Sökning: "unbonded"

Visar resultat 1 - 5 av 7 avhandlingar innehållade ordet unbonded.

  1. 1. Externally unbonded post-tensioned CFRP tendons : a system solution

    Författare :Anders Bennitz; Chris Burgoyne; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; CFRP; prestress; tendon; external; unbonded; anchorage; beams; CFRP; förspänning; vajer; utanpåliggande; icke vidhäftande; förankring; Structural Engineering; Konstruktionsteknik;

    Sammanfattning : The introduction of Fibre Reinforced Polymers (FRP) to the civil engineering market in the late 1980s resulted in the emergence of a range of new tools for rehabilitating and strengthening concrete structures. Strengthening using FRPs is typically accomplished using non-prestressed externally bonded FRPs. LÄS MER

  3. 2. Sliding stability re-assessment of concrete dams with bonded concrete-rock interfaces

    Författare :Alexandra Krounis; Stefan Larsson; Fredrik Johansson; Ignacio Escuder Bueno; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; concrete dams; sliding stability; cohesion; shear strength; uncertainty; bond; Byggvetenskap; Civil and Architectural Engineering;

    Sammanfattning : The shear strength of the concrete-rock interface is an important parameter in sliding stability analyses of concrete dams founded on rock and depends, in addition to the normal stress state, on the bonding conditions of the interface; concrete-rock interfaces can be either unbonded, partially bonded or fully bonded.In the Swedish guidelines for dam safety all dam-foundation contacts are treated as unbonded. LÄS MER

  4. 3. Assessment of Long-Term Losses in Prestressed Concrete Structures - Application for Nuclear Reactor Containments

    Författare :Peter Lundqvist; Avdelningen för Konstruktionsteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; KstrConcrete; Nuclear reactor containments; prestressed concrete; prestress losses; bonded tendons; creep; shrinkage; relaxation; prediction models; resonance frequency; acoustoelasticity.;

    Sammanfattning : Most nuclear reactors, both in Sweden and worldwide, are enclosed by a prestressed concrete containment. The main purpose of the containment is to prevent any radioactive discharge to the environment in the event of a major internal accident. LÄS MER

  5. 4. Upgrading concrete bridges : post-tensioning for higher loads

    Författare :Jonny Nilimaa; Mohammad Al-Emrani; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Concrete; Bridges; Upgrading; Strengthening; Shear; Field testing; Post-tensioning; Prestressing; Structural Engineering; Konstruktionsteknik;

    Sammanfattning : There are a great number of old structures around the world, some of which were designed for completely different purposes than in their current application. Swedish railway bridges were for example only designed for maximum axle loads of 200 kN in the beginning of the 20th century, while the highest axle loads of today are twice as high. LÄS MER

  7. 5. Hydrolytic degradation of dental composites and effects of silane-treatment and filler fraction on compressive strength and thermal expansion of composites

    Författare :Karl-Johan M. Söderholm; Umeå universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Internal frictional theory; filler-matrix debonding; stress-corrosion; stressinfluenced diffusion; m icro-crack form ation; crazing; opacity; wear; osmotic pressure; hoop stresses;

    Sammanfattning : Some researchers have suggested that the weakest link of dental composites is the filler-matrix bond. However, due to incompleteness of information dealing with this bond and its stability in a humid environment, it was considered desirable to investigate the effect of water on this region, as well as the influence of filler bonding and filler fraction on compressive strength and thermal expansionExperimental composites containing different filler fractions of either silane-treated or untreated fillers were made. LÄS MER