Amirkabir University of Technology Amirkabir Journal of Civil Engineering 2588-297X 53 2 2021 04 21 Evaluation of the Effect of Macro-Synthetic Fibers on Thickness and Cost Index of Jointed Concrete Pavements Considering the Impact of Post-Cracking Flexural Strength Evaluation of the Effect of Macro-Synthetic Fibers on Thickness and Cost Index of Jointed Concrete Pavements Considering the Impact of Post-Cracking Flexural Strength 767 784 4241 10.22060/ceej.2021.19050.7048 FA Abolfazl Hassani Department of Roads and Transportation, Faculty of Civil and Environmental Engineering, Tarbiat Modares University, Tehran, Iran Seyed Javad Vaziri Kang Oleyaei Highway Engineering and Transportation, school of civil engineering, Iran University Of science and Technology, Tehran,Iran Mohammad Reza Hajizadeh Department of Civil and Environmental Engineering, Amirkabir University of Technology (Tehran Polytechnic), Tehran, Iran Journal Article 2020 09 24 Considering the effect of post-cracking strength and the cost of pavement construction in designing the thickness of jointed concrete pavements lead to more effective and economical pavement design. Therefore, this study evaluates the effect of the addition of macro-synthetic fibers on the thickness and construction cost of jointed concrete pavements, considering the impact of post-cracking flexural strength. The effect of polypropylene macro fibers in the amounts of 0, 1, 2, and 3 kg/m³ on changes of thickness and construction cost index of jointed concrete pavements was studied considering the modulus of rupture and equivalent flexural strength ratio of each mix design in pavement thickness design. It was observed that the addition of macro fibers reduced the thickness of jointed concrete pavement up to 25%. The highest pavement thickness reduction occurred in fiber consumption from 0 to 1 kg/m³. With the addition of more fibers, no more significant decrease in thickness occurred. The addition of fibers increased the cost index of pavement construction up to 57%. Using macro-synthetic fibers up to 1 kg/m³ caused the lowest pavement cost index's growth rate compared to other consumption contents. It was concluded that the optimal amount of macro-synthetic fibers could be determined for economic reduction of the pavement thickness by considering the growth rate of the pavement cost index, which in this study was obtained at the content of 1 kg/m³. Considering the effect of post-cracking strength and the cost of pavement construction in designing the thickness of jointed concrete pavements lead to more effective and economical pavement design. Therefore, this study evaluates the effect of the addition of macro-synthetic fibers on the thickness and construction cost of jointed concrete pavements, considering the impact of post-cracking flexural strength. The effect of polypropylene macro fibers in the amounts of 0, 1, 2, and 3 kg/m³ on changes of thickness and construction cost index of jointed concrete pavements was studied considering the modulus of rupture and equivalent flexural strength ratio of each mix design in pavement thickness design. It was observed that the addition of macro fibers reduced the thickness of jointed concrete pavement up to 25%. The highest pavement thickness reduction occurred in fiber consumption from 0 to 1 kg/m³. With the addition of more fibers, no more significant decrease in thickness occurred. The addition of fibers increased the cost index of pavement construction up to 57%. Using macro-synthetic fibers up to 1 kg/m³ caused the lowest pavement cost index's growth rate compared to other consumption contents. It was concluded that the optimal amount of macro-synthetic fibers could be determined for economic reduction of the pavement thickness by considering the growth rate of the pavement cost index, which in this study was obtained at the content of 1 kg/m³. https://ceej.aut.ac.ir/article_4241_28f7241796510e838db4a1384ae1279d.pdf