Cracking-resisting compacting agent for concrete

Abstract

The invention discloses a cracking-resisting compacting agent for concrete. The cracking-resisting compacting agent comprises siliceous dust, triethanolamine and an air entraining agent, wherein the doping ratio of the siliceous dust to the triethanolamine to the air entraining agent is 1.5 percent: (0.015-0.045 percent): (0.015-0.030 percent). The cracking-resisting compacting agent is well compatible with other additives (such as a water reducing agent); good collapse protecting effect on freshly mixed concrete can be achieved by adding the cracking-resisting compacting agent; the using of the cracking-resisting compacting agent does not influence the strength of the concrete but increases the early strength of the concrete; and the content of internally-doped cracking-resisting compacting agent is low, so that the increase of engineering cost is small. The cracking-resisting compacting agent does not prolong the condensing time of the concrete; and the concrete does not newly produce calcium-containing matters in the early period of hydration when the cracking-resisting compacting agent is doped into the concrete, so that the low carbon development requirement of the concrete is met. The defects in the aspects of durability, energy consumption and environmental friendliness of C3S, C3A and the like are reduced, and the green degree of gelled materials is improved.

Description

technical field [0001] The invention relates to the technical field of concrete, in particular to an anti-cracking compacting agent for concrete. Background technique [0002] At present, cracks in high performance concrete are a common phenomenon. Strictly speaking, there are almost no crack-free structures, but the key is how to control harmful cracks (the definition of harmful cracks by Japanese scholars is: when the outdoors are subjected to rain and exposure, considering the corrosion of the internal steel bars, at this time The width of harmful cracks in the room is 0.3mm, and the width of indoor harmful cracks is more than 0.6mm. The precondition for the definition is: the occurrence of penetrating shrinkage cracks). If harmful cracks cannot be well controlled and prevented, it will bring great harm to the project. Due to the preparation characteristics of high-performance concrete with high amount of cementitious materials and low water-binder ratio, under special ...

AI Technical Summary

Problems solved by technology

[0012] 1. The shrinkage reducing agent has poor compatibility with other admixtures (such as water reducers), and the final effect after use causes the respective performances of the original two admixtures to decline to varying degrees;

[0013] 2. After the shrinkage reducer, polycarboxylate water reducer, and sodium sulfate are mixed, the slump loss may be too large after use, and the shrinkage reducer mainly based on alcohol ether sometimes does not match other additives;

[0014] 3. The use of shrinkage reducing agent will lead to the reduction of concrete strength. When the shrinkage reducing agent is used alone, the strength of concrete at all ages will decrease by more than 10% with the increase of the dosage:

[0015] 4. There is a large amount of shrinkage reducing agent mixed in, which increases the project cost

[0018] 1. The retarding time is long, so it is not suitable to be used in concrete projects with high early strength requirements. Long retarding time will bring difficulties to maintenance in special climate areas;

[0019] 2. When the concrete is mixed with concrete anti-cracking and anti-seepage enhancers, the concrete will produce a large amount of ettringite in the early stage of hydration, which is not in line with the low-carbon development of concrete

exists C 3 S and C 3 Defects in durability, energy consumption and environmental protection such as A, lack of greenness of cementitious materials

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