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
BITUMEN RUBBER ASPHALT IN SOUTH AFRICA: CONVENTIONAL TECHNIQUES
This paper describes the design procedures and construction practices used for the construction of bitumen rubber asphalt in rehabilitation projects in South Africa. Bitumen rubber products are normally at a disadvantage as they are placed where the conventional asphalts have already failed or where the existing base courses are in severe distress, and on top of this must now provide additional structural capacity for the next 10 to 15 years under severe traffic conditions. The RSA engineers have also advanced far along the futuristic routes to improve B-R products even further. This is a separate topic and dealt with further in our second paper titled 'Bitumen Rubber Asphalt in South Africa: Latest and Futuristic Developments' by CJ Potgieter. This paper concludes that the somewhat higher initial construction cost of B-R asphalt is negligible in view of the savings in traffic accommodation, bypasses and the extended life rendered by the B-R asphalt when assessed over the full life cycle. In South Africa B-R asphalt is considered the product of choice for rehabilitation purposes. For the covering abstract see ITRD E121480.
Mechanical performance of fibers-reinforced asphalt mixture
The fibers-reinforced asphalt mixture is a successful alternative all over the world to improve the pavement performance because of its eminent performance and economical preponderance, but there is fewer researche about its pavement performance. Through the wheel tracking test,low-temperature bending test,creep test, fatigue test and water stability test, this paper discussed the pavement performance of fibers reinforced asphalt mixture.Based on the test results, it also analyzed the fibers micro-characteristics and investigated the fibers-enhanced mechanism with the theory of compound-material.