The Performance of Crystalline Hydrophobic in Wet Concrete Protection

Abstract

Reflecting the need to protect concrete structures from de-icing salt and freeze-thaw loading, the study introduced in this paper springs from the uncertainty that exists in the benefit of in-situ performance Iso-butylsilane as a protection material. It is likely that environmental loading and internal moisture at the time of application are the main contributory factors for under performance. This paper deals with alternative materials, a high solids silane and an aqueous crystallization solution, operating moisture driven crystallization mechanism rather than demanding a dry application regime. The results demonstrated similar substantial reducing performance of both materials at 0-5% moisture on medium (C25:25 N/mm2) and high strength (C40:40N/mm2) concrete. There is greater take-up of protective materials for C25 concrete compared with C40 concrete, together with greater chloride reduction, indicating that the level of achieved dosing is a significant factor. The similarity between the absorption of water and the two protection materials relative to initial water content, points to a possible basis for predicting achievable dossing of surface applied protection materials. The crystallization material achieved greater application volume and chloride reduction than the silane material.