The engineering performance of concrete containing high volume of ground granulated blast furnace slag and pulverized fly ash with polycarboxylate-based superplasticizer

This experimental investigation was conducted to study the development of ternary blended concrete that containing high cement replacement level of ground granulated blast furnace slag (GGBS) and pulverised fly ash (PFA) with the polycarboxylate-based superplasticizer (PCE). In order to make this GGBS-PFA ternary blended cement system at high cement replacement level suitable for practical production, measures need to be developed to enable acceptable early strength development for concrete produced using the materials to be achieved. An optimum combination ratio of GGBS and PFA in ternary blended cement system was prior determined in this study for consistent production control. Besides, an optimum dosage of M-PEG type PCE was determined by using marsh funnel test as well for the compatible use in this GGBS-PFA ternary blended cement system. Experimental results indicated that the optimum ratio for GGBS and PFA was 4:1 at 50% cement replacement level by total binder's weight while the optimum dosage of PCE was 1.0% by total binder's weight in this ternary blended cement system. Mechanical properties such as flexural and compressive strengths and UPV were then examined on hardened concretes at 7, 28, 56 and 90 days. In addition, Scanning Electron Microscopy (SEM) techniques combined with Energy Dispersive X-ray (EDX) had been performed for better understanding the phase changes and microstructures development of maturing GGBS-PFA ternary blended cement system. In this study, the GGBS-PFA ternary blended concrete with 60% cement replacement achieved the optimum performance with the inclusion of 1.0% of PCE superplasticizer by total binder's weight. (C) 2019 Elsevier Ltd. All rights reserved.