Improving Mechanistic-Empirical Design Procedures for Continuously Reinforced Concrete Pavement

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General Information
Solicitation Number: 1174
Status: Solicitation withdrawn
Date Posted: Oct 15, 2007
Last Updated: Jun 20, 2008
Solicitation Expires: Jun 30, 2008
Lead Organization: Texas Department of Transportation
Financial Summary
Commitment Start Year: 2008
Commitment End Year: 2009
100% SP&R Approval: Pending Approval
Commitments Required: $400,000.00
Commitments Received:
Contact Information
Lead Study Contact(s): Frank Bailey
rtimain@txdot.gov
Organization Year Commitments Technical Contact Name Funding Contact Name Contact Number Email Address

Background

NCHRP 1-37A developed mechanistic-empirical pavement design guide for CRCP, which is a major step forward in understanding of factors that might affect the behavior and performance of CRCP. However, punchout is the only structural performance indicator included in the algorithm. Thus, the ability to predict punchout accurately is quite important in this algorithm. In this algorithm, only one punchout mechanism was employed. Field evidence shows more than one mechanism exists for punchout. This fact was presented to NCHRP and it was reported that punchout models for different mechanisms could be incorporated into Version 1.0 or later. This hasn¿t been done. Also, spalling could be another performance indicator in CRCP. Even though spalling may not be a pavement design issue, substantial amount of work has been done in spalling, and the findings could be incorporated to improve current MEPDG.

Objectives

The objectives of this study are to develop improved mechanistic-empirical CRCP design procedures by identifying other punchout mechanisms, developing models for those mechanisms, and incorporating punchout and spalling models.

Anticipated products from this effort will include design algorithms that incorporate additional punchout and spalling models. These algorithms could be standalone design procedures, or the punchout algorithms in current MEPDG could be replaced with the products from this study.

Scope of Work

The tasks in this study will include:

*Identifying punchout and spalling mechanisms: in this task, efforts will be made to identify punchout and spalling mechanisms through laboratory, field, and theoretical analysis. Extensive field evaluations indicate there is more than one mechanism for punchout. One of the punchout mechanisms observed in several states, including Virginia, South Dakota, and Texas, is horizontal cracking at mid-depth of the slab. Another mechanism is due to imbalances of concrete forces at transverse construction joints. Other mechanisms will be identified and proper models developed after the validity and correctness of the models are validated in field experiments. Transfer functions will be developed for punchouts.

*Evaluation of currently available spalling models and identification of areas of needed improvements; in this task, existing spalling models will be evaluated for their reasonableness by comparing the model outputs with field performance data. If improvements are needed to existing models, further efforts will be made to refine the models.

*Field data collection for punchout and spalling; in this task, accurate field information on punchout and spalling will be collected. Punchout will be classified in terms of different mechanisms and proper data set will be used for calibration of each model.

*Developing CRCP design algorithms that incorporate punchout and spalling models; if the source code of MEPDG becomes available, the algorithms will be developed in such a way that they can easily replace the existing models in the MEPDG. If not, stand-alone algorithms will be developed.

*Information sharing among participating DOTs.

Comments

TxDOT currently has a project looking at these issues. The research team includes members from the Center for Transportation Research at The University of Texas at Austin and the Texas Transportation Institute. If this solicitation is successful, TxDOT will terminate the existing project and contribute any remaining funds to this pooled fund project. The pooled fund project is expected to continue with the same research team, and member states will share in results from both projects.

$30,000 per year is requested from each state.

TxDOT Technical Contact: German Claros, gclaros@dot.state.tx.us or 512-467-3881

No document attached.

Improving Mechanistic-Empirical Design Procedures for Continuously Reinforced Concrete Pavement

General Information
Solicitation Number: 1174
Status: Solicitation withdrawn
Date Posted: Oct 15, 2007
Last Updated: Jun 20, 2008
Solicitation Expires: Jun 30, 2008
Lead Organization: Texas Department of Transportation
Financial Summary
Commitment Start Year: 2008
Commitment End Year: 2009
100% SP&R Approval: Pending Approval
Commitments Required: $400,000.00
Commitments Received:
Contact Information
Lead Study Contact(s): Frank Bailey
rtimain@txdot.gov
Commitments by Organizations
No data available.

Background

NCHRP 1-37A developed mechanistic-empirical pavement design guide for CRCP, which is a major step forward in understanding of factors that might affect the behavior and performance of CRCP. However, punchout is the only structural performance indicator included in the algorithm. Thus, the ability to predict punchout accurately is quite important in this algorithm. In this algorithm, only one punchout mechanism was employed. Field evidence shows more than one mechanism exists for punchout. This fact was presented to NCHRP and it was reported that punchout models for different mechanisms could be incorporated into Version 1.0 or later. This hasn¿t been done. Also, spalling could be another performance indicator in CRCP. Even though spalling may not be a pavement design issue, substantial amount of work has been done in spalling, and the findings could be incorporated to improve current MEPDG.

Objectives

The objectives of this study are to develop improved mechanistic-empirical CRCP design procedures by identifying other punchout mechanisms, developing models for those mechanisms, and incorporating punchout and spalling models.

Anticipated products from this effort will include design algorithms that incorporate additional punchout and spalling models. These algorithms could be standalone design procedures, or the punchout algorithms in current MEPDG could be replaced with the products from this study.

Scope of Work

The tasks in this study will include:

*Identifying punchout and spalling mechanisms: in this task, efforts will be made to identify punchout and spalling mechanisms through laboratory, field, and theoretical analysis. Extensive field evaluations indicate there is more than one mechanism for punchout. One of the punchout mechanisms observed in several states, including Virginia, South Dakota, and Texas, is horizontal cracking at mid-depth of the slab. Another mechanism is due to imbalances of concrete forces at transverse construction joints. Other mechanisms will be identified and proper models developed after the validity and correctness of the models are validated in field experiments. Transfer functions will be developed for punchouts.

*Evaluation of currently available spalling models and identification of areas of needed improvements; in this task, existing spalling models will be evaluated for their reasonableness by comparing the model outputs with field performance data. If improvements are needed to existing models, further efforts will be made to refine the models.

*Field data collection for punchout and spalling; in this task, accurate field information on punchout and spalling will be collected. Punchout will be classified in terms of different mechanisms and proper data set will be used for calibration of each model.

*Developing CRCP design algorithms that incorporate punchout and spalling models; if the source code of MEPDG becomes available, the algorithms will be developed in such a way that they can easily replace the existing models in the MEPDG. If not, stand-alone algorithms will be developed.

*Information sharing among participating DOTs.

Comments

TxDOT currently has a project looking at these issues. The research team includes members from the Center for Transportation Research at The University of Texas at Austin and the Texas Transportation Institute. If this solicitation is successful, TxDOT will terminate the existing project and contribute any remaining funds to this pooled fund project. The pooled fund project is expected to continue with the same research team, and member states will share in results from both projects.

$30,000 per year is requested from each state.

TxDOT Technical Contact: German Claros, gclaros@dot.state.tx.us or 512-467-3881

No document attached.

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