Effects of curing temperature and superplasticizer on workability and compressive strength of self-compacting geopolymer concrete

This experimental work focuses on the effects of super plasticizer and curing temperature on the workability and compressive strength of self-compacting geopolymer concrete (SCGC). SCGC is an improved way of concreting execution that does not require compaction and is made by complete elimination of ordinary portland cement content. The parameters investigated were superplasticizer (SP) dosage and curing temperature. SCGC were synthesized from low calcium fly ash, activated by combinations of sodium hydroxide and sodium silicate solutions, and by incorporation of superplasticizer for self compactability. The SP dosages were 3%, 4%, 5%, 6% and 7% and the different curing temperatures were 60°C, 70°C, 80°C and 90°C. The effects of SP dosage on workability properties such as filling ability, passing ability and resistance to segregation were evaluated. The fresh properties were measured using slump flow, T-50 V-funnel, L-Box and J-ring test methods. The essential workability requirements for self compactability according to European Federation of National Associations Representing Producers and Applicators of Specialist Building Products for Concrete (EFNARC) were satisfied. Results showed that the workability and compressive strength improved with the increase in Super plasticizer dosage. An increase in strength was observed with the increase in curing temperature up to 70°C. However, the strength decreased when the curing temperature increased beyond 70°C. The compressive strength of 51.52MPa was obtained for SCGC with SP dosage of 6% and cured at 70°C oven temperature.