This paper reports the results of an experimental investigation to determine the effects of chemical treatment of polypropylene fibers (PPF) used in reinforced concretes. The control group concrete was designed at 4, 000 psi. The chemical solution used to treat the fiber surfaces was a basic solution of linear alcohol alkoxylates. The investigation included comparison of some static strength as well as the interfacial bond characteristics of unreinforced, plain fiber reinforced, and chemically treated fiber reinforced concretes that were cured for two different periods of 28 and 45 days. Three separate methods of testing were conducted to ascertain the mechanical measures of the concrete samples: compression testing (ASTM 4.02, C-39), flexure strength tests (ASTM 4.02, C-78), and splitting tensile tests (ASTM 4.02, C-496). A random sampling of the failed PPF specimens was prepared and observed using the scanning electron microscopy (SEM) technique. The interfacial features of the fiber surfaces were evaluated to determine the bonding characteristics between the fiber and the concrete matrix. A correlation between the chemical surface treatment of the PPF and the mechanical measures were statistically analysed.
Abstract