The Influence of Thermo-Mechanical Activation of Bentonite on the Mechanical and Durability Performance of Concrete

Safi Ur Rehman,Malik Muneeb Abid,Muhammad Noman,Muhammad Fahad,Akhtar Gul,Babar Ali,Muhammad Nasir Ayaz Khan,Muhammad Yaqub

doi:10.3390/app9245549

Abstract

Despite presenting a very high global warming toll, Portland cement concrete is the most widely used construction material in the world. The eco-efficiency, economy, and the overall mechanical and durability performances of concrete can be improved by incorporating supplementary cementitious materials (SCMs) as partial substitutions to ordinary Portland cement (OPC). Naturally found bentonite possesses pozzolanic properties and has very low carbon footprint compared to OPC. By applying activation techniques, the reactivity of bentonite can be improved, and its incorporation levels can be maximized. In this study, the influence of mechanical and thermo-mechanical activation of bentonite is investigated on properties of concrete. Bentonite was used for 0%, 10%, 15%, 20%, 25%, 30%, and 35% mass replacements of OPC. Mechanical (compressive strength and split tensile strength) and durability (water absorption, sorptivity coefficient, and acid attack resistance) properties were studied. Results of experimental testing revealed that, concrete containing bentonite showed good mechanical performance, while durability was significantly improved relative to control mix. Application of thermo-mechanical activation can enhance the incorporation levels of bentonite in concrete. At 15% and 25%, bentonite produced optimum results for mechanical and thermo-mechanical activation, respectively. Bentonite inclusion is more beneficial to the durability than the mechanical strength of concrete.

Highlights

In developing countries like Pakistan, the demands for housing and infrastructure development are increasing each day due to rapid urbanization and population growth
This study explored the mechanical and thermo-mechanical activation of bentonite clay to enhance its incorporation level in concrete
The general trend in results indicates that an increasing level of mechanically activated bentonite (MAB) reduces the compressive strength

Summary

Introduction

In developing countries like Pakistan, the demands for housing and infrastructure development are increasing each day due to rapid urbanization and population growth. Being a major construction material, the demand for cement has increased abruptly in the recent past to fulfill the infrastructure. The production of cement exceeded 4.1 billion tons in 2018 alone, which makes it the most used material after water [1]. Global, ordinary Portland cement (OPC) production has always been a big threat to the environment, resources, and economy. Cement manufacturing accounts for more than 5% of worldwide CO2 emissions [2]. The cost of cement has increased almost 150% in the short span of 10 years [3]

Methods

Results

Conclusion