Feasibility of Using Pulse Velocity to Evaluate Asphalt Concrete Properties
Saad Issa Sarsam1*, Nazar Sajad Kadium2
1Professor, Department of Civil Engineering, College of Engineering, University of Baghdad, Iraq.
2MSc. Student, Department of Civil Engineering, College of Engineering, University of Baghdad, Iraq.
The construction of asphalt concrete pavement is usually accompanied by the quality control measures during spreading and after compaction. Samples are usually obtained to verify the various strength and volumetric properties of the asphalt concrete mixture. Such sampling and testing are time and labor consuming. A desirable method is the one which neither causes disruption to traffic, nor causes any damage to the existing pavement structure. Highway transportation agencies are moving towards the use of innovative non-destructive testing (NDT) methods for evaluating the in-situ condition of pavement structures. For quick acquisition of test data, a reliable and consistent test technique is needed. NDT methods provide all these features and are ideally suited for application to pavements. In this investigation, the feasibility of implementing non-destructive testing technique was investigated using pulse velocity to investigate the strength and volumetric properties of asphalt concrete wearing course. Specimens were prepared in the laboratory at various asphalt percentages and tested for pulse velocity, then subjected to indirect tensile strength and punching shear strength determination. The impact of moisture damage and testing temperature on pulse velocity were also investigated. Data were analyzed and modeled. It was concluded that implementation of non-destructive testing with the aid of pulse velocity is feasible for predicting the quality of asphalt concrete within the limitations of the testing program implemented. The good correlation between the pulse velocity and the volumetric and strength properties demonstrates the potential benefit of using the wave parameters for condition assessment of asphalt concrete. The moisture damage exhibits negative influence on pulse velocity by 13%, while the testing temperature shows no significant influence on pulse velocity.
Key words: Non-destructive test, pulse velocity, asphalt concrete, tensile and shear, volumetric properties.