Mechanical Properties of Fibre-Reinforced High Strength Concrete

摘要

The increased use of high strength concrete in structural applications dictates thernneed to enhance its brittle behaviour under compressive and tensile loads. Anrnexperimental programme has been conducted to investigate the effects ofrnintroducing polypropylene fibres into higher strength concrete applications.rnDifferent fibre volume fractions were used in the study. Three types of concreterngrades were cast. Uni-axial compressive and splitting cylinder tests were conducted.rnLongitudinal, transverse and volumetric strains were monitored and reported atrndifferent stress levels during testing. Material properties including peak compressivernstresses for both cylinders and cubes, splitting cylinder tensile strengths, elasticrnmoduli and Poisson’s ratios were determined.rnThe study revealed that polypropylene fibres significantly enhanced the tensilernproperties of higher strength concretes, increased the ductility under compressivernloads, reduced transverse deformations however reduced the peak attainable strengthrnunder compressive loads. A model for calculating the tensile strength of concrete asrna function of both the concrete grade and the fibre volume fraction has beenrndeveloped. The model shows excellent agreement with the experimental results.