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Visar resultat 1 - 5 av 80 avhandlingar som matchar ovanstående sökkriterier.

1. 1. Cracking in concrete : crack prevention with air-cooling and crack distribution with steel fibre reinforcement

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

   Sammanfattning : This Licentiate Thesis consists of four parts. The first two parts, paper A and B, deal with air-cooling by means of embedded pipes in order to reduce thermal cracking in concrete structures. These two papers are submitted for publication to RILEM Journal; ‘Materials and Structures'. LÄS MER

3. 2. Self-Healing Concrete

   Författare :Magdalena Rajczakowska; Andrzej Cwirzen; Karin Habermehl-Cwirzen; Hans Hedlund; Erik Schlangen; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; cementitious materials; self-healing; exposure; fly ash; calcite; C-S-H; cracking; Byggmaterial; Building Materials;

   Sammanfattning : Concrete is a brittle material prone to cracking due to its low tensile strength. Crack repairs are not only expensive and time-consuming but also increase the carbon footprint. Designing a novel concrete material possessing the ability to self-repair cracks would enhance its sustainability. LÄS MER

4. 3. Restraint Effects in Concrete Bridges : A Study of Cracking due to Thermal Actions and Shrinkage in Portal Frame Bridges

   Författare :Erik Gottsäter; Avdelningen för Konstruktionsteknik; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Tvång; Betong; Uppsprickning; Temperaturlast; Plattrambro; FE-analys; Restraint; Concrete; Cracking; Thermal action; Portal frame bridge; FE-analysis;

   Sammanfattning : Thermal actions and shrinkage cause volume changes in concrete structures. In structures which are restrained from movements, the restraint effects can cause cracking. However, when cracking occurs, the structure can deform to some extent, which reduces the restraint stresses and thus also the crack widths. LÄS MER

5. 4. Hardening concrete : measurments and evaluation of non-elastic deformation and associated restraint stresses

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

   Sammanfattning : If a structural member of hardening concrete is restrained to some degree against expansion and contraction during the heating phase of the hydration process and the subsequent contraction phase, stresses will be induced. The issue of primary interest is whether or not these induced stresses will lead to cracking. LÄS MER

7. 5. Multiscale Modelling of Reinforced Concrete

   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; multiscale; bond-slip; cracking; computational homogenisation; reinforced concrete;

   Sammanfattning : Since concrete cracks at relatively low tensile stresses, the durability of reinforced concrete structures is highly influenced by its brittle nature. Cracks open up for ingress of harmful substances, e.g. chlorides, which in turn cause corrosion of the reinforcement. LÄS MER