Fracture and tensile characteristics of engineered cernentitious composites containing POFA

摘要

The fracture and tensile characteristics of engineered cementitious composites (ECCs) containing palm oil fuel ash (POFA) have been investigated. POFA obtained from a palm oil mill was treated first by grinding and then by heat treatment. The treated POFA was then utilised to produce ECCs in combination with polyvinyl alcohol fibres with proportions of POFA ranging from 0 to 1.2 from the mass of cement. The performance of the POFA-ECCs was evaluated by means of matrix fracture and direct tensile tests. The experimental results indicate that the ECC mix containing POFA exhibits lower fracture toughness and fracture energy values than a mix without POFA. Nonetheless, the addition of POFA contributes to a greater pseudo-strain hardening index, in particular at higher POFA content. This reveals that the use of POFA should be helpful for achieving strain hardening behaviour. In addition, an increase in POFA content increases the tensile strain capacity of the ECC. Furthermore, the crack width of the ECC decreases significantly with an increase of POFA content. Thus, the overall findings exhibit that the POFA used brings about promising positive effects on the fracture and tensile characteristics of ECCs.