A review of debonding problems reported nationwide was carried out at the start of this project. A new adhesion test was then developed to evaluate the adhesion of waterproof membranes to both concrete and asphalt. This test, the blister test, enables adhesion to be measured directly at any of the different interfaces that make up a waterproof membrane system for bridge decks. Previous test methods have been less direct and limited to measuring only the overall behaviour of the whole system. Using the test, the effect of concrete type, texture and age has been investigated as well as the effect of screeds and concrete curing agents. The durability of the full waterproof system with asphalt has been studied for weathering periods of up to 2.5 years. Some other aspects of membrane adhesion have also been studied, namely asphalt (sand carpet type) and bitumen temperatures, the effect on adhesion of moisture and natural weathering of membranes prior to asphalt application. The results of this study have shown that with good quality concrete the age and type of concrete have little effect and the adhesion at the concrete to membrane interface is good and remains durable throughout the period studied. Deterioration in adhesion of the membrane to the asphalt was however discovered after about 1.5 years and this seemed to be due to a combination of changes in the asphalt itself and weakening of adhesion at the membrane to asphalt interface. In the final part of the project a prototype site test was developed to enable non-destructive evaluations of membrane adhesion to be made on a bridge deck prior to the application of asphalt.

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