effect of polypropylene fibers on strength and thermal resistance of concrete

in this paper, the effect of polypropylene fibers added to concrete on strength and thermal resistance of high strength concrete has been investigated. therefore, five tests have been carried out to reach this goal which it includes; effect of weight percent of polypropylene fibers on mechanical properties of concrete, effect of fiber’s length on the strength of high strength concrete, effect of fiber’s volume on the thermal stability of high strength concrete, examine the phenomenon of spalling concrete high resistance against heating, determine the changing of compressive strength of high strength concrete in different temperatures. the results present that the compressive strength has declined with the percentage of fiber concrete after 0.7 kg/m3 . moreover, in all cases the tensile strength and concrete’s bending strength will be increased by fiber content.