In this study, a performance evaluation was conducted on a composite elastic asphalt precast expansion joint developed to replace steel expansion joints that frequently suffer from various damages, such as blow-up owing to increased traffic volume and abnormal weather. Two types of elastic asphalt binders were prepared by mixing a latex-based modifier, and their basic properties and performance were evaluated. Elastic asphalt binders were mixed with 8–13 and 13–19 mm aggregates to prepare elastic asphalt joint mixtures, and their permanent deformation and adhesive performance were evaluated using Hamburg wheel-tracking and direct-shear tests. Elastic asphalt joint blocks and internal reinforcement for crack prevention were applied to produce the elastic composite expansion joints, and their performance was evaluated through contraction–extension tests to determine fatigue cracking, maximum load during contraction– extension, and repeated contraction–extension tests. As a result of the performance evaluation of the developed elastic asphalt binder, both the high- and low-temperature performances were improved, and the temperature sensitivity was superior to that of general asphalt binders, exhibiting high resistance to cracking. In addition, the joint block specimens manufactured by mixing the elastic asphalt binder with 13–19 mm aggregates exhibited excellent permanent deformation in the dynamic stability and Hamburg wheel-tracking tests, and they had higher adhesive performance than the method of repairing with rapid-hardening concrete materials at low and room temperatures, where significant contraction of the concrete joint occurs. We confirmed that when a compression spring-type reinforcement was applied, the compressive force for contraction decreased significantly compared with the unreinforced state, and the tensile force for extension increased, thereby reducing the stress applied to the mixture itself. The composite elastic asphalt precast expansion joint developed in this study is expected to have superior durability against cracks and secure continuity with the road surface through the tensile force dispersing effect using expansion reinforcement. Thus, it has better drivability than the existing steel expansion joint and can absorb shocks such as vibrations and noise applied to a structure.
PURPOSES: The purpose of this study was to break away from the workforce method using cold-mix asphalt mixtures and has a constant quality and has develop repair materials of pre-production asphalt-precast types. METHODS: The selection of the repair material was determined as the results obtained through physical properties of materials and the field applicability. In case of repair materials, values obtained through Marshall stability test & the dynamic stability test & retained stability test as well as the site conditions was considered. In case of adhesive, test results were obtained through examination of the bond strength(tensile, shear) and the field applicability of the adhesive was examined through combined specimens to simulate field applications. RESULTS : According to the results of laboratory tests, in the case of repair materials, Marshall stability and dynamic stability, retained stability of cold-mix reaction type asphalt mixture is the highest. In the case of adhesive, two-component epoxy-urea has a very high bonding strength(tensile, shear) was most excellent. According to the results of field tests, when epoxy-urea was excellent workability. Also, the repair body through actual mock-up test did not occur large deformation and fracture after 12 months. CONCLUSIONS : A suitable repair material is cold-mix reaction type mixture of asphalt-precast, a suitable adhesive is a two-component epoxy-urea.
In recent years, many potholes in asphalt pavement occurred. In order to facilitate the repair, in this study, repair materials with high durability and excellent productivity appropriate for asphalt pre-cast materials was developed. Physical properties test and durability test of various repair materials(SMA, PMA, guss mixtures, water-reactive mixtures) were performed. In order to evaluate the workability at pre-production time of samples using repair materials were made in different shapes and sizes. Finally, after comparing mixtures, water-reactive mixture was selected as repair material. This was verified through several testing.