CONCRETE MIX CONTAINING RECYCLED CONCRETE AGGREGATE FOR LOW VOLUME TRAFFIC

Abstract

Roads are the backbone of the development of a country. India with its second largest road network globally is through a rapid development phase. Several infrastructural projects are under work requiring huge economic support to upgrade the country's road network. Huge amount of materials are required to carry these projects further, same is happening with nearly all developing countries around the globe. As much as about 25,000 tons of virgin aggregate are consumed per kilometer of pavement construction. Considering the rapid pace with which quarrying has been carried out, it is for sure in the near future there will be huge shortage of virgin materials to meet such huge demands of materials. With the rising cost and dwindling supply of virgin aggregates, recycled concrete aggregate (RCA) is becoming a viable alternative. Efforts have also been made in the past by various researchers to minimize this huge gap between demand and supply of aggregates by proposing the use of recycled materials into fresh construction works. Concrete is the most widely used construction material, which upon construction demolition could be obtained in a healthy percentage as high as about 70 % fiom demolition sites. Recycled concrete aggregate is a valuable resource, which upon beneficiation could be used for various construction applications. This study is an effort to examine the impacts of inclusion of recycled concrete aggregates in pavement quality concrete mix. Literature from past studies has discussed how the properties vary upon inclusion of recycled concrete aggregates in fresh concrete; however no specifications or codes have been brought up regarding the same especially for low volume roads. In this study laboratory investigations have been carried out to evaluate the effects of incorporating recycled concrete aggregates with different proportions and the effect of moisture states on fresh and hardened concrete mixes. For this, separate concrete specimens were prepared using primary aggregates and recycled concrete aggregates. The variation of slump loss was measured significantly. Hardened concrete specimens were tested for variations in mechanical properties such as compressive strength, flexural strength etc. For this M20 and M30 grades of concrete were considered and check the suitability for rural roads.