2019 CSCE Annual Conference - Laval (Greater Montreal) Conference
Self-consolidating concrete (SCC) requires excellent filling ability and passing ability as well as adequate segregation resistance for successful applications. However, achieving the required segregation resistance for SCC is a challenging task. This study presents the segregation resistance of SCC incorporating palm oil fuel ash (POFA), which is an agro-waste generated in palm oil industry. Twenty SCC mixtures were produced based on the water to binder (W/B) ratios of 0.25-0.40 and incorporating POFA in the range of 0-30% by weight of cement. Sufficient dosage of high-range water reducer (HRWR) was used to achieve the required self-consolidation capacity for the concrete mixtures. The segregation resistance of the SCC mixtures was examined by sieve and column segregation tests. The segregation indices and segregation factors of the SCC mixtures were obtained from sieve and column segregation tests, respectively. In both tests, the effects of W/B ratio and POFA on the segregation resistance of SCC were observed. Test results revealed that the segregation index varied in the range of 9–18.9%. The lowest value of segregation index was obtained for the SCC produced with the W/B ratio of 0.40 and a POFA content of 0% and the highest value was achieved for the SCC prepared with the W/B ratio of 0.25 and a POFA content of 30%. On the other hand, the segregation factor varied in the range of 8–21.8%. The lowest segregation factor was found for the SCC mixture produced with the W/B ratio of 0.35 and 0% POFA content whereas the highest value was achieved for the SCC mixture made with the W/B ratio of 0.25 and 30% POFA content. Higher segregation index and segregation factor indicate a lower segregation resistance for SCC. The recommended maximum limit for segregation index is 18% and the acceptable maximum segregation factor is 20%. The overall test results showed that both W/B ratio and POFA content significantly affect the segregation resistance of SCC depending on the dosage of HRWR used in concrete mixture. However, all concretes passed the requirements of segregation resistance, except for the concrete mixture produced with the W/B ratio of 0.25 and 30% POFA content. On the whole, the research findings suggest that SCC can be produced successfully using POFA as a partial replacement of cement.