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Develop/Improve American Association of State Highway and Transportation Officials Concrete Coefficient of Thermal Expansion Test

Project Information

Project ID: 
FHWA-PROJ-10-0061
Project Status: 
Completed
Start Date: 
Friday, October 1, 2010
End Date: 
Tuesday, September 30, 2014
FHWA Program: 
Infrastructure
FHWA Subprogram: 
Pavement and Materials
FHWA Topics: 
Research/Technologies--Turner-Fairbank Highway Research Center (TFHRC)
TRT Terms: 
Hydraulic Cement; Thermal Expansion; Pavements; Portland Cement Concrete; Infrastructure; Research; Aggregates
FHWA Discipline: 
Pavement and Materials
TRB Subject Area: 
Pavements, Materials, Research

Contact Information

First Name: 
Ahmad
Last Name: 
Ardani
Telephone: 
(202) 493-3422
Email Address: 
Team: 
Infrastructure Materials Team
Office:
Office of Infrastructure Research and Development
Office Code: 
HRDI-10

Project Details

Project Description: 

Coefficient of Thermal Expansion (CTE) has been found to be a very important factor in the performance of concrete pavement, and having more accurate CTE values for the actual mixture will improve the accuracy of performance predictions and evaluations of concrete pavement sections. As so, this project aims to refine the American Association of State Highway and Transportation Officials (AASHTO) Standard Test Method for the Coefficient of Thermal Expansion of Hydraulic Cement Concrete. Subsequently, it involves leading and participating in a ruggedness and precision evaluation using various CTE equipment options: Pine, Gilson, and manual. During ruggedness testing, specimen size, initial temperature, time for temperature stabilization, water level, degree of saturation, and number of segments will be evaluated. This project also encompasses assisting AASHTO on modifying the standard test method and implementing the test method.

Partners and Other Sponsor/Managing/Performing Organizations: 
Project Findings: 

During the evaluation and testing of the Thermal Coefficient of Expansion (CTE) of concrete cores taken from many Long-Term Pavement Performance (LTPP) portland cement concrete pavement (PCCP) test sections, it was discovered that the CTE is an important parameter in the design and evaluation of PCCP performance. The test method has been refined and improved. All of the LTPP CTE data are now available for each section in the Long-Term Pavement Performance Database. Many technical papers and reports have been written utilizing CTE data from the Turner-Fairbank Highway Research Center tests of PCCP cores. In addition, all the recommended modifications to the AASHTO T336, as well as the precision statement, have been approved by AASHTO and included in the standard test method.

Deliverables

Deliverable Name: 
Improved testing methods for the Coefficient of Thermal Expansion (CTE) of concrete with an estimate of variability and LTPP update
Deliverable Type: 
Research report or guidelines
Deliverable Description: 
The test method has been refined and improved: all the modifications recommended to the AASHTO T336, as well as the precision statement, have been approved by AASHTO and included in the standard test method. In addition, all of the Long-Term Pavement Performance (LTPP) Thermal Coefficient of Expansion (CTE) data have been updated and are now available for each section in the LTPP Database. Many technical papers and reports have been written either utilizing CTE from the LTPP database or additional data produced at TFHRC as well as the results of the ruggedness and precision studies. TFHRC has assisted many State DOTs to implement this testing methodology so that they could use the AASHTO Pavement ME Design software, since the CTE is one of the most important inputs for this software. As a result of this assistance, the improvement of the test method and the confidence on the results obtained using AASHTO T336: over 30 State highway agencies, over 60 private sector companies, 18 universities, 2 local agencies, 10 international agencies and 4 Canadian provinces licensed the AASHTO Pavement ME Design software; Caltrans has included CTE testing in quality control; and Texas DOT has set a maximum limit on the aggregates CTE.
Deliverable Name: 
Coefficient of Thermal Expansion (CTE) Testing Protocol.
Deliverable Type: 
Data
Deliverable Description: 
A fine-tuned Coefficient of Thermal Expansion (CTE) testing protocol approved by American Association of State Highway and Transportation Officials.