Preparation method of one-time large-thickness-forming sprayed sculpture concrete

Abstract

The invention discloses a preparation method of one-time large-thickness-forming sprayed sculpture concrete, which relates to the technical field of materials, and comprises the following steps: weighing assistants: anti-crack fibers, cellulose ether, starch ether, a concrete expanding agent, organic modified bentonite, an air entraining agent and a retarder, adding the components into a stirrer,and uniformly mixing the components; weighing portland cement, graded river sand, aggregate, fly ash and the mixed auxiliary agent and adding the components into a concrete mixer to be uniformly mixed; and adding water into the mixed materials in the concrete mixer, and uniformly stirring all the materials to finish the preparation of the sprayed concrete. According to the preparation method disclosed by the invention, the river sand and the aggregate are added in a grading manner, wherein the granularity of the river sand and the aggregate are controlled to be not less than 2.0 meshes, and the anti-cracking fibers, the composite thickening agent, the expanding agent and the air entraining agent are matched for use, so that the water-retaining property, thixotropy, forming consistency andgood wire drawing property of the sprayed sculpture concrete are improved, resilience is reduced, and one-time spray forming thickness is increased.

Description

technical field [0001] The invention relates to the technical field of material preparation, in particular to a method for preparing spray sculpture concrete capable of forming large thickness at one time. Background technique [0002] Shotcrete for sculpture is a material used to construct the base of sculpture, which belongs to the series of sprayed concrete products. Shotcrete is cement, sand, stone, water and other aggregates that are dynamically compacted at high speed under pneumatic pressure. Because shotcrete has the characteristics of short setting time, strong self-drilling effect, high bonding strength, coordinated deformation, wide application range and fast construction, it has gradually been applied and developed. Shotcrete has stable performance, easy long-term storage, and is conducive to transportation. Adding water on site to prepare shotcrete is the main direction of development of concrete materials. In the sculpture market, shotcrete, as the underlying...

AI Technical Summary

Problems solved by technology

When using spraying construction, in order to maintain the smoothness of spraying, the water-cement ratio of concrete is relatively high, which leads to certain defects in the poured concrete structure, and also limits the thickness of the one-time spraying that cannot be too thick when spraying is used for construction.

Focusing on the above problems, relevant research work on the mix ratio of shotcrete has been carried out, revealing that the rebound rate of shotcrete can be reduced by adjusting the formula ratio of concrete: (1) Cheng Liangkui (Material composition and main properties of shotcrete[J]. Industrial Construction. 1986 (01)) reported the use of adding suitable accelerators in concrete to accelerate the initial setting speed of concrete and reduce rebound, but the addition of accelerators made the spraying process complicated; (2) In order to improve the performance of shotcrete To reduce the rebound rate of shotcrete and improve the molding quality of shotcrete, the addition of mixed materials including silica fume, fly ash and limestone powder and other mineral admixtures is used; but for the production of shotcrete, the addition of silica powder can compensate for the sprayed concrete. Loss of strength in the later stage, but due to the small particle size of silicon micropowder, it is also easy to affect the health of operators and lacks environmental protection

(3) Germany adopts the method of adding adhesives to sprayed concrete to improve the cohesiveness of concrete and reduce the rebound rate. Japan also uses organic polymers as tackifiers. Xu Jiayou and others in my country reported that acrylamide-sodium acrylate was used - The acrylonitrile copolymer tackifier has also achieved a certain effect on reducing the rebound rate; at the same time, the addition of the adhesive can reduce the bleeding and rebound of the concrete; but the addition of the tackifier increases the water-cement ratio, The amount of water will increase, so that the strength of the concrete will decrease in the later stage. For this reason, a water reducing agent must be added, and the addition of the water reducing agent will cause the shotcrete to sag easily, so the added adhesive and water reducing agent must be reasonably adjusted Blending, which increases the complexity of product production formula and configuration of product formula

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