Bending mechanical properties research on prestressed airport concrete pavements

Abstract

To prevent airport pavements from suffering fatigue failure before the end of designed life and to construct high‐grade airport concrete pavements quickly, this study has developed a method which applies the prestressed concrete to airport pavements. A three‐point bending loading scheme has been designed to conduct the bending, flexural strength, and fatigue tests on 96 concrete beams. The results showed that, compared with ordinary concrete beams, the resistance of prestressed concrete beam to bending deformation was greatly enhanced. For the beams subjected to the vertical load with increasing prestressing force, however, the deflection of the beams was decreased by a minor degree while both of their tensile stress and tensile stress area showed a sharp decrease. Moreover, the flexural strength of the concrete showed an evident increased with verified degrees while both the numbers and the width of cracks generated at the bottom of specimens decreased significantly. The average fatigue life of the prestressed concrete beams was extended 3 to 6 times longer than that of the ordinary concrete beams depending on the increasing levels of prestressing force. In general, the bending fatigue life of the prestressed concrete beams follows the two‐parameter Weibull distribution with a correlation coefficient greater than 0.96. Based on this Weibull distribution, a double‐logarithmic fatigue equation among three parameters, that is, the survival rate P, the stress level S, and the fatigue life N has been developed.