东非地区大吸水率骨料对混凝土性能的影响研究

Research on the impact of high water absorption aggregate on concrete in East Africa

采用东非地区大吸水率骨料和国内普通吸水率骨料,对比研究了大吸水率骨料对混凝土性能的影响,结果表明:大吸水率骨料配制混凝土的初始工作性状态较普通骨料混凝土差,且1 h后坍落度损失大;大吸水率骨料配制混凝土28 d龄期之前的抗压强度与普通骨料混凝土相当,28 d以后强度增长率下降,90 d时抗压强度较普通吸水率骨料混凝土降低5.2 MPa;大吸水率骨料混凝土的抗氯离子渗透性能、密实性、抗冻性能和长期收缩性能均较普通骨料混凝土差,为了保证工程服役的100年设计寿命,解决好大吸水率骨料混凝土的耐久性问题至关重要。

The influence of the aggregate with high water absorption ratio on the properties of concrete was studied by using the large water absorption aggregate in East Africa and the common absorbent aggregate in China,the results show that the initial working condition of concrete with large water absorption aggregate is worse than ordinary aggregate concrete, and the slump loss is large. The compressive strength of the concrete before the 28 d age was similar to the ordinary aggregate concrete. The strength growth rate decreased after 28 d, and the compressive strength of two groups was 5.2 MPa when 90 d. The chloride ion permeability resistance,compactness,frost resistance and long-term shrinkage of concrete with large water absorption aggregate are not as good as ordinary aggregate concrete. In order to ensure the designed service life of 100 years,it is vital to solve the durability problem of the large water absorption of aggregate.