Structural integrity of glass/epoxy composites embedded in cement or geopolymer mortars

The main goal of the present work is to study the mechanical response of glass/epoxy composites when exposed to cement and geopolymer (metakaolin) mortars, as it happens in Civil Engineering applications. For this purpose, specimens were embedded into mortar followed by a period of curing, which was done under the air laboratory environment. For cement, curing was also performed inside a container filled with water. The specimens were removed from the mortars after 30, 60 or 90 days of curing and then tested. Three point bending (3 PB) tests, tensile and transverse impact tests were carried out. The degradation was evaluated, both by the residual mechanical properties and by the failure damage mechanisms. In terms of 3 PB, and comparatively to the control samples, decreases around 29.5%, 31.3% and 37.9% were found after 90 days of exposure to cement, cement with water and metakaolin mortar, respectively. The same comparison for the impact strength reveals decreases about 39%, 40.1% and 44.3% for impacts in tensile mode, while these values are 7%, 11.6% and 63.1% for impacts in transverse mode, respectively. Therefore, the exposure to both cementitious and geopolymeric matrices affects significantly the mechanical properties, but their effects are strongly dependent of the exposure time. Finally, it was possible to conclude that the worst results are obtained with the metakaolin mortar.