VERTICAL MOVEMENT OF JOINTED CONCRETE PAVEMENTS

The vertical deflection of a concrete pavement under truck loading may be the determining factor in predicting the service life of the pavement. Consequently, it is of prime importance to know the effect of different variables on this vertical movement. To study experimentally the effects of the variables, a test pavement was constructed as part of US-23 in Chillicothe, Ohio. Data have been collected on this pavement continuously since 1972. To isolate the variables, the pavement was divided into 10 sections of approximately 10 joints each. Vertical measurements were taken by using a truck with a measured axle load. The measurements provided continuous plots of the vertical movements as the test truck traveled over the joint. Measurements were repeated at different speeds to determine the effect of truck speed on pavement deflection. Measurements were also repeated both morning and afternoon to study the effect of pavement curl. The measurements were analyzed statistically to determine the relative effects of the different variables on the behavior of the slab. The analysis indicated that there is a significant effect on slab behavior caused by difference in the subbase, location of the truck on the pavement, speed of the truck, and time of measurement (morning versus afternoon). Only a minor effect was noted due to spacing of joints, types of dowels, and a configuration of the saw cut.