An analysis of the interfacial bond between polypropylene reinforcing fiber and cement matrices

The problem of this study was to develop a method to improve the interfacial bond between polypropylene fiber and Type l Portland cement and also to investigate the improved qualities of the interfacial bond. The process chosen to improve the interfacial bond between polypropylene fiber and the cement matrix was a chemical surface treatment. The fibers were bathed in specific chemicals to create active sites on the surface of the polypropylene fibers;A standard concrete design mix recommended for laboratory use by the American Concrete Institute was utilized. The test samples were cast into concrete cylinders, flexural beams and tensile briquettes. Standard procedures were adhered to for the casting and curing of 28-day concrete samples;The results of this study indicated that the crystalline growth on the fiber surface could be enhanced by the use of a chemical treatment. In comparing plain concrete with plain fiber or chemically treated fiber reinforced concrete, a significant strength increase was noted. When testing the concrete samples, the most significant increase was found to be in flexural and tensile strength. The statistical results also confirmed the mechanical measures by indicating a significant difference;Scanning electron microscope (SEM) photographs did reveal a higher amount of crystalline growth on the chemically treated fiber surface than on the untreated fiber surface area. Additional research is recommended to determine ways to increase the amount and type of crystalline growth that can be developed on the interfacial surface of the polypropylene fibers