EVALUATION OF CEMENT TREATED BASE MATRIX WITH OR WITHOUT CHEMICAL ADDITIVE

Abstract

Full depth reclamation (FDR) is old yet less explored flexible pavement rehabilitation technique, due to non-availability of standard guidelines. Now a days agencies are looking forward to use this technique for pavement rehabilitation because of its advantages over other methods in terms of cost & time of construction, environmental conservation. As there is no current standard code available for FDR mixes in India (current standards are limited6to stabilization of soil & granular materials, Cement treated base CTB & cement treated6sub6base6CTSB), Therefore proper laboratory as well as field study need to be done before adopting technique. Past research indicate effective utilization of cement for stabilizing base layer mix throught Full Depth Reclamation (FDR) Technique. The technology is established and even successfully implemented in field but utilization of cement raises significant concerns with respect to sustainability aspects. Therefore, an attempt has been made to incorporate Commercial Chemical Stabilizer (CCS) in conventional stabilized mixes to reduce the dosage of cement. Improved mechanical properties were observed by addition of CCS in the conventional cement stabilized mix. The target UCS was achieved by several combinations of cement and CCS, however, mix B4GP was concluded as the optimum mix because the formulation fulfilled all the design criteria for strength and durability and still allowed a scope of cement reduction by 2%. The Scanning Electron Microscopy (SEM) confirmed significant formations of C-S-H gels in the stabilized mixture, which governs the significant strength enhancement of the treated samples. The results showed limited Ettringite formations, ensuring sufficient bonding of the mixture contributing to the durability of stabilized mix.