Temperature Changes as Decesive Loads for Concrete Slabs and Joint Sealings

Temperature changes within concrete pavements are transient. Therefore the temperature characteristics along pavement thickness are not linear and have to be split into constant, linear and equilibrium parts for further investigations. The linear temperature gradients are causing additional loading on concrete slabs, which if not considered will influence the long-term properties of the pavement by cracking. Both the changes within the linear and within the constant temperature parts are decisive for the loading of joint filling materials for jointed plain concrete pavements (JPCP). For more than one year the temperature distributions along the cross-sections (thickness or z-axis) of typical pavements for highways and airports (22cm up to 40cm thick concrete pavements on a 15cm thick cement treated base layer) have been measured. This database has been used to analyse the decisive stress distributions. Based on simulation work using 2-D FE-models the effective linear temperature gradients were determined, which are decisive for the pavement design procedure. Furthermore the data served as a basis for calculating both the resulting expected average changes in joint gap width at different seasonal temperature levels and respective rates of change. Hot and cold sealing compounds or compression sealing materials have to withstand those loadings.