Sökning: "Concrete"

Visar resultat 31 - 35 av 1184 avhandlingar innehållade ordet Concrete.

1. 31. Applied Modeling of Moisture Phenomena in Concrete

   Författare :Marcin Stelmarczyk; Andrzej Cwirzen; Hans Hedlund; Klaas van Breugel; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Concrete; Modeling degree of hydration; Modeling chemically bounded water; Modeling moisture sorption; Modeling moisture transport; Hysteresis; Byggmaterial; Building Materials;

   Sammanfattning : This thesis contains new and improved calculation models, based on applied research merging numerical modeling and material research, in the areas of hydration and chemical binding of water, sorption of moisture and transport of moisture in concrete. The proposed model for hydration and chemical binding of water is based on general kinetics modeling and calculates degree of hydration directly, without using of equivalent time of maturity. LÄS MER

3. 32. Structural assessment procedures for existing concrete bridges : Experiences from failure tests of the Kiruna Bridge

   Författare :Niklas Bagge; Björn Täljsten; Paulo Cruz; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Anchorage; carbon fibre reinforced polymers; concrete; existing bridges; finite element analysis; flexure; full-scale test; load-carrying capacity; residual prestress force; punching; safety verification; shear; structural assessment; structural behaviour; Structural Engineering; Konstruktionsteknik;

   Sammanfattning : Assessing existing bridges is an important task in the sustainable management ofinfrastructure. In practice, structural bridge assessments are usually conducted usingtraditional and standardised methods, despite knowledge that these methods oftenprovide conservative estimates. LÄS MER

4. 33. Quasi-instantaneous and Long-term Deformations of High-Performance Concrete with Some Related Properties

   Författare :Bertil Persson; Avdelningen för Byggnadsmaterial; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Shrinkage; Relative humidity; Long-term; Hydration; High-Performance Concrete; Elastic modulus; Deformations; Creep; Concrete; Cement; Quasi-instantaneous; Strength; Building construction; Byggnadsteknik;

   Sammanfattning : This report outlines an experimental and numerical study on quasi-instantaneous and long-term deformations of High-Performance Concrete, HPC, with some related properties. For this purpose about two hundred small cylinders and about one thousand cubes of eight types of HPC were cast. The age at loading varied between 18h and 28 days. LÄS MER

5. 34. 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

7. 35. 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