Creep tests on GFRP pultruded specimens subject to traction or shear

In this paper, experimental long-term tests on pultruded GFRP specimens are presented. Both plain composite specimens and specimens stiffened with carbon fiber sheets have been subject to testing. The specimens have been tested under tension and shear for about a 760 days duration, with the load kept constant in time. The specimens under traction loadings have been cut from plates and from the flanges of a wide flange GFRP pultruded beam; the specimens under shear loadings have been extracted from the web of the same beam. Moreover, some specimens have been strengthened by gluing CFRP sheets to both sides, in order to study how their addiction may reduce the specimen deformability under long term loading. The tests have been performed under controlled temperature (20° C) and humidity (60% RH) in a climatic room. The results are given in terms of strains or creep coefficients evolution in time.