The Investigation of Nano Silica Gel and Silica Fume on the Properties of Cement Based Materials

Nowadays, pozzolans are used as cement replacement materials. In recent decades, a large number of studies have investigated the effect of nano silica on the properties of cement based materials. In many cases it has been shown that the use of nano silica as a pozzolan could improve the properties such as mechanical properties and durability of concrete and it has caused to increase service life of structures. Due to the large variety of nano-silica, some of them such as nano silica gel have been studied scarcely. Nano silica gel could have widespread applications, especially in dry mortars. The aim of this study is to provide a method for the production of nano-silica gels and their effects on the properties of cement mortars. The results indicate the good performance of nano silica gel in the process of compressive strength development at early ages. Furthermore, the microstructure was improved considering the results of water permeability and Rapid chloride Migration Test (RCMT) at 28days. By increasing the percent of substitution, strength properties and microstructure were improved.