Fungal Influenced Corrosion in Post-Tension Structures

2001 ◽  
Vol 10 (4) ◽  
pp. 44-48
Author(s):  
Brenda Little ◽  
Roger W. Staehle
Keyword(s):  
Tension Structures ◽  
Post Tension

A new steel anchorage system for post-tensioning applications using carbon fibre reinforced plastic tendons

1998 ◽  
Vol 25 (1) ◽  
pp. 113-127 ◽  
Author(s):  
Ezzeldin Y Sayed-Ahmed ◽  
Nigel G Shrive
Keyword(s):  
Carbon Fibre ◽  
Prestressed Concrete ◽  
Fatigue Tests ◽  
Direct Tension ◽  
Element Analysis ◽  
Prestressing Steel ◽  
Reinforced Plastics ◽  
Anchorage System ◽  
Post Tensioning ◽  
Post Tension

During the past half century, the use of prestressing in different structures has increased tremendously. One of the most important techniques of prestressing is post-tensioning. The main problem associated with post-tensioning in different structures is the corrosion of the prestressing steel tendons even with well-protected steel. New materials, fibre reinforced plastics or polymers (FRP), which are more durable than steel, can be used for these tendons/strands and thus overcome the corrosion problem. However, different shortcomings appear when FRP tendons are introduced to post-tensioning prestressing applications. For carbon fibre plastic tendons (CFRP), there is no suitable anchorage system for post-tensioning applications. Some of the anchorages developed by others for use with FRPs are therefore described and assessed. A new anchorage system developed by the authors, which can be used with bonded or unbonded CFRP tendons in post-tensioning applications, is described. The results of direct tension and fatigue tests on CFRPs anchored with the new system are presented.Key words: anchorage system, cyclic loading, fatigue, fibre reinforced plastics, finite element analysis, post-tension, prestressed concrete, prestressed masonry, strands, tendons.

scholarly journals A Scale Model of Tension Structures in Road Tunnels to Optimize the Use of Solar Light for Energy Saving

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Antonio Peña-García ◽  
Luisa-María Gil-Martín ◽  
Roberto Escribano ◽  
Antonio Espín-Estrella
Keyword(s):  
Energy Savings ◽  
Construction Materials ◽  
Electricity Consumption ◽  
Scale Model ◽  
Major Influence ◽  
Road Tunnels ◽  
Tension Structures ◽  
Materials Used ◽  
Set Up ◽  
New Equation

Shifting the threshold zone of road tunnels with semitransparent tension structures has shown itself to be an effective way of saving energy in regards to electricity consumption, maintenance, and construction materials used in the electrical lighting, thus lessening negative environmental impacts. Even though the shape of the tension structure has a major influence on energy savings, the optimal type of structure for each tunnel is often difficult to determine, because experiments using real tunnels are extremely expensive. It is thus necessary to find methods of doing this that are both reliable as well as economical. In this research study, three candidate structures were set up at the portal of a scale model of a real tunnel. The energy savings in each case were analyzed and compared. As a result, it was possible to formulate a new equation that calculates the energy savings in the threshold zone.

Diagnostics and monitoring of the longest span extradosed bridge in Europe

2019 ◽  
Author(s):  
Mikołaj Miśkiewicz ◽  
Krzysztof Wilde
Keyword(s):  
Health Monitoring ◽  
Diagnostic Procedures ◽  
Theoretical Assumptions ◽  
Speed Up ◽  
Internal Forces ◽  
Post Tension ◽  
Cantilever Construction ◽  
Final Acceptance ◽  
Acceptance Tests

<p>The article presents complex diagnostic procedures applied for the purpose of behavior analysis of the extradosed bridge with the longest span in Europe that was built in 2018 in Poland. The system of health monitoring was used to: register internal forces in temporary supports, monitor concrete bonding, perform in situ diagnostics and operation tests. The bridge is a continuous four‐span structure with spans theoretical lengths equaling: 132.5+206.0+206.0+132.5 m. During the construction of the bridge, two technical monitoring systems were used. As a consequence of their application, it was possible to carry out works with the lowest level of risk and therefore the work schedule was accelerated. The first of systems was designed to measure forces transferred to temporary supports during cantilever construction stages. The second system was designed to measure changes of the strength of curing concrete, after it was poured at the site, which allowed to speed up the removal of the scaffoldings and post‐tension of cross section with cables. When the bridge was finished, a Structural Health Monitoring (SHM) system was installed and final acceptance tests were launched. The obtained results were used to validate theoretical assumptions done at the stage of the bridge structural design and provided insight into the complex bridge behavior.</p>

Sign in / Sign up

Export Citation Format

Share Document