基于FWD和温度梯度的CRCP反演方法修正

Corrections were made to reduce the error caused by temperature gradient based on the existing continuously reinforced concrete pavement (CRCP) backcalculation method given the condition of temperature difference (|ΔT|≥13.32℃) between the top and bottom of CRCP slab. Multiple finite element models given different combinations of temperature difference (|ΔT|=4.44, 8.88, 13.32, 17.76 ℃) and FWD (falling weight deflectometer) load were established using ILLISLAB, a 2-D finite element analysis software, to simulate a two-lane CRCP. The study was conducted based on the theoretical deflection values from the finite element model with the main factor being the influence of temperature difference on backcalculated results. The results show that maximum errors in backcalculated results (k-value, E and h_eff) reached 66.6%, 27.8% and 8.5%, respectively, when temperature difference is greater than 13.32 ℃ given the crack spacing in CRCP being higher than 3.0 m (10 feet), which cannot be ignored and as a result, an updated CRCP backcalculation method given higher temperature gradient condition was developed. The proposed backcalculation method was applied to a field CRCP test section near Chicago with the bonding condition between slab and base assessed to be overall good.