||Nowadays, expansive problems in concrete works are a real problem in Spain, affecting mainly to hydraulic works (dams and channels), but also to other type of structures as bridges. Some of these problems have arisen in recent constructions, showing the lack of effectiveness of preventive tests used in our country to avoid the appearance of these adverse phenomena. The most common expansive pathology of concrete in Spain is related to alkali-silica reactivity caused by the presence of slow-reacting aggregates with high strained quartz, mainly in granite aggregates. Preventive tests for this type of reaction are still controversial in the international field, where research is very active aimed to find new tests. This project will be focussed also in this type of reaction. On the other hand, when the expansive pathology has already started in a construction in use, the unique solution is monitoring the structure, being essential to develop mathematical models to predict the future behaviour. The interest of this project relies on two basic columns, trying to solve the mentioned problems: â€¢ Prevent the appearance of this pathology in new works. This project will try to adapt tests for detecting fast reactive aggregates to slow reactive aggregates; as well as developing easier, faster and more objective new tests with numerical results. â€¢ Improve the management of constructions affected by expansive phenomena. Models to predict the structural behaviour of affected constructions will be developed.