New Trends in Prestressed Concrete Bridges

2000 ◽  
Vol 1696 (1) ◽  
pp. 238-272
Author(s):  
Michel Virlogeux
Keyword(s):  
Prestressed Concrete ◽  
High Performance ◽  
High Performance Concrete ◽  
Concrete Structures ◽  
Concrete Bridges ◽  
Prestressed Concrete Bridges ◽  
External Prestressing ◽  
Different Types ◽  
Composite Bridges ◽  
Cable Stayed Bridges

An overview of the recent evolution in the design and construction of prestressed concrete bridges worldwide is provided. Several major trends are evidenced. Certainly those trends that have had greater influences on the industry because of their wide applications are the development of external prestressing, which is now systematically used in some countries for medium-span bridges; the emergence of high-performance concrete, which extends the possibilities at the same time as it improves the durability of concrete structures; and the more frequent association of steel and concrete for composite bridges of different types and composite elements in bridges, allowing the construction of many innovative structures. For more specific applications, cable-stayed bridges, for which interesting developments have been seen in the last 10 years, and the more extensive use of heavy prefabrication in large projects, with elements up to several thousands of metric tons, are also described. Bridge architecture is also discussed in terms of the fact that good structural designs can produce elegant prestressed concrete bridges.

scholarly journals Application of Large Prestress Strands in Precast/Prestressed Concrete Bridges

2020 ◽  
Vol 6 (1) ◽  
pp. 130-141
Author(s):  
Amin K Akhnoukh
Keyword(s):  
Prestressed Concrete ◽  
High Performance ◽  
High Performance Concrete ◽  
Large Diameter ◽  
Concrete Bridges ◽  
Bridge Construction ◽  
Prestressed Concrete Bridges ◽  
Research Findings ◽  
Flexure Capacity ◽  
Precast Prestressed Concrete

The objective of this research is to investigate the advantage of using large-diameter 0.7-inch (18 mm) strands in pretention applications. Large-diameter strands are advantageous in bridge construction due to the increased girders capacity required to sustain exponential increase in vehicle numbers, sizes, and weights. In this research, flexure capacity of girders fabricated using 0.7-inch (18 mm) diameter strands will be calculated and compared to bridge capacities constructed using smaller strands. Finally, two similar bridge sections will be designed using 0.6-inch (15 mm) and 0.7-inch (18 mm) diameter strands to quantify the structural advantages of increased strand diameter. The research findings showed that a smaller number of girders is required for bridge construction when larger strands are used. Four girders are required to design the bridge panel using high performance concrete and large diameter strands, as compared to 6 girders required when regular concrete mix designs and normal size strands are used. The advantages of large strands and high-performance concrete mixes include expedited construction, reduced project dead loads, and reduced demand for labor and equipment. Thus, large strands can partially contribute to the improvement of bridge conditions, minimize construction cost, and increase construction site safety.

scholarly journals MEASUREMENT OF DEFLECTION LINE ON BRIDGES

2013 ◽  
Vol 95 (1) ◽  
pp. 64-75
Author(s):  
Rudolf Urban ◽  
Martin Štroner
Keyword(s):  
Prestressed Concrete ◽  
Concrete Structures ◽  
Measurement Procedure ◽  
Concrete Bridges ◽  
Prediction Methods ◽  
Prestressed Concrete Bridges ◽  
Long Span ◽  
Bridge Structures

Abstract Prestressed concrete bridges are very sensitive to the increase in long-term deflections. Reliable forecasts of deflections of bridge structures during construction and durability are crucial for achieving good durability. The main results of measurements are the changes of the deflection line of the bridge structures, which places special demands on the measurement procedure. Results from measurements are very useful for the improvement of mathematical prediction methods of behaviour of long span prestressed concrete structures.

Disease Analysis and Solutions of the Prestressed Concrete Bridge Cracks

2012 ◽  
Vol 178-181 ◽  
pp. 2398-2400
Author(s):  
Da Zhang ◽  
Hong Bo Yao
Keyword(s):  
Prestressed Concrete ◽  
Preventive Measures ◽  
Concrete Structures ◽  
Concrete Bridges ◽  
Concrete Bridge ◽  
Bridge Function ◽  
Prestressed Concrete Bridges ◽  
Treatment Measures ◽  
Prestressed Concrete Bridge ◽  
Disease Analysis

Prestressed concrete bridge, once completed, will inevitably generate a lot of cracks.These cracks seriously impact on the use of the bridge function. Cited a variety of cracks in prestressed concrete bridges, and from the cracks of prestressed concrete structures and components, described the causes of the prestressed concrete bridge cracks ,thus proposed a crack-effective preventive measures and treatment measures.

Flexural design of precast, prestressed ultra-high-performance concrete members

PCI Journal ◽  
2020 ◽  
Vol 65 (6) ◽  
pp. 35-61
Author(s):  
Chungwook Sim ◽  
Maher Tadros ◽  
David Gee ◽  
Micheal Asaad
Keyword(s):  
Prestressed Concrete ◽  
High Performance ◽  
High Performance Concrete ◽  
Limit State ◽  
Design Guidelines ◽  
Design Tool ◽  
Supplementary Cementitious Materials ◽  
Ultra High Performance Concrete ◽  
Concrete Members ◽  
Cylinder Strength

Ultra-high-performance concrete (UHPC) is a special concrete mixture with outstanding mechanical and durability characteristics. It is a mixture of portland cement, supplementary cementitious materials, sand, and high-strength, high-aspect-ratio microfibers. In this paper, the authors propose flexural design guidelines for precast, prestressed concrete members made with concrete mixtures developed by precasters to meet minimum specific characteristics qualifying it to be called PCI-UHPC. Minimum specified cylinder strength is 10 ksi (69 MPa) at prestress release and 18 ksi (124 MPa) at the time the member is placed in service, typically 28 days. Minimum flexural cracking and tensile strengths of 1.5 and 2 ksi (10 and 14 MPa), respectively, according to ASTM C1609 testing specifications are required. In addition, strain-hardening and ductility requirements are specified. Tensile properties are shown to be more important for structural optimization than cylinder strength. Both building and bridge products are considered because the paper is focused on capacity rather than demand. Both service limit state and strength limit state are covered. When the contribution of fibers to capacity should be included and when they may be ignored is shown. It is further shown that the traditional equivalent rectangular stress block in compression can still be used to produce satisfactory results in prestressed concrete members. A spreadsheet workbook is offered online as a design tool. It is valid for multilayers of concrete of different strengths, rows of reinforcing bars of different grades, and prestressing strands. It produces moment-curvature diagrams and flexural capacity at ultimate strain. A fully worked-out example of a 250 ft (76.2 m) span decked I-beam of optimized shape is given.

Sign in / Sign up

Export Citation Format

Share Document