The bond strength of repairing systems applied to concrete elements: Analysis of historical data

The use of protection and repairing systems aimed at increasing the durability of concrete structures is a widespread technique. In particular, the use of external thermal insulation composite systems resulted to be a very promising repairing technique enhancing also the insulating behavior of the repaired construction works. This paper examines the performances of several protection systems when applied to concrete standard support elements. The effectiveness of this protection systems is evaluated by means of tests carried out according to ETAG 004 (Guideline for European Technical Approval of External Thermal Insulation Composite Systems "ETICS" with rendering.), before and after ageing (water immersion). The behavior of protection products is determined through the use of standard concrete slab produced according to EN 1776 (Products and systems for the protection and repair of concrete structure-Test methods-Reference concretes for testing). The research activity describes the comparison of different types of protecting materials and systems, produced and tested in a decade (2007-2017), in order to verify different behaviors according to product families and according to the evolution of product mechanical properties.