Resistance Spot Welding of Advanced High Strength Steels

The introduction of advanced high strengths steels enabled automotive manufacturers to simultaneously reduce weight and increase safety of vehicles. However issues were reported concerning the weldability of these steels. These issues concerned both the manufacturability as well as the performance of resistance spot welded joints. The...

Shear Capacity of Concrete Beams under Sustained Loading

Long-term tests on large-scale concrete beams without shear reinforcement, which are tested for more than two years under sustained loading close to the ultimate shear capacity (load ratio ranging from 87% to 95%) under climate controlled condition, show that sustained loading has no significant effect on the shear capacity. Although many...

Nonlinear finite element analysis of reinforced concrete slabs: Comparison of safety formats

According to the new fib Model Code 2010 the design shear resistance of a reinforced concrete (RC) structure can be evaluated through analytical and numerical calculation methods that fall into four different levels of approximations; the complexity and the accuracy of the calculated shear resistance increases with increasing the level of...

Time-dependent behavior of cracked concrete beams under sustained loading

Under sustained loading, the propagation of cracks in concrete is assumed to be related to the elastic deformation, material parameters and time. Based on the fictitious crack model (FCM), a finite element method is proposed to explain the behavior of cracks in time using current constitutive relations to approximate the time-dependent crack...

Influence of particle packing density on the rheology of low cement content concrete

Optimizing concrete mixtures with regard to cement content is one of the most important solutions in sustainable concrete design. Workability o f these low cement content or ecological mixtures is very important. Eleven mortar mixtures are presented, which show how a higher packing density can be used to obtain mixtures that require less water....

The use of particle packing models to design ecological concrete

Ecological concrete can be designed by replacing cement with fillers. With low amounts of cement it becomes increasingly important to control the water demand of concrete mixtures. In this paper a cyclic design method based on particle packing is presented and evaluated on the basis of experiments on cement pastes combined with quartz powder....

Rotation capacity of self-compacting steel fibre reinforced concrete beams

Steel fibres are known to enhance the toughness of concrete in compression and in tension. Steel fibres also improve the bond properties between concrete matrix and reinforcing steel bars. In order to investigate the effect of steel fibres on the rotation capacity of reinforced concrete members, four simply supported beams were loaded in three...

Rechargeable power supply

The invention relates to a rechargeable power supply suitable to be used in a battery-operated device comprising at least one supercapacitor and at least a first and a second DC-DC converter connected in series, wherein the supercapacitor is connectable to an entry of the first DC-DC converter and the device is connectable to an exit of the...

Structural Consequences of ASR: An Example on Shear Capacity

Since the beginning of the nineties of the last century numerous viaducts in the Netherlands have been traced that suffer from ASR. Uniaxial tensile tests on cores drilled from the bridge decks sometimes showed a dramatically low tensile strength. Since these decks are not provided with shear reinforcement, the question was raised whether the...

A bond model for ribbed bars based on concrete confinement

A new bond model for ribbed bars embedded in concrete has been developed. The model is based on the confining capacity of the concrete surrounding the bar. This confinement capacity is evaluated with the help of a thick-wailed-cylinder model, with which the relation between the radial displacement and the radial compressive stress at the steel...

Structural lightweight concrete: Recent research

As a result of a number of reasons new interest developed into the use of lightweight aggregate concrete. Within the scope of this development, a modernized code for lightweight concrete had to be written. In order to support this development, a number of research projects have been carried out. The aim of the research was to verify the...

Onderzoek lichtbeton. Fase 3: Constructief gedrag van lichtbeton. Tekst & Figuren

Deelproject 3, afschuifdraagvermogen van lichtbeton. Experimenteel onderzoek aan balken met afschuifwapening.

De zuurwinningssektie

De zuurwinningssektie

Document uit de collectie Chemische Procestechnologie

Verbundeigenschaften von Litzen unter einmaliger und wiederholter Beanspruchung