Engineering & Research International, Inc.

Pavement, Geotechnical and Materials Engineers

ERI’s in-house developed Pavement Analysis Software is customized specifically for use with nondestructive deflection testing (NDT) using Falling Weight Deflectometers (FWD). Modules available under this package include the following:

Load Normalization

During testing, the applied load will vary as a function of the pavement stiffness for a given load mode and drop height. To compare data between the tested points, the deflection data needs to be normalized to a user specified design/analysis load. This module will perform such a function on the raw FWD data.

Temperature Normalization

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. The program also has the capability to normalize the back-calculated asphalt concrete layer moduli to any required temperature.

Load Transfer

When testing concrete pavements, the slabs are tested across the joints with one slab loaded and a sensor bridging over to the unloaded slab. From these deflections, the load transfer between slabs can be calculated. This is important at the Design/Analysis stage to determine the extent of stress reduction on the loaded slab due to load transfer.

Void Detection

This module utilizes the deflections measured at the corner of concrete slabs to determine the presence of voids under the slab.

Backcalculation of Pavement Layer Moduli: Asphalt 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. Up to five layers can be analyzed.

Backcalculation of Pavement Layer Moduli: Concrete Pavement

This module utilizes a closed form solution based on extensive and comprehensive evaluation of concrete slabs using a finite element program. This program is capable of predicting the modulus of concrete slab for a given slab thickness, or the concrete slab for a given slab modulus.

Concrete Slab Analysis

Given a slab thickness, strength, and the anticipated load and tire pressure, this module will calculate the induced stresses and deflections in the slab thereby allowing for determination of its structural capacity.

Overlay Design for Asphalt Airfield Pavements

This is a very powerful computer program capable of utilizing any aircraft loading configuration in conjunction with back-calculated pavement layer moduli values to calculate the overlay thickness required for a given design period. One of its capabilities is to divide the year into different seasons. This is important to account for the variation in the anticipated pavement support condition and/or traffic intensity.

Overlay Design for Asphalt Roads

Similar to the program for airfield pavements, this module can calculate the overlay thickness for highway pavements. However, it accounts for traffic differently since the applied traffic is converted to Equivalent Single Axle Loads.

ERI’s pavement software is comprehensive, user friendly, expandable, and functionally sound. It’s a series of software applications designed for the Personal Computer environment. The software programs make use of data collected from a thorough evaluation of an entire pavement system, which logs the actual surface deflections of each segment of the pavement. The software is modular and expandable, easily updated, and comes with complete training manuals and warranty. This software can be purchased as either a complete package, or customized to include as many modules as applicable to the pavement types to be analyzed.