PSI - Issue 70

R. Mohanraj et al. / Procedia Structural Integrity 70 (2025) 409–416

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NaCl, which frequently come into contact with the settled concrete surface. In the case of the conventional concrete mix, an apparent weight gain of 0.23 kg from an initial stabilized weight of 8.420 kg resulted in a percentage gain of 2.73%; however, for the improved concrete mix at an optimal material substitution percentage of 9% RFA with 9% SS, the percentage gain in weight was only 1.22%, Fig. 3(a). As a result, the improved concrete mix outperformed the control concrete in terms of MgSO 4 settlement resistance. With a relative weight gain of 0.95% as opposed to 2.61% for the control concrete mixture, the better concrete mixture was also chosen by the common salt or NaCl dip (Fig. 3(b)). Therefore, the enhanced concrete mixture (9% RFA+9% SS) demonstrated higher longevity in terms of reduced corrosion by acid contact and reduced incrustation by salt deposition compared to the standard concrete mixture, regardless of whether weight is lost due to acid attack or increased due to salt incrustation. Unlike acid attack, which causes weight loss, salt encrustation causes weight gain through deposition over the concrete material and interconnecting hollow spaces. For the MgSO 4 plunge, the control concrete mix showed an apparent weight increase of 0.23 kg from an initial stabilized weight of 8.42 kg (2.73% weight gain). The same value was discovered for the improvised concrete mix: 1.22%. Similarly, in the case of a salt chloride mixture, the weight gain of the control concrete mixture was 2.61%, whereas the weight gain of the makeshift concrete mixture was only 0.95%. Thus, in terms of salt incrustation, the improved concrete mix CRACS has demonstrated significant resistance to salt accumulation.

Fig. 2. (a) Comparison between initial and final weight loss due to HCl dip (b) Comparison between initial and final weight loss due to H 2 SO 4 dip

Fig. 3. (a) Comparison between the initial weight gain and final weight gain due to the MgSO 4 dip (b) Comparison of the initial and final gains in weight due to NaCl dip