Prediction Model of Internal Relative Humidity During Self-desiccation in Hardened Cement Pastes

Abstract

This study proposes a simplified prediction model of internal relative humidity during self-desiccation in hardened cement pastes at early ages. The proposed model is composed of the pore-structure development model based on the water-cement system, the water adsorption isotherm model, and the hydration process model. The mathematical expression of the final form of the model consists of algebraic equations with some parameters that were derived from concrete engineering. The proposed model can be easily calculated using spreadsheet software. The calculation results of the proposed model agree well with the experimental results of relative humidity in hardened cement pastes with a low water cement ratio under sealed curing and constant temperature curing conditions.