Análise da frente de carbonatação em corpos de prova cilíndricos utilizando concreto convencional expostos ao meio ambiente natural

Abstract

The present study is about the study of the carbonation front, in cylindrical test bodies of 10x20 cm dimensions, using conventional concrete, exposed to the natural environment of the Laboratory of Materials of the Federal Institute of Goiás (IFG), campus Annapolis, at 7, 28, 56 and 357 days, respectively. The carbonation process consists of a natural phenomenon related to permeability to gases, penetrating the carbon gas (CO2) in the concrete pore structure by a difference in concentration, the diffusion occurring through the interconnected capillary pores, present in the concrete and, in the presence of water, the CO2 reacts with calcium hydroxide, forming the calcium carbonate, initiating front air of carbonation. The objective of this study is to measure the depth of the carbonated surface by testing the test bodies for compression and traction by diametral compression, comparing the results with those obtained by testing the non-carbonated test bodies. The RILEM CPC-18 method was used to measure the carbonation front using a phenolphthalein solution and is a pH indicator. Comparing the traction resistance values with carbonated test bodies and those without carbonation, there is a reduction in compression resistance, when comparing the carbonated and non-cabonated samples, of 1.15%, 2.13% and 2.9%, compared to 28 days, 56 and 357 days respectively. The same comparison was made with test bodies tested for traction by diagonal compression, with or without carbonation, resulting in a reduction in resistance for carbonated samples of 23.8%, 18.8% and 2.9%, compared to 28 days, 56 and 357 days, respectively. The cross-compression traction tests, there was a greater advance of the carbonation front compared to the axial compression tests.