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CN-121974615-A - Low-carbon low-shrinkage high-ductility solid waste concrete and preparation method thereof

CN121974615ACN 121974615 ACN121974615 ACN 121974615ACN-121974615-A

Abstract

The invention belongs to the technical field of building materials, and discloses low-carbon low-shrinkage high-ductility solid waste concrete and a preparation method thereof. The low-carbon low-shrinkage high-ductility solid waste concrete comprises the following raw materials, by weight, 690 parts to 710 parts of cement, 140 parts to 160 parts of silica fume, 140 parts to 160 parts of fly ash microbeads, 1080 parts to 1090 parts of quartz sand, 5 parts to 15 parts of defoamer, 5 parts to 15 parts of water reducer, 150 parts to 170 parts of water, 110 parts to 165 parts of steel fiber and 0 to 18 parts of basalt fiber. The low-carbon low-shrinkage high-ductility solid waste concrete provided by the invention is a high-solid waste doped low-carbon concrete material, can realize low shrinkage without a large amount of additives, and has high compressive strength and high ductility, thereby solving the problems of insufficient strength and strong shrinkage control dependence in the prior art.

Inventors

  • LIANG WEI
  • WANG HUI
  • JIANG WU
  • ZHAO DUANFENG
  • ZHU JUNHUA

Assignees

  • 中建三局第一建设工程有限责任公司
  • 清华大学

Dates

Publication Date
20260505
Application Date
20251209

Claims (10)

  1. 1. The low-carbon low-shrinkage high-ductility solid waste concrete is characterized by comprising the following raw materials in parts by weight: 690-710 parts of cement, 140-160 parts of silica fume, 140-160 parts of fly ash microbeads, 1080-1090 parts of quartz sand, 5-15 parts of defoamer, 5-15 parts of water reducer, 150-170 parts of water, 110-165 parts of steel fiber and 0-18 parts of basalt fiber.
  2. 2. The low carbon, low shrinkage, high ductility solid waste concrete of claim 1, wherein the cement comprises a P.O 52.5 grade portland cement, and/or, Based on the total mass of the cement, the mass ratio of CaO is 55% -57%, and/or, The specific surface area of the cement is 410m 2 /kg~430m 2 /kg.
  3. 3. The low-carbon low-shrinkage high-ductility solid waste concrete according to claim 1 or 2, wherein the silica fume has a specific surface area of 1.8X10 4 m 2 /kg~1.9×10 4 m 2 /kg and/or, Based on the total mass of the silica fume, the mass ratio of SiO 2 is 93% -94%.
  4. 4. The low-carbon low-shrinkage high-ductility solid waste concrete according to claim 1 or 2, wherein the specific surface area of the fly ash microbeads is not less than 1200m 2 /kg, and/or, The volume average particle diameter d50 of the fly ash microbeads is less than or equal to 3 mu m.
  5. 5. The low-carbon low-shrinkage high-ductility solid waste concrete according to claim 1 or 2, wherein the particle size of the quartz sand is 20-40 mesh.
  6. 6. The low carbon, low shrinkage, high ductility solid waste concrete of claim 1 or 2, wherein the steel fibers comprise copper plated steel fibers, and/or, The steel fibers are shaped as end hooks, and/or, The length of the steel fiber is 11.7 mm-14.3 mm, and/or, The effective diameter of the steel fiber is 180-220 mu m, and/or, The tensile strength of the steel fiber is more than or equal to 2850MPa.
  7. 7. The low-carbon low-shrinkage high-ductility solid waste concrete according to claim 1 or 2, wherein the length of the basalt fiber is 11mm to 13mm, and/or, The basalt fiber has an effective diameter of 13-20 mu m and/or, The tensile strength of the basalt fiber is more than or equal to 1250MPa and/or, The elastic modulus of the basalt fiber is more than or equal to 30GPa.
  8. 8. The low-carbon low-shrinkage high-ductility solid waste concrete according to claim 7, wherein the defoaming agent is an inorganic carrier-based mixture of liquid hydrocarbon and polyglycerin, and/or, The water reducer comprises modified polycarboxylic acid, and/or, The density of the water reducer is 0.40g/cm 3 ~0.55g/cm 3 .
  9. 9. A method for preparing the low carbon, low shrinkage and high ductility solid waste concrete according to any one of claims 1 to 8, comprising: Uniformly mixing cement, silica fume, fly ash microbeads and a defoaming agent, adding a mixed solution of a water reducing agent and water which are uniformly mixed in advance, stirring for 3-4 min to obtain uniform slurry, adjusting the stirring speed to 275 r/min-295 r/min, adding quartz sand into the uniform slurry, stirring for 2-3 min to obtain uniform mortar, reducing the stirring speed to 135 r/min-145 r/min, uniformly adding steel fibers and basalt fibers for multiple times, and stirring for 8-10 min to obtain a fiber mixture; and (3) filling the fiber mixture into a die with the inner wall coated with the thin layer mineral oil, standing for 20-25 h, removing the die, and curing to obtain the low-carbon low-shrinkage high-ductility solid waste concrete.
  10. 10. The method according to claim 9, wherein the resting temperature is 18-22 ℃, and/or, The relative humidity of the environment is 50-70% RH during standing, and/or, The curing temperature is 18-22 ℃ and/or, The relative humidity of the maintenance environment is more than or equal to 95% RH.

Description

Low-carbon low-shrinkage high-ductility solid waste concrete and preparation method thereof Technical Field The invention belongs to the technical field of building materials, and particularly relates to low-carbon low-shrinkage high-ductility solid waste concrete and a preparation method thereof. Background As an important field of carbon emission and resource consumption in the construction industry, development of a green low-carbon building material system is urgently needed. The traditional concrete has the problems of large cement consumption, poor ductility and self-shrinkage cracking, and is difficult to meet the current dual requirements on sustainable development and engineering performance. Meanwhile, a large amount of industrial solid wastes are piled up, so that not only is land resources occupied, but also the problem of environmental pollution is brought, and the resource utilization of the industrial solid wastes becomes an important subject to be solved urgently. The high-ductility concrete is used as a novel material with excellent tensile deformation capacity and crack control capacity, and has remarkable advantages in the aspects of structural earthquake resistance, durability improvement, assembly type building connection parts and the like. However, the existing high-ductility concrete generally has the problems of high preparation cost, large carbon footprint, remarkable early shrinkage and the like, and the large-scale popularization and application of the high-ductility concrete in actual engineering are severely limited. Therefore, the novel solid waste ultra-high performance concrete material with the characteristics of low carbon emission, low shrinkage performance and high ductility is developed, the service performance and durability of the building structure can be effectively improved, the large-scale resource utilization of industrial solid waste can be promoted, the unification of economic benefit, environmental benefit and engineering benefit is realized, and the novel solid waste ultra-high performance concrete material has important practical significance and wide application prospect. At present, the high-ductility solid waste concrete material prepared by the composite aggregate of the low-carbon gel material system composed of solid waste has the defects that the compressive strength of the concrete is low, the low shrinkage, the high tensile strength and the high compressive strength are difficult to be achieved simultaneously, meanwhile, the low shrinkage high-performance concrete is often realized by adding a shrinkage reducing agent, the shrinkage cannot be reduced by utilizing the characteristics of the solid waste material, and the low shrinkage high-ductility solid waste concrete is a difficult point in the preparation field of the low shrinkage high-ductility solid waste concrete. The prior art aims at the proportioning design and research and development of low-carbon low-shrinkage high-ductility solid waste concrete, and realizes the utilization of solid waste resources and the improvement of the ductility of concrete to a certain extent, but most of low-shrinkage high-ductility concrete relies on a shrinkage reducing agent and an expanding agent to control shrinkage deformation, so that the self-shrinkage of the solid waste material is not fully utilized, the self-shrinkage is naturally reduced, the hidden danger exists in the long-term stability of the concrete material, the compressive strength of the existing solid waste high-ductility concrete is generally low, the high-strength requirements of bridge pavement layers, large-span members and the like are difficult to meet, and the low-shrinkage high-ductility solid waste concrete with excellent performance cannot be prepared. Therefore, a low-shrinkage high-solid waste mixing amount low-carbon concrete material which can realize low shrinkage without a large amount of additives and has high compressive strength and high ductility is developed, and the problems of insufficient strength, strong shrinkage control dependence and the like in the prior art are solved. Disclosure of Invention The present invention aims to solve at least one of the technical problems in the related art to some extent. Therefore, an object of the present invention is to provide a low-carbon low-shrinkage high-ductility solid waste concrete and a preparation method thereof, wherein the low-carbon low-shrinkage high-ductility solid waste concrete is a high-solid waste mixed amount low-carbon low-shrinkage high-ductility solid waste concrete material, and can realize low shrinkage without a large amount of additives, and has high compressive strength and high ductility, so that the problems of insufficient strength and strong shrinkage control dependence in the prior art are solved. In the first aspect of the invention, the invention provides low-carbon low-shrinkage high-ductility solid waste concrete which comprises, by weight, 69