Alkali-activated composite recycled powder recycled aggregate pervious concrete and preparation method thereof

Abstract

The invention provides alkali-activated composite recycled powder and recycled aggregate pervious concrete. The pervious concrete is prepared from, by weight, 6-16 parts of fly ash, 5-15 parts of mineral powder, 2-6 parts of brick powder, 2-8 parts of water, 30-50 parts of single-particle-size coarse aggregate, 10-30 parts of recycled coarse aggregate and 4-6 parts of alkali activator. Adding the single-particle-size coarse aggregate, the recycled coarse aggregate and water accounting for 20-30% of the total water into a stirrer, stirring for 30 seconds, then sequentially adding the mineral powder, the fly ash, the silica fume, the brick powder and the residual water, and continuously stirring for 1 minute and 30 seconds; and finally, adding water glass and a polycarboxylic acid water reducer, and continuously stirring for 2 minutes to form the porous concrete. And carrying out mold filling, vibrating and forming, curing with a mold, demolding, and curing to 28 days to obtain a pervious concrete finished product. The product not only has the characteristics of rough surface, strong water permeability, good ductility and the like, but also effectively utilizes the solid waste brick powder, the recycled aggregate, the solid waste mineral admixture and the like, so that the wastes are recycled.

Description

technical field [0001] The invention relates to a method for preparing concrete and its products, in particular to a method for preparing alkali-activated composite recycled powder recycled aggregate permeable concrete and its products, belonging to the technical field of building materials. Background technique [0002] With the rapid development of urbanization, the ground hardening of traditional concrete makes it difficult for ground rainwater to infiltrate quickly, resulting in frequent waterlogging disasters in large and medium-sized cities in my country. In recent years, extreme rainstorms have occurred frequently, making this problem particularly prominent. Based on this, scholars put forward the concept of sponge city. The permeable concrete is one of the important ways to realize the sponge city. The permeable concrete has excellent properties such as water seepage, noise reduction and anti-skid. At the same time, the rapid development of urbanization has also pro...

AI Technical Summary

Problems solved by technology

However, the pervious concrete still needs to use 3% to 8% cement and 60% to 80% natural aggregate, and the carbon emission is still high, and the concrete is cured by steam. The material is less practical

[0006] Xiao Liguang and Meng Xiangbo reviewed the research and application status of recycled aggregate permeable concrete in the paper "Research Progress of Recycled Aggregate Permeable Concrete" (Concrete and Cement Products. 2021, (07): 1-6). It can be found that the existing Recycled aggregate permeable concrete partially utilizes recycled coarse aggregate, which realizes the recycling of waste construction waste to a certain extent. body, the existing recycled aggregate permeable concrete has not been used

And these recycled powders that have not been properly disposed of will also pose a great threat to the environment and cause a waste of resources

[0007] Through the analysis of the above-mentioned patents and academic papers, it can be seen that the existing technical means are not enough to fully digest construction waste, and its single-size coarse aggregate is mainly made of natural sandstone aggregate, which has high production costs and increases The mining of natural sand and gravel aggregates, while still requiring a large amount of high-energy consumption products such as Portland cement, cannot achieve the ecological sustainable development of the construction industry

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