A modelling capability was developed for concrete pavements to provide a sound basis for refining the design method. Trial use was made of the STRAND finite element software, for modelling joint and crack behaviour in rigid pavements. A range of pavement structures, loading conditions and design issues was studied. Modelling of tied shoulders and dowelled transverse joints gave results consistent with the AUSTROADS design procedure, which allows significantly thinner pavements in these cases. However, the modelling of various sub-base types suggested that the AUSTROADS design procedure needs review in respect of its nomination of effective subgrade CBR values for different sub-bases. The modelling of thermal modelling of thermal gradients on undowelled slabs showed that the surface horizontal tensile stress near the slab corner could be a governing factor for design. Also, variation of the slab corner angle from 90 degrees to 60 degrees showed that slab corner stresses increase significantly with acuity, justifying the use of steel fibre reinforced concrete for acute-angled slabs. The insights gained into the structural behaviour of concrete pavements, appeared to justify the use of STRAND as a modelling tool. (A)
Abstract