FEASIBILITY STUDY OF USE OF RECYCLED AGGREGATES IN ROAD PAVEMENT CONSTRUCTION

摘要

Recent infrastructural development in India paved the necessity for highway construction where Recycled Coarse Aggregate (RCA) has been considered as an alternative to ensure sustainability. Use of RCA to replace the natural crushed aggregate in road pavement, can reduce waste disposal problem and energy consumption. However, the use of RCA in rigid pavement is limited due to inconsistency in the properties and performance of concrete caused by the variations in the properties of RCA and lack of guidelines for RCA to be used in pavement construction. Present study was performed to evaluate the feasibility of the use of RCA as a replacement of natural aggregates in concrete pavement in highways and low volume rural roads in India. Replacements of coarse aggregates in different proportions were done to achieve the desired strength of concrete as 40MPa. Concrete mix with a specific water-cement ratio has been used in the present work with PSC and PPC cement. Dynamic nature of loading on the pavement indicates flexural strength as a governing criterion for its design. Therefore, 90 days flexural strength of concrete was determined from compressive strength data using relevant guideline of IRC for design of highways and rural road pavement. In order to ascertain the strength of concrete by non-destructive approach, Rebound Hammer test was conducted on different faces of concrete cubes. It has been observed that the strength of concrete reduces with an increase in replacement level of RCA. Hence optimization of RCA content in concrete indicates 40% replacement level as the most suitable proportion at which both desired compressive and flexural strength can be achieved.