再生混凝土磨耗性能改善技术研究

基于磨耗试验,并以单位面积磨损量为评价指标,研究了再生粗集料取代率、掺加粉煤灰和聚合物乳液、对再生粗集料界面进行改性等4种方法对再生混凝土耐磨性能的影响。研究结果表明:对于再生混凝土宜采用磨损量作为其耐磨性能的评价指标。为改善再生混凝土的磨耗性能,可采取的技术措施有:掺入适量粉煤灰(等量取代水泥10%,超量取代系数不超过1.4)、掺入聚合物乳液及对再生集料进行界面改性。再生混凝土磨耗性能随再生粗集料取代率的增加而降低,且与集料的洛杉矶磨耗损失密切相关;聚合物乳液的掺入显著改善再生混凝土的耐磨性能,且随着聚合物乳液掺量增加抗磨耗性能越好;采用水泥浆包裹法进行再生集料界面改性处理有利于改善再生混凝土的磨耗性能。

Technical approach to improve abrasion properties of recycled aggregate concrete

The weight loss per unit area is adopted as index to evaluate the abrasion properties of recycled aggregate concrete(RAC).Four technical methods which influence the abrasion properties of RAC are considered,they are named replace ratio of recycled coarse aggregate to natural aggregate,the addition of fly ash and polymer emulsion and interface modification of recycled coarse aggregate.The results show that weight loss per unit area is an appropriate evaluation index to assess the wear-resisting performance of RAC.To improve the wear-resisting performance of RAC,the following technical approaches can be taken:the addition of moderate amount of fly ash(equivalent replace ratio is 10%,and super-substitute ratio is not more than 1.4)、the addition of polymer emulsion and the interface modification of recycled coarse aggregate.The wear-resisting performance of RAC is closely related to the Los Angeles abrasion resistance losses of aggregate used in RAC,and the weight loss is increased as the increased replace of recycled aggregate to natural aggregate.The addition of polymer emulsion can improved the abrasion properties of RAC noticeably,and the greater dosage of polymer emulsion,the better wear-resisting performance of RAC.Slurry package method for interface modification of recycle aggregate is help to improve the wear-resisting performance of recycled concrete.