The Mechanical Properties of High Strength Concrete with Additional Fiber Variations

Abstract

The Concrete is generally known to have good compressive strength but weak against tensile strength. To improve the performance of concrete against tensile strength is to add fiber to the concrete mixture.. The purpose of this study was to determine the mechanical behavior of high strength concrete with variations in the addition of fibers, namely bamboo and polypropylene fibers. Bamboo fiber and polypropylene fiber added to the concrete mixture with a percentage of 0%, 0.5%, 1% and 1.5% by weight of cement. The use of 0% fiber in the concrete used as comparison concrete. The compressive strength of the f'_c 60 MPa plan with an FAS value of 0.25 where the coarse aggregate used is crushed stone with a maximum diameter of 12 mm, a super plasticizer of 2% of the weight of cement is also used and a filler (palm shell ash) of 15% of the weight cement. The design of this high strength concrete mixture uses the weight comparison method. The concrete compressive strength test carried out at the age of 28 and 56 days, 24 cylindrical specimens with a diameter of 15 cm and a height of 30 cm were 24 for bamboo fiber concrete and 24 cylinders for polypropylene fiber concrete with total 48 cylindrical specimens. In the 28-day-old concrete compressive strength test (0% fiber), the compressive strength was 62.47 MPa and 57.38 MPa. At the age of 56 days (0% fiber), the compressive strength is 62.56 MPa and 61.23 MPa. The use of 0.5% bamboo fiber obtained the optimum compressive strength, namely 60.77 MPa and 60.10 MPa for the test age of 56 days. While the use of 0.5% fiber in the 28 day test obtained the optimum compressive strength, namely 59.07 MPa and 54.87 MPa. The strain of 28 days old concrete obtained by the addition of 0.5% bamboo fiber is 0.00168 compared to 0% fiber concrete is 0.0008. The strain value of 0.5% polypropylene fiber concrete obtained a strain value of 0.00296 compared to 0% fiber concrete, namely 0.00284. The optimum compressive strength obtained when using 0.5% fiber. The optimum split tensile strength obtained in 1.5% fiber concrete, namely 5.34 MPa and 4.81 MPa. The use of bamboo and polypropylene fibers in high strength concrete affects the tensile value of the concrete. Fiber concrete is more ductile than non-fiber concrete.