Load bearing capacity of existing concrete half-joints

Concrete half-joints are a specific support detail in reinforced concrete structures, which reduce the construction height of the total structure. The use of concrete half-joints became popular around 1950s, but decreased its interest as a result of new insights on structural behaviour and collapses of these structures. Typical issues regarding...

Bridging the gap between mathematical optimization and structural engineering: Design, experiments and numerical simulation of optimized concrete girders

Concrete, as the most widely used construction material, is associated with a high environmental impact. Within the present study, structural optimization is the method of choice to counter this issue. The entire process, from optimization, to design, experiments and numerical simulation is outlined. Embedded in the framework of a design...

Optimization-based strut-and-tie model generation for reinforced concrete structures under multiple load conditions

Strut-and-Tie modelling (STM) has been widely applied to design D-regions of reinforced concrete structures. For economic and environmental reasons there is a need for optimized Strut-and-Tie models. How to optimize Strut-and-Tie models considering multiple load combinations has not been investigated extensively in the literature. In order to...

Towards a systematic design approach of D-regions in reinforced concrete: Optimization-based generation of Strut-and-Tie models

Reinforced Concrete (RC) structures are widely used in our society for more than a century. In order to design safe and economical RC structures, various methods have been proposed by engineers and researchers. Remarkably, it still is a challenging task for engineers to design D-regions of RC structures, regions with nonlinear strain...

Shear Capacity of Large Structural Elements: A case study of the shear behavior of the itaipu concrete lock walls

The concept of shear loading and the shear resistance is well known for ‘regular’ sized beams, meaning beams that can be characterized as a slender beam. However, once the beam increases in size such that it is characterized as a deep beam or even falls outside the range of the typical deep beam, less knowledge is available....

Adjusting design models for pile caps and wall girders by using non-linear Finite Element Analysis

The strut-and-tie method is a reliable tool for designing the reinforcement in discontinuity regions in reinforced concrete structures. It provides safe designs, but it is on the other hand also acknowledged to provide conservative designs. As the strut-and-tie model is widely used in the design of structural elements as wall girders and pile...

Non-Linear Finite Element Analysis and Parametric Study of Four-Pile Pile Caps

Piles and pile caps are commonly used in the Netherlands due to the soft shallow subsurface soil that is predominant in the country which does not have sufficient bearing capacity to support heavy structures. Pile caps are currently designed analytically using the strut and tie model (STM). This is believed to be conservative and results in an...

Printing Reinforcement Steel: A study towards optimised, additive manufactured steel for reinforced concrete

In light of the global attempts to reduce material use by the construction industry, this research focuses on combining topology optimisation with additive manufacturing of steel. It is investigated whether an automated procedure can be developed to generate reliable strut and tie models for reinforced concrete elements, while satisfying the...

Automated optimization-based generation and quantitative evaluation of Strut-and-Tie models

Strut-and-Tie modelling (STM) is a well-known approach to design D-regions in reinforced concrete structures. Because the STM method is based on lower-bound analysis, finding a suitable truss-analogy model is the most important aspect to guarantee good structural and economic performance of a resulting design. Continuum topology optimization ...

Evaluating strut-and-tie models for concrete elements by nonlinear finite element analysis

The strut-and-tie method (STM) has been acknowledged as one of the most reliable tools for designing discontinuity regions in structural concrete. It is capable of producing safe designs consistently since it was developed as an extension of the lower-bound theorem of plasticity theory. However, to aptly address a physical problem of a concrete...

Generation and Evaluation of Truss Structures for the Strut-and-Tie Model: Based on Topology Optimization Results for Deep Concrete Beams

The Strut-and-Tie model (STM) is an efficient technique for the design of concrete structures, but the creation of suitable truss structures gets complicated when these structures become more complex. The topology optimization (TO) is a convenient technique that has been used in recent years for the creation of trusses of complex structures for...

The Arched Strut: a Tool for Modelling Column-Slab Connections

The arched strut is an addition to the strut-and-tie (STM) tool kit. It models the combination of disturbed behavior in one direction with slender behavior in the perpendicular direction. Common applications for the arched strut are in the design of connections between a reinforced concrete slab and its supporting columns or punching of bridge...

Detailing Aspects of the Reinforcement in Reinforced Concrete Structures: Retaining wall (case study)

This thesis studies the impact of reinforcement detailing on the behaviour of a reinforced concrete structure. Using a retaining wall as a case-study, the performance of two commonly used alternative reinforcement layouts (of which one is wrong) are studied and compared. Reinforcement Layout 1 had the main reinforcement (from the wall) bent...

Optimisation of Reinforced Concrete Structures

The design of reinforcement in concrete structures is a complex procedure, often resulting in inefficient designs. One possible solution to improve the design process and create more efficient designs is structural optimisation. This Master’s Thesis focusses on the development of a technique for optimisation of reinforcement in 3D concrete...

Concrete walls: The evaluation of the reinforcement design methods in D-regions around openings and overhangs

Unlike for concrete beams and plates, relative little amount of theory is present for concrete walls. In combination with the underexposure of the reinforcement design of D-regions in the codes when concrete walls are considered, engineering companies struggle to find a clear reinforcement design procedure which is agreed upon by all relevant...

Discrete elements in structural concrete design

In the sixties Prof. J. Witteveen introduced a discrete model for the elastic analysis of slabs (Heron 1966). This article presents a similar approach for the design of reinforced concrete walls and deep beams, with holes or otherwise. The model – which is called stringer-panel model – combines the advantages of the popular strut-and-tie method...