This project was designed to investigate the importance of drainage maintenance for pavement performance and to recommend a maintenance strategy. With restrained funding for pavement renewals drainage maintenance is a cost-effective method to ensure optimum pavement performance.
A combination of repeated load triaxial testing and modelling of water movement has shown that once water has infiltrated the basecourse it can take weeks for the water content to return to its equilibrium condition. During this time significant damage can take place and there is a high probability that further rainfall will occur and thus re-saturate the pavement.
A drainage risk rating score card was developed and it is recommended that this be adopted by road controlling authorities.