Effect of Utalization of Natural Aggregates by Rap Aggregates and Cement by Ggbs in Alkali Activated Concrete Pavement

Abstract

Coarse aggregates and cement are the main constituents of the concrete in the rigid pavement structure. The procurement and generation of natural aggregates are getting difficult day by day because of a lack of natural resources. Search for alternatives to natural coarse and fine aggregates leads to the usage of Reclaimed Asphalt Pavement aggregates, which are produced abundantly due to the replacement of flexible pavement with the rigid pavement. Ground Granulated Blast Furnace Slag (GGBS) is a waste material/by-product from steel and iron industries that can be used as an alternative binder in the alkali enacted system in place of cement. This study is taken up to determine the physical properties of materials, strength parameters and durability aspects of alkali-activated concrete are studied with GGBS which is the complete replacement for cement. The RAP aggregates are procured from KR market flyover Bangalore. And it is checked in the effective utilization in geopolymer concrete pavements. RAP fine aggregates and RAP coarse aggregates are partially replaced with river sand and natural aggregates with a variation of 100%, 75%, 50%, and 25% for M40 grade of concrete. Na2O dosage of 4.5% and activator modulus of 1.25 is taken and kept constant throughout the study. The cubes, cylinders and beams were casted and tested for strength. And fatigue test and non destructive test such as ultrasonic pulse velocity and rebound hammer test is conducted. The results can be analyzed to identify the importance of RAP fine aggregates and RAP coarse aggregates in the geopolymer concrete pavement for its effective usage for present scenario. Concluding all the test results the replacement of 25% RAP coarse aggregates and 50% RAP fine aggregates giving more strength than normal concrete which can be used for pavement construction.