Incorporation of Eco Process Pozzolan (EPP) as Partial Cement Replacement and Superplasticisers in Concrete

Abstract

Eco Process Pozzolan (ePP) is obtained from the calcination of Spent Bleaching Earth (SBE) originating from the by-product of manufacture of edible oils. Studies have shown that ePP has cementitious properties and can be utilised as partial cement replacement in concrete. The limitations of ePP as partial cement replacement includes a decrease in concrete consistence, or workability. Superplasticisers are becoming commonly used in concreting works for increasing concrete workability; however, due to its chemical nature, may lead to possible side-reactions, especially when used with a new alternative material. This study focuses on the use of superplasticisers in concrete incorporated with ePP as partial cement replacement, and the resulting properties of the concrete. Concrete mixes include mixes using 100% ordinary Portland cement (i.e. 0% ePP), and mixes with ePP at 20% replacement level (i.e. 80% OPC), at 0.3 and 0.5 water to cement ratios. Three different types of superplasticisers were used, at various dosages in which one of them (polyethene-based) produces the best result. Slump tests and compressive strength tests were done at concrete ages of 7, 28, 56 and 91 days. The results show that utilisation of superplasticisers improved concrete workability and strength, regardless of the type of superplasticiser used, leading to easier compaction. The compressive strengths at long-term ages continually increases and were almost comparable to concrete using 100% OPC.