Study On Mechanical Properties And Salt Freezing-resistance Of Recycled Aggregate Concrete

With large number of concrete is used in the process of urbanization，humankind isfaced with the problem of waste disposal and shortage of mineral resources. Researchershave been studied the recycling of waste concrete to solve the environmental problemscaused by waste treatment process and mitigate the gap between supply and demand ofaggregate concrete. At present, domestic and foreign scholars have studied theperformance of recycled concrete to promote the mass product of recycled aggregate, so asto solve all the problems mentioned above.The bottom lines of this paper were as followings:(1) with the same size grading, thephysical properties of the recycled coarse aggregate was poorer than the natural coarseaggregate;(2) the slump of recycled concrete was lower than natural concrete;(3) thecompressive failure mode of recycled aggregate concrete and natural concrete were almostthe same; the compressive strength of recycled aggregate concrete was higher than naturalconcrete, but its elastic modulus, splitting tensile strength and flexural strength were lowerthan natural concrete;(4) at the beginning of the experiment, frost resistance of recycledconcrete was better than natural concrete, but after16times of freeze-thaw cycles, theconclusion reversed.The performance, mechanical properties and frost resistance of recycled aggregateconcrete and natural concrete mainly decided by their physical nature; the bestreplacement of recycled aggregate rate was50%. This article only studied the frostresistance of recycled aggregate concrete, future study may focus on the sulfate resistance,shrinkage, and other aspects of anti-carbonation; and obtain a more realistic reference datain engineering practice.