Experimental and comparative investigation of flexural behavior of basalt and steel fiber reinforced concrete beam

Concrete is a widely used material in structural engineering construction in different ways, whereas concrete has a low tensile strength and fails in a brittle manner. These shortcomings are generally overcome by using several technics. One of them was the inclusion of fibers into the concrete. The experimental study in this thesis is achieved to show the improvement gained by the addition of basalt, steel, and glass fibers to the concrete mix on the flexural performance of reinforced concrete beams. Thirteen different beams were tested and the results are compared. All beams with an effective span of 1300 mm were tested until failure under 4-point flexural test. The beams were designed as a balance-section. All beams are the identical size of "1500 x 150 x 200 mm" and divided into four groups. Group A consists of three beams strengthened with different volumetric ratios (0.5, 1.0, and 1.5 %) of basalt fiber. Group B consists of three beams strengthened with different volumetric ratios (0.5, 1.0, and 1.5 %) of steel fiber. Group C consists of three beams (0.25-0.75, 0.5-0.5, and 0.75-0.25 %) of basalt and glass hybrid fibers. Group D consists of three beams (0.25-0.75, 0.5-0.5, and 0.75- 0.25 %) of steel and glass hybrid fibers, and the last one is a control beam. The concrete mixtures was designed for high strength concrete. For each mix three-cubes and three cylinders are cast to obtain the effect of the fibers on concrete compressive and tensile strength. Very few researchers were presented in literature on the hybrid effect of steel, glass and basalt fibers in reinforced concrete beams. This thesis presents the effect of hybrid fiber on the compressive, tensile and flexural strength of concrete. Basalt fiber concrete usually has a high tensile strength but slightly smaller than steel fiber. The flexural strength of basalt fiber reinforced concrete increased with increasing fiber content in a gradual fashion. It is observed from the test results that there is a negative effect of fiber inclusion on the compressive strength of concrete.