Effect Of PVA Modified Recycled Aggregate On Properties Of Recycled Concrete

With the continuous expansion of the country's construction scale,natural aggregates are consumed in large quantities.At the same time,a large amount of construction waste was not treated in time,landfill,incineration and open-air accumulation,causing serious environmental pollution.Reasonable treatment of construction waste to make it into recycled aggregates can not only alleviate the market's large demand for natural aggregates,but also effectively solve the problem of construction waste disposal.Because the quality of recycled aggregate is relatively poor compared with natural concrete,it has the characteristics of large porosity,high water absorption and high crushing index,which makes it impossible to apply in large quantities.The modification of recycled aggregate has become the key to solve the current problem.In this paper,polyvinyl alcohol(PVA)was used to modify two different quality recycled aggregates,and natural aggregates were added for comparison.The properties of the aggregates were tested.At the same time,the aggregates before and after modification were made into recycled concrete,and the effects of PVA modification on the basic mechanical properties and frost resistance of recycled concrete were studied.Studies have shown that PVA modification can mainly form a hydrophobic film on the surface of recycled aggregates,which greatly reduces the water absorption of recycled aggregates and reduces the crushing index of recycled aggregates.The long-term compressive strength of the modified recycled concrete is enhanced,the tensile strength of the splitting is not obvious,and the frost resistance is improved to some extent.Figure[67]table[10]reference[61]...