GEOPOLYMER CONCRETE AN ECO-FRIENDLY ALTERNATIVE TO PORTLAND CEMENT PAVING GRADE CONCRETE

The geopolymer cement is formed by polymerization process which involves the reaction between an aluminosilicate source material such as fly-ash, GGBS, etc. with an alkaline activator solutions. The process results in the creation of a network of a tetrahedral chain of SiO4 and AlO4 to shared oxygen atoms alternatively [2]. Hardening of GC takes place through polycondensation of potassium oligo (sialate-siloxo) into potassium poly (sialate-siloxo) cross-linked network [1]. The GC, so formed binds the aggregates and inert materials to form a matrix called geopolymer concrete (GPC). Present days, lots of researchesare being carried out on the utilisation of industrial by-product such as fly-ash, GGBS, silica fumes, metakaolin as an aluminosilicate precursor material for geopolymers[3]. The alkaline liquids used in the production of GC mainly are of soluble alkali metals that are usually sodium or potassium based. The most commonly used alkaline liquid is the combination of Sodium Hydroxide (NaOH) and Sodium Silicate (Na2SiO3) or Potassium Hydroxide (KOH) and Potassium Silicate (K2SiO3) [4].