Influence of steel fibres on tension stiffening and cracking of reinforced geopolymer concrete

An experimental investigation was conducted to study the influence of steel fibres on the tension stiffening effect and cracking behaviour of geopolymer concrete (GPC). A total of ten concentrically reinforced concrete prisms (60 x 60 x 600 mm) were cast and tested under uniaxial tension. Out of these, two were made of GPC and the remainder were of steel-fibre-reinforced GPC. The grade of concrete was M40. Different volume fractions of 0.25% (16.62 kg/m(3)), 0.50% (39.25 kg/m(3)), 0.75% (58.87 kg/m(3)) and 1% (78.50 kg/m(3)) of crimped steel fibres of aspect ratio 66 were used. The test results indicate that the incorporation of steel fibres improves the tension stiffening effect and reduces the spacing and width of cracks. A method was also proposed to predict the width of cracks.