This paper describes a numerical thermo-mechanical model for concrete pavement, implemented in OOFEM software. The thermal part is a heat transfer problem with appropriate initial and boundary conditions (sun irradiation, radiation and convection), calibrated from experimental data. Heat release from cement hydration is also included, calibrated for commonly used cements to demonstrate the difference that can be achieved with the binder selection. The mechanical part of the problem is composed of a 3D elastic concrete slab, subsoil Winkler-Pasternak elements and 1D interface elements, allowing separation in tension. The Winkler-Pasternak constants C1 and C2 were firstly determined from TP170 document and refined later from static load tests on the highway. The model validates well temperature field, static load test and provide several useful insight such as feasible time for summer casting, stress/strain fields and slab separation from the base.

Concrete pavements are subjected to the combination of moisture transport, heat transport and traffic loading. A hygro-mechanical 3D finite element model was created in OOFEM software in order to analyse the stress field and deformed shape from a long-term non-uniform drying. The model uses a staggered approach, solving moisture transfer weakly coupled with MPS viscoelastic model for ageing concrete creep and shrinkage. Moisture transport and mechanical sub-models are calibrated with lab experiments, long-term monitoring on D1 highway and data from 40 year old highway pavement. The slab geometry is 3.5×5.0×0.29 m, resting on elastic Winkler-Pasternak foundation. The validation covers autogenous and drying strain on the slab. The models predict drying-induced tensile stress up to 3.3 MPa, inducing additional loading on the slab, uncaptured by current design methods.

This paper is focused on the analysis of concrete pavements using finite element method (FEM). Specifically, it deals with the analysis of temperatures in the initial phasis of hardening and their influence on mechanical behavior of concrete pavement. High temperatures from hydration and climatic conditions in the early phase of concrete hardening co-operate and may initiate the formation of a network of micro-cracks on the surface of the concrete slab. The resulting temperatures (from hydration and climate) can theoretically be positively influenced by determining the start of concreting, so that the maximum temperatures do not meet at the same time. However, from a practical point of view the use of retarders is more realistic. Another possibility is to reduce the hydration heat by changing the composition of the concrete mixture (amount of cement, type of cement, use of alternative binders). Based on the knowledge of the material composition of the concrete and the specific temperature behavior during the concrete laying, it will be possible to predict the durability of concrete pavement in the future. Using weak formulation FEM model with quadratic base functions, the 2D heat transfer model was created. Boundary conditions were determined from experimental measurement on highway D1 in the Czech Republic. When this model was fitted to experimental data, the 3D coupled thermo - mechanical model was created. Soil and concrete elastic material characteristics had been taken over from Czech technical norms. Soil was modelled as Winkler-Pasternak 2D plate. Parameters c1 a c2 were assessed from comparison with 3D model with soil modelled as multiple layer system.