高强自密实次轻混凝土工作性能研究

Research on the workability of high-strength semi-lightweight self-compacting concrete

研究了不同陶粒取代率时自密实混凝土的工作性变化规律。研究结果表明陶粒取代率对自密实混凝土的坍落度、坍落扩展度、T500流动时间影响较小。但随着陶粒取代率的增加,拌合物在U型仪和L型仪中的离析越严重。在此基础上,取陶粒取代率为50%,水灰比0.325,胶凝材料总量530kg/m3,制备出了自密实等级为2、不离析不分层、工作性良好、28d抗压强度54.6MPa的高强自密实次轻混凝土。

The workability changing rules of self- compacting concrete at different lightweight aggregate replacement rate were studied.The research result indicate that, with lightweight aggregate replacement rate changing, effect on the slump flow, slump divergence and time required to reach 500 mm of slump flow of self-compacting concrete is small.However, with replacement rate increasing, when testing in U-box and L-box, segregation tendency of the mix increased.On this basis, when lightweight aggregate replacement rate is 50%, water-cement ratio is 0.325, total binding materials is 530 kg/m^3, high-strength semi-lightweight self-compacting concrete with self-compacting grade 2, no segregation and laminate ,compressive strength is 54.6 MPa at the 28th day and good workability could be prepared.