Distinction of road categories by road users compared to road classification in design guidelines

2014 ◽  
Vol 9 (3) ◽  
pp. 23-34
Author(s):  
Gabriella Iván
Keyword(s):  
Design Guidelines ◽  
Road Users

A FRAMEWORK TO EVALUATE ROAD USERS’ SATISFACTION LEVEL

2013 ◽  
Author(s):  
Suthathip Suanmali ◽  
◽  
Veeris Ammarapala ◽  
Paphitchaya Kobsanthia ◽  
Theerarat Siriaramsakul ◽  
...  
Keyword(s):  
Satisfaction Level ◽  
Road Users

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.

Seismic design guidelines for solid and perforated hybrid precast concrete shear walls

PCI Journal ◽  
2014 ◽  
Vol 59 (3) ◽  
pp. 43-59 ◽  
Author(s):  
Brian J. Smith ◽  
Yahya C. Kurama
Keyword(s):  
Seismic Design ◽  
Precast Concrete ◽  
Shear Walls ◽  
Design Guidelines
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