IMPACT TEST ON GEOPOLYMER CONCRETE SLABS

Abstract

Geopolymer is an eco-friendly binding material alternative for Ordinary Portland Cement (OPC). Geopolymer concrete is produced by mixing fly ash, GGBS, alkaline solution, fine aggregate and coarse aggregate. Alkaline solution is composed of NaOH and Na2SiO3 solution. This paper deals with the study of impact resistance capacity of geopolymer concrete slabs subjected to impact loading. For this study, ten specimens of size 600 mm (length) × 600 mm (width) × 60 mm (thick) were casted with nine different combination of geopolymer concrete mix using different molar sodium hydroxide solutions and different percentages of mineral admixtures and a normal concrete slab as control slab. The molarity of NaOH solution used was 8M, 12M and 16M. Fly ash and GGBS admixtures were used in three different ratios of 100:0, 75:25 and 50:50.The slabs were oven cured at 60 0 C for 24 hours. These slabs were subjected to impact loading by drop weight test method. All the slabs were tested under a drop weight of 75.50 N through a guide pipe from a height of 700mm. The results obtained from this study showed that with the increase in molarity of NaOH solution, the strength characteristics and the impact resistance capacity of the specimen increases. Also increase in percentage of GGBS content as replacement for Fly ash content increases the impact resistance and overall strength characteristics of geopolymer concrete. From the test results, geopolymer concrete slab with 16M NaOH solution using 50:50 Fly ash and GGBS content showed higher impact energy absorption capacity as compared other geopolymer mixes.