Special admixture for fair-faced concrete and preparation method thereof

Abstract

The invention discloses a special admixture for fair-faced concrete and a preparation method thereof. The special admixture comprises the following raw materials: 30%-35% of a water reducing agent, 0.02%-0.05% of an air entraining agent, 0.04%-0.08% of an antifoaming agent, 1.8%-2.5% of a retarder, 1%-3% of a corrosion inhibitor, 2%-4% of a waterproof enhancer, 1%-2% of a shrinkage reducing agentand 55%-60% of water. According to the special admixture for the fair-faced concrete, cinnamamide is introduced into a molecular structure design, so the sensitivity of the water reducing agent to inorganic salt is reduced, the stretching conformation of the water reducing agent is kept, and a good early strength effect is achieved; the raw materials of the special admixture are easy to obtain, and the process of the method is simple; and the preparation operation of the special water reducing agent is simple, convenient and safe and is easy for large-scale production, so further control on the cost of the fair-faced concrete admixture can be realized.

Description

technical field [0001] The invention relates to the field of building materials, in particular to a fair-faced concrete admixture. Background technique [0002] Clear-water concrete, also known as decorative concrete, is different from ordinary concrete that requires further surface decoration. Clear-water concrete directly uses the natural surface effect of cast-in-place concrete as a finish, thus eliminating the use of chemical products such as coatings and finishes; at the same time, clear-water The concrete structure is formed at one time, without chiseling and repairing, and without plastering, which reduces a lot of construction waste. In recent years, with the strengthening of environmental awareness and the excellent aesthetic appearance of fair-faced concrete structures such as strength, cleanliness, and material sense, fair-faced concrete works have become more and more popular among people, not only in large buildings, such as large bridges, factory buildings, etc...

AI Technical Summary

Problems solved by technology

However, the performance of ordinary polycarboxylate superplasticizers is more inclined to the level of water reducing rate. If it is used alone in clear-water concrete, the final clear-water concrete is prone to surface bubbles, pockmarks, honeycomb, and serious color difference. Problem, therefore, when it is used in fair-faced concrete, it needs to be used together with other admixtures. In addition, it is also necessary to optimize and adjust the performance characteristics of the water reducer

For example, in the patent "a low air-entraining type fair-faced concrete admixture and its preparation method" with the publication number CN 1097760621 A, dibutylene glycol maleate, higher fatty alcohol methacrylate, crosslinking monomer and EO / PO random copolymerized acrylate monomers are copolymerized to obtain a low air-entraining polycarboxylate water reducer, which reduces the air content of concrete to a certain extent, reduces the generation of air bubbles, and improves the apparent quality of fair-faced concrete. The water-reducing and slump-preserving properties of low-air-entraining water-reducing agents are affected to a certain extent, and the cost of the water-reducing agent is high, the production process is relatively complicated, and the stability of the product is difficult to control

And the clear-water concrete admixture proposed in the patent "special admixture for clear-water concrete and its preparation method and its clear-water concrete and application" in the publication number CN108545988 is simple to prepare and practical, but does not clearly point out each added component main ingredient of

Because there are too many kinds of substances in each component, and the effect is also very different, if there is no restriction, it is difficult to achieve the technical effect expected in the patent if it is not restricted and used in combination. There is still a lack of systematic research on admixtures

Most of the patent documents optimize and adjust the performance of one of them, but fail to comprehensively consider its working performance, appearance quality, durability and cost, etc.