In order to compare the effect of several measures by modifying recycled coarse aggregate on improving compressive strength of concrete , the HCl solution with different concentrations ,H2 C2 O4 solution with concentration of 8% ,waterproofing mortar solution with concentration of 25% and PVA solution with concentration of 2% were used to treat the recycled coarse aggregate samples by chemical immersion or physical filling ,respectively .By using the treated recycled coarse aggregate ,some cubic concrete samples with the dimension of 100 mm × 100 mm × 100 mm were fabricated for testing the compressive strength .The results show that different treatments may achieve an increase in the compressive strength of the mixed concrete to some different extents .Comparing with the untreated recycled coarse aggregate ,the aggregates treated respectively with the above-mentioned HCl solution with concentration of 2% (closing to the best effect) ,H2 C2 O4 solution with concentration of 8% ,waterproofing mortar solution with concentration of 25% ,and PVA solution with concentration of 2% contribute to an increase in the compressive strength of the mixed concrete for 11 .84% , 7% , 4 .37% and 11 .31% ,respectively .The increased compressive strength achieves a good level as high as 96 .63% , 92 .44% ,90 .18% and 96 .17% of the concrete mixed with the natural coarse aggregate ,which has the same grain composition with the recycled coarse aggregate .%为对比粗骨料多种改性方法对混凝土抗压强度的提升效果,分别采用不同质量分数的盐酸溶液和8%质量分数草酸溶液以及25%质量分数防水砂浆浆液和2%质量分数聚乙烯醇浆液对再生粗骨料进行化学浸洗或物理填充,将处理得到的再生粗骨料制成边长为100 m m的立方体混凝土试件进行抗压强度测试.结果表明:粗骨料的不同处理方式对混凝土抗压强度均有不同程度的提高,其中2%质量分数盐酸溶液(处理效果接近最佳)、8%质量分数草酸溶液、25%质量分数防水砂浆浆液和2%质量分数聚乙烯醇浆液处理骨料分别可使混凝土抗压强度提高11.84%,7%,4.37%,11.31%,并达到同级配天然碎石骨料混凝土抗压强度的96.63%,92.44%,90.18%,96.17%.
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