Semester of Graduation

Fall 2018


Master of Civil Engineering (MCE)


Department of Civil and Environmental Engineering

Document Type



Chip seal and microsurfacing are pavement maintenance activities typically used in relatively low traffic roads with the aim to reduce the rate of deterioration and to defer the need for costly rehabilitation activities. Chip seal is widely used in Louisiana, and Louisiana’s $6.3 million microsurfacing program is amongst the largest microsurfacing programs in the United States. As these surface treatments seal the road surface, the effectiveness of this treatment in such a setting has been a concern in recent years by linking it to moisture damage caused by the trapped moisture underneath the pavement. Furthermore, the cost-effectiveness and optimal timing of chip seal and microsurfacing applications are also not well established for the South-Central United States.

The primary objective of this study was twofold. First, the short and long-term performances of chip seal and microsurfacing treatments were evaluated as related to the pre-treatment conditions of the pavement. Performance curves were developed to assess the cost-effectiveness of the treatment. Effectiveness models in conjunction with the cost-benefits of the projects were used to identify the optimum timing for this preventive maintenance activity. Second, treated sections were evaluated to assess whether chip seal or microsurfacing significantly contribute to moisture damage. Field performance of 51 chip sealed and 28 microsurfaced sections were monitored for at least eight years. Long-term pavement performance data were used to quantify the benefits of chip seal and microsurfacing treatments in terms of the appropriate pavement performance indicators for the specific treatment type.

Results indicated that chip seal is most effective in reducing cracking intensity in the pavements, and microsurfacing is most effective in addressing rutting damages as compared to the other performance criteria. Chip seal extended the service life by 6.5 to 10.4 years and for microsurfacing, the service life extensions were observed to be 4.9 to 8.8 years. The effectiveness was found to be optimum when the treatment is applied to pavements with pre-treatment conditions ranging from 70-75 and 80-85 for chip seal and microsurfacing, respectively. No significant evidence was found indicating chip seal or microsurfacing being the primary factor contributing to moisture damage of the pavements.



Committee Chair

Elseifi, Mostafa