Experimental analysis of the carbonation and humidity diffusion processes in aerial lime mortar

A multi-physics modelling based on coupled diffusion equations to simulate the carbonation process

“…For structures with smaller dimension, the humidity diffusion happens faster, because of the smaller contribution of those parts. In coherence with the results obtained in the parametric analyses herein, experimentally, the work presented by Oliveira et al [11] and Oliveira [10] considered a geometry simulating axisymmetric conditions in aerial lime mortar, the results indicated that there is an effect of the specimen´s size on the carbonation depth. The smaller specimens presented higher carbonation depth.…”

“…When carbon dioxide (CO2) from the atmosphere penetrates into the concrete pores, it dissolves in the interstitial solution and thereby modifies the chemical balances between the solution and the hydrates. This leads to the precipitation of calcium carbonates (CaCO3) in ordinary Portland cementitious materials [9]- [11], as well as the densification of the microstructure and the decrease of the pH of interstitial solution [3]. Therefore, the reinforcement is not protected anymore, in this sense, carbonation leads to the degradation of the reinforced concrete structures.…”

“…In recent times, the interest in lime-based materials is increasing due to study, restoration and preservation of historic buildings [10], [11], as they are compatible with traditional building materials [6], [18], since Portland cement shows low chemical and physical affinity [6], [19], [20]. There are few studies about carbonation in aerial lime-based materials, when comparing with concrete, especially regarding the numerical aspect [10], [21], [22].…”

Estudo experimental do fluxo de umidade em argamassas de cal aérea

“…Argamassas à base de cal aérea foram utilizadas em diversas partes do mundo, inclusive no Brasil [2]. Para essas argamassas o processo de carbonatação é de fundamental importância para o ganho de resistência [2,[5][6][7][8][9][10]. Vários parâmetros ambientais influenciam o processo de carbonatação, como temperatura, umidade relativa e concentração de dióxido de carbono [11,12].…”

“…Com relação a esse fenômeno, vários autores já mediram a difusão da umidade em materiais à base de cimento [13][14][15][16][17]. Para argamassas históricas, poucos resultados podem ser encontrados em outras literaturas [7,18].…”