Development and characterization of strengthening systems
Laboratory tests were carried out in order to determine the main mechanical properties of TRM composites. TRM systems under investigation included steel and high strength galvanized fabrics, stainless steel fabrics and basalt textiles, embedded in a cement and natural hydraulic lime mortars. The systems with unidirectional steel cords are designed for localized applications on structural elements, whereas those with bidirectional basalt meshes for widespread applications on walls and non-structural elements.
Laboratory tests included:
- tensile tests on bare textiles and composites coupons, in order to determinate strength, stiffness, ultimate deformation and adhesion capacity between textile and matrix;
- bond tests in order to determine: the adhesion capacities of TRM composites applied upon brick, tuff or stone masonry substrates; the failure mode (cohesive debonding within the substrate or detachment at the textile-to-matrix or mortar-to-substrate interface, or, finally, by slippage of the textile within the matrix.
In the laboratory tests the innovative technique of optical contactless Digital Image Correlation (DIC) was successfully used for the measurement of displacement and strain fields, as well as for the analysis of the crack pattern (number, distance and width of the cracks).
