The objective of this research project was to conduct a literature review on longitudinal joint construction for hot- mix asphalt pavements. The review covered the issues related to the principles of hotmix asphalt paving and compaction for longitudinal joint construction, longitudinal joint problems, and some longitudinal joint construction techniques and specifications from different studies. Specific recommendations have also been made for application in the State of Kansas.

Construction procedures that will provide an improved centerline joint in asphalt concrete pavements.

The objective of this study is to evaluate seven different longitudinal joint construction techniques used in one HMA paving project in Colorado and two different techniques used in another paving project in Pennsylvania.

When placing hot-mix asphalt concrete (HMAC), paving the full width of the pavement in a single pass is usually impossible; therefore, most bituminous pavements contain longitudinal construction joints. These construction joints can often be inferior to the rest of the pavement and can eventually cause an otherwise sound pavement to deteriorate more quickly. The objectives of this project were to (1) assess the density along the longitudinal construction joint of several Texas pavements to determine if a problem exists; (2) document information from the literature; (3) synthesize aviation construction data where a history of a joint density specification exists to determine if such a requirement can be met by paving contractors; and (4) modify current HMAC specifications to require joint density measurements if justification is verified.

Longitudinal joints are one of the critical factors that cause premature pavement failure. Poor-quality joints are characterized by a low density and high permeability; which generates surface distresses such as ravelling or longitudinal cracking. Density has been traditionally considered as the primary performance indicator of joint construction. Density measurements consist of taking cores in the field and determining their density in the laboratory. Although this technique provides the most accurate measure of joint density, it is destructive and time consuming. Nuclear and non-nuclear gauges have been used to evaluate the condition of longitudinal joint non-destructively, but did not show good correlation with core density tests. Consequently, agencies are searching for other non-destructive testing (NDT) options for longitudinal joints evaluation. NDT methods have significantly advanced for the evaluation of pavement structural capacity during the past decade. These methods are based either on deflection or wave velocity measurements. The light weight deflectometer (LWD) is increasingly being used in quality control/quality assurance to provide a rapid determination of the surface modulus. Corresponding backcalculation programs are able to determine the moduli of the different pavement layers; these moduli are input parameters for mechanistic-empirical pavement design. In addition, ultrasonic wave-based methods have been studied for pavement condition evaluation but not developed to the point of practical implementation. The multi-channel analysis of surface waves (MASW) consists of using ultrasonic transducers to measure surface wave velocities in pavements and invert for the moduli of the different layers. In this study, both LWD and MASW were used in the laboratory and in the field to assess the condition of longitudinal joints.