To Study the Effect on Mechanical Properties of Concrete by Partially Replacement of OPC with Fly Ash and GGBS

Abstract

This study investigates the mechanical properties of concrete with partial replacement of ordinary Portland cement (OPC) by fly ash and ground granulated blast furnace slag (GGBS). Various mix proportions were tested to evaluate compressive, tensile, and flexural strength over different curing periods. Results show a reduction in early-age strength due to slower hydration but improved long-term strength, and workability. The use of fly ash and GGBS also reduces the environmental impact, highlighting their potential as sustainable alternatives in concrete production

Introduction

Objective:
The study investigates the impact of partially replacing Ordinary Portland Cement (OPC) with Fly Ash and Ground Granulated Blast Furnace Slag (GGBS) to improve concrete’s mechanical properties and promote sustainable construction by reducing CO? emissions.

Key Materials Used:

• OPC (Ambuja Cement)

• Fly Ash: Byproduct of coal combustion; rich in silica and alumina.

• GGBS: Byproduct of steel manufacturing; enhances strength and durability.

• Fine Aggregates (Sand) and Coarse Aggregates (Gravel/Crushed Stone) per IS standards.

• Potable Water conforming to IS 456:2000.

Mix Design Highlights:

• Cement: 50 kg

• Sand: 71 kg

• Coarse Aggregate: 155 kg (for 1 bag); 1211 kg for 1 m³

• Water-cement ratio: 0.45

• Adjustments made for moisture and absorption properties of aggregates.

Tests Conducted:

1. Compressive Strength Test (7, 14, and 28 days)

2. Workability Test (Slump test)

Test Results:

Compressive Strength (N/mm²):

• 7 Days:

  • 0% replacement: 10.55

  • 30% replacement: 8.84

  • 50% replacement: 6.35

• 14 Days:

  • 0%: 14.34

  • 30%: 15.24 (Highest)

  • 50%: 11.75

• 28 Days:

  • 0%: 19.5

  • 30%: 19.78 (Highest)

  • 50%: 16.67

Workability (Slump in mm):

• 0%: 70 mm

• 30%: 85 mm

• 50%: 115 mm (Highest)

Conclusion

The study highlights the effectiveness of replacing Ordinary Portland Cement (OPC) with a combination of Fly Ash and GGBS in concrete. the combination of Fly Ash and GGBS not only enhances the long-term strength and workability of concrete but also plays a crucial role in mitigating environmental impact, aligning with the growing need for sustainable construction practices.

References

[1] Kumar, Anant & Deep, Krishna. (2022). Experimental research comparing conventional Concrete to concrete made with waste cementitious materials like GGBS and fly ash [2] Anand Kumar B.G. (2012). His conclusions may be obtained using binder blends Containing at least 50% fly ash. Utilizing GGBS up to 70% of fly ash as binder, high Volume fly ash concrete may be created. [3] Pofale, A. D. and Deo, S. V. (2010), Comparative Long study of Concrete Mix Design Procedure for Fine Aggregate Replacement with Fly Ash by Minimum Voids Method and Maximum Density Methods, KSCE Journal of Civil Engineering, Vol. 14-Number 5, pp- 759-764 [4] Neville, A. M. (2009), Properties of concrete, Fourth Impression, Pearson Education. [5] Namagg, C. and Atadero, R. A. (2009), Optimization of fly ash in Concrete: High Lime Fly Ash as a Replacement for Cement and Filler Material Proceedings of World of Coal Ash Conference, 4-7 May, Lexington, USA, pp 1-6. [6] Malhotra, V. M. and Ramezanpour, A. A. (1994) Fly Ash in Concrete Second Edition, Natural Resources, Canada. [7] Subramaniam, K. V., Gromotka, R., Shah, S. P., Obla, K. and Hill, R. (2005) Influence of Ultrafine Fly Ash on the Early Age Response and the Shrinkage Cracking Potential of Concrete, Journal of Materials in Civil Engineering, Jan-Feb 2005, pp-45-53. [8] Rao, M V S, (2004), Self Compacting High-Performance Concrete, the Master Builder, Vol. 6, No.4 pp-84-90. [9] Siddique, R. (2004), Performance Characteristics of High-Volume Class F Fly Ash Concrete, Cement and Concrete Research, Vol. 34, pp 487- 493. [10] Poon, C S, Lam, L. and Wong, Y. L. (1999) Effect of Fly Ash and Silica Fume on Interfacial Porosity of Concrete, Journal of Materials in Civil Engineering, pg-197 -205).

Copyright

Copyright © 2025 Mr. N. V. Avhad, Miss. S. D. Deshmukh, Miss. S. N. Gaikwad, Mr. T. A. Tribhuvan, Mr. S. A. Rajput. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.