Eco-Friendly Asphalt Approach for the Development of Sustainable Roads

Currently, various types of recyclable materials are used in civil engineering applications. One of the future challenges in the civil engineering field facing sustainability and the bulk utilization of waste materials without affecting the performance of the product related to the civil engineering field. Presence of bulk amounts of disposed and demolished materials including aggregates and undecomposed recycled polymers can be recycled. The main aim of reducing environmental impact and also reduction in the cost. Present research focusing on recycled polymers as partial replacement of bitumen in addition to recycled coarse aggregate in different percentages are investigated for its feasibility used in road construction. To achieve the objectives of the current research, 6 batches of bituminous samples were prepared and each case considered three samples for repeatability. The first batch is considered as a control sample without adding Recycled Coarse Aggregates (RCA) and recycled polymer. The second batch consists of 15% partial replacement of bitumen using polymer without recycled aggregate. Remaining batches 3 to 6 were 15% partial replacement of bitumen with polymer and partial replacement of coarse aggregates using recycled coarse aggregate say 25%, 50%, 75%, and 100%. Each batch was tested by reliable and standard tests in order to determine the most efficient mix (batch). The testing methods followed in this investigation are sieve analysis test, impact test, Los Angeles test, penetration test and marshal test. The results of sieve analysis test showed that the fineness modulus value for RCA equals to 4% with uniform graded graph. The specific gravity test results showed that RCA specific gravity is 2.61 which indicates that RCA is considered as coarse grained soils. Moreover, the Impact test for RCA equals 9.3%. In addition, the result for Los Angeles for RCA value is 19.07% and comparing it with the standard and it should be less than 30% is suitable for road construction. Furthermore, penetration test results of 15% partial replacement of bitumen using polymer showed that the average value equals 58 mm compared to 63.7 mm for bitumen without polymer. Finally, the result obtained from the Marshall Stability test showed that batch 5 partial replacement of bitumen 15% using polymer and the partially replaced normal coarse aggregate 75% with RCA gives better results in all aspects. A fruitful conclusion from this study is to follow the approach of utilization of recycled coarse aggregate along with recycled polymers in road construction. Doi: 10.28991/HEF-2020-01-03-01 Full Text: PDF