STUDY ON SPECIFIC SURFACE AREA OF HYDRATION PRODUCTS IN HARDENED CEMENT PASTE

Abstract

C-S-H is a dominant hydration product of cementitious materials. Therefore, its chemical composition and physical properties affect the properties of concrete. However, the composition and the properties of C-S-H, and the relation between both have not been completely clarified. In order to evaluate the concrete performance accurately, the physical properties of concrete should be evaluated accuracy. Therefore, it is important to clarify the chemical composition and the physical properties of C-S-H.
The purpose of this study is to clarify the chemical composition（the C/S ratio and H/S ratio）and specific surface area of C-S-H. The C/S ratio, the H/S ratio and the specific surface area of C-S-H were estimated by using synthesized C-S-H and C-S-H generated from synthesized alite paste. In addition, the specific surface area of calcium hydroxide and calcium aluminate hydrates were estimated by synthesized hydration products. Furthermore, the specific surface area of hardened cement paste was measured.
From the experimental results, the H/S ratio of C-S-H under each relative humidity is proportional to the C/S ratio independent of the mix proportion and curing temperature. From these results, the relation equation between the C/S ratio and specific surface area of C-S-H is proposed. Moreover, the specific surface area of hardened cement pastes can be estimated by the amount of hydration products and each specific surface area of hydration products.