Estimation of carbonation front based on statistical analysis: using European modeling in Brazilian territory

Abstract

This paper aims to evaluate the applicability of the carbonation front prediction model recommended by CEB Bulletin 34 (2006) in Brazilian territory. For this, data from concrete mixtures produced in laboratory and exposed to natural carbonation for 10 years were used as benchmarks. Time of exposure, water/binder ration, different types of mineral admixtures and curing were considered as independent variables, while carbonation depth and coefficient as dependent ones. Analysis of variance and linear regression were performed between the actual and estimated data in order to establish criteria that allowed verifying the applicability of the model. It was considered the environmental and climatic conditions of the city of Goiânia/GO located in the tropical zone of Brazil Central with a hot semi-humid climate. As a result, based on the correlation and determination coefficients - equal to 0.83 and 0.68 respectively - it is concluded that the model needs to be revised before being applied in Brazil. More specifically, the inverse effective normal carbonation resistance factor, which associates the water/binder ration and the type of mineral admixture, should be readjusted so that it represents the effects in orders of magnitude similar to the real ones.

Keywords:
Carbonation; Service life;Predictive model; CEB Bulletin 34