掺煤矸石粉高强高延性混凝土的力学与流变性能研究

Study on mechanical and rheological properties of high strength and high ductility concrete with coal gangue powder

采用L_(16)(4^(5))正交试验研究了煤矸石粉掺量(40%~100%)、硅灰掺量(14%~20%)、PVA纤维体积掺量(0.5%~1.7%)、水胶比(0.18~0.30)和砂胶比(0.3~0.9)对高强高延性混凝土(HSHDC)力学性能、工作性及流变性能的影响,并对比分析了Bingham模型和Herschel-Bulkley模型对流变参数的拟合效果。结果表明:配制的掺煤矸石粉HSHDC的28 d抗压强度基本大于60.0 MPa,28 d抗折强度最大为21.2 MPa;与Bingham模型相比,Herschel-Bulkley模型更适用于描述掺煤矸石粉HSHDC的流变性能;掺煤矸石粉HSHDC的等效塑性黏度与扩展度中度相关,屈服应力与扩展度不相关。

The effects of coal gangue powder content(40%~100%),silica fume content(14%~20%),PVA fiber volume content(0.5%~1.7%),water-cement ratio(0.18~0.30),and sand-cement ratio(0.3~0.9)on the mechanical properties,workability,and rheological properties of high strength and high ductility concrete(HSHDC)were studied using L_(16)(4^(5))orthogonal experiment.The fitting effects of Bingham model and Herschel-Bulkley model on rheological parameters were compared and analyzed.The results show that the 28 d compressive strength of the HSHDC with coal gangue powder is basically greater than 60.0 MPa,and the maximum 28 d flexural strength is 21.2 MPa.Compared with the Bingham model,the Herschel-Bulkley model is more suitable for describing the rheological properties of HSHDC with coal gangue powder.The equivalent plastic viscosity of HSHDC with coal gangue powder is moderately correlated with its slump-flow,while the yield stress is not correlated with its slump-flow.