Publications associées à Acoustic emission and ultrasonic testing for fatigue damage detection in a RC bridge deck slab

A WIM-Based Assessment of Multiple Vehicle Presence Effects on Fatigue Damage of Highway Bridges

Alain Nussbaumer, Scott Walbridge, Matthew James Sjaarda

The fatigue provisions for bridge design in North America and Europe are highly simplified for the sake of practical implementation, in comparison with the state of the art in understanding of the true fatigue behavior. Historically, one significant simpli ...

2024

Influence of model uncertainty and long term deformations in action effects calculation in reinforced concrete structures

Xhemsi Malja

Most codes of practice adopt a semi probabilistic design approach for the dimensioning and assessment of structures. Accordingly, structural safety is ensured by performing limit state verifications using design values determined with adequately calibrated ...

EPFL2024

Shear and steel-fibre reinforcement for the punching resistance of flat slabs at internal and edge columns

Diego Hernández Fraile

Reinforced concrete flat slabs consist of a continuous, thin concrete plate that rests on a grid of columns. The supporting surface of the columns is very small compared to the floor plan dimensions, leading to concentrations of shear forces near the colum ...

EPFL2024

Experimental and analytical investigation of shear-reinforced concrete and dowel action

Marko Pejatovic

Codes of practice can be overly conservative, particularly for the shear resistance of reinforced concrete beams with shear reinforcement when large loads act close to supports. This thesis addresses the topic by proposing a refined design approach based o ...

EPFL2024

Contributions to rebar-to-concrete interaction and its structural implications for design and monitoring applications

Enrique Corres Sojo

Bond between reinforcing bars and concrete has been the focus of extensive research over the last century. This is well-justified as the functioning of reinforced concrete intimately depends on the interaction between rebar and concrete, as for example cra ...

EPFL2024

Reuse of cut concrete slabs in new buildings for circular ultra-low-carbon floor designs

Numa Joy Bertola, Célia Marine Küpfer, Corentin Jean Dominique Fivet

The study explores an original idea that responds to the urgent need to reduce the detrimental environmental impacts of load-bearing floor construction in new buildings by reusing saw-cut reinforced concrete (RC) pieces salvaged from soon-to-be demolished ...

2024

A concrete answer for circular construction: three prototypes reusing saw-cut elements

Maléna Bastien Masse, Célia Marine Küpfer, Corentin Jean Dominique Fivet

Existing concrete buildings should be retained for as long as possible to reduce the environmental burden of demolition and new construction. However, when urban pressure makes demolition unavoidable, salvaging and reusing concrete elements elsewhere in ne ...

2024

Reusability assessment of reinforced concrete components prior to deconstruction from obsolete buildings

Maléna Bastien Masse, Julie Rachel Devènes, Corentin Jean Dominique Fivet

A large part of building demolitions is motivated by purely socio-economic reasons. Hence, about-to-be-demolished structures, commonly made of reinforced concrete, very often present no or little degradation. When adaptive reuse of the entire building is n ...

2024

Social-Transmotion: Promptable Human Trajectory Prediction

Alexandre Massoud Alahi, Saeed Saadatnejad, Yang Gao, Kaouther Messaoud Ben Amor

Accurate human trajectory prediction is crucial for applications such as autonomous vehicles, robotics, and surveillance systems. Yet, existing models often fail to fully leverage the non-verbal social cues human subconsciously communicate when navigating ...

2024

Structural component reuse of precast and cast-in-place reinforced concrete in architecture since the late 1960s in Europe

Célia Marine Küpfer, Corentin Jean Dominique Fivet

The reuse of concrete pieces salvaged from structures undergoing transformation or demolition into new architectural projects has gained a sudden and visible interest over the past five years. However, the practice of reusing concrete pieces in new structu ...

vdf Hochschulverlag AG2024

Experimental investigation of dowel action in reinforcing bars using refined measurements

Aurelio Muttoni, Marko Pejatovic

In typical reinforced concrete design, reinforcement is designed to carry axial forces, but it can also resist transversal forces by dowel action. This is usually neglected for simplicity's sake in the design phase, but it can be accounted for either expli ...

Ernst & Sohn2024

Estimation of the bar stress based on crack width measurements in reinforced concrete structures

Aurelio Muttoni, Enrique Corres Sojo

Estimating the stress of reinforcing bars and its variations in service conditions can be useful to determine the reserve capacity of structures or to assess the risk of fatigue in the reinforcement. This paper investigates the use crack width measurements ...

Ernst & Sohn2024

Strain engineering and strain measurement by spring tethers on suspended epitaxial GaN-on-Si photonic crystal devices

Romuald Houdré, Jun Wang

Suspended epitaxial gallium nitride (GaN) on silicon (Si) photonic crystal devices suffer from large residual tensile strain, especially for long waveguides, because fine structures tend to crack due to large stress. By introducing spring-like tethers, des ...

Iop Publishing Ltd2024

Strain-based analysis on the influence of local undercut geometry on fatigue crack initiation life

Alain Nussbaumer, Heikki Tapani Remes, Abinab Niraula

The local undercut defects at the weld toe provide a potential initiation site for fatigue cracks and significantly impact the structure's fatigue strength. The influence of continuous undercut depth on fatigue performance is widely studied, but the resear ...

2024

Inverse Problems in Pulse-Echo Ultrasound: Exploiting Coherence for Image Enhancement and Quantitative Imaging

Samuel Denys Beuret

Whereas pulse-echo ultrasound imaging relied on focused acoustic waves since its inception, the last two decades have seen the development of techniques based on unfocused waves, including ultrafast ultrasound imaging. In large part due to the emergence of ...

EPFL2024

Ultrasound inspection training system

Romain Christophe Rémy Fleury, Janez Rus

An ultrasound inspection training system comprising a test object (1), an ultrasound producing device (3) configured to generate ultrasonic signals in the test object and read ultrasonic response signals emitted from the test object, a property altering de ...

2024

Combined Passive and Active Ultrasonic Stress Wave Monitoring of UHPFRC Properties on a Structural Level

Eugen Brühwiler, Numa Joy Bertola, Thomas Schumacher

Ultra-High-Performance Fiber-Reinforced Cementitious Composite (UHPFRC) is becoming popular in designing lightweight and durable structures. UHPFRC structural elements remain crack-free and waterproof under service conditions, significantly improving durab ...

2023

Environmental and Life-Cycle Cost Evaluation of a Composite Timber-UHPFRC Bridge

Eugen Brühwiler, Numa Joy Bertola

Ultra-High-Performance Fibre Reinforced Cementitious Composite (UHPFRC) has recently been used to design lightweight structures and strengthen existing ones, with more than 300 applications in Switzerland. Several composite timber-UHPFRC bridges have been ...

2023

A hybrid microscopic model for multimodal traffic with empirical observations from aerial footage

Nikolaos Geroliminis, Georgios Anagnostopoulos

Microscopic traffic flow models can be distinguished in lane-based or lane-free depending on the degree of lane-discipline. This distinction holds true only if motorcycles are neglected in lane-based traffic. In cities, as opposed to highways, this is an o ...

2023

Experimental testing and structural analysis of composite tile – reinforced concrete domes

Savvas Saloustros

Conventional formworks for concrete curved shells either are expensive, complex and wasteful or have formal restrictions. Using tile vaults (also known as timbrel, Guastavino, thin-tile or Catalan vaults) as stay-in-place formwork for concrete shells could ...

2023