Temperature Correction of Multiload-Level Falling Weight Deflectometer Deflections

Abstract

A new temperature correction procedure was developed for multiload-level falling weight deflectometer (FWD) deflections for flexible pavements in North Carolina. In this procedure, temperature correction factors were dependent on the radial offset distance from the FWD load plate. Temperature and FWD multiload-level deflection data used in developing this procedure were collected from 11 pavements in three different climatic regions of North Carolina. The effect of the FWD load level on this temperature correction procedure was investigated. Research efforts focused on improving the accuracy of the current temperature correction procedure of the North Carolina Department of Transportation. The measured deflection and temperature data were also used to validate the long-term pavement performance (LTPP) temperature correction procedure. It was found that the effective pavement temperature prediction algorithm in the LTPP procedure is relatively accurate and that the temperature-deflection correction procedure undercorrects the deflections at higher temperatures in pavements with an asphalt concrete layer thicker than 242 mm. The main reason for this deficiency is that the LTPP procedure was developed from the national database and cannot fully consider the local variation in mixture characteristics.

Development of an Artificial Neural Network-Based Procedure for the Verification of Traffic Speed Deflectometer Measurements

“…Temperature Correction and Deflection Normalization. TSD and FWD deflections were adjusted to a reference temperature of 68°F (20°C) using the procedure presented by Park et al (19). TSD and FWD deflections can be adjusted by multiplying the deflection value at a given spacing by the temperature correction factor calculated by Equation 1.…”

The Application of Frequency-Temperature Superposition Principle for Back-Calculation of Falling Weight Deflectometer

“…On the basis of the BELLS temperature prediction model proposed by Lukanen et al [16], Park et al [17] established a temperature prediction model appropriate for Michigan State in the United States by using temperature data from the seasonal monitoring of the US Long-Term Pavement Performance project. Park et al [18] and Marshall et al [19] verified another model, named BELLS3, in North Carolina and Tennessee, respectively. Zheng et al [20] employed the BELLS equations as a basis for establishing a temperature prediction model for Henan, China.…”

Temperature Correction of Deflections and Backcalculated Elasticity Moduli Determined from Falling Weight Deflectometer Measurements on Asphalt Pavements

“…This has to be considered in diagnostics and evaluation of asphalt pavement bearing capacity. The necessity of temperature correction has already been clearly proven in numerous scientific publications, e. g. [2][3][4][5][6][7][8][9][10][11].…”

“…According to [12], the temperature of pavement during the measurement has to be in the range of 0 -30 °C. The temperature of pavement is characterized by the average temperature of asphalt layers, which is considered as the temperature in a certain depth under the pavement surface, e. g. 40 mm [1][2][3][4][5][6][7][8][9][10][11][12] or 50 mm [10].…”