Strength development and thermal conductivity of POFA lightweight geopolymer concrete incorporating FA and PC

摘要

In this study, the compressive strength, water absorption, and thermal conductivity of palm oil fuel ash (POFA) lightweight geopolymer concrete (LWGC) incorporating high-calcium fly ash (FA) and Portland cement (PC) are reported. The POFA was replaced by FA or PC at the dosages of 60% by weight of binder. The wet density of POFA-based LWGC incorporating FA and PC was designed at 1000 kg/m3, based on ASTM C796. Test results found that the incorporation of FA and PC in POFA-based LWGC could significantly improve the strength development of LWGC. The reactive Ca ions could react with SiO2 from POFA, leading to the additional formation of reaction products within the LWGC. The thermal conductivity of LWGC showed an excellent option for reducing the temperature change in the wall section during a day. It was positive effects on the building's electricity cost. A combination of POFA-based LWGC with PC met the 28-day strength and water absorption requirements as per TIS.2601-2556. Therefore, POFA-based LWGC incorporated with PC can be used as the non-load-bearing brick masonry units.