Regenerated hardened cement mortar powder cementing material and preparation method thereof

Abstract

The invention provides a regenerated hardened cement mortar powder cementing material and a preparation method thereof. The cementing material comprises the following components in parts by mass: 55-75 parts of waste hardened cement mortar, 25-45 parts of phosphorus slag, 1.0-3.5 parts of sodium hydroxide, 4-10 parts of water glass, 0.5-1.0 part of tartaric acid, 0.5-1.2 parts of water reducer and 25-35 parts of water. The water glass is metered on the basis of solid content in the water glass, and the water contains liquid water in the water glass. The cementing material can be prepared by directly milling mortar in waste cement concrete or waste cement mortar products, the hardened cement slurry does not need to be separated from sand in the preparation process, and thus, the method is simple and low in energy consumption; and the cementing material has the advantages of high setting speed, moderate strength, low shrinkage and favorable corrosion resistance.

Description

technical field [0001] The invention belongs to the field of resource utilization of building materials and solid waste, and relates to a recycling technology of waste cement concrete, in particular to a regenerated cementitious material prepared from waste hardened cement mortar separated from waste cement concrete and its preparation method. Background technique [0002] The disposal and utilization of waste cement concrete has become a topic of global concern. In the past, waste cement concrete was mostly used for landfill treatment, occupying land, polluting the environment, and wasting resources. In recent years, people have begun to pay attention to the recycling of waste cement concrete, mainly to prepare recycled aggregates to replace natural aggregates. However, since recycled aggregate contains cement mortar, its strength is low, its porosity is high, and its water absorption rate is high, which affects the performance of concrete, and the hardened cement mortar w...

AI Technical Summary

Problems solved by technology

However, due to the cement mortar contained in the recycled aggregate, its strength is low, the porosity is high, and the water absorption rate is large, which affects the performance of concrete, and the hardened cement mortar with finer particles screened out in the preparation of recycled aggregate cannot be effectively used

If the hardened cement mortar is ground and used as the raw material for the production of cement clinker by the traditional method, the quality of the cement clinker will be reduced due to the low grindability and burnability of the fine aggregate.

Although some people have proposed to separate the cement slurry in the waste cement concrete, and use it as a cementitious material after heat treatment at a certain temperature, but there are problems of complicated separation process, dust pollution and high cost.

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