Investigating the Strength of Hybrid Fiber Reinforced Concrete through Experimental Analysis

Abstract

Cementitious materials are among the most commonly used and essential
substances in the construction industry. While these materials are initially incorporated into
well-established systems and fundamental designs during the construction process, their
inherent fragility and susceptibility to cracking under stress necessitate ongoing maintenance or
even replacement within a relatively short lifespan. To address this issue, there is a growing
need for new concrete-based materials with improved durability characteristics, particularly in
terms of crack resistance. Traditional concrete, being a brittle material, has been largely
replaced by fiber-reinforced concrete due to its enhanced properties. While using a single type
of fiber can have beneficial effects on the mechanical properties of concrete, hybridization
offers the opportunity to combine different fiber types to leverage their respective advantages.
In this study, the influence of incorporating both glass fiber and polypropylene fiber into
concrete mixes is examined to evaluate the mechanical properties of the composite material.
Fifteen cubes and fifteen cylinders of glass fiber-reinforced concrete (GFRC) at varying
proportions (0.2%, 0.4%, 0.6%, 0.8%, 1.0%, 1.2% by volume of M30 grade concrete) were cast
and tested for optimal compressive and tensile strength at 28 days. Additionally, threedimensional
specimens with different proportions of polypropylene fiber were cast, while
maintaining the glass fiber content constant, to identify the ideal combination for enhancing
mechanical strength. The results indicate that the hybrid fiber-reinforced concrete (HFRC),
comprising 1% glass fiber and 0.6% polypropylene fiber, exhibits improved compressive,
tensile, flexural, and shear properties compared to conventional concrete.