Impact of Joint-Filling Materials on Cracking in Concrete Gutters at Large Airfields

In the last few years at several airports cracking in the internals of concrete gutters has been detected. This was mainly observed, where large airfields (about 60 to 100 m in length) are located next to these drainage lines. In order to reveal the influences on this cracking both laboratory investigations as well as numerical analyses referring the expansion joints and the gutters were performed. Due to seasonal variations in temperature concrete pavements casted in wintertime tend to expand by higher temperatures in summer, whereas the deformations of the free edges can amount up to 5 to 10 mm. Such deformations should be met without any restrain. If this cannot be ensured, horizontal stresses up to 5 to 10 MPa are activated. However, the concrete gutters are normally not designed and constructed for such horizontal loads. The result is an extensive cracking in the interior of the gutters and finally their complete destruction. In adequate laboratory tests the stress-strain-relations for various materials was determined. For the mostly used bituminous soft board a comparatively stiff behaviour was proved. Besides this optimization of the filling materials methods for refitting of such expansion joints in already existing airfields were developed.