Method of reinforcing quality of regenerated coarse aggregate by three stages with strong acid

Abstract

The invention discloses a method of reinforcing quality of regenerated coarse aggregate by three stages with strong acid, particularly including: 1) soaking the regenerated coarse aggregate in a hydrochloric acid solution for a certain time; 2) adding a nitric acid solution to the hydrochloric acid solution after the soaking for a certain time to soak the coarse aggregate for a certain time, and moving out the coarse aggregate; 3) repeatedly washing the coarse aggregate in clear water until the water is neutral, and moving out the coarse aggregate; 4) placing the coarse aggregate in a sulfuricacid solution to soak the coarse aggregate for a certain time, and moving out the coarse aggregate; 5) repeatedly washing the coarse aggregate in clear water until the water is neutral, and moving out the reinforced coarse aggregate. In the method, the regenerated coarse aggregate is soaked in the strong acids, so that firstly, the mortar attached to the surface and in interior is corroded, and then sulfuric acid and residual Ca<2+> are reacted to form a compact layer, thus improving the apparent density and water absorption rate. The method reinforces the regenerated coarse aggregate in useperformance and reaches engineering application specification standard.

Description

technical field [0001] The invention belongs to the technical field of performance strengthening of recycled building waste, and relates to a method for strengthening the quality of recycled coarse aggregate in three stages by using strong acid. Background technique [0002] With the rapid development of the construction industry, the demand for natural sand and gravel aggregates is increasing day by day, and the production of natural sand and gravel aggregates requires the excavation of a large number of mountains, which will inevitably cause great damage to the environment. At present, natural sand and gravel resources Also close to exhaustion. In addition, in the process of urbanization in my country, natural disasters such as earthquakes and landslides and demolition projects have produced a large amount of construction waste. These construction wastes are of various types, 41% of which are waste concrete, which accounts for a huge proportion. Construction waste piled u...

AI Technical Summary

Problems solved by technology

Since a large amount of old mortar adheres to the surface of recycled coarse aggregate, resulting in high porosity and high water absorption, it will reduce the strength of concrete

At present, domestic researchers mostly use external materials of different properties (such as fly ash, silica fume, cement, mortar, nanomaterials, etc.) to impregnate, rinse, and dry recycled aggregates. It has the characteristics of cementation and covers the surface of recycled concrete. However, the above methods strengthen the recycled aggregate only on the surface, and have little impact on the internal structure, and the purchase cost of most admixtures is relatively high.

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