ON THE ANCHORAGE TO CONCRETE OF SIKACARBODUR CFRP STRIPS: FREE ANCHORAGE, ANCHORAGE DEVICESAND TEST RESULTS
Abstract
The paper describes laboratory tests carried out in order to determine the ultimate force that a CFRP strip is able to obtain when bonded to concrete. Test series have been carried out for varying values of parameters such as concrete strength, anchorage length, thickness of the adhesive, and special anchorage devices like bonded transverse strips and bolted anchor plates. The bonded transverse strips and the bolted anchor plates have been tested in various numbers and positions across the anchorage length. The ultimate free anchorage force has been tested in relation to concrete strength (determined by LOK-test, CAPO-test, BOND-test and TORQ-test) including various types of SikaCaboDur CFRP strips (types S, M, and H). The mechanism of failure of free anchorage is explained and compared with the test observations. The test observations are also compared with the German recommendation for the design of the strengthening of structural components with SikaCarboDur CFRP strips. The structural behaviour of the anchorage devices is explained and compared with observations made during the laboratory tests in order to develop a mathematical model of the anchorage of CFRP strips bonded to concrete. On the basis of the tests carried out, it is discussed how the anchorage devices could be improved in future test series, and if the test set-up is relevant to the problem.