Comparisons between Asphalt Pavement Responses under Vehicular Loading and FWD Loading

Abstract

The strain responses of asphalt pavement layer under vehicular loading are different from those under falling weight deflectometer (FWD) loading, due to the discrepancies between the two types of loadings. This research aims to evaluate and compare the asphalt layer responses under vehicular loading and FWD loadings. Two full-scale asphalt pavement structures, namely, flexible pavement and semirigid pavement, were constructed and instrumented with strain gauges. The strain responses of asphalt layers under vehicular and FWD loadings were measured and analyzed. Except for field measurements, the finite element (FE) models of the experimental pavements were established to simulate the pavement responses under a wide range of loading conditions. Field strain measurements indicate that the asphalt layer strain under vehicular loading increases with the rising temperature roughly in an exponential mode, while it decreases with the rising vehicular speed approximately linearly. The strain pulses in the asphalt layer generated by FWD loading are different from those induced by vehicular loading. The asphalt layer strains generated by FWD loading are close to those induced by low vehicular speed (35 km/h). The results from the FE model imply that the asphalt layer strains under FWD loading and vehicular loading are distributed similarly in the depth profile. For flexible pavement, the position of critical strain shifts gradually from the bottom of the asphalt layer to the mid-depth of the layer, as the temperature increases. For semirigid pavement, the position of critical strain is always located at the intermediate depth of the asphalt layer, regardless of temperatures.

Performance Evaluation of Traffic Speed Deflectometer Based on Virtual Standard Test Road

“…This is mainly because the asphalt pavement is viscoelastic. Its mechanical properties are related to the loading time of the rear wheel [30].…”

“…In addition, considering that the modulus of viscoelastic pavements is influenced by the loading time [30], RD k,T theoretically should not cross each other at the three speeds and have a good linear relationship with RD k,F . From this perspective, the measuring performance of TSD can also be qualitatively evaluated.…”

“…Wix et al [16] compared the TSD measurements in New South Wales in two years and found better repeatability of the maximum deflection. Liao et al [1] showed that the variability of TSD measurements at three speeds (30,50, and 80 km/h) was lower than 5%. Shrestha et al [17] discussed the repeatability and correlation of TSD using approximately 9540 km of measuring data.…”

Estimation of Asphalt Mixture Fatigue Behaviour Using the Two-Point Bending Test

“…The asphalt mixture being a viscoelastic and anisotropic material, its mechanical characteristics change depending on certain factors: temperature, loading frequency and loading method Sun, 2019, Cheng, Wang andLiu, 2021c), Guo et al, 2021, Hu et al, 2022, Liu et al, 2022a, Xing et al, 2022, Yang et al, 2020, Zhang et al 2021. Fatigue resistance is influenced by different load variations (Mateos et al 2018, Xiao et al 2022.…”

Field Measurement and Analysis on the Mechanical Response of Asphalt Pavement Using Large-Particle-Size Crushed Stone Base Treated with Fly Ash and Slag Powder

“…Ai et al [2] measured the mechanical response within three pavement structures: semi-rigid base asphalt pavement, inverted pavement, and composite asphalt pavement. Cheng et al [22][23][24] constructed and compared the mechanical response of a typical semi-rigid base asphalt pavement and a flexible base asphalt pavement under different temperature and speed conditions. The pavement structures for which mechanical response studies have been carried out can be divided into two main categories: asphalt pavements with flexible and semi-rigid bases.…”