Research For Polypropylene Fiber Concrete Applied In Large-area Ground Engineering

Polypropylene fiber putted in concrete was an important measure for improving the performance of concrete. Polypropylene fiber is a special fiber with high strength accompanied by a certain amount of additives and made by a modification process. After mixing with concrete by a certain proportion, the integrity and continuity of concrete improved greatly, thus it improved the technical performance of concrete materials.In this study, by the room experiment, the mix composition of concrete than over 5.5MPa bending tensile strength and than over 35MPa compressive strength was achived that the mix proportion was: C (cement): S (sand): G (gravel): F (fly ash): W (water) = 410: 735: 1005: 68: 165 with 0.9kg/m~3 of polypropylene fiber.Herin, compressive tests, split tests, bending tests and shear tests were carried out when putting 0.6kg/m~3, 0.9kg/m~3, 1.2 kg/m~3 of 10mm long polypropylene fibers into concrete, and 0.9kg/m~3 with 20mm long polypropylene fibers. The results showed that when fiber length fixed, the strengths increased with fiber content increasing. Moreover, when fiber content fixed, the the strengths of fiber reinforced concrete tends to increase with fiber length.In the same time, polypropylene fiber reinforced concrete was applied in large-area ground leveling project. It once more proved that polypropylene fiber concrete had high tensile properties, crack resistance, resilience, and high bearing capacity.A feasible construction technology was also summarized in this engineering.