Sökning: "Concrete Structures"

Visar resultat 21 - 25 av 296 avhandlingar innehållade orden Concrete Structures.

1. 21. Natural corrosion in reinforced concrete structures

   Författare :Samanta Robuschi; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Natural corrosion; pitting corrosion; reinforced concrete structures; chloride-induced corrosion.; neutron imaging; anchorage; plain bars; X-rays CT;

   Sammanfattning : Among the threats to the durability of concrete structures, corrosion of the reinforcement bars is undoubtedly the most common one. Corrosion damages impair safety and durability of infrastructure, and assessment of the safety is challenging due to the complex nature of the corrosion process. LÄS MER

3. 22. Reliability-based assessment procedures for existing concrete structures

   Författare :Joakim Jeppsson; Avdelningen för Konstruktionsteknik; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; concrete; reliability theory; service life; assessment; monitoring; hydraulic engineering; Civil engineering; offshore technology; soil mechanics; Väg- och vattenbyggnadsteknik;

   Sammanfattning : A feasibility study of reliability theory as a tool for the assessment of present safety and residual service life of damaged concrete structures has been performed in order to find a transparent methodology for the assessment procedure. It is concluded that the current guidelines are open to interpretation and that the variation in the results obtained regarding the structural safety is too great to be acceptable. LÄS MER

4. 23. Multiscale Modelling of Reinforced Concrete Structures

   Författare :Adam Sciegaj; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; cracking; reinforced concrete; computational homogenisation; bond-slip; multiscale;

   Sammanfattning : Concrete cracks at relatively low tensile stresses; cracks open up for ingress of harmful substances, negatively affecting the durability of reinforced concrete structures. Crack widths are thus limited in the design codes, and accurate predictions are needed, especially for large reinforced concrete structures such as bridges or nuclear reactor containment buildings. LÄS MER

5. 24. Frost-induced deterioration of concrete in hydraulic structures : Interactions between water absorption, leaching and frost action

   Författare :MARTIN ROSENQVIST; Avdelningen för Byggnadsmaterial; []
   Nyckelord :Vattenbyggnader; Dammar; Betong; Cement; Vattenabsorption; Vattenmättnadsgrad; Nedbrytning; Frostbeständighet; Spjälkning; Makroskopisk islinsbildning; Urlakning; Synergi; Hydraulic structures; Dams; Concrete; Cement; Water absorption; Degree of saturation; Deterioration; Frost resistance; Spalling; Macroscopic ice lens growth; Leaching; Synergy;

   Sammanfattning : Frost deterioration of concrete can result in severe consequences to the safety, durability and functionality of a structure since it impairs the strength of the concrete. Frost damage may occur to structures that are in contact with water and subjected to frost action. LÄS MER

7. 25. Toward Realistic Failure Evaluations for Concrete Buttress Dams

   Författare :Jonas Enzell; Anders Ansell; Erik Nordström; Andreas Sjölander; Richard Malm; Leif Lia; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; concrete dams; buttress dams; stability analysis; dam failure behavior; physical model tests; FEM; betongdammar; lamelldammar; stabilitetsanalys; dammbrott; fysiska modellförsök; FEM; Betongbyggnad; Concrete Structures;

   Sammanfattning : Concrete dams, complex structures supporting massive loads, have traditionally been assessed using simplified 2D analytical stability analyses based on the rigid body assumption. Previous studies have shown that 3D behavior, such as the interaction between the monoliths and the valley's geology, can greatly impact the load-bearing capacity of gravity dams but remains largely unexplored in buttress dams. LÄS MER