Coupled chemo-transport-mechanical modelling and numerical simulation of external sulfate attack in mortar

Coupled Mechanical and Chemo-Transport Model for the Simulation of Cementitious Materials Subjected to External Sulfate Attack

“…We note that the value b ¼ 0:72 gives results of free expansions close to the measured values for the two considered cases, while b ¼ 0:6 overestimates them significantly for the 44 g/L Na 2 SO 4 case. The approach described in (8.3) and (8.4) appears then to satisfactorily reproduce the observed free expansions, contrary to the crystallization pressure approach alone, which leads to notable underestimations (unless exhibiting unrealistically high crystallization pressures of several thousands of MPa [10]). The same conclusion has been reported in [11].…”

“…This model has been successfully applied to the determination of cracking initiation consecutive to ESA in cement pastes. However, it has been shown in [10] that the application of this approach leads to very small macroscopic free expansions, very far from the experimental measurements (about two orders of magnitude lower). The reason is that the calculated crystallization pressures are not sufficient to generate strains values comparable to experimental ones with a purely elastic approach.…”

“…The expression of a AFt is detailed in [10]. The model defined by (8.3) and (8.4) is implemented in the platform ALLIANCES.…”

Recent durability studies on concrete structure

“…They considered that microcracks might be bridged or filled by some expansive secondary ettringite under external sulfate attack and restrained force, as shown in Fig. 4 [60]. 2) A diffusion-reaction numerical model was proposed to simulate the response of concrete exposed to external sulfate attack by Ikumi et al The described approach allowed the consideration of different filling rates and capacities to accommodate expansive products for each pore size considered [61].…”

Experimental Study on Diffusion Process of Sulfate Ion in Cemented Gangue Backfill Material

“…Exploring the diffusion process of corrosive ions inside materials is the basis for determining the redundancy of the section size as the backfill design. Benoit et al found that sulfate attack was a diffusion reaction process of concrete when exposed to environment with sulfate [10]. Wang et al immersed cement mortar in sulfate solutions used layered sampling method combined with chemical analysis, and calculated diffusion coefficients of SO 2− 4 used XRD and SEM to analyze the formation of reaction products.…”