Introduction: With the rapid economy growth and continuously increased consumption, a large amount of tire waste materials is generated Objective: This study attends to test the performance of many samples of asphalt concrete mix with adding the crumb rubber modifier (CRM) of 5%, 10%, 15%, 20% and 25% as percentage of asphalt cement content (AC) to address the best content of CRM (optimum) for asphaltic mixes the hot one HMA Methods: The Marshall design was used here to examine the influence of the Optimum CRM content. The CRM is blended with AC using wet process. Subsequently, by obtaining low price and economic mixes that will reduce the optimum asphalt content OAC Results and Discussion: The laboratory tests show that optimum rubber content is 17% by the weight of the asphalt cement. This meets the ASTM Standards 2001and Jordanian MPWH requirements Conclusion: Adding the CRM to HMA will increase the consistency and viscosity of the mixes which leads to higher rutting resistance, reduce fatigue and reflecting cracking and improve durability

Introduction: With the rapid economy growth and continuously increased consumption, a large amount of tire waste materials is generated Objective: This study attends to test the performance of many samples of asphalt concrete mix with adding the crumb rubber modifier (CRM) of 5%, 10%, 15%, 20% and 25% as percentage of asphalt cement content (AC) to address the best content of CRM (optimum) for asphaltic mixes the hot one HMA Methods: The Marshall design was used here to examine the influence of the Optimum CRM content. The CRM is blended with AC using wet process. Subsequently, by obtaining low price and economic mixes that will reduce the optimum asphalt content OAC Results and Discussion: The laboratory tests show that optimum rubber content is 17% by the weight of the asphalt cement. This meets the ASTM Standards 2001and Jordanian MPWH requirements Conclusion: Adding the CRM to HMA will increase the consistency and viscosity of the mixes which leads to higher rutting resistance, reduce fatigue and reflecting cracking and improve durability