Backcalculation of Pavement Layer Moduli: Concrete Pavement This module utilizes a theoretical representation of the pavement structure in conjunction with the collected FWD data to back-calculate the moduli values of the pavement’s layers. Backcalculation of Pavement Layer Moduli: Asphalt Pavement This module utilizes the deflections measured at the corner of concrete slabs to determine the presence of voids under the slab. This is important at the Design/Analysis stage to determine the extent of stress reduction on the loaded slab due to load transfer. From these deflections, the load transfer between slabs can be calculated. When testing concrete pavements, the slabs are tested across the joints with one slab loaded and a sensor bridging over to the unloaded slab. The program also has the capability to normalize the back-calculated asphalt concrete layer moduli to any required temperature. Prediction of mean asphalt layer temperature and normalization of maximum deflection values to a standard temperature of 70° F are accomplished using the Asphalt Institute methods. This module will perform such a function on the raw FWD data.
![backcalculation layered pavement structure backcalculation layered pavement structure](https://ascelibrary.org/cms/asset/b329723a-2c0b-4c18-bb83-879a75160499/2.gif)
To compare data between the tested points, the deflection data needs to be normalized to a user specified design/analysis load. Modules available under this package include the following: Load Normalizationĭuring testing, the applied load will vary as a function of the pavement stiffness for a given load mode and drop height.
#Backcalculation layered pavement structure software#
ERI’s in-house developed Pavement Analysis Software is customized specifically for use with nondestructive deflection testing (NDT) using Falling Weight Deflectometers (FWD).