Efficiency of Un-Reinforced Bottle Shapped Struts in Glass Fiber Reinforced Concrete

An experimental investigation was carried out to determine the performance of concrete under compression and tension for different amounts of glass fibers in concrete. Fibers are added in the amounts of 0%, 0.5%, 1.0%, 1.5%, 2% and 2.5% of weight of cement. It is observed that characteristic compressive strength of concrete is increased by 10% and 14 % and split tensile strength was increased by 18% and 10 % for M25 and M40 grade concrete respectively for 1 % of fibers. As the transverse tension is the main problem in bottle-shaped struts, addition of fibers in concrete will increase the performance of bottle-shaped struts. Performance of the strut is assessed from the efficiency factor#. Test specimen consisted of 400mm X 400 mm X 100 mm panels, tested for in plane loading under compression for two different grades of concrete and different amounts fiber contents. From the test results, it was observed that efficiency of bottle shaped struts increased up to 34% and 28% for M25 and M40 grade concrete respectively for 1% fibers in cement weight. Also addition of fibers to the concrete delayed the occurrence of main crack in the bottle-shaped strut. Therefore it can be concluded that addition of glass fibers to the concrete is an economical solution to increase the performance of the concrete in terms of capacity and serviceability.