PSI - Issue 71

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ScienceDirect

Procedia Structural Integrity 71 (2025) 424–429

5 th International Structural Integrity Conference & Exhibition (SICE 2024)

Potential of Gluconic Acid as Retarding Admixture in Concrete Garima Choudhary*, Swapnil P. Wanjari Department of Civil Engineering, Visvesvaraya National Institute of Technology, Nagpur,440010, India

Keywords: Retarder; Gluconic acid; Setting time; Retention time 1. Introduction The rapid pace of urbanization and infrastructure development has significantly increased the demand for ready-mix concrete (RMC), necessitating the use of advanced admixtures to optimize its performance (Jaiswal et al. 2023 and Lr and Anvekar 2015). Among these, retarders play a crucial role in controlling the setting time of concrete, particularly in large-scale construction projects and in hot climates where delayed setting is essential (Liu et al. 2019 and Plank et al. 2015). Organic acids and their derivatives have emerged as promising retarders, offering an effective solution for enhancing the workability and performance of RMC (Bedada et al. 2023). Gluconic acid (GA), a naturally occurring organic acid, is derived from glucose and has been extensively used in various industrial applications, including food processing and pharmaceuticals (Chib et al. 2023 and Leandro et al. 2023). Although GA is known for its industrial applications, its potential as a retarding admixture in concrete has not been comprehensively explored. In the context of concrete technology, its ability to chelate calcium ions interferes with the early hydration phases of cement, leading to a delay in setting time. This characteristic makes GA an attractive option for concrete formulations requiring extended workability, such as those used in mass concreting, Abstract The increasing demand for ready-mix concrete (RMC) due to rapid urbanization and infrastructure development has necessitated the use of efficient admixtures to enhance workability and control setting time. This study investigates gluconic acid (GA), a weak organic acid derived from glucose, as a sustainable retarding admixture in concrete. GA was incorporated at dosages ranging from 0.02% to 0.1% by weight of cement. Its effects on setting time, workability retention, compressive strength, and durability were systematically evaluated. Results showed that GA significantly prolonged the initial setting time up to 170 minutes and the final setting time up to 550 minutes. At a dosage of 0.1%, workability was maintained with a slump above 150 mm for up to 180 minutes. Furthermore, compressive strength increased by 10.8% at 3 days and 6% at 28 days, compared to the control mix. Durability, assessed using the Rapid Chloride Permeability Test (RCPT), indicated extremely low chloride ion penetration across all mixes. These findings demonstrate that GA is an effective and eco-friendly alternative to conventional retarders in concrete applications, offering both early strength enhancement and extended workability. © 2025 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of SICE 2024 organizers

* Corresponding author. Tel.: 0712-280-1287; E-mail address: garimagchoudhary@gmail.com

2452-3216 © 2025 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of SICE 2024 organizers 10.1016/j.prostr.2025.08.057