JP6148156B2 - Construction method of buried type expansion device, bridge and buried type expansion device - Google Patents

Description

  The present invention relates to an embedded expansion / contraction device that forms a continuous pavement surface between bridges, a bridge using the same, and a method for constructing the embedded expansion / contraction device.

  Conventionally, in a road bridge, an expansion / contraction device has been installed between the floor slabs and between the abutments and the floor slabs, and the expansion / contraction device absorbs fluctuations in the inter-play distance due to changes in temperature and load. , Keeps the road surface flat and continuous. As an expansion / contraction device, there is a device in which a finger-like joint body or a plate-like joint body is fixed to an end portion of a floor slab and the joint body is exposed on a road surface. However, this type of expansion and contraction device has inconvenience that noise and vibration are generated when the wheel climbs over the joint body, and there is a problem that a step is generated between concrete and asphalt pavement that fixes the joint body to the floor slab. .

  In view of this, conventionally, there has been proposed an embedded expansion and contraction device in which a pavement is continuously installed on a floor slab separated by a play and a seamless pavement surface is formed. As an embedded expansion and contraction device, as described in Patent Document 1, a lower layer plate formed by reinforcing cement with high-strength vinylon fibers is fixed on the end portions of a floor slab facing both sides of a play with an adhesive. In some cases, the first and second upper layer plates made of the same material as the lower layer plate are installed on the lower layer plate so as to bridge the floor slabs on both sides of the play. A plate-like member using a resin-impregnated aramid fiber plate is further disposed on the second upper layer plate. A base layer made of goose asphalt is provided on the side of the lower layer plate, the first and second upper layer plates and the plate-like member on the floor slab, and formed on the base layer and the plate-like member by modified asphalt. A continuous pavement surface is formed above the play. Even if the gap between the floor slabs expands and contracts due to a temperature change, this buried type expansion and contraction device slides the lower plate fixed to the floor slab with respect to the first upper layer plate, and the plate-like member in contact with the surface layer is the first. 2 Slide against the upper layer board. Thereby, the first and second upper layer plates are formed so that the plate-like member and the surface layer extend uniformly while hardly expanding and contracting. As a result, while maintaining durability by the first and second upper layer plates, it is possible to improve the durability of the embedded expansion and contraction device and prevent cracking of the pavement surface so that local distortion does not occur on the surface layer. Is going.

  Moreover, as another conventional buried type expansion and contraction device, there is one as shown in FIG. The embedded expansion and contraction device 101 is disposed on the end of the two floor slabs 102 and 102 and the strain absorbing layer 104 disposed on the gap 103, and on the strain absorbing layer 104 and the floor slabs 102 and 102. The stretchable part base layer 105 and an expanded metal 106 embedded in the stretchable part base layer 105 in parallel with the surface of the floor slab 102 are provided. Both ends of the expanded metal 106 are fixed to the floor slabs 102 and 102 by anchors 107, and both end surfaces of the stretchable base layer 105 in which the expanded metal 106 and the anchor 107 are embedded are bonded to the floor slab portion by an adhesive tape 108. It is in contact with the base layer 109. A surface layer 110 is provided on the surfaces of the stretchable part base layer 105, the adhesive tape 108, and the floor slab part base layer 109. A back-up material 111 is provided in a gap 103 separating the floor slabs 102 from the bottom surface of the strain absorbing layer 104 to a predetermined depth. At the ends of the floor slabs 102 and 102, a gap adjusting portion 112 for reinforcement is provided.

  When the floor slabs 102 and 102 are displaced in the horizontal direction and the distance between the play gaps 103 is changed, the embedded expansion / contraction apparatus 101 disperses the strain generated in the expansion / contraction portion base layer 105 by the expanded metal 106 in the expansion / contraction portion base layer 105. It is formed as follows. Thereby, the crack resulting from the horizontal displacement of the floor slab 102 does not arise in the surface layer 110 continuously laid on the gap 103 and the two floor slabs 102 and 102.

  The stretchable base layer 105 in which the expanded metal 106 and the anchor 107 are embedded is formed of goose asphalt, and the floor slab base layer 109 installed on the floor slab 102 is formed of dense grain asphalt. As described above, the adhesive tape 108 formed of rubber asphalt is used to bond the stretchable portion base layer 105 and the floor slab base layer 109 formed of different materials.

JP 2009-249953 A

  When the vehicle travels on the pavement installed on the bridge slab, a rotational load and a vertical displacement are generated in addition to the horizontal displacement at the end of the floor slab due to the live load of the vehicle moving on the floor slab. However, since the conventional embedded type expansion and contraction device shown in Patent Document 1 and FIG. 4 only supports the expansion and contraction between the horizontal displacements of the floor slab, the rotational displacement and vertical generated repeatedly at the end of the floor slab. The displacement may cause cracks on the pavement surface.

  Then, the subject of this invention is providing the embedment type expansion-contraction apparatus which can prevent effectively the crack resulting from the rotational displacement and vertical displacement which arise in the edge part of a floor slab.

In order to solve the above problems, the embedded expansion and contraction device according to the present invention is an embedded expansion and contraction device that is installed between the support structure members of the bridge and forms a continuous pavement surface on the surface,
A strain absorbing layer continuously disposed on the support structure member facing the gap with a gap between the support structure member;
An aggregate disposed continuously on the support structure member and the strain absorption layer, formed of crushed stone and having a gap particle size distribution, and a viscosity at 60 ° C. of 1,000 Pa · s to 30,000 Pa · s, And a base layer formed of a crushed mastic asphalt mixture obtained by mixing an asphalt composition having a bending strain at −10 ° C. of 180 × 10 ⁻³ or more and 500 × 10 ⁻³ or less.

According to the above configuration, the embedded expansion and contraction device is continuously disposed on the support structure member and the strain absorption layer which are continuously disposed on the opposing support structure member and the gap, and on the support structure member and the strain absorption layer. And a base layer formed of a crushed mastic asphalt mixture. A surface layer for forming a paved surface is provided on the base layer. The crushed stone mastic asphalt mixture forming the base layer is composed of an aggregate formed of crushed stone and having a gap particle size distribution, a viscosity at 60 ° C of 1,000 Pa · s to 30,000 Pa · s, and a bending at -10 ° C. Since the asphalt composition having a strain of 180 × 10 ⁻³ or more and 500 × 10 ⁻³ or less is mixed, the flexible asphalt composition is filled between the skeleton formed by the aggregate having a high meshing effect. Thus, both durability and flexibility can be achieved. Therefore, the base layer can be hardly damaged by the rotational load and the vertical displacement repeatedly generated at the end portion of the support structure member due to the live load of the vehicle traveling on the support structure member. As a result, a buried expansion and contraction device can be obtained in which cracks are unlikely to occur on the surface layer installed on the base layer, and durability of the portion on the pavement gap can be increased as compared with the conventional one. Here, the support structure member of the bridge is a member that supports the load acting on the road surface by pavement being laid on the upper side among members constituting the bridge, and corresponds to, for example, an abutment or a floor slab. Further, the strain absorbing layer refers to a layer having a function of relaxing horizontal strain generated in the base layer when horizontal displacement occurs between the support structural members. Further, the gap particle size distribution means that the region of a predetermined particle size is discontinuous in the aggregate particle size distribution form. The viscosity at 60 ° C. of the asphalt composition is a viscosity obtained by measuring the asphalt composition heated to 60 ° C. with a reduced pressure capillary viscometer. The bending strain of the asphalt composition is based on the pavement survey and test method manual published by the Japan Road Association and the bending test method of A063T polymer modified asphalt, and the bending test is performed at -10 ° C. Is the amount of strain obtained.

  In one embodiment, the asphalt composition of the crushed stone mastic asphalt mixture that forms the base layer includes asphalt, a thermoplastic elastomer, and a process oil.

  According to the above embodiment, the asphalt composition including the asphalt, the thermoplastic elastomer, and the process oil can effectively enhance the durability of the base layer against the rotational displacement and the vertical displacement generated at the end of the support structure member. .

  As for the embedding type expansion-contraction apparatus of one Embodiment, the asphalt composition of the said crushed stone mastic asphalt mixture contains a ductile material.

  According to the above-described embodiment, the ductility material can improve the ductility and malleability of the asphalt composition without deteriorating the properties such as elasticity of the thermoplastic elastomer and the properties such as softness of the process oil.

  In the embedded expansion / contraction apparatus according to one embodiment, the aggregate of the crushed mastic asphalt mixture forming the base layer has a 2.36 mm sieve passage in a synthetic particle size of 20 to 35% by mass.

  According to the above-described embodiment, the rotational displacement generated at the end of the support structure member by the crushed stone mastic asphalt mixture using the aggregate of the gap particle size distribution in which the 2.36 mm sieve passage in the synthetic particle size is 20 to 35% by mass and A base layer having high durability against vertical displacement is obtained.

  In one embodiment, the crushed mastic asphalt mixture forming the base layer is 2 to 20 parts by mass of the asphalt composition and 0.1 to 1 part by mass with respect to 100 parts by mass of the aggregate. Including fiber material.

  According to the above embodiment, the end portion of the support structural member is obtained by the crushed mastic asphalt mixture containing 2 to 20 parts by weight of the asphalt composition and 0.1 to 1 parts by weight of the fiber material with respect to 100 parts by weight of the aggregate. A base layer having high durability against rotational displacement and vertical displacement generated in the above can be formed. Here, it is more preferable to mix 3 to 15 parts by mass of the asphalt composition with respect to 100 parts by mass of the aggregate, and it is particularly preferable to mix 5.5 to 7.5 parts by mass. Moreover, it is more preferable to mix 0.2 to 0.5 parts by mass of the fiber material with respect to 100 parts by mass of the aggregate.

  In one embodiment of the embedding type expansion and contraction device, the strain absorbing layer is formed of a rubber asphalt sheet sandwiched between a lower layer and an upper layer in which a bitumen material is coated on the front and back surfaces of a base material, and the lower layer and the upper layer. Intermediate layer.

  According to the above embodiment, the strain absorption includes a lower layer and an upper layer formed by coating a bitumen material on the front and back surfaces of the base material, and an intermediate layer formed of a rubber asphalt sheet sandwiched between the lower layer and the upper layer. The layer can effectively reduce the friction between the support structure member and the base layer. Therefore, when the support structural member is displaced in the bridge axis direction and the distance between the play is expanded and contracted, the force in the bridge axis direction acting on the base layer can be effectively reduced. As a result, the base layer and the base layer are installed on the base layer. Can be effectively prevented from being damaged.

  The embedded expansion-contraction apparatus of one Embodiment is provided between the said strain absorption layer and a base layer, and is provided with the reinforcement layer located above the support structure member which opposes across the said play.

  According to the above-described embodiment, the base layer is cracked due to a live load when the vehicle travels by the reinforcing layer that is provided between the strain absorption layer and the base layer and is positioned above the support structure member that is opposed to each other with a gap. In contrast, the resistance can be effectively improved. As a result, it is possible to effectively prevent cracking between the base layer and the surface layer installed on the base layer.

The bridge of the present invention, a plurality of support structure members separated from each other by play,
A plurality of the embedded expansion and contraction devices installed so as to bridge between the plurality of support structure members,
A base layer continuous with the base layer of the plurality of embedded type stretching devices is provided on the plurality of supporting structure members, and the base layer on the plurality of supporting structure members and the base layer of the plurality of embedded type stretching devices are provided. Further, a continuous surface layer is provided.

  According to the above configuration, the base layer provided on the plurality of support structure members and the plurality of embedded molds are bridged between the plurality of support structure members by the plurality of embedded type stretching devices according to the present invention. The base layer of the expansion / contraction device can be formed continuously, and a continuous surface layer can be formed on the base layer on the plurality of support structural members and the base layer of the plurality of embedded type expansion / contraction devices. As a result, it is possible to form a seamless pavement surface on the surface of the surface layer provided on the plurality of support structure members and on the plurality of embedded expansion and contraction devices. As a result, it is difficult to cause cracks in the pavement surface due to rotational displacement and vertical displacement that occur at the end of the support structure member, and a bridge that can provide a good riding comfort to the vehicle is obtained.

The construction method of the buried type expansion and contraction device of the present invention is a construction method of the buried type stretching device that is installed between the support structure members of the bridge and forms a continuous pavement surface on the surface,
A step of disposing a continuous strain absorbing layer on the support structure members facing each other with a gap therebetween, so as to bridge these support structure members;
An aggregate formed of crushed stone and having a gap particle size distribution on the support structure member and the strain absorption layer, a viscosity at 60 ° C of 1,000 Pa · s to 30,000 Pa · s, and -10 ° C And continuously arranging a base layer formed of a crushed stone mastic asphalt mixture obtained by mixing an asphalt composition having a bending strain of 180 × 10 ⁻³ or more and 500 × 10 ⁻³ or less.

According to the above configuration, the continuous strain absorbing layer is disposed on the support structure member facing with a gap between them, and the aggregate is formed of crushed stone and has a gap particle size distribution on the strain absorbing layer. A crushed stone mastic obtained by mixing an asphalt composition having a viscosity at 1000 ° C. of 1,000 Pa · s to 30,000 Pa · s and a bending strain of −10 ° C. of 180 × 10 ^{−3 to} 500 × 10 ^−3. A base layer formed of an asphalt mixture is placed in succession. The base layer formed of the crushed stone mastic asphalt mixture can be placed on a general construction machine such as an asphalt finisher, so the base layer can be placed continuously on the support structure members on both sides of the play, effectively improving construction efficiency. Can be improved. In this way, the surface layer can be continuously and efficiently disposed on the base layer continuously disposed on the support structure member spaced apart by a general construction machine. Thus, according to the construction method of the buried type expansion and contraction device of the present invention, since the base layer and the surface layer can be continuously arranged by the construction machine, the portion corresponding to the end of the support structure member facing the play is different from the base layer. The construction efficiency can be improved more effectively than in the case of forming with, and the construction period can be shortened and the construction work can be reduced. In addition, since the base layer can be formed flat by continuous construction using a construction machine, the surface layer on the base layer can be formed flat, and as a result, the flatness of the pavement surface on the embedded expansion and contraction device and the support structure member can be improved. , Can improve the ride comfort of the vehicle.

The construction method of the embedded expansion and contraction device according to an embodiment includes a step of disposing a reinforcing layer positioned above the support structure member facing the gap between the strain absorption layers on the strain absorbing layer,
In the step of disposing the base layer, the base layer is continuously disposed on the support structure member, the strain absorbing layer, and the reinforcing layer.

  According to the embodiment, the base layer caused by the live load when the vehicle travels is disposed between the strain absorbing layer and the base layer by disposing the reinforcing layer positioned above the support structure member that is opposed to each other with a gap. Resistance to cracking can be effectively improved. As a result, an embedded expansion / contraction device that can effectively prevent cracking between the base layer and the surface layer installed thereon can be obtained.

It is sectional drawing which shows the embedding joint as embodiment of the embedding type expansion-contraction apparatus of this invention. It is an enlarged view which shows the detail of a floor slab edge part. It is sectional drawing which shows the test apparatus which performs a crack penetration test. It is sectional drawing which shows the conventional buried type expansion-contraction apparatus.

  Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.

  FIG. 1 is a cross-sectional view showing an embedded joint as an embodiment of the embedded expansion / contraction apparatus of the present invention. The buried joint 1 is installed across a gap 3 formed between a floor slab 2 as a support structure member constituting a road bridge as a bridge and a floor slab 2 connected to the floor slab 2 in the bridge axis direction. Then, a continuous pavement surface is formed on the floor slabs 2 and 2 and the gap 3.

  The buried joint 1 includes a three-layer sheet structure 6 as a strain absorbing layer disposed continuously on the gap 3 and on the ends of the two floor slabs 2 and 2 facing each other with the gap 3 therebetween. . On this three-layer sheet structure 6, the reinforcement as a reinforcing layer that is continuous over the gap 3 and the ends of the two floor slabs 2 and 2 and is installed over a wider range than the gap 3 in the bridge axis direction. A sheet 7 is provided. The surface of the portion of the floor slabs 2, 2 where the three-layer sheet structure 6 is not installed, the surface of the portion of the three-layer sheet structure 6 where the reinforcing sheet 7 is not installed, and the surface of the reinforcing sheet 7 In addition, a base layer 8 formed of a crushed mastic asphalt mixture is continuously arranged. A surface layer 9 formed of an asphalt mixture is continuously disposed on the surface of the base layer 8. At the end portions of the floor slabs 2 and 2, a gap adjusting portion 4 for reinforcement is provided. A backup material 5 that fills the upper part of the gap 3 is provided immediately below the three-layer sheet structure 6 of the gap 3.

  The floor slab 2 provided with the buried joint 1 is a concrete floor slab, and is supported by a PC (precast) girder (not shown). The floor slab 2 is not limited to a concrete floor slab, and may be a steel floor slab or a steel concrete composite floor slab. Further, the floor slab 2 is not limited to a PC girder but may be supported by a girder of another structure or material such as a steel girder. Moreover, although this embodiment demonstrates the embedment joint 1 which bridges between the floor slab 2 and the floor slab 2 as a support structure member, the embedment type expansion and contraction device of the present invention includes an abutment as a support structure member, and a support The present invention can also be applied to a case where it is bridged with a floor slab as a structural member. That is, the present invention can be widely applied to an embedded expansion / contraction device that bridges between the support structure members and spans the gaps formed in the bridge.

  FIG. 2 is a cross-sectional view showing the end portions of the two floor slabs 2 and 2 facing the gap 3. At the end portions of the floor slabs 2 and 2, there are provided gap adjusting portions 4 and 4 that adjust the width and level difference of the gap 3 and reinforce the load of the vehicle passing through the embedded joint 1. The clearance adjustment portion 4 is provided in a chip portion formed by scraping the ends of the floor slabs 2 and 2, and the reinforcing bars 42 arranged in the plane direction of the chip portions and the reinforcing bars 42 are welded. A reinforcing bar 43 extending perpendicularly below the reinforcing bar 42, a sleeve driving type anchor 44 that is driven into the bottom of the chip and welded to the supporting bar 43, and covers the reinforcing bar 42 and the supporting bar 43. And a reinforcing plate 41 which is formed of an angle material and is provided at the corner between the end face of the floor slab 2 and the surface. The backup material 5 is provided in the space 3 between the floor slabs 2 and 2 from the installation position of the space adjusting portions 4 and 4 downward, and is formed of urethane foam. The backup material 5 may be formed of other materials such as polyethylene foam in addition to urethane foam.

  The three-layer sheet structure 6 has a lower layer and an upper layer formed by coating special asphalt or rubber asphalt on the front and back surfaces of a synthetic fiber nonwoven fabric made of an ethylene copolymer resin or the like as a base material. An intermediate layer formed of a rubber asphalt sheet is provided between them. A commercially available waterproof sheet can be used for the lower layer and the upper layer, for example, PM sheet TM manufactured by Nichireki Co., Ltd. can be used. A commercially available strain absorbing mat can be used for the intermediate layer, for example, a pie mat manufactured by Nichireki Co., Ltd. can be used. The three-layer sheet structure 6 is laid on the surface of a concrete floor slab 2 after a rubber asphalt primer such as Nachireki Co., Ltd. Kachicoat R is applied.

  The reinforcing sheet 7 is formed of a woven fabric of glass fiber, and for example, a Sammy sheet manufactured by Nichireki Co., Ltd. can be used. The reinforcing sheet 7 as the reinforcing layer can use glass fiber, synthetic resin fibers such as vinylon, and woven fabrics of metal fibers, and can also use nonwoven fabrics and meshes formed of various materials. it can.

  The base layer 8 is formed of a crushed stone mastic asphalt mixture. The crushed stone mastic asphalt mixture is composed of an aggregate formed of crushed stone and having a gap particle size distribution and an asphalt composition having a penetration at 25 ° C. of 150 (1/10 mm) or more and 190 (1/10 mm) or less. Is formed.

  The aggregate of the crushed stone mastic asphalt mixture is formed by mixing No. 6 crushed stone and No. 7 crushed stone at a predetermined ratio, and sand and stone powder can be mixed as necessary. As for the particle size distribution of the aggregate, the passage through the 2.36 mm sieve in the synthetic particle size is 20 to 35% by mass.

  The asphalt composition of the crushed mastic asphalt mixture includes asphalt, a thermoplastic elastomer, process oil, and a ductile material.

  The asphalt can be appropriately selected from petroleum asphalt such as natural asphalt such as lake asphalt, straight asphalt, blown asphalt, semi-blown asphalt, solvent deasphalted asphalt (for example, propane deasphalted asphalt). These materials may be used alone or in combination of two or more.

  The thermoplastic elastomer is at least one selected from styrene-based thermoplastic elastomers, olefin-based thermoplastic elastomers, and ethylene-based thermoplastic elastomers. Here, as the styrene-based thermoplastic elastomer, for example, styrene-butadiene-styrene copolymer (SBS), as the olefin-based thermoplastic elastomer, butyl copolymer (butyl rubber, IIR), as the ethylene-based thermoplastic elastomer, for example, Examples thereof include, but are not limited to, ethylene-vinyl acetate copolymer (EVA).

  The process oil is an oil that is also called a petroleum-based blended oil. Process oils are large and contain aroma (aromatics) as the main component and an aromatic process oil whose aromatic carbon number is 35% or more of the total number of carbons, and naphthene content and naphthenic ring carbon number as the main component. Is classified into naphthenic process oils that have 30 to 45% of the total carbon number and paraffinic process oils that contain paraffin as the main component and have a paraffin side chain carbon number of 50% or more of the total carbon number. However, as the process oil according to the present embodiment, at least one of them can be appropriately selected and used. Accordingly, two or more kinds may be selected and mixed for use. Further, if the process oil contains an aroma-based process oil, the elongation of the asphalt composition, that is, the ductility becomes high. Therefore, it is preferable to select an aroma-based process oil as a main component. In addition, as a process oil, in consideration of the influence on surroundings during use or after construction, a process oil having a low content of polycyclic compounds and having no carcinogenicity is selected.

The ductile material is a material that improves the ductility and malleability of the asphalt composition without degrading the properties such as elasticity of the thermoplastic elastomer and the properties such as the softness of the process oil. Aromatic extender oil which is an additive added to vinyl resin, cellulose resin, natural rubber, synthetic rubber and the like can be mentioned. According to this ductile material, the ductility and malleability of the asphalt composition can be enhanced while maintaining the elasticity of the thermoplastic elastomer and the softness of the process oil. Therefore, the base layer 8 formed of the crushed stone mastic asphalt mixture using the asphalt composition maintains high durability against the rotational displacement and vertical displacement generated at the end of the floor slab 2 due to the live load on the floor slab 2. it can. Note that the asphalt composition of the crushed mastic asphalt mixture has a viscosity at 60 ° C. of 1000 Pa · s to 30,000 Pa · s and a bending strain at −10 ° C. due to the asphalt, the thermoplastic elastomer, and the process oil. When a physical property value of 180 × 10 ⁻³ or more and 500 × 10 ⁻³ or less is obtained, the ductile material may not be included.

  The content of asphalt, thermoplastic elastomer, process oil, and ductile material in the asphalt composition is 5 to 20 parts by mass of thermoplastic elastomer, 10 to 40 parts by mass of process oil, relative to 100 parts by mass of asphalt, The ductile material is 1 to 5 parts by mass.

  By setting the thermoplastic elastomer to 5 to 20 parts by mass with respect to 100 parts by mass of asphalt contained in the asphalt composition, the degree of dependence on the temperature of the asphalt mixed object, such as plastic deformation, is slowed down, and a predetermined elasticity can be maintained. . Here, when content of a thermoplastic elastomer is lower than 5 mass parts, the distortion amount (ductility) of an asphalt composition will fall and an asphalt mixed object will also become difficult to distort. On the other hand, when the content of the thermoplastic elastomer is higher than 20 parts by mass, the viscosity of the asphalt composition becomes high and workability is deteriorated, and the asphalt mixed object becomes too hard and is hardly distorted.

  By setting the content of the process oil to 10 to 40 parts by mass with respect to 100 parts by mass of the asphalt contained in the asphalt composition, good flexibility of the asphalt mixed object is ensured without impairing the workability of the asphalt mixture. be able to. Here, if the content of process oil is lower than 10 parts by mass, the softness of the asphalt composition tends to be low, and the amount of distortion tends to be low. On the other hand, if the content of process oil is higher than 40 parts by mass, the softness of the asphalt composition becomes high, the hardness is remarkably lowered and the fluidity is increased. Therefore, when mixed with aggregate, the asphalt composition becomes dull. It becomes easy and workability (workability) deteriorates.

  By setting the content of the ductile material to 1 to 5 parts by mass with respect to 100 parts by mass of the asphalt contained in the asphalt composition, an asphalt composition having both strength and durability can be obtained. Here, when the content of the ductile material is lower than 1 part by mass, the ductility and malleability of the asphalt composition are not sufficiently increased. On the other hand, when the content of the ductile material is higher than 5 parts by mass, the ductility and malleability of the asphalt composition become too high, and as a result, the strength of the asphalt mixed object decreases.

Table 1 shows various physical property values of the asphalt composition used for the crushed mastic asphalt mixture forming the base layer 8 of the present embodiment. Table 1 also shows various physical property values of general straight asphalt. The bending strain values shown in Table 1 are obtained by molding an asphalt composition into a predetermined size in accordance with the pavement survey and test method manual published by the Japan Road Association and the bending test method for A063T polymer-modified asphalt. It is the result of having performed the bending test about -10 degreeC about this shape | molded asphalt composition. Furthermore, various physical property values of straight asphalt shown in Table 1 comprehensively show various physical property values of straight asphalt having different penetrations such as 40/60, 60/80, 80/100, 100/120, etc. is there.

  As can be seen from Table 1, it can be seen that the asphalt composition according to the present embodiment has a large bending strain (−10 ° C.) although the range of the viscosity at 60 ° C. is higher than that of straight asphalt. By forming the base layer 8 with a crushed mastic asphalt mixture using such an asphalt composition, high durability against rotational displacement and vertical displacement generated at the end of the floor slab 2 can be obtained.

  In the asphalt composition according to the present embodiment, the base asphalt is heated to a predetermined temperature (for example, 150 ° C. to 200 ° C.), and a thermoplastic elastomer, process oil, and ductile material are added to the asphalt by stirring means such as a mixer. Can be mixed for a predetermined time. As an asphalt composition applicable to the present invention, Reaxphalt manufactured by Taisei Rotech Co., Ltd. may be mentioned.

なお、舗装設計施工指針、日本道路協会発行、平成18年版、ｐ３１８、付録１１用語の説明によれば、ギャップ粒度分布を有する骨材とは、粗骨材、細骨材及びフィラーを含み、これらの粗骨材、細骨材及びフィラーの合成粒度における６００μｍ〜２．３６ｍｍまたは６００μｍ〜４．７５ｍｍの粒径部分が、骨材の全質量に対して１０％以下である不連続の粒度分布を呈するものである。本実施形態では、砕石マスチックアスファルト混合物の骨材は、６００μｍ〜２．３６ｍｍの粒径部分が全体に対して１０％以下であるのが好ましく、特に好ましくは６〜７％である。 The crushed mastic mastic asphalt mixture forming the base layer 8 has the above asphalt composition 5.5-7 with respect to 100 parts by mass of aggregate having a gap particle size distribution of 2.36 mm sieve passage in the synthetic particle size. .5 parts by mass and 0.2 to 0.5 parts by mass of fiber material. As the fiber material, a vegetable fiber mainly composed of α-cellulose is preferable. Here, the aggregate preferably has a particle size distribution shown in the particle size range of Table 2.

According to the description of pavement design and construction guidelines, published by the Japan Road Association, 2006 edition, p318, appendix 11 terms, aggregates having a gap particle size distribution include coarse aggregates, fine aggregates and fillers. The particle size portion of 600 μm to 2.36 mm or 600 μm to 4.75 mm in the composite particle size of the coarse aggregate, fine aggregate and filler of the present invention has a discontinuous particle size distribution in which the total particle mass is 10% or less. It is presented. In the present embodiment, the aggregate of the crushed mastic asphalt mixture preferably has a particle size portion of 600 μm to 2.36 mm of 10% or less, particularly preferably 6 to 7%.

  The crushed stone mastic asphalt mixture is produced by stirring and mixing a predetermined amount of aggregate and a predetermined amount of the asphalt composition using mixing means such as an asphalt mixer. The crushed stone mastic asphalt mixture is continuously spread on the surface of the floor slab 2, the three-layer sheet structure 6 and the reinforcing sheet 7 by a spread leveling machine such as a general asphalt finisher, and thereafter, Macadam Roller, Tandem The base layer 8 is manufactured by setting it to a predetermined compaction density with a general compacting machine such as a roller, a tire roller, or a ramp. Thus, by using the crushed stone asphalt mixture according to the present embodiment, the base layer 8 can be continuously produced on the floor slab 2 and the play gap 3 using a general pavement machine. Therefore, as compared with the case of forming a pavement having a different composition between the stretchable portion base layer 105 on the edge of the play 103 and the floor slab 102 and the floor slab base layer 109 on the floor slab 102 as in the past, It is possible to effectively reduce the labor of manufacturing the pavement. Moreover, since it is possible to perform machine construction using a general pavement machine, it is possible to ensure the flatness of the base layer 8 and to facilitate construction work and uniform quality. As a result, the flatness of the surface layer 9 placed on the base layer 8 can be ensured.

  The surface layer 9 can be formed using a fine particle size asphalt mixture, a fine particle size asphalt mixture, a fine particle size gap asphalt mixture, a fine particle size gap asphalt mixture, an open particle size asphalt mixture, a porous asphalt mixture, and the like, as necessary.

  [Example 1] Next, in order to confirm the durability of the base layer 8, the reinforcing sheet 7 and the base layer 8 of the buried joint 1 according to the present invention, the asphalt composition having physical properties shown in Table 3 was used. A crushed stone mastic asphalt mixture was formed by blending, and a specimen was prepared and subjected to a bending test, a bending fatigue test, and a crack penetration test. Asphalt composition is 100 parts by mass of straight asphalt (pen 60/80) as asphalt, 15 parts by mass of styrene-butadiene block copolymer as thermoplastic elastomer, 25 parts by mass of process oil, and as ductile material. An aromatic extender oil was mixed to prepare 3 parts by mass. In Table 4, the amount of asphalt and the amount of plant fiber are the ratio to the total mass of the crushed stone mastic asphalt mixture. The aggregate blending ratio is a ratio of the constituent aggregate to the total mass of the aggregate. Table 5 shows the particle size distribution of the aggregate expressed in terms of the synthetic particle size. The dynamic stability of the crushed mastic asphalt mixture with this formulation was 3150 times / mm, and the standard Marshall stability was 5.24 kN.

  [Comparative Example 1] On the other hand, as a comparative example, a specimen was prepared using a goose asphalt mixture often used for a base layer on a floor slab, and subjected to a bending test, a bending fatigue test, and a crack penetration test. The asphalt composition of the goose asphalt mixture was prepared by mixing 33 parts by mass of Trinidad Lake Asphalt from Trinidad and Tobako Republic with 100 parts by mass of straight asphalt (pen 20/40). Table 3 shows the physical property values of the asphalt composition of the goose asphalt mixture. Table 6 shows the composition of the goose asphalt mixture, and Table 7 shows the particle size distribution of the aggregate particle size of the goose asphalt mixture. The dynamic stability of the goose asphalt mixture with this formulation was 380 times / mm.

[Bending test]
The bending strength of the asphalt mixture was measured and the strain at breakage was measured in accordance with the pavement survey and test method manual published by the Japan Road Association and the B005 bending test method. The specimen size is 30 cm × 10 cm × 5 cm. The test temperature is −10 ° C., the loading speed is 50 mm / min, and the span length is 20 cm.

[Bending fatigue test]
In accordance with the Pavement Survey and Test Method Handbook issued by the Japan Road Association and the bending fatigue test method of B018T asphalt mixture, the test specimen is repeatedly loaded and the number of times it takes to break is measured. Durability was examined. Tests were performed with three specimens under the same conditions, and the results were arithmetically averaged to obtain test results. The specimen size is 40 cm × 4 cm × 4 cm. The test temperatures are 5 ° C., 0 ° C. and −10 ° C., the loading method is strain control of 500 μm and 700 μm, the loading input waveform is a sine wave, the loading frequency is 5 Hz, and the span length is 30 cm.

[Crack penetration test]
Using a wheel tracking tester, the load conditions at the ends of the floor slabs facing each other with a gap between them were reproduced, and the durability of the specimen against cracking was evaluated. FIG. 3 is a crack penetration tester manufactured using a wheel tracking tester. The crack penetration testing machine 12 has a steel plate 13 for height adjustment arranged on the bottom surface between support frames 18 arranged on both sides in the running direction of the wheel 20, and two rubber plates 14, 14 on the steel plate 13. The concrete plates 15 and 15 are arranged separately so as to form a slit in the center of the traveling range of the wheel 20. The slit width of the rubber plate 14 and the concrete plate 15 is 3 mm. A plastic plate 18 is disposed in the slit. Both ends of the concrete plates 15 and 15 are supported by support blocks 16 and 16 which are installed on the steel plate 13 and are in contact with the support frame 18. A specimen 17 is placed on two concrete plates 15 and 15 separated by a slit, and a wheel 20 having a predetermined load is reciprocated on the surface of the specimen 17 as indicated by an arrow R. Perform the test. Adhesion between the concrete plate 15 and the specimen 17 is not performed by a tack coat or the like. Both ends of the specimen 17 are fixed by presser plates 19 fixed to the upper end of the support frame 18. The specimen size is 30 cm × 8 cm × 2 cm. The test temperatures are 10 ° C., 25 ° C., and 40 ° C., the traveling frequency of the wheel 20 is 42 (times / minute), the traveling distance is 25 cm, and the loaded load is 110 kg. The traveling by the wheel 20 was performed until a crack appeared on the surface of the specimen 17. The number of runs when a crack occurred on the bottom surface of the specimen 17 and the number of runs when the crack reached the surface of the specimen 17 and penetrated were recorded. Tests were performed with three specimens under the same conditions, and the results were arithmetically averaged to obtain test results.

  Moreover, the crack penetration test was done about the test body formed by sticking the reinforcing sheet to the lower surface of the 30 cm x 8 cm x 2 cm rectangular parallelepiped formed using the crushed mastic asphalt mixture of Example 1. As the reinforcing sheet, glass fiber sheet (Sammy sheet of Nichireki Co., Ltd.), vinylon fiber mesh (RC mesh manufactured by Toa Road Industry Co., Ltd.), and glass fiber grid (glass grid manufactured by Daika Sangyo Co., Ltd.) Tests were performed on the specimens that were set and affixed to each. For comparison, a test was also conducted for the case where no reinforcing sheet was attached. The test temperature was 25 ° C., the test was performed with three specimens under the same conditions, and the result was arithmetically averaged to obtain the test result.

[Evaluation]
Table 8 shows the results of the bending test, Table 9 shows the results of the bending fatigue test, Table 10 shows the results of the crack penetration test, and Table 11 shows the results of the crack penetration test when the reinforcing sheet is used for reinforcement. is there. Table 12 shows the maximum load, the deformation coefficient, the specimen size, and the curvature value calculated based on these values when the result of the bending test was obtained.

  As can be seen from the results of the bending test in Table 8, both the bending strength and the breaking strain of the specimen made of the crushed mastic asphalt mixture of Example 1 are larger than those of the specimen made of the goose asphalt mixture of Comparative Example 1. Therefore, it can be said that the crushed mastic asphalt mixture is more excellent in flexibility at low temperatures than the goose asphalt mixture.

  In addition, as can be seen from the results of the bending fatigue test in Table 9, the specimen by the crushed mastic asphalt mixture of Example 1 is more susceptible to bending fracture in all the test conditions than the specimen by the goose asphalt mixture of Comparative Example 1. There are many loading times. Therefore, it can be said that the crushed mastic asphalt mixture is more resistant to fatigue cracks than the goose asphalt mixture.

  In addition, as can be seen from the results of the crack penetration test in Table 10, the specimen made of the crushed mastic asphalt mixture of Example 1 was more likely to penetrate the crack in all the test conditions than the specimen made of the goose asphalt mixture of Comparative Example 1. There are many trips to reach. Therefore, it can be said that the crushed mastic asphalt mixture is more resistant to penetration cracking than the goose asphalt mixture.

  Moreover, as can be seen from the results of the crack penetration test in Table 11, when the glass fiber sheet, the vinylon fiber mesh, and all the reinforcing sheets of the glass fiber grid are pasted, the number of running times until the occurrence of cracks, Each of the number of running times until the crack penetrates is greater than when the reinforcing sheet is not attached. In particular, the number of times traveled until the occurrence of cracks is significantly large. Therefore, it can be said that the resistance to the occurrence of cracks can be increased by applying the reinforcing sheet.

  Further, as can be seen from Table 12, the specimen made of the crushed mastic asphalt mixture of Example 1 has a larger curvature than the specimen made of the goose asphalt mixture of Comparative Example 1, and thus has a low bending rigidity. This indicates that the crushed mastic asphalt mixture has a property of bending more easily than the goose asphalt mixture, and thus can be said to be excellent in the property of following deformation.

Further, according to another test, when the viscosity of the asphalt composition at 60 ° C. is smaller than 1,000 Pa · s, the flowability of the asphalt composition becomes excessive, resulting in separation of the aggregate and sufficient strength. On the other hand, it was confirmed that when the viscosity of the asphalt composition at 60 ° C. is larger than 30,000 Pa · s, the flowability of the asphalt composition becomes too small and the construction becomes difficult. Further, according to other tests, if the bending strain at −10 ° C. of the asphalt composition is smaller than 180 × 10 ⁻³ , cracks are likely to occur on the base layer, while the bending strain at −10 ° C. is 500 ×. It was confirmed that the rigidity is insufficient when it is larger than 10 ⁻³ .

  As described above, the base layer 8 using the crushed stone mastic asphalt mixture is provided on the free space 3 and the floor slabs 2 and 2, and further, the reinforcing sheet 7 is installed on the bottom surface of the base layer 8, thereby running on the floor slab 2. It is possible to exhibit excellent resistance to rotational displacement and vertical displacement repeatedly generated at the end portion of the floor slab 2 due to the live load of the vehicle. Therefore, the embedded joint 1 of the present embodiment can prevent cracks on the gap 3 more effectively than before, and as a result, has higher durability than before. Thus, since the embedded joint 1 of this embodiment has high durability with respect to cracks, the conventional embedded type expansion and contraction device has not been installed because of the occurrence of cracks, for example, between diameters of 25 m or more. It can also be applied to bridges.

DESCRIPTION OF SYMBOLS 1 Embedded joint 2 Floor slab 3 Spacing 4 Spacing adjustment part 5 Backup material 6 Three-layer sheet structure 7 Reinforcement sheet 8 Base layer 9 Surface layer

Claims (9)

It is an embedded expansion and contraction device that is installed between the support structure members of the bridge and forms a continuous pavement surface on the surface,
The support structure members are arranged continuously on the support structure members that are opposed to each other with a gap between them, and when the horizontal displacement occurs between the support structure members, the horizontal strain of the base layer is reduced. A strain absorbing layer to relax,
An aggregate disposed continuously on the support structure member and the strain absorbing layer, formed of crushed stone and having a gap particle size distribution, and a viscosity at 60 ° C. of 1000 Pa · s to 30,000 Pa · s, and A base layer formed of a crushed stone mastic asphalt mixture formed by mixing an asphalt composition having a bending strain at −10 ° C. of 180 × 10 ⁻³ or more and 500 × 10 ⁻³ or less ,
The strain absorbing layer has a lower layer and an upper layer formed by coating a bituminous material on the front and back surfaces of a base material, and an intermediate layer formed by a rubber asphalt sheet sandwiched between the lower layer and the upper layer. An embedded expansion and contraction device. It is an embedded expansion and contraction device that is installed between the support structure members of the bridge and forms a continuous pavement surface on the surface,
The support structure members are arranged continuously on the support structure members that are opposed to each other with a gap between them, and when the horizontal displacement occurs between the support structure members, the horizontal strain of the base layer is reduced. A strain absorbing layer to relax,
An aggregate disposed continuously on the support structure member and the strain absorbing layer, formed of crushed stone and having a gap particle size distribution, and a viscosity at 60 ° C. of 1000 Pa · s to 30,000 Pa · s, and A base layer formed of a crushed mastic asphalt mixture obtained by mixing an asphalt composition having a bending strain at −10 ° C. of 180 × 10 ⁻³ or more and 500 × 10 ⁻³ or less ;
An embedded expansion and contraction device, comprising: a reinforcing layer disposed between the strain absorbing layer and the base layer and positioned above the support structure member facing the gap with a gap . The buried type expansion and contraction device according to claim 1 or 2 ,
An embedded expansion and contraction device, wherein the asphalt composition of the crushed mastic asphalt mixture forming the base layer contains asphalt, a thermoplastic elastomer, and process oil. The buried type expansion and contraction device according to claim 3 ,
An embedded expansion and contraction device, wherein the asphalt composition of the crushed stone mastic asphalt mixture includes a ductile material. The buried type expansion and contraction device according to any one of claims 1 to 4 ,
The embedded expansion-contraction apparatus, wherein the aggregate of the crushed stone mastic asphalt mixture forming the base layer has a passage of 2.36 mm sieve in a synthetic particle size of 20 to 35 mass%. The buried type expansion and contraction device according to any one of claims 1 to 5 ,
The crushed stone mastic asphalt mixture forming the base layer contains 2 to 20 parts by mass of the asphalt composition and 0.1 to 1 parts by mass of material fibers with respect to 100 parts by mass of the aggregate. Embedded expansion and contraction device. A plurality of support structural members separated from each other by play;
A plurality of embedded type expansion and contraction devices according to any one of claims 1 to 6 installed so as to bridge between the plurality of support structure members;
A base layer continuous with the base layer of the plurality of embedded type stretching devices is provided on the plurality of supporting structure members, and the base layer on the plurality of supporting structure members and the base layer of the plurality of embedded type stretching devices are provided. The bridge is characterized by having a continuous surface layer. It is a construction method of an embedded expansion and contraction device that is installed in a play formed between support structural members of a bridge and forms a continuous pavement surface on the surface,
The support structure members that are opposed to each other with a gap between them are continuous so as to bridge the support structure members, and the lower layer and the upper layer that are coated with the bitumen material on the front and back surfaces of the base material, these lower layers and A step of disposing a strain absorbing layer that has an intermediate layer formed of a rubber asphalt sheet sandwiched between upper layers and relaxes the horizontal strain of the base layer when a horizontal displacement occurs between the support structural members. When,
An aggregate formed of crushed stone and having a gap particle size distribution on the support structure member and the strain absorption layer, a viscosity at 60 ° C of 1,000 Pa · s to 30,000 Pa · s, and -10 ° C And a step of continuously arranging a base layer formed of a crushed stone mastic asphalt mixture obtained by mixing an asphalt composition having a bending strain of 180 × 10 ⁻³ or more and 500 × 10 ⁻³ or less. Construction method for buried expansion and contraction device. It is a construction method of an embedded expansion and contraction device that is installed in a play formed between support structural members of a bridge and forms a continuous pavement surface on the surface,
These support structure members are continuous over the support structure members facing each other with a gap between them, and when horizontal displacement occurs between the support structure members, the horizontal strain of the base layer is reduced. Arranging the strain absorbing layer;
An aggregate formed of crushed stone and having a gap particle size distribution on the support structure member and the strain absorption layer, a viscosity at 60 ° C of 1,000 Pa · s to 30,000 Pa · s, and -10 ° C A step of continuously arranging a base layer formed of a crushed stone mastic asphalt mixture obtained by mixing an asphalt composition having a bending strain of 180 × 10 ⁻³ or more and 500 × 10 ⁻³ or less in
A step of disposing a reinforcing layer located above the supporting structure member facing the gap between the play pieces on the strain absorbing layer;
In the step of disposing the base layer, the base layer is continuously disposed on the support structure member, the strain absorbing layer, and the reinforcing layer, and a method for constructing an embedded type expansion and contraction device.

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