Special cementing agent for self-curing pervious concrete and application thereof

Abstract

The invention discloses a special cementing agent for self-curing pervious concrete and application of the special cementing agent. The cementing agent comprises the following components in parts by mass: 1-5 parts of an internal curing agent, 2-6 parts of a water reducing agent, 10-30 parts of a reinforcing agent and 60-85 parts of an expanding agent, wherein the internal curing agent is any oneor more selected from the group consisting of super absorbent polymers (SAP) with particle sizes of 0.075 to 0.2 mm, 0.2 to 0.3 mm, 0.3 to 0.4 mm and 0.4 to 0.5 mm; and the SAP is any one selected from the group consisting of starch super absorbent resin, cellulose super absorbent resin and synthetic polymer super absorbent resin. All the components of the special cementing agent for the perviousconcrete disclosed by the invention have a good synergistic effect; the cementing agent absorbs excess water in the production and transportation stage, weakens a water loss condition before concretehardening, improves the slurry hanging property of slurry in transportation, slowly releases water after hardening, can provide water for a reaction of the expanding agent, achieves the dual effects of internal curing, can reduce the shrinkage of the pervious concrete, and reduces concrete cracks.

Description

technical field [0001] The invention relates to the technical field of permeable concrete in building materials, in particular to a special cement for self-curing permeable concrete and its application. Background technique [0002] Permeable concrete has good water permeability, high water storage capacity and good decoration. It is a new type of material worth promoting in the construction of "sponge city". It is currently widely used in sidewalks, parking lots and squares. Permeable concrete is a kind of porous lightweight concrete made by mixing aggregates, cementitious materials and water. It does not contain fine aggregates. The surface of coarse aggregates is covered with a thin layer of cement paste to bond with each other to form uniform distribution of pores. of honeycomb structure. [0003] There are many problems in the current use of pervious concrete. Permeable concrete has a low water-to-binder ratio (0.25-0.35). After pouring and paving, it is porous and th...

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Problems solved by technology

[0008] Aiming at the problems existing in the current permeable concrete, the present invention proposes a special cement for self-curing permeable concrete, which can solve the early rapid water loss of permeable concrete before hardening, improve the groutability of aggregate, release water after hardening to realize self-curing, and reduce shrinkage cracking and prevent the strength backlash problem

[0009] The purpose of the present invention is to overcome the disadvantages of the existing permeable concrete, and propose a method: the cement absorbs and stores excess water during the production stage, and due to the special structure of SAP, prevents the rapid loss of water before the concrete is hardened, and solves the problem of peeling off of surface stones after hardening. The problem of strength shrinkage; the synergistic effect of the internal curing agent and the reinforcing agent during transportation can better improve the slurry-hanging performance of the aggregate, and there will be no problem of slurry sinking to the bottom, which is convenient for the popularization and use of ready-mixed permeable concrete; it will be stored after hardening The slow release of water can not only provide moisture for the expansion agent reaction, but also achieve the dual effect of internal curing, which can reduce shrinkage and cracks; the pore structure of hardened concrete can be designed through different particle sizes of SAP and different graded stones, SAP After dehydration in the concrete, a circular hole is formed; the hole formed by SAP after dehydration can be designed according to the size of the SAP, with different pore diameters, especially tiny holes and regular round holes with larger holes and irregular holes contribute to strength

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