Dynamic elastic modulus of cement based materials predicted by its microstructure

For achievement of long-term durability of concrete structures, it is important to get knowledgeabout properties of concrete. Nowadays, properties of concrete are determined by experimental or predicting from empirical equation. However, it is difficult to predict concrete properties at long-term,because it is impossible to do experiment. Therefore, it is necessary to make a model by considering its microstructure. Microstructure is a key for predicting the properties of concrete. Some properties are determined by microstructure such as C-S-H, calcium hydroxide, pores, unhydrated cement particles, interfacial transition zone and these interactions. In this study, we investigated dynamic elasticmodulus of hardened cement pastes in view point from microstructure. Backscattered electron image wasused for acquiring the microstructure image and autocorrelation function (ACF) of each phase was calculated by these images. The ACF was applied for reconstructing three dimensional structures from two dimensional images. Finally, three dimensional structures were used for calculating dynamic elastic modulus of specimen. It was cleared that the prediction result of dynamic elastic modulus used with micro indentation result was good agreement with experimental result in high W/C.