Effect of processed pozzolans on residual mechanical properties and macrostructure of high‐strength concrete at elevated temperatures

Abstract

Recently, use of processed pozzolans such as rice husk ash (RHA) and bagasse ash (BA) have been identified as promising mineral admixtures to produce HSC. As fire is considered one of the severe hazards to which a structure may be exposed, there is a requirement to evaluate the performance of HSC containing pozzolanic admixtures, namely, RHA and BA at elevated temperatures. In this study, the residual mechanical properties comprising, compressive and splitting tensile strength, compressive stress-strain response, and static elastic modulus of HSC mixtures made with 10% RHA, 10% BA as cement replacement are presented. The properties were investigated at different temperatures up to 800 C, at a slow heating rate of 3 C/min. Results reveal that the residual mechanical properties of pozzolanic concretes deteriorate at elevated temperatures with significant loss above 200 C. Visual observations of the physical deterioration reveal that the cracking in specimens mostly initiates during the cooling phase and develops extensively in all concrete types at exposure temperature of above 400 C. K E Y W O R D S amorphous silica, high temperature, macrostructure, mechanical properties, mineral admixtures, pozzolanic activity

The effects of synthetic wollastonite developed with calcite and quartz on high performance mortars

“…In addition, while increasing demand on HPC is necessary and associated with construction industry growth and rapid global development, cement is the principal and most expensive component of HPC 11 . Therefore, environmental and economic factors played an important role in the utilization of pozzolanic minerals such as blast furnace slag, silica fume, and fly ash as well as better performance in terms of strength and durability by improving microstructure of concrete 12–17 . Not only supplementary cementitious minerals (pozzolanic minerals) but also inert minerals can provide better filling effect for cement paste, mortar and concrete, 18 and also these minerals.…”

Effect of Elevated Temperature on Compressive Strength and Physical Properties of Neem Seed Husk Ash Concrete

“…Hence, the issues of materials sustainability and environmental pollution accelerated by the concrete industry need to be addressed. Many researchers of our century have been looking for eco-friendly materials that can partially or totally replace cement in the mix with the aim of handling the raised concern on depletion of raw materials, atmospheric pollution, global warming and waste disposal [4]. However, such replacement should result in improved concrete properties in terms of strength and durability.…”

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