"Characterization of Calcined Clay Blended Self Compacting Concrete-Correlation between Superplasticizer dosage and Self-Compacting Concrete Properties"

Abstract

Sustainability in the construction industry is essential to economic development and can be achieved by the use of locally available construction materials. This research work, thus, uses locally available materials -calcined clay and Sandcrete SPR-300 superplasticizer in the production of Self Compacting Concrete (SCC) by investigating the correlation between the superplasticizer dosage and the fresh and hardened states properties of a grade 30 SCC made by incorporating a Calcined Clay (CC) -Portland Limestone Cement (PLC) blend as the cementitious material at 15% replacement of PLC with CC and using CC as filler. The superplasticizer dosage was varied from 0.0 to 3.0% by weight of cementitious material and the fresh state properties -measured using slump flow tests, v-funnel time test and L-box testas well as strength parameters investigated. The result shows a positive correlation between the increased dosage of the superplasticizer and the fresh and hardened states properties of the SCC up to 2% dosage of the SCC. The JSpread, t500J, Slump flow, L-box H2/H1 ratio and strength, all increases with SP dosage while the V-funnel flow decreased with SP dosage. Overall, SP ratio of 1.5 and 2.0% by mass of cementitious material can be used in improving the properties of SCC produced using calcined clay both as filler and SCM. However, because of the volume of clay used and the nature thereof, the target strength could not be reached. It is therefore recommended that SP dosage of Sandcrete SPR-300 of between 1.5 and 2.0% be used with calcined clay as SCM but different filler, like limestone powder, be used. .