4 is in the form of a fluid with low viscosity, it can flow smoothly into the aggregate 51 and can be efficiently filled up to the deepest part of the road bed 5. Thereafter, when the asphalt-based structural material fluid 4 overflows from the uppermost portion of the road bed 5, spraying of the asphalt-based structural material fluid 4 is stopped (third step). At this time, the frame plate 6 prevents the asphalt-based structural material fluid from flowing down to the deepest part of the road bed 5 and then flowing out to the side of the road bed 5.
[0062]
After the filling of the asphalt structural material fluid 4 is stopped, the road bed 5 is left as it is and cooled. By this cooling, the fluid asphalt-based structural material 4 is hardened to become a hardened asphalt-based structural material, and forms an asphalt-based structural material filling structure which is a kind of composite structure in cooperation with the aggregate 51 ( (4th process).
[0063]
In the asphalt-based structural material-filled structure described above, the asphalt-based structural material filling the gaps between the aggregates 51 is hardened to become a hardened asphalt-based structural material. Shows viscoelasticity. Accordingly, each aggregate 51 is viscoelastically supported by the asphalt-based structural material cured product. For this reason, even if a load or vibration is applied from above, the aggregate does not cause consolidation or lateral flow, and the subsidence of the road bed is prevented. Therefore, when used for a railway roadbed, the maintenance work of the roadbed becomes unnecessary, the work cycle of the roadbed maintenance becomes very long, and the maintenance cost of the railway can be greatly reduced.
[0064]
As the asphalt-based structural material filling structure formed as described above, several types are conceivable as shown in FIG. 3 (A), (B), and (C) show examples used for a railroad bed.
[0065]
In the example shown in FIG. 3 (A), among the aggregates 51 laid on the roadbed 7 in a floor shape having a substantially trapezoidal cross section, the asphalt extends from just above the roadbed 7 to the side aggregates of the sleepers 8. This is a structure filled with the cured system structural material 41.
[0066]
With this configuration, not only can the roadbed sink, but also the horizontal displacement and movement of the sleeper 8 due to train loads and vibrations can be restricted. Aggregate falling and scattering can also be prevented.
[0067]
However, in this case, the sleepers 8 are all embedded in the asphalt-based structural material-filled structure. Therefore, if the sleeper 8 and the rails 9 and 9 are to be repositioned or replaced, The asphalt-based structural material filling structure on the side of the gap 8 has to be partially removed, and there is a problem that the construction is somewhat difficult.
[0068]
Moreover, the example shown in FIG. 3 (B) is an aggregate (upper ballast) and a pillow that are slightly below the sleeper 8 among the aggregates 51 laid on the roadbed 7 in a floor shape having a substantially trapezoidal cross section. Up to the side aggregate of the gap 8 is filled with the asphalt-based hardened material 42, the aggregate below the upper ballast (lower ballast) is not filled and remains as an unfilled portion 53, and the top surface of the roadbed And the side slope is paved with asphalt to form a paved portion 52.
[0069]
Thus, in order to fill only the upper part and prevent the asphalt-based structural material from spreading to the lower part, partition members such as vinyl sheets and non-woven fabrics for partitioning both near the boundary between the filled part and the unfilled part (Not shown) or place the aggregate in the filling section after taking measures to prevent the filling material from penetrating to the bottom by paving the top surface once forming the roadbed to the top of the unfilled section It is necessary to take measures such as laying and filling asphalt-based structural materials.
[0070]
When configured as in the example shown in FIG. 3B, the function of preventing the horizontal movement of the subsidence and sleeper 8 can be expected to some extent although not as much as in the example shown in FIG. It is also possible to prevent the aggregate from falling or scattering from the slope of the roadbed. Also, the great advantage of the example shown in FIG. 3B is that the amount of asphalt-based structural material used for filling can be greatly reduced compared to the example shown in FIG. Can be kept very low.
[0071]
The example shown in FIG. 3C is an asphalt-type structure from the aggregate 51 laid on the roadbed 7 in a floor shape having a substantially trapezoidal cross section to the aggregate immediately below the roadbed 7 to the aggregate just below the sleeper 8. The structure is filled with the cured material 43 and the aggregate on the side of the sleeper 8 is not filled but left as an unfilled portion 54.
[0072]
If comprised in this way, the same effect as the example shown to FIG. 3 (A) can be anticipated about a roadbed subsidence prevention function, and it can also prevent the fall and scattering of the aggregate from the slope of a roadbed by train vibration and wind pressure. it can. However, in this case, the function of preventing the horizontal movement of the sleeper 8 is not as great as the example shown in FIG. However, in this case, contrary to the example shown in FIG. 3A, the position of the sleeper 8 and the rails 9 and 9 is changed because the asphalt structural material is not filled up to the side of the sleeper 8. There is an advantage that it can be easily exchanged.
[0073]
【Example】
About the asphalt type structural material and the asphalt filling method shown in the first to fifth embodiments, a blending example of the actual experiment is shown below. In the following, the figures are weight percentages relative to the total asphalt-based structural material.
[0074]
(1) Example A
Blown asphalt 47.5%
Pre-powder asphalt 40.0%
Carbon fiber 0.5%
Mica powder 10.0%
Amorphous polyalphaolefin 2.0%
[0075]
(2) Example B
Blown asphalt 25.0%
Pre-powder asphalt 52.5%
Carbon fiber 0.5%
Mica powder 20.0%
Styrene butadiene rubber 2.0%
[0076]
In each of the above examples, a blown asphalt having a penetration of about 10 to 20 was used. Pre-powder asphalt having a penetration of about 0 to 5 was used. Carbon fibers having a length of about 3 mm or less and a diameter of about 1 mm or less were used. Further, mica powder having a diameter of about 62 μm or less was used. The amorphous polyalphaolefin is a blend of amorphous polypropylene and amorphous polyethylene. Here, alpha represents that a substituent is bonded to the position of the carbon atom to which the main functional group is bonded in the polymer compound, and most of the bond between polypropylene and polyethylene is an alpha bond. In each of the above-described embodiments, blown asphalt and pre-powder asphalt are mixed in both cases A and B, but only one of them may be used. Moreover, in any case of Example A and B, although carbon fiber and mica powder are mixed, only either one may be sufficient about this.
[0077]
For the asphalt-based structural material of Examples A and B described above and the conventional asphalt filler, a test body formed in a cube shape with a side of 6 cm was prepared, and JIS R2226 (measurement method of compressive strength of firebrick) was used. The compressive strength was measured according to the test method specified. A conventional asphalt-based structural material is a mixture of blown asphalt and straight asphalt in a ratio of 1: 1. The value of the compressive strength at each elapsed time in this case is shown below. In the measurement results below, the elapsed time is the elapsed time after the end of pouring into a test specimen mold such as asphalt, and the unit is minutes. The unit of the compressive strength value is MPa.

[0078]
Further, FIG. 4A shows the above results with the elapsed time (unit: minutes) on the horizontal axis and the compressive strength (unit: MPa) on the vertical axis. In FIG. 4 (A), curve A3 represents the case of the asphalt-based structural material blended in Example A, curve B3 represents the case of the asphalt-based structural material blended in Example B, and curve C3 represents the filling of the conventional asphalt alone. The case of materials is shown respectively. As can be seen from these figures and figures, if 0.1 MPa is adopted as the strength standard value σ _B of the asphalt-based structural material, in the case of a conventional asphalt-only filler, the time point after 60 minutes, that is, one hour has elapsed. Shows 60% of the strength standard value σ _B , the initial strength is low, and the road bed settlement prevention performance is insufficient when used for filling the road bed. On the other hand, in each of Examples A and B, the strength standard value σ _B exceeded the time point after 1 hour, and the initial strength is high. When used for filling the road bed, the road bed is sufficient. It can be seen that it has the ability to prevent settlement. In particular, in the case of Example B, the compressive strength after 1 hour has reached 0.21 MPa, which is twice the strength standard value σ _B. It is considered that asphalt reinforcement with mica powder is quite effective.
[0079]
Next, for the asphalt-based structural material of Examples A and B and the asphalt filler having the same composition as above, a test body similar to the above was prepared and compressed according to the test method prescribed in JIS R 2226. The strength was measured. The value of the compressive strength at each atmospheric temperature after reaching the final strength is shown below. In the following measurement results, the unit of temperature is ° C, and the unit of the value of compressive strength is MPa.

[0080]
FIG. 4B shows the above results, with the horizontal axis representing the ambient temperature (unit: ° C) and the vertical axis representing the compressive strength (unit: MPa). In FIG. 4 (B), curve A4 represents the case of the asphalt-based structural material blended in Example A, curve B4 represents the case of the asphalt-based structural material blended in Example B, and curve C4 represents the filling of the conventional asphalt alone. The case of materials is shown respectively. As can be seen from these figures and figures, in this case as well, if 0.1 MPa is adopted as the strength standard value σ _B of the asphalt-based structural material, in the case of a conventional asphalt-only filler, it becomes the original. When the final strength itself is low and the temperature is high, the degree of decrease in the compressive strength is large, the compressive strength at 60 ° C is only 0.15 MPa, and the compressive strength falls below the strength standard value σ _B at about 70-80 ° C. This indicates that there is a possibility that the road bed settlement prevention performance may not be ensured in the midsummer season when exposed to direct sunlight. On the other hand, it can be seen that the asphalt-based structural materials of Examples A and B have a margin in both the final strength and the strength reduction rate. In particular, in the case of Example B, the compressive strength at 60 ° C. is 0.4 MPa, and the temperature at which the compressive strength falls below the strength standard value σ _B is considered to be 150 ° C. or higher. This indicates that there is no possibility that the strength will fall below the strength standard value σ _{B, and} that sufficient road bed settlement prevention performance can always be ensured.
[0081]
About the asphalt-type structural material of the blending of each of the above-described Examples A and B, a test construction was further performed on the railway roadbed. That is, fibers, powders, additives and the like are mixed at a first temperature (for example, 120 to 185 ° C.) with a mixed material of blown asphalt and pre-powder asphalt as a base material, and the mixed material is heated to a temperature higher than the first temperature. To a second temperature (for example, about 220 to 260 ° C.) to make the filler fluid. Next, when this fluid was sprayed from above the aggregate laid in the shape of a railroad floor, the filler flowed smoothly between the aggregates, and it was possible to efficiently fill the deepest part of the aggregate. After that, asphalt-based structural material overflowed from the top of the roadbed, spraying of the filler was stopped and allowed to cool. Thereafter, the asphalt-based structural material was cured by cooling, and exhibited a predetermined strength after about 1 hour. From this result, it can be seen that the above asphalt-based structural material can be used satisfactorily even on railway business lines that require the start of train travel after a short period of time after injection.
[0082]
The present invention is not limited to the above embodiments. Each of the above-described embodiments and examples is illustrative, and has any configuration that is substantially the same as the technical idea described in the claims of the present invention and that exhibits the same operational effects. However, it is included in the technical scope of the present invention.
[0083]
For example, in each of the above embodiments, as aggregate, crushed stone having a large ridge angle made of granite, andesite, hard sandstone or the like, or crushed stone having a relatively small particle size distribution (for example, particle size of about 15 to 75 mm). However, the present invention is not limited to this, and other types of aggregates such as crushed stones, gravel, coal galley, blast furnace slag, ceramics, etc. that are crushed natural rocks of other materials are used. The material may be an artificial aggregate or the like, and the particle size distribution may be another particle size, or may be a cobblestone aggregate having a small ridge angle or no ridge angle.
[0084]
In each of the above embodiments, asphalt-based structural materials, asphalt mixed with fibers at an appropriate ratio (first embodiment), and asphalt mixed with powder at an appropriate ratio (second embodiment). As an example, an asphalt mixed with fibers and fluidizing material in appropriate ratios (third embodiment), and an asphalt mixed with fibers and viscoelastic materials in appropriate ratios (fourth embodiment) The present invention is not limited to this, and the present invention is not limited to this. Asphalt-based structural materials having other configurations, for example, powders mixed with the composite according to the first embodiment (asphalt mixed with fibers at an appropriate ratio), Either a fluidizing material, a viscoelastic material, or an appropriate combination thereof may be mixed at an appropriate ratio, or the mixture of the second embodiment (asphalt mixed with powder at an appropriate ratio). The ones) fibers, fluidizing material, any or a suitable combination of these viscoelastic reduction material may be mixed at an appropriate ratio.
[0085]
For example, in addition to those described above, limestone (limestone) powder is also effective for powders that are mixed with asphalt to contribute to strength improvement. The main component of limestone is calcium carbonate (CaCO ₃ ). Slaked lime (calcium hydroxide: Ca (OH) ₂ ) powder and calcium oxide (CaO) powder are also effective. All of these contain calcium. In general, when water and aggregates such as sand and crushed stone are mixed with cement such as Portland cement, the cement and water undergo a hydration reaction, and the hydration reaction product of the cement firmly solidifies the aggregates. It becomes high strength concrete. Under the present circumstances, the main thing of the hydration reaction product of cement is a calcium salt (calcium silicate). Therefore, when powder of a substance containing calcium is mixed with asphalt, it is considered that the strength is improved by a product similar to the case of concrete. These materials correspond to calcium-based materials.
[0086]
Further, as fibers or powders to be mixed in asphalt, silica (silicon dioxide: SiO ₂ ) such as silica sand, alumina (Al ₂ O ₃ ), magnesia (MgO), zirconia (ZrO ₂ ), mullite (3Al ₂ O _3. 2SiO ₂ ), aluminum titanate (Al ₂ TiO ₅ or Al ₂ O ₃ .TiO ₃ ), LAS (Li ₂ O—Al ₂ O ₃ —SiO ₂ ), cordierite or MAS (2MgO.2Al ₂ O _3. 5SiO ₂ ), boron nitride (BN), aluminum nitride (AlN), silicon nitride (SiN), silicon carbide (SiC), etc. are also effective in improving the strength. These are the main components of ceramics, and when mixed in asphalt, it is considered that the strength is improved by a product similar to ceramics. These materials correspond to ceramic materials.
[0087]
In addition, quartz, feldspar, and fluorite are effective in improving the strength of the powder mixed in asphalt. Quartz has silicon dioxide (SiO ₂ ) as a main component. The feldspar is a mineral containing anorthite (K [AlSi ₃ O ₈ ]), anorthite (N [AlSi ₃ O ₈ ]), and anorthite (Ca [Al ₂ Si ₂ O ₈ ]). The fluorite is a mineral containing fluorite (Na [AlSi ₂ O ₆ ] · H ₂ O) and pyroxenite (Ca ₂ [Al ₄ Si ₁₄ O ₃₆ ] · 12H ₂ O). In general, feldspars and fluorites are constituents of rocks. Therefore, when feldspar or fluorite powder is mixed with asphalt, it is considered that the strength is improved by a product similar to the case of rocks.
For the same reason as described above, as a powder to be mixed into asphalt, stone powder generated by pulverizing rocks and sand is also effective for improving the strength.
These materials correspond to rock mineral materials.
[0088]
In addition, kaolin clay, porcelain stone, and talc are also effective for improving the strength of the powder mixed in asphalt. Kaolin clay is a clay mainly composed of kaolin minerals such as kaolinite (Al ₂ Si ₂ O ₅ (OH) ₄ ) and halloysite (Al ₂ Si ₂ O ₅ (OH) ₄ .2H ₂ O). Further, porcelain stone is a material containing sericite as a main component and containing quartz. Talc is a hydrous magnesium silicate mineral. In general, kaolin-based clay, porcelain stone, talc and the like are solidified by firing to become a ceramic material or a refractory material. Therefore, when asphalt is mixed with powder of kaolin clay, porcelain stone, talc, etc., it is considered that the strength is improved by a product similar to the case of ceramics. These materials correspond to ceramic materials.
[0089]
Further, as described above, glass is also effective as a fiber or powder to be mixed for the purpose of improving the strength of asphalt. The glass is generally obtained by mixing and melting silicate, borate or phosphate and a basic oxide and solidifying them in an amorphous state. For example, soda lime glass or the like in which silica (silicon dioxide: SiO ₂ ), sodium carbonate (Na ₂ CO ₃ ) and calcium carbonate (CaCO ₃ ) are mixed and melted and rapidly cooled is known. Hard ingredients such as glaze and cloisonne in ceramics are glassy. Therefore, it is considered that when a glassy substance powder is mixed with asphalt, the strength is improved by a product similar to that of glass or ceramics. These materials correspond to glass-based materials.
[0090]
Further, as described above, mica (mica) is also effective as a powder to be mixed in asphalt. Mica is a phyllosilicate mineral, and naturally produced muscovite (mascobite: KAl ₂ (Si ₃ Al) O ₁₀ (OH) ₂ ), soda mica (paragonite: NaAl ₂ (Si ₃ Al) O ₁₀ ( OH) ₂ ), phlogopite (phlogopite: KMg ₃ (Si ₃ Al) O ₁₀ (OH) ₂ ), biotite (biotite: K (Mg, Fe) ₃ (Si ₃ Al) O ₁₀ (OH) ₂ ) Is included. In addition, fluorine phlogopite containing fluorine (F) instead of the OH group of phlogopite is produced industrially and is called synthetic mica. These mica are used as materials such as mica crystallized glass that can improve the brittleness of glass and can be machined while having the properties of glass. Therefore, when mica powder is mixed with asphalt, it is possible to improve brittleness, that is, to improve viscoelasticity by a product similar to that of mica ceramics, etc., and to improve the final strength compared to asphalt alone. Conceivable. Therefore, these mica can be used both as a small-diameter mixed member and as a viscoelastic material. Each of the above mica corresponds to a mica material.
[0091]
The powders of calcium carbonate, calcium hydroxide, silicon dioxide, glass and the like described above have a relatively large specific gravity compared to asphalt (hereinafter, these powders are referred to as “large specific gravity powder”). For this reason, when these are mixed alone in asphalt, the powder component may precipitate at the bottom of the asphalt, and material separation between the asphalt component and the powder component may occur. If such material separation occurs, the strength of asphalt cannot be improved. On the other hand, since the specific gravity of mica powder is relatively small compared to asphalt, when mixed in asphalt, the powder component floats in the asphalt for a long time, and material separation between the asphalt component and the powder component occurs. There are few things. Utilizing this fact, when mixing the above-mentioned high specific gravity powder such as calcium carbonate into the asphalt, if the mica powder is also mixed, the mica powder floating in the asphalt acts to prevent the precipitation of the high specific gravity powder. To do. In this case, when the distribution ratio between the large specific gravity powder and the mica powder was approximately 1: 1, the precipitation preventing effect of the large specific gravity powder was the best. Moreover, mica powder is preferable from the viewpoint of improving the properties of asphalt because it also has an effect of improving the viscoelasticity of asphalt as described above. In addition, mica powder is less expensive than large specific gravity powder, and is effective in reducing the cost of asphalt-based structural materials.
[0092]
In the description of the second embodiment, the diameter of the powder as viewed from the viewpoint of dispersion performance in asphalt has been described by taking a value of about 10 to 100 μm as an example. In consideration of powder and the like, the range of the diameter of the powder is acceptable up to about 10 μm to 1 mm.
[0093]
In the description of the second embodiment described above, the upper limit value of the mixing ratio of the powder from the viewpoint of strength is described by taking a value of about 30% as an example by weight percent with respect to the entire asphalt-based structural material. However, in consideration of mixing the above-mentioned high specific gravity powder into asphalt, this upper limit value is acceptable up to about 50% by weight percent with respect to the entire asphalt-based structural material.
[0094]
In the description of the third embodiment described above, an amorphous polyolefin-based synthetic resin has been described as an example of a fluidizing material for improving the fluidity of the fluidized asphalt-based structural material. The fluidizing material in the asphalt-based structural material of the invention is not limited to this. In general, a thermoplastic resin can be used as the fluidizing material. A thermoplastic resin is a synthetic resin that is solid at normal temperature, but softens when heated and melts into a fluid state when heated. For this reason, if mixed into the asphalt-based structural material, the thermoplastic resin is also in a fluid state in the flow state of the asphalt-based structural material, which is considered to increase the fluidity of the asphalt-based structural material. In addition to the above-mentioned polyethylene, polypropylene, etc., thermoplastic resins include polyvinyl chloride, polyvinyl chloride acetate, polyvinylidene chloride, polyvinyl acetate, polyvinyl alcohol, polyvinyl formal, polyvinyl butyral, polyvinyl acetal, ethylene vinyl acetate copolymer resin. (EVA resin), polystyrene, ABS resin, AS resin, fluororesin, polymethylpentene, polysulfone, polyamide, polyamideimide, polyetherimide, styrene copolymer resin, polycarbonate, polymethyl methacrylate, polyurethane, cellulose acetate, Other cellulosic resins, polyethylene terephthalate, polybutylene terephthalate, polyphenylene ether, polyphenylene oxide, polyphenylene sulfide, silica Down resin, polysulfone, polyether sulfone, polyarylate, polyimide, polyallyl ether, polyether ether ketone, polybutylene, ACS resins, ASA resins include MBS resin.
[0095]
Other substances can also be used as the fluidizing material in the asphalt-based structural material of the present invention. In general, asphalt emulsifiers are effective in improving the fluidity of heated asphalt. This asphalt emulsifier is classified into an anionic emulsifier, a cationic emulsifier, and a nonionic emulsifier, and is a substance for emulsifying asphalt as fine particles, and this asphalt emulsification performance is considered to contribute to improvement of fluidization of asphalt during heating. .
Examples of the anionic emulsifier include alkali metal salts of carboxylic acid or sulfonic acid, which are by-products of wood products such as rosin, lignin, and tall oil, and alkali metal salts such as fatty acid, higher alcohol sulfate, or alkylbenzene sulfonic acid. Rosin is a yellow to brown translucent substance obtained by distilling crude turpentine oil extracted from pine resin, and mainly contains abithienic acid, parastronic acid and the like. Lignin is a colorless to brown substance that forms the wood part of plants together with cellulose, and is obtained from a sulfite solution of paper pulp. Tall oil (tall oil) is a yellow to black resinous substance composed of rosin, fatty acid, sterol, high molecular weight alcohol, and the like, and is obtained from a waste liquid during production of wood pulp.
Examples of the cationic emulsifier include hydrochlorides or acetates of fatty acid derivative amines (diamine, triamine, imidazoline, etc.) made from beef tallow or coconut oil.
[0096]
Further, if the fluidizing material is used, the fluidity of asphalt can be increased at the same temperature. Therefore, if a fluidizing material is used, the heating temperature (first temperature) necessary to obtain the same level of fluidity can be reduced.
[0097]
Further, it is considered that the strength of the asphalt-based structural material after solidification is improved by mixing a thermosetting resin with the asphalt-based structural material of the present invention. Generally, a thermosetting resin is a synthetic resin that cures when heated. For this reason, if it mixes in an asphalt type structural material, it will be thought that it contributes to the improvement of the hardness of an asphalt type structural material. Thermosetting resins include phenolic resin, urea resin, melamine resin, xylene resin, diallyl phthalate resin, phthalic acid resin, unsaturated polyester, epoxy resin, furan resin, benzoguanamine resin, thermosetting polybutadiene, and the like.
In the case of a thermoplastic resin as well, since it solidifies after cooling, it is considered that the strength of the asphalt-based structural material after solidification is improved. Accordingly, in general, synthetic resins (plastics) are effective in improving the strength of asphalt-based structural materials.
[0098]
Further, in the above-described embodiment, as a member to be mixed in asphalt, fiber and powder have been described as an example, but the present invention is not limited to this, and generally, if it is a small diameter mixed member, Any shape may be sufficient and the particle | grain shape larger than a powder may be sufficient. Moreover, this small diameter mixing member may be a member that can maintain a mixed state without being fused with asphalt even in molten asphalt, such as a metal material. In this case, in the asphalt-based structural material after solidification, the mixed small-diameter member is dispersed in the asphalt and is not fused and disappeared in the asphalt. be able to. On the other hand, the small-diameter mixed member in the present invention may be a member that fuses with asphalt in a high-temperature molten asphalt and generates an asphalt material having a composition different from that of pure asphalt, such as a synthetic resin. Good. In this case, in the asphalt-based structural material after solidification, the mixed small-diameter member is fused and disappeared in the asphalt, and a new substance is synthesized. Can do. The term “hybrid” in the above description is used as a term that expresses a concept that combines two concepts of a mixture and a composite.
In addition, the “modifier” in the above description is used as a term representing a general concept including the concept of fluidizing material and viscoelastic material, and improves the properties of the mixed state after flowing state or curing. It corresponds to the substance to be.
[0099]
In each of the above embodiments, as a structure using an asphalt-based structural material as an aggregate filler, a railway roadbed has been described as an example, but the present invention is not limited to this, Types of structures, such as floors on roads, floors on wharves and other port structures, floors on airport structures such as runways and aprons, floors on landfills, floors on buildings Or a floor-shaped part in an agricultural structure.
[0100]
Further, the asphalt-based structural material according to the present invention is not limited to the filling method in which the aggregate is laid in a floor shape and poured into a pre-formed filler in a fluid state to construct the asphalt-based structural material filled structure. It can also be used for the construction of asphalt structures. For example, an asphalt-based structural material according to the present invention and an aggregate such as sand and crushed stone are mixed to form an asphalt-aggregate composite, which is laid and compacted to form a layered structure. You can also
The asphalt-based structural material according to the present invention includes fibers or powders mixed with asphalt, has a composition similar to so-called natural asphalt, and is hard and highly wear-resistant.
Therefore, the asphalt-based structural material according to the present invention includes a pavement material for construction of a new road, a repair material for cracks and holes in an existing road pavement, a repair material for pavement of a joint portion on a bridge, or a step in a bridge, etc. It can also be used as a material for rubbing parts.
Thus, when using as a natural asphalt-like material, in order to further improve the wear resistance, it is advisable to mix particulate natural crushed stone, artificial crushed stone, sand or the like having a particle size of about 1 to 5 mm.
[0101]
Also, other construction methods using the asphalt-based structural material according to the present invention are possible. For example, after heating the asphalt to a first temperature (a temperature at which a mixed material such as fiber can be stirred) to obtain a stirrable viscosity, the asphalt has a predetermined strength, a predetermined heat resistance, and an asphalt. After mixing and stirring at an appropriate ratio of any of fibers and powders made of a material having a predetermined dispersion performance, or an appropriate combination thereof, this is cooled and cured, and then crushed. At the time of construction, such as filling into aggregates, filling between aggregates, mixing with aggregates, etc., this aggregated material can be filled at a second temperature higher than the first temperature (such as aggregates). A temperature at which the fluid is brought into a fluid state) and fluidized and used.
[0102]
【The invention's effect】
As described above, according to the present invention, a small-diameter mixing member that increases strength and a fluidizing material that increases fluidity are mixed into asphalt heated to 120 to 185 ° C. and mixed to produce a composite. After that, the composite was heated to 220-260 ° C. and fluidized to fill the gaps between the aggregates, so that the initial strength, final strength and fillability were improved as compared to the case of asphalt alone, and the aggregates It is possible to effectively prevent the subsidence of the railway road floor and to reduce the construction cost to a low price.
[Brief description of the drawings]
FIG. 1 is a conceptual diagram showing characteristics relating to strength of an asphalt-based structural material according to an embodiment of the present invention.
FIG. 2 is a conceptual diagram showing a configuration of an asphalt filling method according to another embodiment of the present invention.
FIG. 3 is a view showing an example of a track structure constructed by the asphalt filling method shown in FIG. 2;
FIG. 4 is a diagram showing characteristics relating to strength of an asphalt-based structural material that is an example of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Asphalt filling apparatus 2 Asphalt heating mixing part 3 Asphalt transfer part 4 Asphalt structure material fluid 5 Road bed 6 Frame board 7 Roadbed 8 Sleeper 9 Rail 21 Heating container 22 Motor 23 Stirring blade 31 Motor 32 Pump 33, 34 Transfer pipe 41-43 Hardened asphalt-based structural material 51 Aggregate 52 Pavement 53, 54 Unfilled part

Claims (15)

A step of heating the asphalt to 120 to 185 ° C., and then mixing a small-diameter mixing member for increasing the strength and a fluidizing material for increasing the fluidity into the asphalt and stirring to produce a composite;
Next, the composite is heated to 220 to 260 ° C. and melted to produce a fluid asphalt-based structural material;
Next, the asphalt-based structure material having a step of filling the fluidized asphalt-based structural material into the gap between the aggregates from the side of the sleeper to just above the roadbed among the aggregates of the railroad bed, and then hardening by cooling. A method for constructing a railway roadbed using materials,
As the small diameter mixed member,
It consists of a metal material, ceramic material, rock mineral material, carbon, glass material, synthetic resin, plant material, or animal material, and has a length of 1 to 10 mm and a diameter of 0.01 ~ 1mm short diameter fiber,
Alternatively, it is made of a metal material, calcium-based material, ceramic-based material, rock mineral-based material, ceramic-based material, carbon, glass-based material, mica-based material, or synthetic resin, and has a diameter of 10 to 100 μm. While fine powder is used, the weight ratio to the entire asphalt-based structural material is 30% or less,
As the fluidizing material, an amorphous polyolefin resin and an anionic asphalt emulsifier are used, and the weight ratio with respect to the entire asphalt structural material is 5% or less. Construction method for the roadbed. A step of heating the asphalt to 120 to 185 ° C., and then mixing a small-diameter mixing member for increasing the strength and a fluidizing material for increasing the fluidity into the asphalt and stirring to produce a composite;
Next, the composite is heated to 220 to 260 ° C. and melted to produce a fluid asphalt-based structural material;
Next, the asphalt-based structure material having a step of filling the fluidized asphalt-based structural material into the gap between the aggregates from the side of the sleeper to just above the roadbed among the aggregates of the railroad bed, and then hardening by cooling. A method for constructing a railway roadbed using materials,
As the small diameter mixed member,
It consists of a metal material, ceramic material, rock mineral material, carbon, glass material, synthetic resin, plant material, or animal material, and has a length of 1 to 10 mm and a diameter of 0.01 ~ 1mm short diameter fiber,
Alternatively, it is made of a metal material, calcium-based material, ceramic-based material, rock mineral-based material, ceramic-based material, carbon, glass-based material, mica-based material, or synthetic resin, and has a diameter of 10 to 100 μm. While fine powder is used, the weight ratio to the entire asphalt-based structural material is 30% or less,
An anionic asphalt emulsifier is used as the fluidizing material, and the weight ratio with respect to the entire asphalt-based structural material is 5% or less. In the construction method of the railway roadbed using the asphalt-based structural material according to claim 1 or 2,
When the small-diameter mixed member has conductivity, the weight ratio with respect to the entire asphalt-based structural material is set to 5% or less. In the construction method of the railway roadbed using the asphalt-based structural material according to claim 1,
The amorphous polyolefin-based resin is an amorphous or rubber-like resin-like substance produced by polymerization of an olefin that is an unsaturated hydrocarbon having one carbon-carbon double bond, and includes polyethylene, Alternatively, a method for constructing a railway roadbed using an asphalt-based structural material characterized by containing polypropylene or polybutene. In the construction method of the railway roadbed using the asphalt-based structural material according to claim 1 or 2,
The anionic asphalt emulsifier is a rosin obtained by distilling crude turpentine oil extracted from a pine resin, or a lignin that forms a woody part of a plant, or a carboxyl of tall oil having the rosin, a fatty acid, a sterol, and a polymer alcohol. A method for constructing a railway roadbed using an asphalt-based structural material, comprising an alkali metal salt of an acid or sulfonic acid, a fatty acid, a higher alcohol sulfate, or an alkali metal salt of an alkylbenzene sulfonic acid. A step of heating the asphalt to 120 to 185 ° C., and then mixing a small-diameter mixing member for increasing the strength and a fluidizing material for increasing the fluidity into the asphalt and stirring to produce a composite;
Next, the composite is heated to 220 to 260 ° C. and melted to produce a fluid asphalt-based structural material;
Next, the asphalt-based structural material in the fluidized state is filled with a gap between aggregates from the side of the sleeper to the lower part of the sleeper among the aggregates of the railway bed, and then cured by cooling;
Next, a method for constructing a railway roadbed using an asphalt-based structural material having a step of paving the side surface of the roadbed,
As the small diameter mixed member,
It consists of a metal material, ceramic material, rock mineral material, carbon, glass material, synthetic resin, plant material, or animal material, and has a length of 1 to 10 mm and a diameter of 0.01 ~ 1mm short diameter fiber,
Alternatively, it is made of a metal material, calcium-based material, ceramic-based material, rock mineral-based material, ceramic-based material, carbon, glass-based material, mica-based material, or synthetic resin, and has a diameter of 10 to 100 μm. While fine powder is used, the weight ratio to the entire asphalt-based structural material is 30% or less,
As the fluidizing material, an amorphous polyolefin resin and an anionic asphalt emulsifier are used, and the weight ratio with respect to the entire asphalt structural material is 5% or less. Construction method for the roadbed. A step of heating the asphalt to 120 to 185 ° C., and then mixing a small-diameter mixing member for increasing the strength and a fluidizing material for increasing the fluidity into the asphalt and stirring to produce a composite;
Next, the composite is heated to 220 to 260 ° C. and melted to produce a fluid asphalt-based structural material;
Next, the asphalt-based structural material in the fluidized state is filled with a gap between aggregates from the side of the sleeper to the lower part of the sleeper among the aggregates of the railway bed, and then cured by cooling;
Next, a method for constructing a railway roadbed using an asphalt-based structural material having a step of paving the side surface of the roadbed,
As the small diameter mixed member,
It consists of a metal material, ceramic material, rock mineral material, carbon, glass material, synthetic resin, plant material, or animal material, and has a length of 1 to 10 mm and a diameter of 0.01 ~ 1mm short diameter fiber,
Alternatively, it is made of a metal material, calcium-based material, ceramic-based material, rock mineral-based material, ceramic-based material, carbon, glass-based material, mica-based material, or synthetic resin, and has a diameter of 10 to 100 μm. While fine powder is used, the weight ratio to the entire asphalt-based structural material is 30% or less,
An anionic asphalt emulsifier is used as the fluidizing material, and the weight ratio with respect to the entire asphalt-based structural material is 5% or less. In the construction method of the railway roadbed using the asphalt-based structural material according to claim 6 or 7,
When the small-diameter mixed member has conductivity, the weight ratio with respect to the entire asphalt-based structural material is set to 5% or less. In the construction method of the railway roadbed using the asphalt-based structural material according to claim 6,
The amorphous polyolefin-based resin is an amorphous or rubber-like resin-like substance produced by polymerization of an olefin that is an unsaturated hydrocarbon having one carbon-carbon double bond, and includes polyethylene, Alternatively, a method for constructing a railway roadbed using an asphalt-based structural material characterized by containing polypropylene or polybutene. In the construction method of the railway roadbed using the asphalt-based structural material according to claim 6 or 7,
The anionic asphalt emulsifier is a rosin obtained by distilling crude turpentine oil extracted from a pine resin, or a lignin that forms a woody part of a plant, or a carboxyl of tall oil having the rosin, a fatty acid, a sterol, and a polymer alcohol. A method for constructing a railway roadbed using an asphalt-based structural material, comprising an alkali metal salt of an acid or sulfonic acid, a fatty acid, a higher alcohol sulfate, or an alkali metal salt of an alkylbenzene sulfonic acid. A step of heating the asphalt to 120 to 185 ° C., and then mixing a small-diameter mixing member for increasing the strength and a fluidizing material for increasing the fluidity into the asphalt and stirring to produce a composite;
Next, the composite is heated to 220 to 260 ° C. and melted to produce a fluid asphalt-based structural material;
Next, the asphalt-based structural material in the fluidized state has a step of filling the gap between the aggregates from directly below the sleeper to directly above the roadbed among the aggregates of the railroad bed, and then hardening by cooling. A method for constructing a railway roadbed using
As the small diameter mixed member,
It consists of a metal material, ceramic material, rock mineral material, carbon, glass material, synthetic resin, plant material, or animal material, and has a length of 1 to 10 mm and a diameter of 0.01 ~ 1mm short diameter fiber,
Alternatively, it is made of a metal material, calcium-based material, ceramic-based material, rock mineral-based material, ceramic-based material, carbon, glass-based material, mica-based material, or synthetic resin, and has a diameter of 10 to 100 μm. While fine powder is used, the weight ratio to the entire asphalt-based structural material is 30% or less,
As the fluidizing material, an amorphous polyolefin resin and an anionic asphalt emulsifier are used, and the weight ratio with respect to the entire asphalt structural material is 5% or less. Construction method for the roadbed. A step of heating the asphalt to 120 to 185 ° C., and then mixing a small-diameter mixing member for increasing the strength and a fluidizing material for increasing the fluidity into the asphalt and stirring to produce a composite;
Next, the composite is heated to 220 to 260 ° C. and melted to produce a fluid asphalt-based structural material;
Next, the asphalt-based structural material in the fluidized state has a step of filling the gap between the aggregates from directly below the sleeper to directly above the roadbed among the aggregates of the railroad bed, and then hardening by cooling. A method for constructing a railway roadbed using
As the small diameter mixed member,
It consists of a metal material, ceramic material, rock mineral material, carbon, glass material, synthetic resin, plant material, or animal material, and has a length of 1 to 10 mm and a diameter of 0.01 ~ 1mm short diameter fiber,
Alternatively, it is made of a metal material, calcium-based material, ceramic-based material, rock mineral-based material, ceramic-based material, carbon, glass-based material, mica-based material, or synthetic resin, and has a diameter of 10 to 100 μm. While fine powder is used, the weight ratio to the entire asphalt-based structural material is 30% or less,
An anionic asphalt emulsifier is used as the fluidizing material, and the weight ratio with respect to the entire asphalt-based structural material is 5% or less. In the construction method of the railway roadbed using the asphalt-based structural material according to claim 11 or 12,
When the small-diameter mixed member has conductivity, the weight ratio with respect to the entire asphalt-based structural material is set to 5% or less. In the construction method of the railway roadbed using the asphalt-based structural material according to claim 11,
The amorphous polyolefin-based resin is an amorphous or rubber-like resin-like substance produced by polymerization of an olefin that is an unsaturated hydrocarbon having one carbon-carbon double bond, and includes polyethylene, Alternatively, a method for constructing a railway roadbed using an asphalt-based structural material characterized by containing polypropylene or polybutene. In the construction method of the railway roadbed using the asphalt-based structural material according to claim 11 or 12,
The anionic asphalt emulsifier is a rosin obtained by distilling crude turpentine oil extracted from a pine resin, or a lignin that forms a woody part of a plant, or a carboxyl of tall oil having the rosin, a fatty acid, a sterol, and a polymer alcohol. A method for constructing a railway roadbed using an asphalt-based structural material, comprising an alkali metal salt of an acid or sulfonic acid, a fatty acid, a higher alcohol sulfate, or an alkali metal salt of an alkylbenzene sulfonic acid.

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