METHODS FOR ADHESION TESTING BETWEEN COMPOSITE AND BUILDING MATERIALS SUBSTRATES (BIM-24)
Use of composite materials in construction is becoming increasingly popular as a technique for static and seismic upgrading of both masonry structures and reinforced concrete. Reasons for this new trend are various and are closely related to intrinsic properties of these materials: very good strength/weight ratio, lightness, total or partial reversibility, durability, versatility.
At same time, however, in order to make effective reinforcing action, the bonding system must be perfect and must meet the minimum requirements of adhesion levels. Hence the need to carry out some experimental adhesion characterization tests of two different types: normal adhesion (pull-off tests) and tangential adhesion (DSS test - Direct Shear Strip Test ). Of these two types of test, only one is regulated (ie the normal adhesion test), although it is still not updated for all types of more recent used materials such as, for example, inorganic matrices. For second type of test (tangential adhesion test), however, at present there is no technical rules that standardize the methodology.
CETMA has carried out wide series of laboratory scale trials (organic and inorganic matrices, reinforcements of different materials and with multiple textile architectures, masonry or concrete substrates) and has developed a series of practical and technical devices via which can comprehensively and reliably perform adhesion test of bonding system.
Finally, unlike other testing methods, such as infrared thermography or ultrasound, which provide a qualitative estimate of the composite-material substrate bonding system, the aforementioned adhesion tests provide a quantitative estimate and, then , easily comparable with reference standard specifications.
CETMA has matured over many years extensive experience in development of practical and technical precautions and proper procedure to be followed in testing phase and for processing experimental data
CETMA is therefore able to offer a service for characterization of bonding system of composite/masonry or concrete substrate in quality controls and / or structural testing.