Prolonging the service life of existing reinforced concrete slab bridges through experimental studies on the shear capacity

A large number of existing reinforced concrete slab bridges are found to be insufficient for shear when calculated according to the governing codes. Seeking improved methods, for example, based on new experimental evidence, to assess the residual shear capacity and prolonging their service life can avoid large economic, environmental and social...

Shear assessment of reinforced concrete slab bridges

The capacity of reinforced concrete solid slab bridges in shear is assessed by comparing the design beam shear resistance to the design value of the applied shear force due to the permanent actions and live loads. Results from experiments on half-scale continuous slab bridges are used to develop a set of recommendations for the assessment of...

Concrete slabs under a combination of loads in shear

Previous experimental research at Delft University of Technology indicated an increased shear capacity of slabs under concentrated loads as a function of decreasing distance to the adjacent line support. Expressions have been derived for this increase, including the definition of an appropriate effective width. However, it is unknown if the...

Shear capacity of slabs under a combination of loads

Existing solid slab bridges under a combination of wheel loads and distributed traffic loads sometimes do not fulfil the code requirements for shear. However, reinforced concrete slabs loaded close to the support are subjected to shear stresses which might result in a failure mode of combined punching and shear. This behaviour is studied in a...

Recommendations for the shear assessment of reinforced concrete slab bridges from experiments

Upon assessment of existing reinforced concrete short-span solid slab bridges according to the recently implemented Eurocodes that include more conservative shear capacity provisions and heavier axle loads, a number of these structures were found to be shear-critical. The results from recent experimental research on the shear capacity of slabs...

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...

Calibration of partial factors in the safety assessment of existing concrete slab bridges for shear failure

The assessment of the structural safety of existing bridges and viaducts becomes increasingly important in many countries due to the age of the structures and an increase in traffic loads. Many structures need to be reassessed in order to find out whether the safety requirements are met. Most existing standards, however, are developed for the...

Reuse of hollow core slabs from office buildings to residential buildings

The subject of this thesis is the reuse of hollow core slabs from office building to residential buildings. It was written as final part of the master Civil Engineering of the TU Delft. The occasion for this particular topic is the short functional lifetime of buildings compared to the technical lifetime of their concrete load bearing structure....

Extension and Verification of Sequentially Linear Analysis to Solid Elements

When analyzing three-dimensional problems with nonlinear finite element analysis (NLFEA) often problems are encountered such as bifurcation and divergence of the solution. In particular, cases subjected to tension softening tend to encourage the emergence of multiple equilibrium paths. In order to overcome these problems the Sequentially Linear...

Crack formation in structural slabs on underwater concrete

Structural slabs on underwater concrete are widely applied in the construction of tunnels, parking garages, rail- and road construction. Over the years many problems have been reported with aquiferous crack formation in structural slabs on underwater concrete. Aquiferous trough crack formation threatens the durability of structural slabs on...

Dispersion of Electromagnetic Waves in a Periodic Open Waveguide

We model guided modes for an infinitely long metallic structure in the lateral direction that is invariant in the transverse direction, and mechanically supported by a dielectric layer This modeling is done without making any assumptions about the width of the slots relative to the spatial period. We do this by representing the electric field by...

Shear and Anchorage Behaviour of Fire Exposed Hollow Core Slabs

Hollow core (HC) slabs are made of precast concrete with pretensioned strands. These slabs are popular as floor structures in offices and housing. At ambient conditions, the load bearing capacity can be dominated by four different failure modes, i.e. flexure, anchorage, shear compression and shear tension. As the economic production process does...

Designing Stone Pitchings

Design guide for stone pitchings. The following subjects are covered in this report: - Construction - Failure Mechanisms - Stability of individual elements - Transport of material - Sliding - Design of other construction parts - Required parameters

Physical behaviour of shear connections in steel-concrete composite slabs.Numerical simulation of free-surface flows with steep gradients

Jettisoning ballast en route to the next millennium

Railway engineering has been a traditional discipline for over hundred years. Most developments were based upon experience and progressed thus very slowly. Recent proposed new railway structures and new applications make the traditional empirical approach ineffective. To support the new developments much more research, both experimental and...

Fire-exposed continuous span composite steel-concrete slabs

From experimental evidence, it was concluded that existing rules for the calculation of the behaviour of fire-exposed composite beams and slabs often lead to conservative solutions. Furthermore, the range of common applications had grown beyond the limits of existing calculation rules. It was felt that existing rules lacked a fundamental basis,...

Analysis of concrete structures under thermal loading

Wave attenuation by a floating slab

To predict the effect of a floating viscoelastic slab on the propagation and attenuation of gravity waves, a theoretical linear model has been developed. The slab has been modeled as a Kelvin-Voigt model and the fluid is assumed to be ideal. For long and short wave theory a dispersion relation for gravity waves covered by a viscoelastic slab of...