骨料级配对再生透水混凝土性能的影响

Effect of Aggregate Grade on Performance of Recycled Pervious Concrete

对废弃混凝土路面经破碎、筛分获得的再生骨料的物理性能进行测试与分析,在此基础上设计透水混凝土配合比,选择再生粗骨料粒径为5~10 mm和10~20 mm,以水灰比0.3、骨灰比4.5、替代水平100%、单双级配为主要指标制作试件。通过对试件的抗压强度、劈裂抗拉强度、有效孔隙率、透水系数的测定,综合考虑透水混凝土各项性能指标。结果表明:采用双级配的透水混凝土密度较单级配粒径为10~20 mm的低,试件的劈拉强度与抗压强度正相关,拉压比范围在21%~27%之间,脆性降低,韧性增加。此外,抗压强度随孔隙率的增大而降低。

The recycled aggregate was obtained by crushing and sieving the abandoned concrete pavement,and the physical properties of the recycled aggregate were tested and analyzed.On this basis,the permeable concrete mix proportion was designed.The recycled coarse aggregate was 5-10 mm and 10-20 mm,and the water cement ratio is 0.3,the ratio of aggregate binder is 4.5,the alternative level is 100%,and the single and double gradation(0∶1,1∶1,1∶2,2∶1,2∶3 and 3∶2)were the main indexes.Through the determination of the compressive strength,splitting tensile strength,effective porosity and permeability coefficient of the specimen,the performance indexes of the permeable concrete were considered.The results show that the density of pervious concrete with double gradation is better than that of single 10-20 mm graded aggregate concrete,compressive strength and splitting tensile strength of RPC1-2 compared with other double gradation are higher,but the porosity and permeability decrease;the porosity and permeability coefficient of RPC3-2 are larger,and the compressive strength is lower;the splitting tensile strength of the specimen has a positive correlation with the compressive strength,and the tension ratio range is between 21%-27%,the brittleness decreases and the toughness increases.In addition,the compressive strength decreases with the increase of porosity.