Assessment of the durability of grout submitted to accelerated carbonation test

Durability and useful life of the structural concrete are related to the environmental conditions and degrading factors present in the environment. One of most concerning aggressive agents in the civil construction industry is carbon dioxide that penetrates into the pores of the concrete reacting with the interstitial hydrates reducing its pH, promoting depassivation of the steel armours inside the concrete, thus enabling to start the corrosion process. This paper produced grout proof-bodies, concretes with high fluidity used to fill the blocks in structural masonry, with different resistance to compression: 15 MPa, 20 MPa, 25 MPa. The specimens were submitted to a carbonation front in an accelerated chamber under controlled humidity, temperature and carbon dioxide. A numerical model was used aiming to estimate the forecast of the useful life by making a comparison of the values forecasted by the Brazilian and international performance rules. It was observed that the 15 MPa grout has a useful life forecast lower than that recommended by the standard, around 60% lower, while the 20 MPa and 25 MPa grout presented a satisfactory useful life. Hence, it was certified the importance of controlling the grout resistance and coverage in structural masonry works as a form to assure the desired durability to the structure.