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Testing and Evaluation of RAP and RAS Experimental Pavement Sections

Project Summary

Validation of the Maximum Allowable Amounts of Recycled Binder, RAP & RAS Using Accelerated Pavement Testing. In February 2013, 12 flexible pavement test sections were constructed for accelerated pavement testing (APT) through this project using Texas mixes in typical TxDOT pavement structures. Two sections were tested to failure in the period from March 15 to May 1, 20l4. APT testing will be conducted on the remaining 10 test sections in order to validate the cracking and rutting potential of both control and RAP and RAS modified mixes.

These key issues will be evaluated in this project: (1) Validate that poor results on lab prepared RAP and RAS samples translate to poor field performance under axle loads. Industry groups claim the lab studies do not simulate plant produced mixes. (2) Validate overlay design tools that have recently been developed by Texas A&M Transportation Institute (TTI) to predict mix cracking and rutting of new overlays. These models will be validated and calibrated for RAP and RAS mixes. Having a validated design system will then permit TxDOT designers to predict the performance of mixes containing different RAP and RAS levels for a range of existing pavement types with different pavement structures and different pre-existing cracking levels. (3) Determine if the proposed balanced mix design procedures, which incorporate both a cracking and rutting evaluation in the lab design phase, can be used to design RAP and RAS mixes with performances comparable to virgin mixes.

Project Number

0-6823

Status

Completed

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