PSI - Issue 70

Rupankar Chakraborti et al. / Procedia Structural Integrity 70 (2025) 279–286

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3.4 GGBFS It is used as 20%, 30% and 40% replacement of cement in terms of weight of concrete. It is mainly used to check how it affects on the strength of concrete. In our project, the specific gravity of GGBFS is obtained as 2.8. 3.5 Silica fume In our project, it is used as 5%, 10% and 15% replacement of cement in terms of weight of concrete. The specific gravity is obtained as 2.3. Water in high-strength concrete (HSC) plays a critical role in hydrating the cement, facilitating the chemical reaction that binds the aggregates together and allows the concrete to set and gain strength. The water-to-cement ratio is particularly important in HSC, as it directly affects on the mix strength and durability; lower water content results in higher strength and reduced porosity. However, too little water can compromise workability, making proper control of water content essential to achieving the desired high-strength properties. In our project, w/c ratio of 0.4 is adopted. So, accordingly the water is taken depending upon the weight of cement taken. 3.7 Chemical admixture Chemical admixturesare commonly used in high-strength concrete to improve workability, increase strength, enhance durability, and accelerate or retard the setting time. Admixtures, such as plasticizers, superplasticizers, and accelerators, help reduce the water-to-cement ratio, allowing for a denser mix that enhances the compressive strength of the concrete without sacrificing workability. These admixtures also improve the concrete's resistance to chemical attacks, shrinkage, and cracking, while helping to optimize the curing process. The use of admixtures ensures the production of high-strength concrete with superior performance and longevity in demanding construction applications. In our project, 1-2% of admixture is used in terms of weight of cement as advised in the IS code 10262:2019. The specific gravity of the superplasticizers that is used is 2.3. 3.6 Water

Fig. 1 Materials required for Design Mix