掺加硅藻土混凝土孔隙结构冻融破坏试验研究

为提高寒冷地区混凝土结构的抗冻性，提出掺加硅藻土的方法来改善混凝土内部结构。以中等强度混凝土为研究主体，基于冻融循环试验，通过压汞测孔法与扫描电子显微镜分析混凝土结构孔隙特征，从而探究掺加硅藻土材料改变混凝土抗冻性的作用机理。结果表明:硅藻土掺量为1.5%的C30混凝土与硅藻土掺量为1.0%的C40混凝土的孔隙结构分布更为均匀，使大于100 μm的孔隙数量减少，孔隙比例更小，从而减小了混凝土冻融破坏程度。

Experimental Study on Freezing and Thawing Failure Test of Diatomite Doped Concrete with Pore Structure

In order to improve the frost resistance durability of concrete structures in cold areas, the method of adding diatomite is put forward to improve the internal structure of concrete. Taking medium strength concrete as the research object, on the basis of freeze-thaw cycle test results, the pore characteristics of concrete structure are analyzed by mercury intrusion and scanning electron microscope, so as to explore the mechanism of adding diatomite materials to improve the frost resistance of concrete. The research results show that the pore structure of C30 concrete with diatomite content of 1.5 % and C40 concrete with diatomite content of 1.0 % are more evenly distributed, which reduces the number of holes larger than 100 μm and the pore ratio is smaller, thus reducing the concrete freezing and thawing failure degree.