The role of relative humidity and cement type on carbonation resistance of concrete

Carbonation of concrete is one of the key factors causing deterioration for reinforced concrete structures. Carbonation depth is typically used to estimate the concrete service life. Among the most important factors that can greatly affect carbonation resistance of concrete are relative humidity (RH) and water cement ratio. This paper investigates the effect of variation of RH on carbonation resistance of concrete made with different cementitious materials; CEMI42.5N, CEMIII/A42.5N, and CEMIII/A42.5N with 10% silica fume as an addition. Compressive strength and accelerated carbonation test were conducted on different concrete mixes. The relation between carbonation depth and RH had been analyzed, based on most common carbonation models; model code-FIB, Chinese codes model and Jiang et al. s-model. The results indicated that relation between RH and depth of carbonation is a polynomial function within certain range which agrees with the Chinese code. This finding is crucial for accurately predicting the carbonation behavior of concrete structure using different models. (C) 2019 The Authors. Published by Elsevier B.V. on behalf of Faculty of Engineering, Alexandria University.