Evaluate the Effect of Waste Ground Rubber Tire Powder in Hot Mix Asphalt
In the present study, the effect of waste ground rubber tire powder (WGRTP) modifier on various mechanical properties such as Marshall stability, flow, Marshall quotient (MQ), bulk specific gravity, air voids, voids filled with bitumen (VFB) and percent voids in compacted mineral aggregates (VMA) of asphalt mixture has been evaluated. The Marshall tests of the polymer modified asphalt mixture, prepared through dry process, indicated the optimum waste polymer modifier content to be 5% by weight of mix. The waste polymer modified asphalt mix containing 5% WGRTP showed considerable improvement in various mechanical properties of the mix compared to the conventional asphalt mixture. The appropriate amount of the added WGRTP was found to be 5% by weight of aggregate. This percentage results in the maximum level of stability. Keywords—Hot mix asphalt; Waste ground rubber tire powder; Dry process; Marshall test method
Flexible Pavement: A Review on the Influence of Waste Rubber Particles in Asphalt and Asphalt Mixtures
Asphalt and aggregates are used in the flexible pavement to form asphalt concrete as the surface and binder courses. Both materials are essential components of hot mix asphalt (HMA). The asphalt concrete might not fully have the potential to endure heavy traffic loading, high temperature, and intensive rainfall, especially in tropical regions because of its stiffness, which often developed in fatigue cracking and permanent deformation in road pavement. The number of failures caused by those factors reduces the durability of pavement performance. Until now, the research about newly selected modifiers and techniques to modify asphalt and asphalt mixtures is essential. Using waste rubber particles in asphalt and asphalt mixtures to improve their characteristics has become a technique of great potential for many years round. The modifier makes asphalt and asphalt mixtures more resistant to temperature variations and high traffic loads and reduces the maintenance costs, and improves the riding surface of the pavement as was reviewed. This paper reviews the influence of waste rubber particles in asphalt and asphalt mixtures with particular reference to the dry and wet processes considering design mixes. The primary focus of the review was studied, which highlights some critical issues considering its design mixes (dry and wet processes), testing method, and performance on road pavements. Recommendations called for additional research for performance improvement of waste rubber particles in asphalt and asphalt mixtures.
Interaction mechanism of asphalt with fiber in pavement
This paper analyzes the interaction principle between the asphalt and six kinds of fiber through the mesh dropdown test, penetration test and SHRP DSR test. Test results indicate that the relationship between asphlat and fibers depends on their surface physical and chemical features.The fibers must be used in different condition accoring to their qualities.