Failures in bituminous joint-sealing in concrete pavements

Abstract

In many countries, e.g. Germany, concrete pavements are constructed with plain concrete (JPCP). In such constructions, joints and their sealing are essential elements for a durable longterm behavior. Recently, numerous damages in the joint sealants were detected as early as one to three years after application. Especially delamination of the sealant from the joint edges and tearing of the sealant itself have been observed. In former times none of such phenomena have been known, it is assumed that the bitumen quality had been modified over time. However, the material itself had fulfilled all requirements of the standard specifications. Therefore, also other components of the joint sealing like the adhesion layer or the saw cut resp. the roughness of the joint edges have to be considered as potential causes for the failure. Currently the single components are being tested separately. Thus, a comprehensive test method had to be developed which captures the behavior of the entire sealant system. Herewith, the adhesion layer as well as the surface in the joint edges can be evaluated under the relevant loadings. This had been developed within an extensive research project. In this test, the behavior of the entire joint system can be analyzed under static as well as under cyclic loads. Through this complete technical assessment, it will be possible to design and execute joint sealants in concrete pavements more durable.