Property Assessment of Self-compacting Basalt Fiber Reinforced Concrete

Abstract

AbstractThe aim of the research was to determine the suitability of chopped basalt fibers to reduce the brittleness of high performance concrete (HPC) while maintaining the requirements for self-compacting concrete (SCC). The study investigated the influence of the basalt fiber volume content on the fresh properties of self-compacting concrete and the mechanical properties of basalt fiber reinforced high performance concrete. Basalt fibers were added at the ratios of 0, 0.025, 0.05, 0.075, 0.125, and 0.25% by volume to the concrete mixtures in which 46% of the cement was replaced by ground granulated blast furnace slag (GGBS). The water to binder ratio (w/b) in the SCC mixtures was kept constant at 0.32. The influence of fiber volume content on the fresh properties of SCC, including filling ability (slump diameter, flow time) and passing ability (L-box) of the mixtures as well as mechanical properties such as the compressive strength, tensile splitting strength, flexural strength, and toughness indexes were analyzed after the moist curing of concrete at 7 and 28 days. The toughness, as the one of an important parameter for fiber reinforced concrete, was determined in accordance with ASTM C 1609. None of the basalt fiber reinforced concrete beam specimens reached the intended deflection of span/150. The load-displacement curves showed a rapid decrease in load after peak load, and the beam specimens reinforced with chopped basalt fibers showed their little potential for producing ductile HPC. Nevertheless, the higher content of basalt fibers improved the strength, and toughness of the SCC up to 0.25 vol.% fibers, and therefore the use of these fibers improved the overall SCC performance. The mechanical properties of the sustainable SCC mixtures containing the high content of GGBS as a cement substitute and a low content of basalt fibers falls within ranges suitable for structural engineering applications.KeywordsSelf-compacting concreteBasalt fiberFresh propertiesStrengthToughness