Evaluation of Moisture Transport Properties Based on Modelling of Silane-based Impregnation Agent Effects on Concrete Surface Layer

Department of Civil Engineering, School of Engineering, The University of Tokyo, Hongo 7-3-1, Bunkyo-Ku, Tokyo 113-8656, Japan

^* Corresponding author: katahashi@concrete.t.u-tokyo.ac.jp

Abstract

It is now desirable to establish a technique for long-term prediction of the effects of silane-based impregnation agent on concrete structures exposed to various environments. To meet this requirement, the purpose of this study is set to establish the model to evaluate the effect of a silane-based impregnation agent on the waterproofing properties of cementitious materials based on microscopic mechanisms. Several mortar specimens were prepared with the silane-based impregnation agent, and moisture absorption and evaporation experiments were conducted. The results showed that the application of the agent was shown to effectively inhibit the penetration of moisture into the interior of the cementitious materials. The effect of the silane-based impregnation agent was modeled in a multiscale pore structure model by applying a microscopic water-repellent effect to the pores in which no pore water was present at the time of agent coating. The analysis with proposed model showed that, as in the experiment, the moisture supply was reduced by the application of the agent, whereas the amount of moisture loss remained almost the same with and without the agent. Moreover, the analysis quantitatively showed that the water content can continue to decrease with silane treatments, even under repeated wet-dry conditions.