CN114772956A - High-carbon-absorption early-strength cementing material based on recycled concrete powder and biochar and application thereof - Google Patents
High-carbon-absorption early-strength cementing material based on recycled concrete powder and biochar and application thereof Download PDFInfo
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- 229910052799 carbon Inorganic materials 0.000 claims abstract description 50
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 42
- 239000002245 particle Substances 0.000 claims abstract description 16
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- AYFVYJQAPQTCCC-GBXIJSLDSA-N L-threonine Chemical compound C[C@@H](O)[C@H](N)C(O)=O AYFVYJQAPQTCCC-GBXIJSLDSA-N 0.000 claims description 24
- 239000011148 porous material Substances 0.000 claims description 24
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 16
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 15
- 239000011449 brick Substances 0.000 claims description 9
- 239000004927 clay Substances 0.000 claims description 9
- 239000011521 glass Substances 0.000 claims description 8
- 239000002893 slag Substances 0.000 claims description 8
- 238000001816 cooling Methods 0.000 claims description 7
- 238000010438 heat treatment Methods 0.000 claims description 7
- 238000000465 moulding Methods 0.000 claims description 7
- 239000010902 straw Substances 0.000 claims description 7
- 239000010802 sludge Substances 0.000 claims description 6
- 229910018072 Al 2 O 3 Inorganic materials 0.000 claims description 4
- 235000007164 Oryza sativa Nutrition 0.000 claims description 4
- 238000001354 calcination Methods 0.000 claims description 4
- 239000010903 husk Substances 0.000 claims description 4
- 235000009566 rice Nutrition 0.000 claims description 4
- 235000012239 silicon dioxide Nutrition 0.000 claims description 4
- 239000002023 wood Substances 0.000 claims description 4
- 229910052681 coesite Inorganic materials 0.000 claims description 3
- 230000003750 conditioning effect Effects 0.000 claims description 3
- 229910052906 cristobalite Inorganic materials 0.000 claims description 3
- 239000000377 silicon dioxide Substances 0.000 claims description 3
- 229910052682 stishovite Inorganic materials 0.000 claims description 3
- 229910052905 tridymite Inorganic materials 0.000 claims description 3
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 claims description 2
- 229910052593 corundum Inorganic materials 0.000 claims description 2
- 229910001845 yogo sapphire Inorganic materials 0.000 claims description 2
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- 239000004568 cement Substances 0.000 abstract description 15
- 238000006243 chemical reaction Methods 0.000 abstract description 7
- 239000002994 raw material Substances 0.000 abstract description 6
- 239000002699 waste material Substances 0.000 abstract description 6
- 238000000034 method Methods 0.000 abstract description 5
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- 230000007613 environmental effect Effects 0.000 abstract description 3
- 238000010304 firing Methods 0.000 abstract description 3
- 230000009467 reduction Effects 0.000 abstract description 3
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 abstract description 2
- 230000008569 process Effects 0.000 abstract description 2
- 238000009792 diffusion process Methods 0.000 abstract 1
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- 238000004519 manufacturing process Methods 0.000 abstract 1
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- 229910004298 SiO 2 Inorganic materials 0.000 description 6
- 230000000694 effects Effects 0.000 description 5
- 241000209094 Oryza Species 0.000 description 3
- 239000011575 calcium Substances 0.000 description 3
- 235000012241 calcium silicate Nutrition 0.000 description 3
- 230000005012 migration Effects 0.000 description 3
- 238000013508 migration Methods 0.000 description 3
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 2
- BYFGZMCJNACEKR-UHFFFAOYSA-N aluminium(i) oxide Chemical compound [Al]O[Al] BYFGZMCJNACEKR-UHFFFAOYSA-N 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 229910052791 calcium Inorganic materials 0.000 description 2
- 239000000378 calcium silicate Substances 0.000 description 2
- 229910052918 calcium silicate Inorganic materials 0.000 description 2
- OYACROKNLOSFPA-UHFFFAOYSA-N calcium;dioxido(oxo)silane Chemical compound [Ca+2].[O-][Si]([O-])=O OYACROKNLOSFPA-UHFFFAOYSA-N 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
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- 238000003746 solid phase reaction Methods 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 235000019738 Limestone Nutrition 0.000 description 1
- 239000011398 Portland cement Substances 0.000 description 1
- 238000009825 accumulation Methods 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 230000004913 activation Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
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- 239000013078 crystal Substances 0.000 description 1
- 229910021488 crystalline silicon dioxide Inorganic materials 0.000 description 1
- 238000002425 crystallisation Methods 0.000 description 1
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- 238000010298 pulverizing process Methods 0.000 description 1
- 239000010453 quartz Substances 0.000 description 1
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- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 238000005245 sintering Methods 0.000 description 1
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Classifications
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- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B7/00—Hydraulic cements
- C04B7/24—Cements from oil shales, residues or waste other than slag
- C04B7/246—Cements from oil shales, residues or waste other than slag from waste building materials, e.g. waste asbestos-cement products, demolition waste
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B28/00—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B40/00—Processes, in general, for influencing or modifying the properties of mortars, concrete or artificial stone compositions, e.g. their setting or hardening ability
- C04B40/02—Selection of the hardening environment
- C04B40/0231—Carbon dioxide hardening
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- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B7/00—Hydraulic cements
- C04B7/24—Cements from oil shales, residues or waste other than slag
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2201/00—Mortars, concrete or artificial stone characterised by specific physical values
- C04B2201/50—Mortars, concrete or artificial stone characterised by specific physical values for the mechanical strength
- C04B2201/52—High compression strength concretes, i.e. with a compression strength higher than about 55 N/mm2, e.g. reactive powder concrete [RPC]
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Ceramic Engineering (AREA)
- Materials Engineering (AREA)
- Structural Engineering (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Health & Medical Sciences (AREA)
- Toxicology (AREA)
- Inorganic Chemistry (AREA)
- Curing Cements, Concrete, And Artificial Stone (AREA)
Abstract
Description
技术领域technical field
本发明涉及建筑材料技术与环保领域，具体涉及一种基于再生混凝土粉与生物炭的高吸碳早强胶凝材料及其应用。The invention relates to the field of building material technology and environmental protection, in particular to a high carbon absorption early-strength cementitious material based on recycled concrete powder and biochar and its application.
背景技术Background technique
建筑行业的碳排放约占人类活动产生碳排放的40％，面临巨大碳减排压力。利用水泥基材料吸收CO2，是降低建材行业碳排放、实现 CO2的长期封存的重要途径。硅酸盐水泥中的硅酸钙矿物碳酸盐化活性高，在碳酸盐化养护条件下可以吸收大量CO2，但熟料的制备需要消耗大量高品位的石灰石和煤炭资源，直接应用硅酸盐水泥吸碳的碳减排潜力小。研究发现除了C3S、β-C2S等水硬性硅酸钙以外，γ-C2S、 CS、C3S2等非水硬性硅酸钙矿物也具有优异的碳酸盐化潜力，其中γ-C2S因含钙量低、碳酸盐化速率快而备受关注，有望开发成吸碳胶凝材料。The carbon emissions of the construction industry account for about 40% of the carbon emissions generated by human activities, and are facing enormous pressure to reduce carbon emissions. Using cement-based materials to absorb CO 2 is an important way to reduce carbon emissions in the building materials industry and achieve long-term storage of CO 2 . The calcium silicate minerals in Portland cement have high carbonation activity and can absorb a large amount of CO 2 under the condition of carbonation curing, but the preparation of clinker needs to consume a large amount of high-grade limestone and coal resources, and the direct application of silicon The carbon emission reduction potential of acid salt cement is small. The study found that in addition to C 3 S, β-C 2 S and other hydraulic calcium silicates, γ-C 2 S, CS, C 3 S 2 and other non-hydraulic calcium silicate minerals also have excellent carbonation potential. Among them, γ-C 2 S has attracted much attention due to its low calcium content and fast carbonation rate, and is expected to be developed into carbon-absorbing cementitious materials.
利用废弃混凝土制备再生骨料的过程中会产生大量的再生混凝土粉，其吸水率高、活性低，难以作为辅助性胶凝材料直接利用。再生混凝土粉的CaO含量高，且以C-S-H、Ca(OH)2、CaCO3等形式存在，分解温度低，可作为制备吸碳胶凝材料的钙质原料。再生混凝土粉中SiO2含量较低，且多以石英形式存在，结晶程度与活化能较高，与CaO发生固相反应难度大，严重制约γ-C2S的烧成。因此，如何充分利用再生混凝土粉的高钙特点，促进CaO与SiO2固相反应的发生与γ-C2S的形成，是高效利用废弃物制备吸碳胶凝材料的关键。In the process of preparing recycled aggregate from waste concrete, a large amount of recycled concrete powder will be produced, which has high water absorption and low activity, and is difficult to be used directly as an auxiliary cementitious material. The recycled concrete powder has high CaO content and exists in the form of CSH, Ca(OH) 2 , CaCO 3 , etc., and has a low decomposition temperature, so it can be used as a calcareous raw material for preparing carbon-absorbing cementitious materials. The content of SiO 2 in recycled concrete powder is low, and most of it exists in the form of quartz, the degree of crystallization and activation energy are high, and the solid-phase reaction with CaO is difficult, which seriously restricts the sintering of γ-C 2 S. Therefore, how to make full use of the high calcium characteristics of recycled concrete powder to promote the occurrence of the solid-phase reaction between CaO and SiO 2 and the formation of γ-C 2 S is the key to the efficient use of waste to prepare carbon-absorbing cementitious materials.
现有CO2养护水泥基材料技术中，通常采用成型压力控制水泥制品的初始孔隙率。成型压力提高，制品初始孔隙率降低，CO2渗透受阻，材料碳酸盐化程度受限，强度发展缓慢；成型压力降低，制品初始孔隙率较高，虽然CO2渗透深度提高，但制品初始孔隙率偏高，强度较低。因此，如何提高致密水泥制品中CO2渗透深度，是提高吸碳能力、突破水泥制品碳酸盐化性能的另一关键问题。In the existing CO 2 curing cement-based material technology, the initial porosity of cement products is usually controlled by molding pressure. When the molding pressure increases, the initial porosity of the product decreases, the penetration of CO 2 is blocked, the degree of carbonation of the material is limited, and the strength development is slow; when the molding pressure decreases, the initial porosity of the product is higher. Although the penetration depth of CO 2 increases, the initial porosity of the product increases. The rate is high and the strength is low. Therefore, how to improve the penetration depth of CO2 in dense cement products is another key issue to improve the carbon absorption capacity and break through the carbonation performance of cement products.
发明内容SUMMARY OF THE INVENTION
针对上述问题，本发明基于水泥熟料烧成理论，调控再生混凝土粉与硅质调节组分的比例，采取梯度升温与冷却制度定向诱导γ-C2S 的生成，制备吸碳胶凝材料。此外，根据CO2在多元固体中的渗流原理，利用生物炭的多尺度连通孔隙特征，设计生物炭与吸碳胶凝材料在粒径、掺量、孔结构等方面的匹配。通过控制生物炭体积掺量阈值和成型压力等因素，实现微观尺度孔隙(颗粒堆积联通孔隙)与纳观尺度孔隙(生物炭联通孔隙)的高效联通，在致密水泥制品中形成联通孔隙网络，为CO2的迁移与渗透提供快速通道，从而提高水泥制品的吸碳能力和早期力学性能。In view of the above problems, the present invention controls the ratio of recycled concrete powder and siliceous adjustment components based on the theory of cement clinker firing, and adopts a gradient heating and cooling system to directionally induce the formation of γ-C 2 S to prepare carbon-absorbing cementitious materials. In addition, according to the principle of CO percolation in multi-component solids, the multi-scale connected pore characteristics of biochar were used to design the matching of biochar and carbon-absorbing cementitious materials in terms of particle size, dosage, and pore structure. By controlling factors such as biochar volume dosage threshold and molding pressure, the efficient communication between micro-scale pores (particle stacking interconnected pores) and nano-scale pores (biochar interconnected pores) is achieved, and a interconnected pore network is formed in dense cement products. The migration and permeation of CO 2 provide a fast channel, thereby improving the carbon absorption capacity and early mechanical properties of cement products.
为实现上述目的，本发明采用如下技术方案：To achieve the above object, the present invention adopts the following technical solutions:
一种基于再生混凝土粉与生物炭的高吸碳早强胶凝材料，生物炭体积掺量的阈值按照Vthre＝7.47+2.01P+0.13d-0.0014εr2计算，其中Vthre为生物炭体积掺量的阈值，％；P为高吸碳早强胶凝材料成型时的压力，MPa；d为生物炭的平均粒径，μm；ε为生物炭的孔隙率，％； r为生物炭的平均孔径，μm；将1.1～1.5倍Vthre生物炭与再生混凝土粉制备的吸碳胶凝材料混合成高吸碳早强胶凝材料。A high carbon absorption and early strength cementitious material based on recycled concrete powder and biochar, the threshold value of biochar volume dosage is calculated according to V thre =7.47+2.01P+0.13d-0.0014εr 2 , where V thre is the volume of biochar The threshold value of the content, %; P is the pressure of the high carbon absorption early strength cementitious material when forming, MPa; d is the average particle size of the biochar, μm; ε is the porosity of the biochar, %; r is the biochar Average pore size, μm; Mix 1.1-1.5 times V thre biochar with carbon-absorbing cementitious material prepared from recycled concrete powder to form a high carbon-absorbing early-strength cementitious material.
进一步地，所述生物炭为木材炭、稻壳炭、秸秆炭的一种或两种以上，其平均粒径为50～200μm，孔隙率为50～90％，平均孔径为 0.5～10μm。Further, the biochar is one or more of wood charcoal, rice husk charcoal and straw charcoal, the average particle size is 50-200 μm, the porosity is 50-90%, and the average pore diameter is 0.5-10 μm.
进一步地，所述再生混凝土粉制备的吸碳胶凝材料为：按照率值KH＝0.67～0.70，SM＝2.5～4.0，IM＝1.5～3.0，称取60～90wt％的再生混凝土粉和10～40wt％的硅质调节组分，混合粉磨至比表面积 250～350m2/kg，梯度升温煅烧与冷却后粉磨至比表面积300～450m2/kg，获得γ-C2S含量为55～75wt％的吸碳胶凝材料。Further, the carbon-absorbing cementitious material prepared by the recycled concrete powder is: according to the rate values KH=0.67-0.70, SM=2.5-4.0, IM=1.5-3.0, weigh 60-90wt% recycled concrete powder and 10 ～40wt% of siliceous conditioning components, mixed and ground to a specific surface area of 250-350 m 2 /kg, and then ground to a specific surface area of 300 to 450 m 2 /kg after gradient heating, calcination and cooling, to obtain a γ-C 2 S content of 55 -75 wt% carbon absorbing cementitious material.
进一步地，所述再生混凝土粉CaO含量为40～80wt％，SiO2含量为10～20wt％，Al2O3含量为0～10wt％。Further, the recycled concrete powder has a CaO content of 40-80 wt %, a SiO 2 content of 10-20 wt %, and an Al 2 O 3 content of 0-10 wt %.
进一步地，所述硅质调节组分为粘土砖粉、污泥和玻璃渣的一种或两种以上，其CaO含量为0～20wt％，SiO2含量为60～80wt％，Al2O3含量为0～20wt％。Further, the siliceous adjustment component is one or more of clay brick powder, sludge and glass slag, the CaO content is 0-20wt%, the SiO 2 content is 60-80wt%, the Al 2 O 3 The content is 0 to 20 wt %.
优选地，所述粘土砖粉，其CaO含量0～10wt％，SiO2含量 60～80wt％，Al2O3含量0～15wt％；所述污泥进行干燥处理，控制含水率≤2％，其CaO含量0～5wt％，SiO2含量60～75wt％，Al2O3含量 10～20wt％；所述玻璃渣，其CaO含量0～15wt％，SiO2含量60～75wt％，Al2O3含量0～15wt％。Preferably, the clay brick powder has a CaO content of 0 to 10 wt%, a SiO 2 content of 60 to 80 wt %, and an Al 2 O 3 content of 0 to 15 wt %; The CaO content is 0-5wt%, the SiO2 content is 60-75wt%, and the Al2O3 content is 10-20wt%; the glass slag has a CaO content of 0-15wt%, a SiO2 content of 60-75wt%, and an Al2O content of 0-15wt %. 3 Content 0～15wt%.
进一步地，所述梯度升温煅烧与冷却制度为：以5～30℃/min的速率升温至850～900℃，保温0.5～1h，以使碳酸盐分解和结晶态SiO2活化；然后以5～30℃/min速率升温至1250～1400℃，恒温1～3h，，保证CaO与SiO2充分固相反应生成C2S；以100～300℃/min速率降温至 520～530℃，恒温30min后随炉冷却至室温，利用β-C2S向γ-C2S的晶型转变，使熟料自粉化，同时提高吸碳胶凝材料的碳酸盐化活性。Further, the gradient heating calcination and cooling system is as follows: the temperature is raised to 850-900°C at a rate of 5-30°C/min, and kept for 0.5-1 h to decompose the carbonate and activate the crystalline SiO 2 ; Heat up to 1250-1400°C at a rate of ~30°C/min, and keep the constant temperature for 1-3h, to ensure that CaO and SiO 2 are fully solid-phase reacted to generate C 2 S; cool down to 520-530°C at a rate of 100-300°C/min, and keep the constant temperature for 30min After cooling to room temperature with the furnace, the crystal form of β-C 2 S to γ-C 2 S is transformed to make the clinker self-pulverizing, and at the same time improve the carbonation activity of the carbon-absorbing cementitious material.
一种基于再生混凝土粉与生物炭的高吸碳早强胶凝材料的应用，将70～90wt％的高吸碳早强胶凝材料、10～30wt％的水混合均匀，然后与2～5倍体积的骨料混合均匀,再以2～5MPa压力压制成型，在相对湿度50～70％的反应釜内静置24h，最后在20℃±2℃、CO2浓度20～90％、相对湿度50～70％的环境中养护24h后，抗压强度可达50MPa以上， CO2吸收质量可达吸碳胶凝材料质量的15％以上。An application of a high carbon absorption early strength cementitious material based on recycled concrete powder and biochar, 70-90wt% of the high carbon absorption early-strength cementitious material and 10-30wt% of water are mixed uniformly, and then mixed with 2-5 Aggregates of twice the volume are mixed evenly, and then pressed and formed at a pressure of 2-5 MPa, left for 24 hours in a reaction kettle with a relative humidity of 50-70%, and finally at 20 °C ± 2 °C, CO 2 concentration 20-90%, relative humidity After curing in a 50-70% environment for 24 hours, the compressive strength can reach more than 50MPa, and the CO 2 absorption quality can reach more than 15% of the quality of the carbon-absorbing cementitious material.
与现有技术相比，本发明的有益效果在于：Compared with the prior art, the beneficial effects of the present invention are:
1)基于熟料烧成理论，利用再生混凝土粉、粘土砖粉等废弃物作为原料，采用梯度升温与冷却制度制备吸碳胶凝材料，有利于促进废弃物的高效利用，减少自然资源与一次能源消耗，推动建筑材料行业碳减排。1) Based on the clinker firing theory, using recycled concrete powder, clay brick powder and other wastes as raw materials, and adopting a gradient heating and cooling system to prepare carbon-absorbing cementitious materials, it is conducive to promoting the efficient use of waste and reducing natural resources and primary waste. Energy consumption, and promote carbon emission reduction in the building materials industry.
2)根据渗流原理，基于生物炭的多尺度连通孔隙特征，通过控制生物炭体积掺量阈值和成型压力等因素，实现高致密水泥制品中的孔隙联通，为CO2提供迁移与渗透通道，有效提高水泥制品吸碳能力和早期强度。2) According to the principle of seepage, based on the multi-scale connected pore characteristics of biochar, by controlling factors such as biochar volume dosage threshold and molding pressure, the pore connectivity in high-density cement products can be realized, providing migration and permeation channels for CO2 , effectively Improve the carbon absorption capacity and early strength of cement products.
具体实施方式Detailed ways
下面结合实施例对本发明作进一步详细描述，但本发明的实施方法不限于此。The present invention will be described in further detail below with reference to the examples, but the implementation method of the present invention is not limited thereto.
本发明对比例与实施例中制备的吸碳胶凝材料所用原料为再生混凝土粉、粘土砖粉、污泥和玻璃渣，其化学组成如下列表1所示。The raw materials used for the carbon-absorbing cementitious materials prepared in the comparative examples and examples of the present invention are recycled concrete powder, clay brick powder, sludge and glass slag, and their chemical compositions are shown in Table 1 below.
表1吸碳胶凝材料所用原材料化学成分(wt％)Table 1 Chemical composition of raw materials used in carbon-absorbing cementitious materials (wt%)
将上述原料按照一定比例混合粉磨至比表面积250～350m2/kg，以 5～30℃/min的速率升温至850～900℃，保温0.5～1h；然后以5～30℃/min 速率升温至1250～1400℃，恒温1～3h；以100～300℃/min速率降温至 520～530℃，恒温30min后随炉冷却至室温，再粉磨至比表面积 300～450m2/kg，获得γ-C2S含量为55～75wt％的吸碳胶凝材料。按照计算的生物炭体积掺量的阈值，将一定量的生物炭与再生混凝土粉制备的吸碳胶凝材料混合成高吸碳早强胶凝材料。The above-mentioned raw materials are mixed and ground in a certain proportion to a specific surface area of 250-350m 2 /kg, heated to 850-900°C at a rate of 5-30°C/min, and kept for 0.5-1h; and then heated at a rate of 5-30°C/min to 1250～1400℃, constant temperature for 1～3h; cool down to 520～530℃ at a rate of 100～300℃/min, cool down to room temperature with the furnace after constant temperature for 30min, and then grind to a specific surface area of 300～450m 2 /kg to obtain γ -Carbon-absorbing cementitious material with a C 2 S content of 55-75 wt %. According to the calculated threshold of the volume of biochar, a certain amount of biochar is mixed with the carbon-absorbing cementitious material prepared from recycled concrete powder to form a high carbon-absorbing early-strength cementitious material.
将70～90wt％的高吸碳早强胶凝材料、10～30wt％的水混合均匀，然后与2～5倍体积的骨料混合均匀，再以2～5MPa压力压制成型，在相对湿度50～70％的反应釜内静置24h，最后在20℃±2℃、CO2浓度 20～90％、相对湿度50～70％的环境中养护24h。Mix 70-90wt% of high carbon absorption early-strength cementitious material and 10-30wt% of water evenly, then mix with 2-5 times the volume of aggregate, and then press and form at a pressure of 2-5MPa, at a relative humidity of 50 ~70% of the reaction kettle for 24h, and finally cured for 24h in an environment of 20℃±2℃, CO2 concentration of 20-90%, and relative humidity of 50-70%.
将本发明对比例、实施例中CO2养护24h的砂浆进行抗压强度测试，抗压强度参照GB/T17671-1999《水泥胶砂强度检验方法(ISO法)》进行测试。通过CO2吸收质量表示致密水泥制品的吸碳性能，计算公式如下：The compressive strength of the mortars in the comparative examples and the examples of the present invention, which was cured for 24 hours with CO 2 , was tested. The carbon absorption performance of dense cement products is expressed by the CO2 absorption mass, and the calculation formula is as follows:
其中：m0是CO2养护前砂浆干重，m1是CO2养护后砂浆干重，m2是吸碳胶凝材料的质量。Where: m 0 is the dry weight of the mortar before CO 2 curing, m 1 is the dry weight of the mortar after CO 2 curing, and m 2 is the mass of the carbon-absorbing cementitious material.
对比例1Comparative Example 1
称取87.8wt％的再生混凝土粉和12.2wt％的污泥，混合粉磨至比表面积250～350m2/kg，以10℃/min的速率升温至850℃，保温1h；然后以10℃/min速率升温至1250℃，恒温3h；以300℃/min速率降温至525℃，恒温30min后随炉冷却至室温，然后粉磨至比表面积300～450m2/kg，获得γ-C2S含量为56.7wt％的吸碳胶凝材料。Weigh 87.8wt% recycled concrete powder and 12.2wt% sludge, mix and grind to a specific surface area of 250-350m 2 /kg, heat up to 850°C at a rate of 10°C/min, and keep the temperature for 1 hour; then at 10°C/min. The temperature was raised to 1250°C at a min rate and kept at a constant temperature for 3 hours; the temperature was lowered to 525°C at a rate of 300°C/min, kept at a constant temperature for 30 minutes, and then cooled to room temperature with the furnace, and then ground to a specific surface area of 300-450m 2 /kg to obtain the γ-C 2 S content It is 56.7 wt% carbon-absorbing cementitious material.
将87.1wt％的吸碳胶凝材料、12.9wt％的水混合均匀，然后与4.2 倍体积的机制砂混合均匀，再以2.0MPa压力压制成型，在相对湿度 60％的反应釜内静置24h，最后在20℃±2℃、CO2浓度50％、相对湿度60％的环境中养护24h。其砂浆CO2养护24h抗压强度为28.9MPa， CO2吸收质量为吸碳胶凝材料质量的9.8％。Mix 87.1 wt % carbon-absorbing cementitious material and 12.9 wt % water uniformly, then mix uniformly with 4.2 times the volume of machine-made sand, then press and shape at 2.0 MPa pressure, and let stand for 24 hours in a reaction kettle with a relative humidity of 60% , and finally cured for 24h in an environment of 20℃±2℃, CO2 concentration of 50% and relative humidity of 60%. The 24h compressive strength of its mortar with CO 2 curing is 28.9MPa, and the CO 2 absorption quality is 9.8% of the mass of the carbon-absorbing cementitious material.
对比例2Comparative Example 2
称取88.1wt％的再生混凝土粉和11.9wt％的粘土砖粉，混合粉磨至比表面积250～350m2/kg，以10℃/min的速率升温至850℃，保温 1h；然后以10℃/min速率升温至1300℃，恒温3h；以300℃/min速率降温至525℃，恒温30min后随炉冷却至室温，然后粉磨至比表面积300～450m2/kg，获得γ-C2S含量为65.2wt％的吸碳胶凝材料。Weigh 88.1wt% of recycled concrete powder and 11.9wt% of clay brick powder, mix and grind to a specific surface area of 250-350m 2 /kg, heat up to 850°C at a rate of 10°C/min, and keep for 1 hour; then at 10°C The temperature was raised to 1300°C at a rate of /min and kept at a constant temperature for 3 hours; the temperature was lowered to 525°C at a rate of 300°C/min, kept at a constant temperature for 30 minutes, and then cooled to room temperature with the furnace, and then ground to a specific surface area of 300-450 m 2 /kg to obtain γ-C 2 S The content is 65.2wt% of carbon-absorbing cementitious material.
将86.8wt％的吸碳胶凝材料、13.2wt％的水混合均匀，然后与3.8 倍体积的机制砂混合均匀，再以5.0MPa压力压制成型在相对湿度50％的反应釜内静置24h，最后在20℃±2℃、CO2浓度20％、相对湿度 50％的环境中养护24h。其砂浆CO2养护24h抗压强度为46.2MPa， CO2吸收质量为吸碳胶凝材料质量的4.5％。Mix 86.8wt% carbon-absorbing cementitious material and 13.2wt% water uniformly, then mix well with 3.8 times the volume of machine-made sand, and then press and shape at 5.0MPa pressure in a reactor with a relative humidity of 50% for 24h. Finally, it was cured for 24h in an environment of 20℃±2℃, CO2 concentration of 20%, and relative humidity of 50%. The compressive strength of the mortar under CO 2 curing for 24h is 46.2MPa, and the CO 2 absorption quality is 4.5% of the mass of the carbon-absorbing cementitious material.
对比例3Comparative Example 3
称取86.4wt％的再生混凝土粉和13.6wt％的玻璃渣，混合粉磨至比表面积250～350m2/kg，以10℃/min的速率升温至900℃，保温0.5h；然后以10℃/min速率升温至1350℃，恒温2h；以300℃/min速率降温至525℃，恒温30min后随炉冷却至室温，然后粉磨至比表面积 300～450m2/kg，获得γ-C2S含量为71.2wt％的吸碳胶凝材料。生物炭体积掺量的阈值为Vthre＝7.47+2.01×4.0+0.13×172.42-0.0014×85.7× 3.472＝36.5％，所用生物炭为秸秆炭，其平均粒径为172.42μm，孔隙率为85.7％，平均孔径为3.47μm，将0.5倍Vthre生物炭与再生混凝土粉制备的吸碳胶凝材料混合成高吸碳早强胶凝材料。Weigh 86.4wt% recycled concrete powder and 13.6wt% glass slag, mix and grind to a specific surface area of 250-350m 2 /kg, heat up to 900°C at a rate of 10°C/min, and keep the temperature for 0.5h; then at 10°C The temperature was raised to 1350°C at a rate of /min and kept at a constant temperature for 2 hours; the temperature was lowered to 525°C at a rate of 300°C/min, kept at a constant temperature for 30 minutes, and then cooled to room temperature with the furnace, and then ground to a specific surface area of 300-450 m 2 /kg to obtain γ-C 2 S The content is 71.2 wt% carbon-absorbing cementitious material. The threshold value of biochar volume content is V thre =7.47+2.01×4.0+0.13×172.42-0.0014×85.7×3.47 2 =36.5%, the biochar used is straw char, its average particle size is 172.42μm, and the porosity is 85.7 %, the average pore size is 3.47 μm, and the carbon-absorbing cementitious material prepared by 0.5 times V thre biochar and recycled concrete powder is mixed into a high carbon-absorbing early-strength cementitious material.
将83.2wt％的高吸碳早强胶凝材料、16.8wt％的水混合均匀，然后与3.1倍体积的机制砂混合均匀，再以4.0MPa压力压制成型，在相对湿度70％的反应釜内静置24h，最后在20℃±2℃、CO2浓度40％、相对湿度70％的环境中养护24h。其砂浆CO2养护24h抗压强度为34.5MPa，CO2吸收质量为吸碳胶凝材料质量的8.4％。Mix 83.2wt% high carbon absorption early-strength cementitious material and 16.8wt% water uniformly, then mix well with 3.1 times the volume of machine-made sand, and then press and form at a pressure of 4.0MPa, in a reactor with a relative humidity of 70% Let stand for 24h, and finally cure for 24h in an environment of 20°C ± 2°C, CO 2 concentration 40%, and relative humidity 70%. The 24h compressive strength of its mortar CO 2 curing is 34.5MPa, and the CO 2 absorption quality is 8.4% of the mass of carbon-absorbing cementitious materials.
对比例4Comparative Example 4
称取86.4wt％的再生混凝土粉和13.6wt％的玻璃渣，混合粉磨至比表面积250～350m2/kg，以10℃/min的速率升温至900℃，保温0.5h；然后以10℃/min速率升温至1350℃，恒温2h；以300℃/min速率降温至525℃，恒温30min后随炉冷却至室温，然后粉磨至比表面积 300～450m2/kg，获得γ-C2S含量为71.2wt％的吸碳胶凝材料。生物炭体积掺量的阈值为Vthre＝7.47+2.01×4.0+0.13×172.42-0.0014×85.7× 3.472＝36.5％，所用生物炭为秸秆炭，其平均粒径为172.42μm，孔隙率为85.7％，平均孔径为3.47μm，将3.0倍Vthre生物炭与再生混凝土粉制备的吸碳胶凝材料混合成高吸碳早强胶凝材料。Weigh 86.4wt% recycled concrete powder and 13.6wt% glass slag, mix and grind to a specific surface area of 250-350m 2 /kg, heat up to 900°C at a rate of 10°C/min, and keep the temperature for 0.5h; then at 10°C The temperature was raised to 1350°C at a rate of /min and kept at a constant temperature for 2 hours; the temperature was lowered to 525°C at a rate of 300°C/min, kept at a constant temperature for 30 minutes, and then cooled to room temperature with the furnace, and then ground to a specific surface area of 300-450 m 2 /kg to obtain γ-C 2 S The content is 71.2 wt% carbon-absorbing cementitious material. The threshold value of biochar volume content is V thre =7.47+2.01×4.0+0.13×172.42-0.0014×85.7×3.47 2 =36.5%, the biochar used is straw char, its average particle size is 172.42μm, and the porosity is 85.7 %, the average pore size is 3.47 μm, and the carbon-absorbing cementitious material prepared by 3.0 times V thre biochar and recycled concrete powder is mixed into a high carbon-absorbing early-strength cementitious material.
将83.2wt％的高吸碳早强胶凝材料、16.8wt％的水混合均匀，然后与3.1倍体积的机制砂混合均匀，再以4.0MPa压力压制成型，在相对湿度70％的反应釜内静置24h，最后在20℃±2℃、CO2浓度40％、相对湿度70％的环境中养护24h。其砂浆CO2养护24h抗压强度为19.4MPa，CO2吸收质量为吸碳胶凝材料质量的16.9％。Mix 83.2wt% high carbon absorption early-strength cementitious material and 16.8wt% water uniformly, then mix well with 3.1 times the volume of machine-made sand, and then press and form at a pressure of 4.0MPa, in a reactor with a relative humidity of 70% Let stand for 24h, and finally cure for 24h in an environment of 20°C ± 2°C, CO 2 concentration 40%, and relative humidity 70%. The compressive strength of its mortar under CO 2 curing for 24h is 19.4MPa, and the CO 2 absorption quality is 16.9% of the mass of the carbon-absorbing cementitious material.
实施例1Example 1
称取87.8wt％的再生混凝土粉和12.2wt％的污泥，混合粉磨至比表面积250～350m2/kg，以10℃/min的速率升温至850℃，保温1h；然后以10℃/min速率升温至1250℃，恒温3h；以300℃/min速率降温至525℃，恒温30min后随炉冷却至室温，然后粉磨至比表面积300～450m2/kg，获得γ-C2S含量为56.7wt％的吸碳胶凝材料。生物炭体积掺量的阈值为Vthre＝7.47+2.01×2.0+0.13×172.42-0.0014×85.7× 3.472＝32.5％，所用生物炭为秸秆炭，其平均粒径为172.42μm，孔隙率为85.7％，平均孔径为3.47μm，将1.1倍Vthre生物炭与再生混凝土粉制备的吸碳胶凝材料混合成高吸碳早强胶凝材料。Weigh 87.8wt% recycled concrete powder and 12.2wt% sludge, mix and grind to a specific surface area of 250-350m 2 /kg, heat up to 850°C at a rate of 10°C/min, and keep the temperature for 1 hour; then at 10°C/min. The temperature was raised to 1250°C at a min rate and kept at a constant temperature for 3 hours; the temperature was lowered to 525°C at a rate of 300°C/min, kept at a constant temperature for 30 minutes, and then cooled to room temperature with the furnace, and then ground to a specific surface area of 300-450m 2 /kg to obtain the γ-C 2 S content It is 56.7 wt% carbon-absorbing cementitious material. The threshold of biochar volume dosage is V thre =7.47+2.01×2.0+0.13×172.42-0.0014×85.7×3.47 2 =32.5%, the biochar used is straw char, its average particle size is 172.42μm, and the porosity is 85.7 %, with an average pore size of 3.47 μm, 1.1 times V thre biochar was mixed with the carbon-absorbing cementitious material prepared from recycled concrete powder to form a high carbon-absorbing early-strength cementitious material.
将87.1wt％的高吸碳早强胶凝材料、12.9wt％的水混合均匀，然后与4.2倍体积的机制砂混合均匀，再以2.0MPa压力压制成型，在相对湿度60％的反应釜内静置24h，最后在20℃±2℃、CO2浓度50％、相对湿度60％的环境中养护24h。其砂浆CO2养护24h抗压强度为52.5MPa，CO2吸收质量为吸碳胶凝材料质量的15.2％。Mix 87.1wt% of high carbon absorption early-strength cementitious material and 12.9wt% of water uniformly, then mix well with 4.2 times the volume of machine-made sand, and then press and shape at 2.0MPa pressure, in a reaction kettle with a relative humidity of 60% Let stand for 24h, and finally cure for 24h in an environment of 20°C ± 2°C, CO 2 concentration 50%, and relative humidity 60%. The compressive strength of the mortar under CO 2 curing for 24h is 52.5MPa, and the CO 2 absorption quality is 15.2% of the mass of the carbon-absorbing cementitious material.
实施例2Example 2
称取88.1wt％的再生混凝土粉和11.9wt％的粘土砖粉，混合粉磨至比表面积250～350m2/kg，以10℃/min的速率升温至850℃，保温 1h；然后以10℃/min速率升温至1300℃，恒温3h；以300℃/min速率降温至525℃，恒温30min后随炉冷却至室温，然后粉磨至比表面积300～450m2/kg，获得γ-C2S含量为65.2wt％的吸碳胶凝材料。生物炭体积掺量的阈值为Vthre＝7.47+2.01×5.0+0.13×172.42-0.0014×85.7 ×3.472＝38.5％，所用生物炭为秸秆炭，其平均粒径为172.42μm，孔隙率为85.7％，平均孔径为3.47μm，将1.1倍Vthre生物炭与再生混凝土粉制备的吸碳胶凝材料混合成高吸碳早强胶凝材料。Weigh 88.1wt% of recycled concrete powder and 11.9wt% of clay brick powder, mix and grind to a specific surface area of 250-350m 2 /kg, heat up to 850°C at a rate of 10°C/min, and keep for 1 hour; then at 10°C The temperature was raised to 1300°C at a rate of /min and kept at a constant temperature for 3 hours; the temperature was lowered to 525°C at a rate of 300°C/min, kept at a constant temperature for 30 minutes, and then cooled to room temperature with the furnace, and then ground to a specific surface area of 300-450 m 2 /kg to obtain γ-C 2 S The content is 65.2wt% of carbon-absorbing cementitious material. The threshold value of biochar volume dosage is V thre =7.47+2.01×5.0+0.13×172.42-0.0014×85.7×3.47 2 =38.5%. The biochar used is straw charcoal with an average particle size of 172.42μm and a porosity of 85.7 %, with an average pore size of 3.47 μm, 1.1 times V thre biochar was mixed with the carbon-absorbing cementitious material prepared from recycled concrete powder to form a high carbon-absorbing early-strength cementitious material.
将86.8wt％的高吸碳早强胶凝材料、13.2wt％的水混合均匀，然后与3.8倍体积的机制砂混合均匀，再以5.0MPa压力压制成型，在相对湿度50％的反应釜内静置24h，最后在20℃±2℃、CO2浓度20％、相对湿度50％的环境中养护24h。其砂浆CO2养护24h抗压强度为61.2MPa，CO2吸收质量为吸碳胶凝材料质量的15.7％。Mix 86.8wt% of high carbon absorption early-strength cementitious material and 13.2wt% of water uniformly, then mix well with 3.8 times the volume of machine-made sand, and then press and shape at 5.0MPa pressure, in a reaction kettle with a relative humidity of 50% Let stand for 24h, and finally cure for 24h in an environment of 20°C ± 2°C, CO 2 concentration 20%, and relative humidity 50%. The compressive strength of its mortar under CO 2 curing for 24h is 61.2MPa, and the CO 2 absorption quality is 15.7% of the mass of the carbon-absorbing cementitious material.
实施例3Example 3
称取86.4wt％的再生混凝土粉和13.6wt％的玻璃渣，混合粉磨至比表面积250～350m2/kg，以10℃/min的速率升温至900℃，保温0.5h；然后以10℃/min速率升温至1350℃，恒温2h；以300℃/min速率降温至525℃，恒温30min后随炉冷却至室温，然后粉磨至比表面积 300～450m2/kg，获得γ-C2S含量为71.2wt％的吸碳胶凝材料。生物炭体积掺量的阈值为Vthre＝7.47+2.01×4.0+0.13×172.42-0.0014×85.7× 3.472＝36.5％，所用生物炭为秸秆炭，其平均粒径为172.42μm，孔隙率为85.7％，平均孔径为3.47μm，将1.3倍Vthre生物炭与再生混凝土粉制备的吸碳胶凝材料混合成高吸碳早强胶凝材料。Weigh 86.4wt% recycled concrete powder and 13.6wt% glass slag, mix and grind to a specific surface area of 250-350m 2 /kg, heat up to 900°C at a rate of 10°C/min, and keep the temperature for 0.5h; then at 10°C The temperature was raised to 1350°C at a rate of /min and kept at a constant temperature for 2 hours; the temperature was lowered to 525°C at a rate of 300°C/min, kept at a constant temperature for 30 minutes, and then cooled to room temperature with the furnace, and then ground to a specific surface area of 300-450 m 2 /kg to obtain γ-C 2 S The content is 71.2 wt% carbon-absorbing cementitious material. The threshold value of biochar volume content is V thre =7.47+2.01×4.0+0.13×172.42-0.0014×85.7×3.47 2 =36.5%, the biochar used is straw char, its average particle size is 172.42μm, and the porosity is 85.7 %, with an average pore size of 3.47 μm, 1.3 times V thre biochar was mixed with the carbon-absorbing cementitious material prepared from recycled concrete powder to form a high carbon-absorbing early-strength cementitious material.
将83.2wt％的高吸碳早强胶凝材料、16.8wt％的水混合均匀，然后与3.1倍体积的机制砂混合均匀，再以4.0MPa压力压制成型，在相对湿度70％的反应釜内静置24h，最后在20℃±2℃、CO2浓度40％、相对湿度70％的环境中养护24h。其砂浆CO2养护24h抗压强度为65.3MPa，CO2吸收质量为吸碳胶凝材料质量的16.1％。Mix 83.2wt% high carbon absorption early-strength cementitious material and 16.8wt% water uniformly, then mix well with 3.1 times the volume of machine-made sand, and then press and form at a pressure of 4.0MPa, in a reactor with a relative humidity of 70% Let stand for 24h, and finally cure for 24h in an environment of 20°C ± 2°C, CO 2 concentration 40%, and relative humidity 70%. The compressive strength of the mortar under CO 2 curing for 24h is 65.3MPa, and the CO 2 absorption quality is 16.1% of the mass of the carbon-absorbing cementitious material.
实施例4Example 4
称取87.3wt％的再生混凝土粉、4.6wt％的玻璃渣和8.1wt％的粘土砖粉，混合粉磨至比表面积250～350m2/kg，以10℃/min的速率升温至850℃，保温1h；然后以10℃/min速率升温至1400℃，恒温3h；以300℃/min速率降温至525℃，恒温30min后随炉冷却至室温，然后粉磨至比表面积300～450m2/kg，获得γ-C2S含量为69.3％的吸碳胶凝材料。生物炭体积掺量的阈值为Vthre＝7.47+2.01×3.0+0.13× 132.77-0.0014×75.8×1.232＝30.6％，选用生物炭为木质炭，其平均粒径为132.77μm，孔隙率为75.8％，平均孔径为1.23μm，将1.3倍Vthre生物炭与再生混凝土粉制备的吸碳胶凝材料混合成高吸碳早强胶凝材料。Weigh 87.3wt% recycled concrete powder, 4.6wt% glass slag and 8.1wt% clay brick powder, mix and grind to a specific surface area of 250-350m 2 /kg, and heat up to 850°C at a rate of 10°C/min, Incubate for 1 hour; then raise the temperature to 1400°C at a rate of 10°C/min, and maintain a constant temperature for 3 hours; cool down to 525°C at a rate of 300°C/min, maintain a constant temperature for 30 minutes, then cool down to room temperature with the furnace, and then grind to a specific surface area of 300-450m 2 /kg , a carbon-absorbing cementitious material with a γ-C 2 S content of 69.3% was obtained. The threshold of the volume content of biochar is V thre =7.47+2.01×3.0+0.13×132.77-0.0014×75.8×1.23 2 =30.6%, and the biochar is selected as wood charcoal with an average particle size of 132.77μm and a porosity of 75.8 %, the average pore size is 1.23 μm, and 1.3 times V thre biochar is mixed with the carbon-absorbing cementitious material prepared from recycled concrete powder to form a high carbon-absorbing early-strength cementitious material.
将86.9wt％的高吸碳早强胶凝材料、13.1wt％的水混合均匀，然后与3.7倍体积的机制砂混合均匀，再以3.0MPa压力压制成型，在相对湿度60％的反应釜内静置24h，最后在20℃±2℃、CO2浓度70％、相对湿度60％的环境中养护24h。其砂浆CO2养护24h抗压强度为66.7MPa，CO2吸收质量为吸碳胶凝材料质量的17.2％。Mix 86.9wt% of high carbon absorption early-strength cementitious material and 13.1wt% of water uniformly, then mix well with 3.7 times the volume of machine-made sand, and then press and shape at 3.0MPa pressure, in a reaction kettle with a relative humidity of 60% Let stand for 24h, and finally cure for 24h in an environment of 20°C ± 2°C, CO 2 concentration 70%, and relative humidity 60%. The compressive strength of its mortar under CO 2 curing for 24h is 66.7MPa, and the CO 2 absorption quality is 17.2% of the mass of the carbon-absorbing cementitious material.
实施例5Example 5
称取88.0wt％的再生混凝土粉、6.2wt％的粘土砖粉和5.8wt％的污泥，混合粉磨至比表面积250～350m2/kg，以10℃/min的速率升温至 850℃，保温1h；然后以10℃/min速率升温至1400℃，恒温3h；以 300℃/min速率降温至525℃，恒温30min后随炉冷却至室温，然后粉磨至比表面积300～450m2/kg，获得γ-C2S含量为67.8％的吸碳胶凝材料。生物炭体积掺量的阈值为Vthre＝7.47+2.01×3.0+0.13× 73.54-0.0014×72.6×2.392＝22.5％，选用生物炭为稻壳炭，其平均粒径为73.54μm，孔隙率为72.6％，平均孔径为2.39μm，将1.5倍Vthre生物炭与再生混凝土粉制备的吸碳胶凝材料混合成高吸碳早强胶凝材料。Weigh 88.0wt% of recycled concrete powder, 6.2wt% of clay brick powder and 5.8wt% of sludge, mix and grind to a specific surface area of 250-350m 2 /kg, and heat up to 850°C at a rate of 10°C/min, Incubate for 1 hour; then raise the temperature to 1400°C at a rate of 10°C/min, and maintain a constant temperature for 3 hours; cool down to 525°C at a rate of 300°C/min, maintain a constant temperature for 30 minutes, then cool down to room temperature with the furnace, and then grind to a specific surface area of 300-450m 2 /kg , a carbon-absorbing cementitious material with a γ-C 2 S content of 67.8% was obtained. The threshold value of biochar volume dosage is V thre =7.47+2.01×3.0+0.13×73.54-0.0014×72.6×2.39 2 =22.5%, and the biochar is rice husk charcoal with an average particle size of 73.54μm and a porosity of 73.54μm. 72.6%, with an average pore size of 2.39 μm, 1.5 times V thre biochar was mixed with the carbon-absorbing cementitious material prepared from recycled concrete powder to form a high carbon-absorbing early-strength cementitious material.
将78.6wt％的高吸碳早强胶凝材料、21.4wt％的水混合均匀，然后与2.4倍体积的机制砂混合均匀，再以3.0MPa压力压制成型，在相对湿度60％的反应釜内静置24h，最后在20℃±2℃、CO2浓度90％、相对湿度60％的环境中养护24h。其砂浆CO2养护24h抗压强度为63.7MPa，CO2吸收质量为吸碳胶凝材料质量的16.8％。Mix 78.6wt% of high carbon absorption early-strength cementitious material and 21.4wt% of water evenly, then mix it with 2.4 times the volume of machine-made sand, and then press and shape at 3.0MPa pressure, and put it in a reactor with a relative humidity of 60%. Let stand for 24h, and finally cure for 24h in an environment of 20℃±2℃, CO2 concentration of 90%, and relative humidity of 60%. The compressive strength of the mortar under CO 2 curing for 24h is 63.7MPa, and the CO 2 absorption quality is 16.8% of the mass of the carbon-absorbing cementitious material.
本发明对比例、实施例中CO2养护的高吸碳早强胶凝材料的物理性能如下表2所示。The physical properties of the CO2 -cured high carbon absorption early-strength cementitious materials in the comparative examples and examples of the present invention are shown in Table 2 below.
表2对比例与实施例中CO2养护的高吸碳早强胶凝材料的物理性能Table 2 Physical properties of CO2 -cured high carbon absorption early-strength cementitious materials in comparative examples and examples
与对比例1相比，实施例1在吸碳胶凝材料基础上掺入生物炭，CO2养护24h后砂浆强度由28.9MPa提高到52.5MPa，CO2吸收质量提高5.4％；当成型压力为5.0MPa时，与对比例2相比，实施例2在吸碳胶凝材料基础上掺入生物炭，CO2养护24h后砂浆强度由 46.2MPa提高到61.2MPa，CO2吸收质量提高11.2％；与生物炭掺量为0.5倍Vthr的对比例3相比，实施例3的生物炭掺量为1.3倍Vthre， CO2养护24h后砂浆强度由34.5MPa提高到65.3MPa，CO2吸收质量由8.4％提高到了16.1％；与生物炭掺量为3.0倍Vthre的对比例4相比，实施例3的CO2吸收质量由16.9％降至16.1％，但CO2养护24h后砂浆强度由19.4MPa提高到65.3MPa。上述实施例均表明通过控制生物炭与吸碳胶凝材料在粒径、孔结构等方面的匹配，即生物炭体积掺量在1.1～1.5倍Vthre范围时，可以实现颗粒堆积孔隙与生物炭孔隙的联通，在致密水泥制品中形成联通孔隙网络，有效促进CO2的迁移和渗透，使得本发明实施例制备的高吸碳早强胶凝材料具有优异的吸碳性能和力学性能。实施例4所用生物炭为木质炭，CO2养护24h后砂浆强度为66.7MPa，CO2吸收质量为17.2％；实施例5所用生物炭为稻壳炭，CO2养护24h后砂浆强度为63.7MPa，CO2吸收质量为16.8％，说明采用其他类型的生物炭也具有相同规律和效果。Compared with Comparative Example 1, in Example 1, biochar was added on the basis of carbon-absorbing cementitious materials. After CO2 curing for 24h, the mortar strength was increased from 28.9MPa to 52.5MPa, and the CO2 absorption quality was increased by 5.4%; when the molding pressure was At 5.0 MPa, compared with Comparative Example 2, Example 2 added biochar on the basis of carbon-absorbing cementitious materials, and the strength of the mortar increased from 46.2 MPa to 61.2 MPa after CO 2 curing for 24 h, and the CO 2 absorption quality increased by 11.2%; Compared with Comparative Example 3 with a biochar content of 0.5 times V thr , the biochar content of Example 3 is 1.3 times V thre , the mortar strength increased from 34.5 MPa to 65.3 MPa after CO 2 curing for 24 h, and the CO 2 absorption quality Compared with Comparative Example 4 with a biochar content of 3.0 times V thre , the CO 2 absorption quality of Example 3 decreased from 16.9% to 16.1%, but the mortar strength after CO 2 curing for 24h increased by 19.4MPa increased to 65.3MPa. The above examples all show that by controlling the matching of biochar and carbon-absorbing cementitious materials in terms of particle size, pore structure, etc., that is, when the volume content of biochar is in the range of 1.1 to 1.5 times V thre , particle accumulation pores and biochar can be achieved. The interconnection of pores forms an interconnected pore network in dense cement products, which effectively promotes the migration and penetration of CO 2 , so that the high carbon absorption and early strength cementitious materials prepared in the embodiment of the present invention have excellent carbon absorption properties and mechanical properties. The biochar used in Example 4 is wood charcoal, the mortar strength after CO2 curing for 24h is 66.7MPa, and the CO2 absorption quality is 17.2%; the biochar used in Example 5 is rice husk charcoal, and the mortar strength after CO2 curing for 24h is 63.7MPa , the CO 2 absorption mass is 16.8%, indicating that the use of other types of biochar also has the same law and effect.
以上仅为本发明较佳实施例，并不用以限制本发明，凡在本发明原则之内所做的任何修改、改进，均应包含在本发明的保护范围之内。The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications and improvements made within the principles of the present invention should be included within the protection scope of the present invention.
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| CN115432969A (en) * | 2022-08-30 | 2022-12-06 | 中建一局集团建设发展有限公司 | Biochar concrete with carbon fixing capacity for 3D printing and preparation method thereof |
| GB2623581A (en) * | 2022-10-21 | 2024-04-24 | Adaptavate Ltd | Construction product |
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