An Experimental Study on the Effectiveness of Chopped Basalt Fiber on the Fresh and Hardened Properties of High Strength Concrete

Abstract

This research aimed to investigate the suitability of chopped basalt fibers for inducing ductility in High Strength Concrete (HSC). HSC offers a sustainable option to the rapidly growing construction industry particularly in long span bridges, high-rise structures together with other infrastructures. Until near past, efforts were made to achieve much higher compressive strength of HSC, which causes HSC being more brittle. In view of high brittleness of HSC many researchers focused on fiber reinforced concrete to induce ductility. In this study two series of mixes, one with 100% cement and the other with 80% cement with 20% fly ash were studied. In the both of series mixes, fiber content was varied as 0, 0.25, 0.75, 1, 2 and 3%, respectively. Concrete with 0% fibers is known as the control mix. Since, water/binder ratio and super-plasticizer content was kept constant. The tests result indicated that, slump of concrete mixes showed decline with the increment in the fiber content. The addition of chopped basalt fibers did not help to improve the compressive strength of HSC. However, fibers have improved tensile and flexural tensile strength of HSC, also the area under the stress strain curves increased, which are an indication of ductile mode of HSC as well as its toughness. Similarly, tensile to compressive strength and flexural to compressive strength ratio observed a continuous increment with the increase in fiber content as well as the areas under compressive stress- strain curves. In conclusion, chopped basalt fibers have shown their potential for producing ductile HSC.