The Effect of Emboss Fiber (Modified Polypropylene Fiber) on the Behavior of Concrete used in Concrete Pavements

Concrete pavements are widely used by pavement engineers due to their advantages over flexible pavements such as longer lifetime, good performance and durability, etc. However, concrete pavements represent some drawbacks such as shrinkage that increases the tensile stress in concrete, which may lead to cracking, warping, etc. Drying shrinkage is the most important type of shrinkage in concrete pavements. polypropylene fibers can be used to control or reduce width of cracking by bridging both sides of crack. In this study, the effect of Emboss fiber on the behavior of concrete pavement was investigated. Slump, compressive strength, third-point flexural strength, electrical resistance, skid resistance, free shrinkage and restrained shrinkage by ring test were performed. Two water-cement ratios of 0.35 & 0.4 were used for mix design and the percentage of polypropylene fiber used in mixtures was respectively 0.44% by concrete volume. The results showed that the use of Emboss Fiber reduced the workability of concrete. Also, these reinforcements had different effects on compressive and flexural strength and electrical resistance depend on homogeneity of Emboss fiber reinforced concrete. Furthermore, toughness indices and energy absorption of concrete were significantly increased by using Emboss fiber reinforced concrete. In addition, using fiber indicated a slight reduction in the amount of free and restrained shrinkage and occurrence of first-crack. polypropylene fibers had a key role in controlling crack width by bridging both sides of crack. Finally, no certain relationship was observed between using SRA and changing the skid resistance of concrete pavement.