The evaluation of bonded continuously reinforced concrete overlay over distressed jointed concrete pavement

Many lane miles of Jointed Concrete Pavement (JCP) have passed their design life and have suffered with problematic distresses. Even though extensive repair work has been implemented to the deteriorated JCP sections and a significant amount of repair budget has been spent, the situation has not changed. To solve this problem, Continuously Reinforced Concrete Pavement (CRCP) overlay was selected as a rehabilitation method for the deteriorated JCP. A half-mile section of deteriorated JCP in Sherman, Texas was chosen for this project. The main objectives of this research were to evaluate early age behavior of CRCP overlay over JCP, and to understand the debonding mechanism at the interface between old and new concrete which would greatly affect the performance of this rehabilitation system. Because this rehabilitation method is quite unique and has been rarely implemented, to ensure its performance, several requirements were specified and implemented. These requirements included cold-milling and hook bar installation in the transition section, longitudinal steel location, wet-mat curing, non-woven fabric on the JCP transverse contraction joint, and use of coarse aggregate with low Coefficient of Thermal Expansion (CTE) for concrete used. To evaluate the early age behavior of the overlaid pavement and its performance in the short term, various instruments such as Vibrating Wire Strain Gages (VWSGs), Steel Strain Gages (SSGs), Relative Humidity (RH) sensors, thermo-couples, and Non-Stress Cylinders (NSCs) were placed in the main section as well as in the transition section. Also, Falling Weight Deflectometer (FWD) tests were implemented on the project section before and after the overlay placement for comparison. Data collected from gages were used not only to analyze the pavement behavior, but also to prove whether the construction requirements which were made for this project would be valid or not. Evaluation and analysis of information from installed gages and deflections from the FWD test indicated that this rehabilitation method generally worked well and the designed specifications were effective, with a few exceptions such as the non-woven fabric placement. Wet-mat curing especially appears to reduce the volume change at the early age, and according to analysis of data from gages installed, the interface bond was in very good condition. FWD data presented that deflection was significantly reduced after overlay, to prove the validity of the CRCP overlay on JCP. Evaluations and analyses in this paper show that the CRCP overlay is quite effective for the deteriorated JCP as a rehabilitation method, and the requirements specified for this project are generally adequate. However, because only short-term data was used for this thesis and the information about the previous implementation of this overlay method is very limited, long-term analysis for this project and another implementation will be required to understand this unique rehabilitation method more adequately.