Effect of Polypropylene Fiber on the Strength Properties of Geopolymer Concrete Activated with Water Glass

Abstract

Cement, which is a significant constituent in concrete, plays a crucial role in the construction industry. The manufacturing process of cement releases substantial amounts of CO2, thereby contributing to environmental concerns. To address this issue, geopolymers have emerged as promising alternative substitutes to ordinary Portland cement. However, one of the challenges in utilizing geopolymer binders is the need for activators to initiate the polymerization process. Sodium silicate and sodium hydroxide solution are commonly used activators, but ground granulated blast-furnace slag (GGBS) reacts quickly with these activators and reduces the setting time. In order to arrest quick settings and enhance the efficiency of concrete production, “water glass” is used as an activator. The present study investigates the flexural and split tensile strength of geopolymer concrete by optimizing the dosage of polypropylene fibers for different mix proportions of GPC activated with water glass. The optimum dosage of fibers was obtained by the addition of different dosages of polypropylene fibers ranging from 0, 0.2%, 0.4%, 0.6% and 0.8%. The results from the investigation revealed a consistent augmentation in compressive strength with the incremental addition of fibers up to a threshold of 0.6%; beyond this point, the strength exhibited a dimin-ishing trend, while the flexural strength and split tensile strength were enhanced from 25% to 45% with the addition of an optimum dosage of polypropylene fibers. By optimizing the material formulations and mix proportions, it is possible to achieve a superior performance by minimizing the environmental impact on the construction industry.

Keywords

• geopolymer concrete
• water glass
• compressive strength
• polypropylene fiber
• flexural strength