A STUDY ON PERFORMANCE OF BITUMINOUS MIXES USING FWD

Abstract

A Falling Weight Deflectometer (FWD) is a Non-Destructive Testing (NDT) Device used by civil engineers to evaluate the physical properties of pavement. It is designed to impart a load pulse to the pavement surface which simulates the load produced by a rolling vehicle wheel. FWD is a tool used to achieve rapid and repeatable in-situ characterization of the pavement layer stiffness and to evaluate pavement structural condition. It is being widely used in pavement engineering as it plays a crucial role in selecting optimum pavement maintenance and rehabilitation strategies. FWD data is most often used to calculate stiffness-related parameters of a pavement structure. The process of calculating the elastic moduli of individual layers in a multi-layer system (e.g. asphalt concrete on top of a base course on top of the subgrade) based on surface deflections is known as "back calculation". Instead, initial moduli are assumed, surface deflections calculated, and then the moduli are adjusted in an iterative fashion to converge on the measured deflections. Over a period of' time, research has rendered FWD capable of not only predicting Elastic Modulii of Pavement Layers but For determination of Residual Life of Pavement. Designing of Overlays, assignment of Pavement Classification Numbers (PCNs) to airfield pavements, determination of load transfer characteristics of joints in Concrete Pavements, etc.