Evaluation on durability of interlocking block pavement under repeated loading by heavy vehicles

SUMMARY Interlocking block pavement has been designed by theoretical anaiysis or empirical methods. When it is designed in accordance with. conventional design procedure, i.e. empirical methods, its structural in­ dex is needed. Through observation on serviceabil­ ity of interlocking block pavements, it was concluded that structural index of interlocking block layers was almost equal to that of hot mixed asphalt. When interlocking blocks are used for pavements under heavy load, structure and durability of base courses should be carefully examined. Test pave­ ments with two types of base courses with high bear­ ing capacity, namely asphalt stabilization and ce­ ment stabilization, were constructed at the Pavement Test Field in the Public Works Research Institute and received repeated loading of heavy vehicles. The interlocking block pavement with asphalt stabi­ lized base performed better than that with cement stabilized base. Therefore, it is recommended that the base course of interlocking block pavements for heavy traffic roads should be stabilized with asphalt in order to prevent damages on interlocking blocks. Damages on interlocking blocks and the layers un­ der blocks were examined after repeated loading. When blocks were removed, it was found that the laying course deformed by repeated loading and joint sand disappeared. The deformation was caused by pulverization of sand into smaller parti­ cles. The change of particle size caused deforma­ tion of pavement surface and lead to fatal deteriora­ tion on each piece of blocks llnder wheel paths.