Method for improving quality of waste concrete recycled aggregate by using sodium carbonate solution

Abstract

The invention discloses a method for improving the quality of a waste concrete recycled aggregate by using a sodium carbonate solution. The waste concrete recycled aggregate of which the particle size grade is 5-20mm is soaked in a Na2CO3 solution of which the mass concentration is 4-8%, and the soaking repair time is 15-25 days. The method provided by the invention has the following beneficial effect: the water absorption rate of the recycled aggregate is reduced, the apparent density is increased, the quality of the recycled aggregate is greatly improved, the recycled concrete coarse aggregate repaired by the sodium carbonate solution can be used for preparing new concrete when the water absorption rate and the apparent density of reach a III-grade standard of the recycled concrete coarse aggregate of a national standard GB / T25177-2010, and the problem of waste concrete construction waste disposal is solved.

Description

technical field [0001] The invention belongs to the field of recycling of construction waste, and in particular relates to a method for improving the quality of recycled aggregate of waste concrete by using sodium carbonate solution. Background technique [0002] At present, construction concrete waste accounts for about 40% of construction waste, and the amount is very large, but the amount that can be reused is very small. The main part of the waste concrete powder is sent to the landfill, and the landfill will not only occupy a large amount of land, but also pollute the soil and air. The ideal state of waste concrete recycling is to be able to prepare high-quality recycled aggregates. However, the current methods of processing waste concrete mainly include basic processes such as "crushing, screening and removing impurities". The prepared recycled aggregate contains cement stones, has high porosity, high water absorption, and low apparent density, which leads to recycled...

AI Technical Summary

Problems solved by technology

However, the current methods of processing waste concrete mainly include basic processes such as "crushing, screening and removing impurities". The prepared recycled aggregate contains cement stones, has high porosity, high water absorption, and low apparent density, which leads to recycled concrete. The performance of the

At present, domestic researchers mostly use additive materials of different properties (such as polymers, silicone waterproofing agents, Kim powder mixed with cement, first-class fly ash mixed with cement, etc.). Dipping, rinsing, drying and other treatments are performed to cover the surface of the recycled aggregate. However, the above methods do not change the internal structure of the recycled aggregate, and the reinforcement is not high, and it is easy to fall off.

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