透水模板布改善混凝土表层质量试验研究

为研究透水模板布对混凝土表层微观质量的影响,采用贴透水模板布试模与普通试模成型的水泥净浆和水泥砂浆试块模拟表层混凝土的微观孔隙结构,运用扫描电镜、压汞法及分形理论分别对试块的表观质量和微观孔隙结构进行了测试和分析.试验结果表明:使用透水模板布后水泥净浆与水泥砂浆试块表观质量提高,孔隙体积减小,孔隙率分别降低了3.95%和7.59%.孔隙分布得到了改善;临界孔径分别由93.8和338.4 nm减小到了54.1和58.6 nm,抗渗性增强.分形理论分析表明,贴透水模板布试块孔隙分形维数减小,孔隙分布范围变窄,孔隙结构趋于规则,有利于提高混凝土耐久性.

Study on surface quality of concrete improved by infiltrating formwork texture

In order to investigate the influence of infiltrating formwork texture on concrete surface quality,the test moulds pasted with and without infiltrating formwork texture were made to form cement pastes and mortars samples,which were used to simulate the microstructure of surface concrete.Scanning electron microscope(SEM),mercury intrusion porosimeter(MIP) and fractal theory were used to test and analyze the surface quality and microstructure of the samples separately.The results indicate that the surface quality of cement pastes and mortars samples is enhanced after infiltrating formwork texture is applied,the pore volume reduces due to the proposity declining by 3.95% and 7.59% respectively;the impermeability is reinforced due to the critical pore size reduction from 93.8 nm and 338.4 nm to 54.1 nm and 58.6 nm respectively;fractal theory shows that the pore structure tends to be regular and the pore distribution scope becomes narrow due to the decrease of pore fractal dimension,which is beneficial to the durability of concrete.