大吸水率粗集料高性能海工混凝土配合比设计研

关键字：大吸水率,粗集料,高性能海工,混凝土,中国

（1. 中国路桥工程有限责任公司，北京  100011；2.中交路桥建设有限公司，北京  100027）

 
 
    摘要：以马普托大桥工程为背景，使用吸水率达3.0%以上的粗集料Namaacha碎石（N石）和Hipermaquinas碎石（H石）研究高性能海工混凝土的配合比设计。结果表明，N石的吸水速率以及饱和吸水量均大于H石，主要原因在于N石所含孔体积大于H石，且孔径比H石更大。根据2种碎石的性能，选择N石进行C40海工混凝土配合比设计，确定最佳水胶比为0.38，粉煤灰掺量为35%；选择H石进行C50海工混凝土配合比设计，确定最佳水胶比为0.33，粉煤灰掺量为20%。最佳配合比的C40、C50混凝土海水浸泡180 d的抗压强度与标养条件下接近，RCM法测试的365 d氯离子迁移系数小于1.6×10-12 m2/s，具有抗海水侵蚀性能。
    关键词：配合比设计；大吸水率粗集料；吸水率；海工混凝土；强度
    中图分类号：TU528        文献标识码：A        文章编号：1001-702X（2018）02-0005-08
 

Research on high-performance marine concrete mix design with high water absorption coarse aggregate
BAI Pengyu1，ZHANG Yan2，ZHU Changchun2
（1.China Road and Bridge Corporation，Beijing 100011，China；2.Road & Bridge International Co. Ltd.，Beijing 100027，China）

    Abstract：Based on Maputo bridge project，mix design of high performance marine concrete is studied using coarse aggregate Namaacha gravel（N） and Hipermaquinas gravel（H） with high water absorption above 3.0%. The results show that the water absorption rate and saturated water absorption of N are larger than that of H. The main reason is that the pore volume of N is larger than that of H stone，and the pore diameter is larger than that of H stone. According to the performance of the two kinds of gravel，the mix design of C40 marine concrete using N gravel is water-cement ratio of 0.38 and the fly ash content of 35% and the mix design of C50 marine concrete using H gravel is water-cement ratio of 0.33 and the fly ash content of 20%. Seawater immersion experiment on the optimum mixing ratio of C40，C50 concrete shows that the 180 d compressive strength test results and standard conditions strength test results are similar，chloride Ion diffusion coefficients of concrete in 365 d are less than 1.6×10-12 m2/s by RCM method. The results show that the design of marine concrete has resistance to seawater erosion.
    Key words：mix design，large water absorption coarse aggregate，water absorption rate，marine concrete，strength