机制砂自密实混凝土泵送压力规律研究

摘要

机制砂因石粉含量高、颗粒棱角多、表面粗糙等特点,对自密实混凝土的工作性、泵送性能影响显著.基于流变学理论与Kaplan混凝土泵送压力计算模型,结合机制砂自密实混凝土现场泵送压力测试,利用流变参数坍落度S和倒坍落度筒流出时间t建立了这种混凝土的泵送压力计算模型,并分析了机制砂特性和配合比参数对其泵送压力的影响规律.结果表明:机制砂特性与混凝土配合比参数对机制砂自密实混凝土泵送压力影响显著,呈现出不同的变化规律.%Manufactured sand has a high stone powder content,a large amount of angular particles with rough surface,which has a significant influence on the workability and pumping performance of manufactured sand self-compacting concrete(MSCC).Based on rheological theory and Kaplan's concrete pumping pressure calculation model and combined with the on-site pumping pressure test of MSCC,the pumping pressure calculation model of MSCC was established by applying the rheological parameters of slump(S) and inverted slump cone flow time(t),and the effects of manufactured sand characteristics and concrete mix proportion parameters on pumping pressure of MSCC were analyzed.The results show that manufactured sand characteristics and concrete mix proportion parameters have a significant influence on pumping pressure of MSCC,which show different changing laws.