High Performance Concrete for Bridge A6130 -- Route 412 Pemiscot County, Missouri
Matching Research Agency
|Missouri Department of Transportation (MoDOT)|
|John J. Myers, Assistant Professor|
University of Missouri-Rolla
218 Engineering Research Laboratory
Rolla, MO 65409-0710
|One Ph.D. student, one M.S. student, and one undergraduate student|
The major project objectives for this research program are as follows:
- Assist the Missouri Department of Transportation (MoDOT) in the design and construction of a 5-span bridge structure in Pemiscot County near Hayti, Missouri.
- Update the state-of-the-art in high performance concrete bridge design and construction as reflected by research and engineering practice conducted and reported in the U.S. and elsewhere.
- Provide assistance, if required, to the precast manufacturer and/or ready-mix producer related to the production and placement of the high performance concrete for the precast prestressed girders and cast-in-place deck.
- Determine the properties of the concrete in the bridge for use in design.
- Provide technical support related to quality control and quality assurance for the precast and cast-in-place concrete as required by the Missouri Department of Transportation where feasible.
- Monitor the serviceability and structural performance both short-term and long-term of the concrete members in the structure i.e., monitor deflections of prestressed girders from casting through service conditions, perform condition survey, and monitor any signs of distress.
- Provide information to MoDOT bridge division engineers / RDT to compare the predicted values versus the actual performance of different structural members in the bridge.
- Provide assistance to the contractor, inspection, and design during all phases of construction.
|Through the years concrete has proven to perform best, be the most durable, and require the least maintenance of all bridge construction materials. Rehabilitation of the nation's crumbling infrastructure can be facilitated by further improving the properties of this known performer. An increase in durability alone can be expected to result in a significant savings due to the concomitant longer life with less maintenance of high performance concrete. In the past twenty years there have been major improvements in the field of concrete materials. High performance concrete with design compressive strengths between 10,000 psi and 15,000 psi (69 MPa and 90 MPa) can successfully be produced using conventional materials and concrete production methods. This has been possible through optimization of mix proportions using chemical admixtures and pozzolanic materials. The benefits from the utilization of high performance concrete are enhanced by the latest developments of the pretensioned concrete industry, including the use of 0.6-in. (15.24-mm) diameter strands. In order to take advantage of higher concrete design strengths, higher prestressing forces are required for prestressed precast fabricated members. To accomplish this, larger than traditional prestressing strands are required not only to meet prestressing requirements, but also to improve the constructability of the members. When higher reinforcement ratios are required issues related to excessive congestion of reinforcement and labor intensive fabrication issues often arise. Despite the obvious benefits from the utilization of high performance concrete and 0.6-in. (15.24-mm) diameter strands, the implementation of these developments has been very slow. This is in part due to the uncertainty that current design codes are applicable for the design with high performance concrete and 0.6-in. (15.24-mm) diameter strands. The codes now in use were developed considering normal concrete strengths, usually below 6,000 psi (41 MPa), and smaller strand diameters. Several code provisions and design parameters are empirically related to the concrete strength. Therefore, differences in material properties between normal strength concrete and high performance concrete may warrant revisions in the design provisions. Some of these differences are the characteristics strain-stress relationship, the modulus of elasticity, and the modulus of rupture. Furthermore, larger strands require greater bond stresses for anchorage due to the increased prestressing force per unit surface area. This reluctance to utilize high performance concrete is also due to lack of familiarity of designers and contractors with practices and requirements for proper design and construction of high performance prestressed concrete structures. The recognition of the full benefits of high performance concrete may be limited by traditional practices of design and construction that were developed for normal strength concrete. To date no comprehensive guidelines exist for the design and construction of high performance concrete bridges. This research program aims to address many of these issues related to material availability and standard bridge systems in Missouri.|
|These structures will result in lower construction costs, lower maintenance costs, and a longer service life, thereby a tremendous benefit to the residents of the State of Missouri. Specifically, the findings from this study may result in the following being implemented by the Missouri Department of Transportation: |
Furthermore, this project will provide high performance concrete experience to key concrete producer(s), fabricator(s), and contractor(s) who are involved in the project. Their experience using an innovative material such as HPC and larger pre-tensioning strands will further assist in implementing wider use of these materials within our state.
- The study may well serve to validate or recommend new design assumptions for the Missouri Department of Transportation to use for design of future HPC bridges in Missouri;
- The study may well serve to provide empirical relationships for design which may be implemented by the Missouri Department of Transportation resulting in more efficient designs of HPC bridges in Missouri;
- The study may well serve to validate or recommend modifications to current MoDOT HPC construction specifications for the construction of future HPC bridges in Missouri resulting in improved service life performance;
- The study may well serve to document the cost benefits of using HPC and further stimulate future projects;
- The study may well serve to provide an increased knowledge related to the use of HPC in transportation structures and serve as a successful case study for further implementation.
|Project Start Date:||09/01/2000|
|Project End Date:||02/28/2005|
Relationship to other Research/Projects
|This one of several ongoing research projects carried by the investigator related to high performance concrete under the Center of Infrastructure Engineering Studies.|
Technology Transfer Activities
|Findings will be published in structural, construction, materials and/or bridge related journals and conference proceedings. Interim and final reports will also be available through the University of Missouri-Rolla and the Missouri Department of Transportation. Findings will also be disseminated through seminars and workshops organized by UMR research centers.|
Transportation Research Board Keywords