DefinePK

Abstract

In order to address environmental effects associated with Portland cement, there is need to use other binders to make concrete. An effort in this regard is the development of geopolymer concrete, synthesized from the materials of geological origin or by product materials such as fly ash, which are rich in silicon and aluminum. This paper presents results of an experimental study on the strength and absorption characteristics of geopolymer concrete. The experiments were conducted on fly ash based geopolymer concrete by varying the concentration of NaOH and curing time. Total nine mixes were prepared with NaOH concentration as 8M, 12M, 16M and curing time as 24hrs, 48hrs, and 72hrs. Compressive strength, water absorption and tensile strength tests were conducted on each of the nine mixes. Results of the investigation indicated that there was an increase in compressive strength with increase in NaOH concentration. Strength was also increased with increase in curing time, although the increase in compressive strength after 48hrs curing time was not significant. Compressive strength up to 46 MPa was obtained with curing at 60oC. The results of water absorption test indicated that % water absorption of cubes decreased with increase in NaOH concentration and curing time. Hence, geopolymar concrete has a great potential for utilization in construction industry as it is environmental friendly and also facilitates the use of fly ash, which is a waste product from coal burning industries.