Open AccessSynthesis and characterization of fly ash and slag based geopolymer concrete
Author(s) -
B Kallesten,
Samdar Kakay,
Kidane Fanta Gebremariam
Publication year - 2019
Publication title -
iop conference series. materials science and engineering
Language(s) - English
Resource type - Journals
eISSN - 1757-899X
pISSN - 1757-8981
DOI - 10.1088/1757-899x/700/1/012032
Subject(s) - geopolymer , compressive strength , materials science , curing (chemistry) , fly ash , flexural strength , ultimate tensile strength , portland cement , composite material , potassium hydroxide , geopolymer cement , cement , microstructure , chemistry , organic chemistry
This paper presents the formulation and characterization of composite fly ash and slag based geopolymer concrete. Potassium hydroxide (KOH) and potassium silicate (K 2 SiO 3 ) liquid alkaline activators were used in the preparation of the geopolymer concrete. The mechanical response of the best recipe was investigated through compressive, tensile and flexural strength tests after 3, 7 and 28 days of curing. One batch was tested for compressive strength after 16 and 32 weeks of curing. The microstructure of the concretes was characterized using scanning electron microscopy (SEM). The testing results are compared with a reference ordinary portland cement-based concrete. After 28 days of curing, test results showed that the geopolymer concretes can approach the compressive strength of the reference ordinary concrete. Moreover, the tensile strength and flexural strength attained reached up to 68% and 80% of the reference cement, respectively. The results indicated the potential application of geopolymer that can satisfy the standard strength requirement. After longer time of curing, 32 weeks, some of the geopolymer preparations exhibited 111% compressive strength, compared to the ordinary cement reference.