Fiber reinforced regenerated fine aggregate cement-based composite material

Abstract

The invention relates to a fiber reinforced regenerated fine aggregate cement-based composite material and a preparation method thereof. The composite material consists of water, a cementing material,a water reduction agent, a polypropylene fiber and a fine aggregate through mixing, wherein a water to glue ratio is 0.72; the mass ratio of the water to the cementing material to the fine aggregateis 1:1.38:5.58; the cementing material consists of cement, regenerated glass micro powder and grade-I coal ash; the cement accounts for 70% of the weight of the cementing material; the regenerated glass micro powder and the grade-I coal ash account for 30% of the weight of the cementing material in all; the regenerated glass micro powder accounts for 10-20% of the weight of the cementing material;the grade-I coal ash accounts for 10-20% of the weight of the cementing material; the water reduction agent accounts for 0.5% of the mass of the cementing material; the polypropylene fiber accounts for 0.1-0.6% of the mass of the cementing material; the fine aggregate consists of a regenerated fine aggregate and river sand; the regenerated fine aggregate accounts for 25-50% of the weight of the fine aggregate, and the balance is river sand; a construction waste regenerated fine aggregate accounts for 50% of the weight of the regenerated fine aggregate; and a regenerated glass fine aggregate accounts for 50% of the weight of the regenerated fine aggregate. By adopting the composite material, the cracking resistance can be improved, the compressive strength ratio and the shrinkage rate canbe reduced, and the freezing resistance can be improved.

Description

technical field [0001] The invention relates to the technical field of building materials, in particular to a fiber-reinforced recycled fine aggregate cement-based composite material and a preparation method thereof. Background technique [0002] The recycling of construction waste is imperative. Recycled aggregate of construction waste is a series of processes such as sorting, crushing, cleaning, and grading of waste concrete, bricks, and rubble in construction waste. However, due to the characteristics of high cement slurry, high porosity, high water absorption, and low fluidity of the mixture in the recycled aggregate of construction waste, these defects lead to the mechanical properties and durability of the recycled aggregate series products. The unevenness limits the application fields of recycled aggregates; at the same time, the quality and performance of recycled aggregates from construction waste in different regions are significantly different, which brings inconv...

AI Technical Summary

Problems solved by technology

However, the materials configured by the above technologies do not fully reflect the crack resistance, shrinkage resistance and frost resistance.

An environment-friendly anti-freeze PVA fiber cement-based composite material and its preparation method (201710397629.8) solves the impact of low-temperature freeze-thaw in severe cold areas. According to the "Standard for Test Methods for Long-term Performance and Durability of Ordinary Concrete", the number of freeze-thaw cycles that can be tolerated More than 1,000 times; ecological recycled fine aggregate phase-change temperature-adjusting mortar and its preparation method (application number 201510401817.4) have good crack resistance, but the compression ratio is still large

From the current research results, it can be known that the replacement rate of construction waste recycled fine aggregate should not exceed 50%; after replacing part of the cement with recycled glass powder and Class I fly ash in cement-based composite materials, although the strength will decrease, the cost will also increase. At the same time, due to the shape and pozzolanic effect of recycled glass powder and Class I fly ash, other properties of cement-based composites will be slightly improved; adding polypropylene fibers to cement-based composites will cause the bonding between polypropylene fibers and the matrix The effect increases the strength, especially the flexural strength and crack resistance

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