Flexural performance of green engineered cementitious composites containing high volume of palm oil fuel ash

The flexural performance of green engineered cementitious composites (ECCs) containing high volume of palm oil fuel ash (POFA) has been investigated. Three sets of ECC mixtures with water–binder ratios of 0.33, 0.36, and 0.38 were prepared, and for each set, the ECC mixtures were proportioned to have varying POFA contents of 0, 0.4, 0.8, and 1.2 from the mass of cement. The flexural performance was assessed after 3, 28, and 90 days of curing using the four-point bending test. The results suggest that there is a corresponding reduction in the first cracking strength and flexural strength of the ECC beams with the increase of water–binder ratios and POFA content. Nonetheless, higher water–binder ratio and higher POFA content was found to concomitantly improve the flexural deflection capacity, which indicates a superior deflection hardening behaviour. Furthermore, number of cracks was increased and crack width of the ECC was significantly reduced with an increase of POFA content. In addition, there are good correlations between flexural deflection capacity from the four-point bending test and tensile strain capacity from the uniaxial tensile test.

► POFA exhibits very promising potential as a supplementary binder for ECC.
► The POFA–ECCs show acceptable first cracking strength and modulus of rupture.
► The POFA–ECCs exhibits higher flexural deflection capacity.
► Higher POFA content reduces the crack width and facilitates the formation of multiple fine cracks in the POFA–ECCs.