Vermeidung von Schäden an Schlitzrinnen

Prevention of Damages to Concrete Gutters – Considerations on the Design of Expansion Joints In the last few years at some airports cracking was observed in concrete gutters, which are implemented in large areas as drainage. 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 carried out. The main focus was on the stiffness of the joint filling materials. 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 can not be ensured, horizontal pressures on the side‐walls of the gutters are raised. These pressures mainly depend on the stiffness of the joint filling material. In the 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. Thus the observed cracking mostly can be correlated with restraint stresses raised by such joint filling material.     

Instandsetzung und Verstärkung von Stahlbrücken mit Kategorie‐1‐Schäden

Retrofitting methods for orthotropic steel deck plates with category‐1‐damages. Due to a high increase of traffic load during the last decades orthotropic steel deck plates show more and more fatigue damages in the welded connection between longitudinal stiffeners and steel deck plate (category‐1‐damages). This contribution gives an overview about existing retrofitting methods which have already been applied in pilot projects and currently investigates renovation techniques for retrofitting category‐1‐damages.