Lecture 28 Rigid PavementsTypes of concrete pavementReinforced jointed concrete pavement - RJCPStressesP is the applied load and h is the pavement thicknessLecture 28 Rigid Pavements General discussion related to design method and cracking control and stress in concrete pavements.Types of concrete pavementUnreinforced jointed concrete pavement - PJCPReinforced jointed concrete pavement - RJCPContinuos concrete pavement - CRCPSlab design - Stress due to loads determined by beam on elastic foundation techniquesCracks are going to occur and are controlled by joints,temperature steel and load transfer devicesStresses Load - basically from bending conditions and take the formIn general as233312212hPxhlhIPxMP is the applied load and h is the pavement thicknessOr for specific applications something like l is the radius of relative stiffness and b is the relative radius of the loadTemperature stress - related to differential in temperature between top and bottom of the slabfrom plate theory)1(122utEhMwhen substitute into the bending stress equationIMcproducee is the coefficient of thermal expansion, t is the temperature differential and E is the modulus of elasticity of concrete. This equation is from platetheory Crack control is related to the type and spacing of the joints. Typically is short spacing for PJCPand longer spacing for RJCP. Both types have load transfer devices along the joint to prevent joint destruction and eliminate pumping of the sub grade materials. Typical joints and spacingpatterns are available from MDOT Standard Plans.Pavement