Laboratory Evaluation of Shear Strength for Ultra-Thin White Topping

Laboratory Evaluation of Shear Strength for Ultra-Thin White Topping

Prabhat Ranjan, Neeraj Jain

Dept of Civil Engg.

RNTU Bhopal, INDIA

ABSTRACT

As a rehabilitation technique, Ultra-Thin Whitetopping (UTW) is a process that creates a 50-100 mm thick cement concrete overlay on deteriorated asphalt pavement. From 2003 to 2011, twelve conventional, ultra-thin, and thin whitetopping overlay projects were built in India, although there has been no detailed follow-up on their performance. As a result, using appropriate techniques, it is necessary to investigate the performance evaluation of UTW for Indian traffic and climatic circumstances. The performance of the UTW is evaluated in this study using the Benkelman Beam Deflection Test (BBD) as described in IRC: 81-1997.
The purpose of this research is to investigate the interface bond strength of UTW overlays that have been treated to various interface treatment approaches. Because UTW overlay composite behaviour is affected by bond loss and layer delamination. This will lead to premature failure and reduction in design service life of UTW overlays. To improve the interface bond strength and satisfy the design service life of UTW overlays, a good surface preparation process is necessary. Experiments were carried out in the lab to attain the goal of the current project. The cylindrical HMA mixture specimens were casted and were tested in universal testing machine (UTM). HMA-UTW composite specimens were used, each with a varied proportion of bonding at the interface. Two test methods, the direct shear test and the flexural test, were used to determine the interface bond strength for Various interface treatment approaches. Both tests were carried out under static and dynamic loading conditions.

Key Words : Ultra-Thin Whitetopping, Shear Strength, Marshall Stability, Hot mix asphalt, Compressive Strength and Bitumen.