PSI - Issue 70

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

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a ternary mix with 30% GGBFS and 5% silica fume achieved the maximum compressive strength of 70.12 MPa. Mal and Mukherjee (2023) investigated the strength of concrete prepared using silica fume and GGBFS. Silica fume replaced 10% of the cement by weight, while GGBFS was varied from 0% to 50%. Concrete cubes and cylinders were cast for M30 grade concrete. Venkateswarao and Dattatreya Kumar (2016) studied the strength characteristics of M60 grade concrete by replacing cement with GGBFS at levels of 0%, 10%, 20%, 30%, and 40%, along with the addition of active silica fume at 0%, 5%, 10%, and 15% by weight of cement. Various concrete mixtures were cast and tested. 3. Materials 3.1 Ordinary Portland cement (OPC 53) Ordinary Portland Cement OPC-53 is high-strength cement that achieves a minimum compressive strength of 53 MPa (530 kg/cm²) in 28 days, making it ideal for use in demanding construction projects such as high-rise buildings, bridges, and industrial structures. It is known for its fast setting time, superior durability, and excellent early strength development, which allows for quicker construction and reduced curing times. OPC Grade 53 is commonly used in pre-stressed concrete, high-performance concrete, and applications requiring high tensile strength and resistance to wear, though it is typically more expensive than lower-grade cements. Table 1. Physical Properties of 53 Grade of Ordinary Portland Cement. Properties Values Standard Consistency 53 Fineness of cement as retained on 90 micron sieve 2% Initial Setting Time Specific Gravity 28 days compressive strength 30 minutes 3.15 39MPa 3.2 Coarse Aggregate Coarse aggregates in high-strength concrete (HSC) provide essential bulk and structural support, enhancing the concrete's overall strength and durability. By improving the bonding between the cement paste and aggregates, high quality coarse aggregates contribute to the development of compressive strength. Properly graded aggregates reduce shrinkage and cracking during curing, while also enhancing the workability of the mix. In high-strength concrete applications, such as high-rise buildings and bridges, the choice of coarse aggregate — ensuring good shape, texture, and minimal porosity — plays a key role in optimizing performance, resistance to wear, and longevity. In our project, CA of size that are ranging from greater than 4.75mm and less than 20mm are taken. The Specific Gravity of coarse aggregate is obtained as 2.6. 3.3 Fine aggregate Fine aggregates in high-strength concrete (HSC) play a vital role in achieving a smooth, cohesive mix that ensures proper bonding between the cement paste and coarse aggregates. These aggregates, typically sand or crushed stone dust, fill the voids between coarse aggregates, improving workability and ensuring a dense, uniform structure. Fine aggregates contribute to the overall strength of the concrete by helping to reduce porosity and enhance the packing density, which in turn improves the compressive strength and durability of the concrete. In HSC, the choice of fine aggregates with appropriate particle size distribution is crucial for minimizing shrinkage, cracking, and maximizing the long-term performance of the concrete. In our project, dry sand of zone 4 is typically used. The specific gravity of fine aggregate is obtained as 2.7.