MODELLING FRESH PROPERTIES OF SELF-COMPACTING CONCRETE (SCC) INCORPORATING CASSAVA PEEL ASH (CPA)

Abstract

Self-Compacting Concrete (SCC) is an innovative concrete that flows under its weight, completely filling formwork even in areas of congested reinforcement without the need for vibration to attain adequate compaction. To achieve the SCC, a lower content of aggregates and high content of Portland Cement (PC) are required, which in turn consumes a lot of energy and emits greenhouse gases like carbon dioxide (CO2) and Methane (CH4) to the atmosphere during the PC production. In this study, Cassava Peel Ash (CPA) was used as supplementary cementitious material to partially replace the PC by 5%, 10%, 15%, 20%, and 25%. Response Surface Methodology (RSM) was used to develop a predicting model for the compressive strength of CPA and SCC. This study investigates modeling the workability properties of SCC made with the CPA. The result findings showed that both slump flow and passing ability are affected with the addition of CPA when more than 15% of the cement content is replaced with CPA while the segregation resistance improves as the content of CPA increases. The utilization of CPA in SCC is optimized at 5% replacement of cement with CPA and 28 days of curing age to achieve a compressive strength of grade 35. The developed RSM model showed a high degree of relationship between the variables, responses and can be used to predict the compressive strength of the CPA and SCC accurately.

Keywords

• super-plasticizer
• workability
• slump flow
• blocking ratio
• segregation resistance
• compressive strength