高原环境桥用高性能混凝土的配制技术与性能研究

摘要

对高原环境桥用高性能混凝土的配制技术与性能进行了研究。结果表明,采用骨料级配设计技术、粉煤灰和高性能减水剂双掺技术和引气技术配制的C50高性能混凝土具有早强、高强和低收缩性能,同时具有良好的抗冻性能。分析表明,控制含气量为4.5%~6.0%,气孔的孔径范围为40~280μm,气泡间距系数为120~150μm,其抗冻性均大于300次冻融循环。含气量是提升混凝土抗冻性的重要参数,而所引入气孔的性质也同样重要。适当增加含气量、减小孔径和气泡间距系数,可明显提升混凝土的抗冻性能。%The preparation technology and properties of high performance concrete are studied, which is used for bridges in the plateau environment. The results show that, the high performance concrete which use the aggregate grada-tion design technology, fly ash and high performance reducing water agent of double doped technology and air entraining technology have the properties of early strength and high strength and low shrinkage performance and good frost resistance which can meet the plateau environment with dry winds and freezing thawing. The analysis shows that the air content of concrete is not the only quality of decision parameters of concrete, the properties of introducing bubbles are also impor-tant. Appropriately increasing the air content, reducing the pore diameter and the spacing coefficient of the air bubble can obviously improve the frost resistance of concrete.