浅谈混凝土测孔方法

Discussion on method of pore structure measurement of concrete

混凝土内部存在微观、细观和宏观大孔,不同大小、不同结构的孔对混凝土的强度和耐久性会产生不同的影响。现有的测孔方法有很多种,气体吸附法和压汞法可以测量混凝土中纳米级和微米级的小孔,且可以得出孔径分布信息,但样品在经过高温高压处理后会在某种程度上破坏材料的结构;可以测出细观和宏观大孔,可获得混凝土内部孔的多项参数,包括孔隙率、孔径分布、气泡间距系数等,但该方法需要的样品量较大,且操作过程比较烦琐;相对而言,真空饱水法是最简单易行的测孔方法,但该方法只能笼统的测出孔隙率,不能测出孔结构的其他参数。

According to the size,pore structure inside the concrete are classified to three levels,microstructure,mesoscopic and macroscopic pores.Different sizes and structure of the pores may have different effects on the strength and durability of concrete.There are a number of existing methods in measuring pores inside the concrete.Both BET and MIP methods are able to measure the nano and micro pores,and can offer pore size distribution in the concrete.Though the structure of the sample may have some damage after high temperature and high pressure treatment.Image method can measure mesoscopic and macroscopic pores inside the concrete,and can acquire a number of parameters,including porosity,pore size distribution,bubble spacing factor and so on,but apart from the fact that the sample amount is very large and the operation process is a bit tedious.In relative terms,vacuum water pore density measurement method is simple and easy,it can only measure the porosity in a general way and cannot measure other parameters of the pore structure.