Application of non-corrosive barchip fibres for high strength concrete enhancements in aggressive environments

The trouble of sea water attacks in marine structures has suffered the engineers for decades. Until present, the most popular approach used to minimize the detrimental effects resulted by the sea water is the applications of high strength high performance concrete. The binary or ternary blended cement system is applied to improve the impermeability properties of the resulting concrete. Nonetheless, the sulphate attacks and the expansions and shrinkages caused by the environments would induce cracks at the structures. Once the cracks are initiated, it allows the penetration of harmful substances and ultimately reduces the durability of the structure in a substantial manner. In this experiment, a mechanical approach is employed to improvise the concrete in the aspects of strength and durability properties. The barchip fibre that is non-corrosive, short and discrete is introduced into high strength concrete so as to provide localize reinforcing effects to restrain the cracks development in the matrix. The specimens were exposed to three types of aggressive environments; namely tropical climate (A-series), alternate air and sea water in a 14-day cycle (4 days in sea water + 10 days in air) (N-series) and continuous immersion in the sea water (W-series). Parameters like the compressive strength, permeability, porosity, chloride penetration were examined. The mineralogical and microstructures were studied by the means of X-ray diffraction (XRD) and scanning electron microscope (SEM) examination, respectively. The findings in these studies solidify the justifications provided in the discussions. The results verify that 1.8% would be the optimum dosage of barchip fibre that could provide greatest enhancements to the concrete. When the exposure period is prolonged, the increments in the compressive strength were above 12% and the permeability was also reduced. Together with other improvements, it could be concluded that the incorporation of barchip fibre has successfully suppressed the damaging effects that arise from the aggressive environments.