The effect of Palm Oil Fuel Ash (POFA) and steel fiber addition to the mechanical properties of Ultra High Performance Concrete (UHPC)

Over a period of time, Ultra High Performance Concrete (UHPC) has been innovated more and more. Since it has high performance and durability, thus it is deemed to be expensive due to the material used in the recipe. High cement content due to low water cement ratio and high production cost are a few of UHPC disadvantages. Therefore, a new innovation and alternative to this solution is needed. Incorporating waste material such as Palm Oil Fuel Ash (POFA) in UHPC could be the new innovation, since POFA is abundantly available. Other than that, POFA is proven to improve conventional concrete performance, hence it could also be used to enhance UHPC. Therefore, this paper emphasizes the effect of POFA and steel fiber inclusion to the mechanical properties of UHPC using modified cube method and four-point bending test. Non Destructive Testing (NDT) using Ultrasonic Pulse Velocity (UPV) method was also conducted. The POFA percentages used were 5, 10, and 15% whereas, steel fiber percentage was only 1% by weight of OPC cement. The Test specimen dimension used was 500 mm ╳ 100 mm ╳ 100 mm. The testing in this study was done at a concrete age of 28 days by following the standard of the American Society of Testing and Material (ASTM). Based on the result, the addition of 15% POFA gave the highest flexural strength, while 5% POFA plus 1% steel fiber gave the highest compressive strength. UPV highest value result was obtained from 15% POFA. It is recommended that the optimum addition level of POFA is 15% for good results of both flexural and compressive strength