An experimental study on the long-term behavior of CFRP pultruded laminates suitable to concrete structures

The rheological behavior of structural materials has a significant role indeed in Civil Engineering, where concrete and FRP materials undergo creep in normal environmental conditions, while steel exhibits a sizable creep only at high temperature (above 400°C). With reference to RC structures strengthened by means of FRP laminates, FRP creep generally coexists with concrete cracking. The interaction between these phenomena should be taken into account in order to evaluate the structural durability. Here, the first results of a research program on creep in composite pultruded laminates used in Civil Engineering are presented, under various stress levels and in constant environmental conditions (many theoretical and experimental studies on creep have been performed so far in the aerospace and naval fields, but not as many in Civil Engineering). The specimens tested in this project are made of high-modulus carbon fiber-reinforced polymer - CFRP, whose mechanical properties are tailored for Civil Engineering applications. The tests are still in progress in the Materials and Structures Testing Laboratory of the Civil Engineering Department of the University of Salerno (Italy).