Condition Evaluation of Concrete Bridges Relative to Reinforcement Corrosion.Volume 4. Deck Membrane Effectiveness and a Method for Evaluating Membrane Integrity

摘要

No techniques exist for nondestructively evaluating the integrity of preformedmembranes in place. Further, little is known regarding the continued effectiveness of membranes that are damaged during installation or in service. Therefore, an intensive investigation was conducted to evaluate membrane performance and effectiveness. The main objectives of the study were to: develop a nondestructive test method for evaluating the integrity of membranes in place; investigate the effectiveness of membranes, relative to chloride barrier properties, as a function of membrane integrity; and evaluate the factors that may affect membrane performance, including membrane type and age, climate, and deicer application rate. A nondestructive methodology using ultrasonic pulse velocity was developed to predict the membrane status. The laboratory study and field validation concluded that preformed membrane systems reduce chloride intrusion when properly installed and overlaid with at least 2.5 in. (6.4 cm) of hot-mix asphalt, which should be kept in good service condition. An average life of 40 years is expected for preformed membrane systems, and an increase of 25 years in bridge deck life is expected.