Engineering properties such as compressive strength, splitting tensile strength, modulus of rupture, modulus of elasticity and Poisson"s ratio of geopolymer concrete (GPC) and steel fibre reinforced geopolymer concrete (SFRGPC) have been obtained from standard tests and compared. A total of 15 specimens were tested for determining each property. The grade of concrete used was M 40. The percentages of steel fibres considered include 0.25%, 0.5%, 0.75% and 1%. In general, the addition of fibres improved the mechanical properties of both GPC and SFRGPC. However the increase was found to be nominal in the case of compressive strength (8.51%), significant in the case of splitting tensile strength (61.63%), modulus of rupture (24%), modulus of elasticity (64.92%) and Poisson"s ratio (50%) at 1% volume fraction of fibres. An attempt was made to obtain the relation between the various engineering properties with the percentage of fibres added.

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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 3 60 3 600 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.

An experimental investigation was carried out to study the influence of steel fibres on the bond strength of geopolymer concrete (GPC). Pull-out tests under monotonic loading were carried out. A total of 30 concentrically reinforced concrete cubes were cast and tested. Of these, six were made of GPC and the remainder were made from steel fibre reinforced geopolymer concrete (SFRGPC). High yield strength deformed bars of 10 mm, 12 mm and 16 mm diameter were used as reinforcement, the grade of concrete was M40 and different volume fractions (0·25% (16·62 kg/m3), 0·50% (39·25 kg/m3), 0·75% (58·87 kg/m3) and 1% (78·50 kg/m3)) of crimped steel fibres were used. The test results indicate that the addition of steel fibres to GPC significantly enhances the bond strength.

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