基于最紧密堆积理论的自密实混凝土制备与性能研究

Preparation and performance research of self-compacting concrete based on dense packing theory

基于最紧密堆积理论,对砂石和胶凝材料进行了最紧密堆积设计,选用最佳配合比制备了高速铁路CRTSⅢ型板式无砟轨道自密实混凝土,并对其性能进行了测试。结果表明:当m2区砂∶m3区砂=6∶4,m5~10 mm石∶m5~10 mm石=4∶6,水泥、粉煤灰、矿粉质量比为7.0∶0.5∶2.5,水胶比为0.35,膨胀剂掺量为5%时,所制备的自密实混凝土性能良好,扩展度可达660~680 mm,T500为4~6 s,28 d抗压强度>40 MPa,56 d干燥收缩≤400×10-6,满足相关标准要求。

Based on the dense packing theory,the design of the dense packing of sand and cementitious materials was carried out.The optimal mix proportion was selected to prepare the high-speed railway CRTSⅢtype slab ballastless track self-compacting concrete,and its performance was tested.The results show that when mzone 2 sand∶mzone 3 sand=6∶4,m5~10 mm stone∶m5~10 mm stone=4∶6,the mass ratio of cement,fly ash,and mineral powder is 7.0∶0.5∶2.5,water binder ratio is 0.35,and the content of expansion agent is 5%,the self-compacting concrete has good performance.The expansion can reach to 660~680 mm,T500 is 4~6 s,28 d compression strength>40 MPa and 56 d drying shrinkage≤400×10-6,meeting relevant standard requirements.