Determining the effect of sub-base type and friction coefficient on load transfer values for rigid aircraft pavements

Abstract

Rigid aircraft pavement load transfer can be affected by several factors, including loading regime, sub-layer support, joint type and climate. The effect of using a bound sub-base instead of an unbound sub-base on load transfer is not well understood, with previous literature reporting either an increase, decrease, or no significant effect on load transfer values. Additionally, when modelling load transfer, the friction coefficient between slab and sub-base has been modelled using a large range of values. This research aimed to isolate the effect of sub-base type, as well as quantifying the effect of slab to sub-base friction coefficient on load transfer values. Through finite element methods, it was determined that sub-base type has only a minor effect on typical load transfer values for dowelled and butt construction joints. Consequently, for these joint types, the selection of sub-base type is not critical to achieve effective load transfer. However, the effect on sinusoidal construction joints was significant. It was also determined that modifying the slab to sub-base friction value increased joint deflection and bending stress, however, had negligible impact on load transfer.