An Investigation of Mechanical Properties of Fly Ash Based Geopolymer and Glass Fibers Concrete

This paper presents an innovative approach towards the development of a green concrete. The geopolymer is an environmentally friendly construction/repairing material. In addition, glass fibers are helpful to influence the strength properties and to reduce hair line cracks and bleeding in concrete. This study is based on the use of fly ash and glass fibers as a partial replacement of cement and, subsequently, its effect on compressive strength and split tensile strength of concrete. The geopolymer is manufactured after the process of geopolymerization between class F fly ash and alkali activator fluid (sodium silicate and sodium hydroxide). In geopolymer concretes (GPC), an inorganic polymer called aluminosilicate will act as a binder, the same as conventional concrete has Portland cement (OPC)-generated C-S-H gel. The glass fibers are added in the ratios of 3%, 6%, and 10% by weight of cement. To check the effect of geopolymer and glass fibers on compressive strength and split tensile strength of concrete, concrete cubes of size 150 × 150 × 150 mm and concrete cylinders of size 150 × 300 mm with or without geopolymer and glass fibers were casted and cured for 7, 14, 21, and 28 days. The compressive strength and split tensile strength of all concrete cubes and cylinders were determined by compression testing machine. The findings of the research study revealed that concrete having geopolymer and glass fibers used as a partial replacement of cement showed lesser strength as compared to conventional concrete. Concrete having glass fibers showed reduced workability and more segregation as compared to geopolymer concrete and normal concrete. However, the concrete made either with geopolymer or glass fibers is economical as compared to conventional concrete