Recycling of date kernel powder (DKP) in mass concrete for mitigating heat generation and risk of cracking at an early age
Muneer K. Saeed, Muhammad Kalimur Rahman, Mohammed Alfawzan, M. Shameer Basha, Hany A. Dahish
Abstract
Mass concrete in many structural and non-structural applications is prone to early age cracking and chemo-damage from the exothermic hydration reactions of the cement binder. Date kernels are a waste product generated in large quantities in the date processing industry in the Middle East, North Africa and other countries worldwide. The use of calcined date kernel powder (DKP) as a mineral admixture in concrete to reduce the heat of hydration and temperature rise in mass concrete is a novel idea for which no prior research has been condcuted. A combined experimental and numerical investigation was conducted to assess the performance of DKP as a heat-reducing material in mass concrete. Concrete mixes with 10%, 20% and 30% DKP replacing cement and similar mixes with fly ash (FA) were investigated for evolution of mechanical and thermal properties and the adiabatic heat of hydration. 3D finite element models of mass concrete blocks 2mx2mx2m in size were validated using the data obtained from similar blocks in field instrumented with thermocouples. The 3D FE model was subsequently used to predict the heat of hydration, temperature rise and cracking index of a mass concrete block with 30% DKP powder. Experimental results showed a significant reduction in the heat of hydration in DKP concrete, with levels comparable to the FA concrete without a significant impact of strength properties. The DKP waste material has a strong potential for reducing heat of hydration in mass concrete structures, thereby promoting waste utilization, recycling and sustainability.