Strain-based equivalent temperature gradient in concrete pavement and comparison with other quantification methods

It is well known that temperature along the depth of concrete pavement slabs is highly nonlinearly distributed. Utilising appropriate methods is crucial for quantifying an equivalent temperature gradient and the associated curling and stress calculations. The existing methods to obtain a temperature gradient are either simply by subtracting the bottom surface temperature from the top surface temperature (ΔTtop-bottom) or by converting the nonlinear temperature distribution to an equivalent temperature difference (ΔTeq) based on the measured temperature distribution. None of the above methods are based on the strain which is the direct cause of slab curling. This study measures the strain development at different depths of field-instrumented concrete pavement slabs. A new strain-based quantification method for an equivalent temperature gradient (ΔTstrain) is developed based on the field strain measurements. The quantified ΔTstrain is then compared to ΔTtop-bottom and ΔTeq. Their validity is verified by the field-measured slab-curling data. The newly developed strain-based method provides an alternative way for the temperature-associated performance evaluation of the concrete pavement slab.