基于MAA模型的水泥基UHPC性能研究

Study on Properties of Cement-based UHPC Based on MAA Model

基于最紧密堆积原理,利用改进的MAA模型设计了最大堆积密实度粉煤灰基矿物外加剂(SD-FA),同时设计超高性能混凝土(UHPC)基准配合比,系统研究胶凝材料组成与用量、砂组成、配合比参数(水胶比、灰砂比)、钢纤维掺量对UHPC性能的影响,并选出最佳配合比。研究结果表明,UHPC最佳配合比为水泥∶普通粉煤灰∶SD-FA∶硅灰∶钢纤维∶中砂∶细砂∶减水剂∶水=700∶100∶100∶100∶156∶700∶300∶10∶180kg/m~3,此时配制的UHPC坍落度为285mm,坍落扩展度为720mm,抗折强度为23.4MPa,抗压强度为167.2MPa,弹性模量为49300MPa。

Based on the principle of the most compact packing,using the improved MAA model,the maximum packing density fly ash-based mineral admixture(SD-FA)was designed,and the standard mix proportion of ultra-high performance concrete(UHPC)was designed.The effects of the composition and amount of cementitious materials,sand composition,mix proportion parameters(water-binder ratio,cement and sand ratio)and steel fiber content on the performance of UHPC were systematically studied,and the best mix proportion was selected.The research results show that the best mix proportion of UHPC is cement∶common fly ash∶SD-FA∶silica fume∶steel fiber∶medium sand∶fine sand∶water=700∶100∶100∶100∶156∶700∶300∶10∶180 kg/m~3.At this time,the prepared UHPC has a slump of 285 mm,a slump expansion of 720 mm,a flexural strength of 23.4 MPa,a compressive strength of 167.2 MPa,and an elastic modulus of 49300 MPa.