Mechanical and thermal properties of prepacked aggregate concrete incorporating palm oil fuel ash

Prepacked aggregate concrete (PAC) is a special type of concrete which is made by placing coarse aggregate in a formwork and injecting a grout either by pump or under the gravity force to fill the voids. Use of pozzolanic materials in conventional concrete has become increasingly extensive, and this trend is expected to continue in PAC as well. Palm oil fuel ash (POFA) is one of these pozzolanic ash, which has been recognized as a good pozzolanic material. This paper presents the experimental results of the performance behaviour of POFA in developing physical and mechanical properties of prepacked aggregate concrete. Four concrete mixes namely, prepacked concrete with 100% OPC as a control, and PAC with 10, 20 and 30% POFA were cast, and the temperature growth due to heat of hydration and heat transfer in all the mixtures was recorded. It has been found that POFA significantly reduces the temperature rise in prepacked aggregate concrete and delay the transfer of heat to the concrete body. The compressive and tensile strengths, however, increased with replacement up to 20% POFA. The results obtained and the observation made in this study suggest that the replacement of OPC by POFA is beneficial, particularly for prepacked mass concrete where thermal cracking due to extreme heat rise is of great concern.