CURING BEHAVIOUR OF EPOXY-ADHESIVES FOR BONDED CFRP-REINFORCEMENTS

 ABSTRACT

Polymers open access to new production methods. This also applies for civil engineering.Post-strengthening of concrete structures with bonded CFRP-straps is only one example.For the successful application of such a method the specific mechanical behaviour of the polymers used, especially their temperature and time dependency needs to be considered. Curing of the adhesives that are used is usually determined by stamp pull-off tests. By this method only the adhesion between material and concrete is examined. Thus, the cohesion of the material which dominates the long-term behaviour and the mechanical properties of the material itself are not taken into account. These properties are strongly influenced by the degree of cure of the adhesive. In the scope of this paper a commercial cold curing epoxy based adhesive for bonded CFRP-reinforcements was investigated by means of thermal analysis and mechanical testing. The development of the degree of cure and glass transition temperature (Tg) was determined for curing at room and minimum allowable processing temperature. It was correlated to mechanical short and long-term properties. In addition to that the thermal application limits of the material were determined by dynamic mechanic analysis (DMA).