Compressive Behaviors Of Recycled Lump /Aggregate Concrete Mixed With Wetherthed Residual Soil Of Granite At Room Temperature And After High-temperature Exposure

In order to improve the waste utilization ratio of construction and demolished waste such as waste concrete and excavated soils,this paper uses demolished concrete lumps(DCLs),recycled coarse aggregates(RCA),and processed wetherthed residual soils of granite(WRSG)at the same time to obtain recycled lump/aggregate concrete with wetherthed residual soil of granite(RLACWRSG).In this dissertation,the compressive tests at room and high temperatures were conducted on RLACWRSG to reveal its compressive behaviors.The main works and achievements are listed as follows:1.The uniaxial compressive tests of 24 specimens made with RLACWRSG were carried out,and the effects of the replacement ratio of DCLs,WRSG,and RCA on the compressive behaviors of the concrete were investigated.Experimental results show that:(1)When the compressive strength of waste concrete is significantly lower than that of new concrete,and the water absorption effects of WRSG and RCA are not considered in mix proportions of new concrete,the compressive strength of RLACWRSG gradually increases with the increase of replacement ratio of WRSG,and decrease with the corporation of DCLs.(2)Under the condition mentioned in point(1),the elastic modulus of RLACWRSG mainly remains unchanged or slightly decreases with the use of RCA,decreases with the addition of DCLs and with the increase of replacement ratio of WRSG,but the decreasing amplitude is not obvious on the whole;The peak strain of the concrete increases with the increase of replacement ratio of WRSG,and increases with the use of DCLs and RCA;(3)The proposed formulas can be used to predict the compressive strength,elastic modulus and peak strain of RLACWRSG.2.A total of 45 specimens made with RLACWRSG were fabricated and tested under unaxial compression,and the effects of the specimen shape,the specimen size,and the lump size were analyzed.Test results suggest that:(1)For RLACWRSG,the ratio of cylindrical compressive strength to cubic compressive strength is about 0.91,the ratio of prismatic compressive strength to cubic compressive strength is about 0.84,these two ratios are higher than those of natural aggregate concrete.(2)The compressive strength,elastic modulus,and peak strain of RLACWRSG change little with the increase of the lateral size of specimen from 150 mm to 300 mm.(3)When the characteristic ratio of DCLs is between 0.22～0.55,the characteristic size of DCLs has limited influence on the compressive strength of RLACWRSG,and has almost no impacts on its elastic modulus,peak strain,and Poisson’s ratio corresponding to 0.4 times of the peak load.3.A total of 60 specimens made with RLACWRSG were fabricated and tested after high-temperature exposure.Then the influences of the high-temperature exposure,the replacement ratio of DCLs,WRSG,and RCA on the residual compressive behaviors of the RLACWRSG were analyzed.Test results suggest that:(1)The compressive failure mode of RLACWRSG after high-temperature exposure is similar to that of natural aggregate concrete.(2)Compared with the effect of high-temperature exposure,the effect of DCLs,WRSG,and RCA on the relative compressive strength and elastic modulus of RLACWRSG after high-temperature exposure is relatively limited.(3)The proposed formulas can be used to predict the relative compressive strength,relative elastic modulus,and relative peak strain of RLACWRSG after high-temperature exposure.