Sökning: "Existing concrete structures"

Visar resultat 31 - 35 av 86 avhandlingar innehållade orden Existing concrete structures.

1. 31. Numerical models for degradation of concrete in hydraulic structures due to long-term contact with water

   Författare :Daniel Eriksson; Anders Ansell; Richard Malm; Erik Nordström; Katja Fridh; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; degradation; deterioration mechanisms; hydraulic structures; air-entrained concrete; multiphase model; long-term moisture conditions; pore size distribution; freezing; partially saturated; finite element method; Civil and Architectural Engineering; Byggvetenskap;

   Sammanfattning : The durability of concrete is of major concern in all types of concrete structures where the combined effect of exposure conditions and the type and quality of the concrete material usually determines the rate of degradation. Furthermore, there are synergy effects between different deterioration mechanisms, which means that the combined rate of degradation is higher than the sum of the individual rates of each mechanism. LÄS MER

3. 32. Restraint Effects in Early Age Concrete Structures

   Författare :Majid Al-Gburi; Björn Engström; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Structural Engineering; Konstruktionsteknik;

   Sammanfattning : One of the widespread issues in concrete structures is cracks occurring at early age. Cracks that appear in the young concrete may cause early start of corrosion of rebars or early penetration of harmful liquids or gases into the concrete body. LÄS MER

4. 33. Steel fibre corrosion in cracks : durability of sprayed concrete

   Författare :Erik Nordström; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Structural Engineering; Konstruktionsteknik;

   Sammanfattning : Steel fibre reinforced sprayed concrete is common practice for permanent linings in underground construction. Today there is a demand on "expected technical service life" of 120 years. Thin steel fibres could be expected to discontinue carrying load fast with a decrease of fibre diameter caused by corrosion, especially in cracks. LÄS MER

5. 34. Assessment of Concrete Bridges : Models and Tests for Refined Capacity Estimates

   Författare :Niklas Bagge; Anders Carolin; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Structural Engineering; Konstruktionsteknik;

   Sammanfattning : Optimising the strategy for repairing, upgrading and replacing bridges in the European Union, and elsewhere, is becoming increasingly important due to ageing of the bridge stock, continuously increasing load requirements and budgetary limitations. Thus, there is a clear need to identify or develop, and implement, refined methods for assessing existing bridges in order to determine the most cost-effective options and actions to extend their lives, increase their capacities or replace them. LÄS MER

7. 35. Environmental actions on concrete exposed in marine and road environments and its response - Consequences for the initiation of chloride induced reinforcement corrosion

   Författare :Anders Lindvall; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; corrosion; de-icing salt; road conditions; marine conditions; service life predictions; reinforcement; chloride; concrete; moisture conditions; environmental actions;

   Sammanfattning : The object of the study presented here has been to describe, further explain and model the influence of the exposure conditions on reinforced concrete structures and the consequences on their expected service life. The focus has been on investigating and quantifying the exposure conditions for structures in marine and road conditions exposed to chloride ions. LÄS MER