Sökning: "existing structures"

Visar resultat 1 - 5 av 613 avhandlingar innehållade orden existing structures.

1. 1. In-situ assessment of timber structures - Assessment methods and case studies

   Författare :Thomas Lechner; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; non-destructive testing NDT ; historical structures; density; In-situ assessment; timber structures; mechanical properties; assessment methods; X-ray;

   Sammanfattning : In the assessment of timber structures, diagnostic investigations with reference to the condition and structural performance of these structures are necessary and often require appropriate health monitoring techniques. This thesis covers four aspects within the research area of the in-situ assessment of timber structures based on scientific knowledge and guidelines to perform assessment of existing timber structures:IDetermination of density of wood with portable X-rayThe mechanical performance of timber is often strongly related to the density of wood. LÄS MER

3. 2. Multiphase models for freeze-thaw actions and mass transport in concrete hydraulic structures

   Författare :Daniel Eriksson; Anders Ansell; Richard Malm; Erik Nordström; Stefan Jacobsen; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Degradation; Hydraulic structures; Air-entrained concrete; Multiphase models; Multiphysics; Long-term moisture conditions; Freeze-thaw; Hysteresis; Absorption; Calcium leaching; Finite Element Method; Concrete Structures; Betongbyggnad;

   Sammanfattning : A crucial task for civil engineers is to make appropriate designs of new concrete structures and assessments of existing structures to ensure a long service life and sustainable use of the infrastructure. This doctoral thesis aims to increase the understanding of how advanced mathematical models can be used to describe phenomena and processes governing concrete degradation and thereby ultimately contribute to improving tools for design and assessments. LÄS MER

4. 3. Load-Carrying Capacity of Damaged Concrete Structures

   Författare :Kamyab Zandi; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; frost; bond properties; material properties.; Existing concrete structures; load-carrying capacity; corrosion of reinforcement;

   Sammanfattning : AbstractA growing need for better assessment of existing structures has revealed the need for improved understanding of structural effects of deterioration. The two most common causes of deterioration in concrete structures are corrosion of reinforcement and freezing of concrete. LÄS MER

5. 4. Anchorage of Corroded Reinforcement in Existing Concrete Structures: Experimental Study

   Författare :Mohammad Tahershamsi; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; anchorage; reinforced concrete structures; structural behaviour; natural corrosion; Bond properties; experiments; load-carrying capacity.;

   Sammanfattning : The decrease in bond capacity and its relationship to the crack widths and patterns documented were studied for both the naturally corroded specimens tested in this study and artificial corrosion tests from the literature. A reduction of bond strength with increasingly maximal crack widths was observed in both types of tests. LÄS MER

7. 5. Fracture Mechanics in Design and Assessment of Existing Structures: Two Case Studies

   Författare :Pourya Noury; Raid Karoumi; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Steel Structures; Stålbyggnad;

   Sammanfattning : In the present thesis, the application of fracture mechanics in design and assessment of steel structures has been studied.The first case study concerns a ring-flange connection used in wind turbine towers. The flange is rolled from straight steel profile into a complete ring. LÄS MER