PSI - Issue 71

Garima Choudhary et al. / Procedia Structural Integrity 71 (2025) 424–429

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The effects of gluconic acid (GA) on the compressive strength of concrete at 3, 7, and 28 days are depicted in Fig.5. The compressive strength exhibited an increasing trend across all ages. The impact of GA addition is dosage dependent. At 3 days, the compressive strength increased by 10.8% with a 0.1% GA dosage. After 28 days, the compressive strength was enhanced by 6% compared to the control mix. Thus, the inclusion of GA not only improves workability but also maintains the compressive strength of the concrete, without adverse effects. Durability is a key consideration when incorporating chemical admixtures to evaluate its long-term performance. The Rapid Chloride Permeability Test (RCPT) is the standardized method for assessing the durability of concrete. As presented in Table 4, the RCPT values for all GA dosages indicate extremely low chloride permeability, in accordance with ASTM C1202 (ASTM 2019) specifications. Therefore, the addition of GA does not adversely affect the durability of the concrete.

Fig.2: Variation of Setting Time with Different Dosages of Gluconic Acid.

Fig.3: Effect of Gluconic Acid on Slump Loss Over Time.