Influence of Palm Oil Fuel Ash and W/B Ratios on Compressive Strength, Water Permeability, and Chloride Resistance of Concrete

Wachilakorn Sanawung,Weerachart Tangchirapat,Chai Jaturapitakkul,Tieng Cheewaket

doi:10.1155/2017/4927640

Abstract

This research studies the effects of W/B ratios and palm oil fuel ash (POFA) on compressive strength, water permeability, and chloride resistance of concrete. POFA was ground until the particles retained on sieve number 325 were less than 5% by weight. POFA was used to partially replace OPC at rates of 15, 25, and 35% by weight of binder. The water to binder (W/B) ratios of concrete were 0.40 and 0.50. The compressive strength, water permeability, and chloride resistance of concrete were investigated up to 90 days. The results showed that POFA concrete with W/B ratio of 0.40 had the compressive strengths ranging from 45.8 to 55.9 MPa or 82–94% of OPC concrete at 90 days, while POFA concrete with W/B ratio of 0.50 had the compressive strengths of 33.9–41.9 MPa or 81–94% of OPC concrete. Furthermore, the compressive strength of concrete incorporation of ground POFA at 15% was the same as OPC concrete. The water permeability coefficient and the chloride ion penetration of POFA concrete were lower than OPC concrete when both types of concrete had the same compressive strengths. The findings also indicated that water permeability and chloride ion penetration of POFA concrete were significantly reduced compared to OPC concrete.

Highlights

Palm oil fuel ash (POFA) is a by-product from biomass power plants, in which palm oil residues such as fibers, shells, and empty fruit bunches are burned to generate electricity
The results suggested that the replacement with ground POFA at 35% in 50P35 yielded a compressive strength of 33.9 MPa compared with that of 40P15 concrete, which was 52.8 MPa, but both types of concrete had almost the same total passed charges
The following can be concluded: (1) The effects of water to binder (W/B) ratios on the compressive strengths of the POFA concrete were similar to those of conventional concrete; that is, the compressive strength of POFA concrete increased as the W/B ratio was decreased

Summary

Introduction

Palm oil fuel ash (POFA) is a by-product from biomass power plants, in which palm oil residues such as fibers, shells, and empty fruit bunches are burned to generate electricity. Approximately 312,500 tons of POFA were obtained or approximately 5% by weight of palm oil residue [1]. The main chemical composition of palm oil fuel ash is silicon dioxide (SiO2), and previous studies have shown that POFA in its original size is not suitable as a good pozzolan due to its large particle and high porosity [1]. The POFA should be ground to higher fineness before it is used to partially replace OPC in concrete [2,3,4]. Few studies have jointly considered the three main properties for durability in concrete, that is, compressive strength, water permeability, and chloride ion penetration. The results obtained from this study would be beneficial to understand the POFA concrete’s properties and to apply POFA concrete in the future

Experimental Programs

Results and Discussion

Conclusions