Identification of internal damages in reinforced concrete slabs using probability density field of acoustic emission events

To assess the structural capacity of reinforced concrete structures, identifying the internal cracks is important. Acoustic emission (AE) is promising to estimate the location of internal cracks. However, the localization is influenced by many factors like arrival time picking error, presence of crack, etc., resulting in localization error. The...

Comparing the stretching technique and the wavelet cross-spectrum technique for measuring stress-induced wave-velocity changes in concrete

Coda wave interferometry (CWI) holds promise as a technique for concrete stress monitoring. This is because the coda, which consists of multiply scattered arrivals, is the result of propagation through the medium over large distances. As such, it is sensitive to both minute structural changes and small velocity changes in that medium....

Investigation of concrete crack kinematics through probability density field of the location of acoustic emission events

Monitoring or identifying structural cracks is crucial for assessing the health of existing concrete structures. Key information about structural cracking encompasses the location of the crack and its kinematics, which include movements perpendicular and parallel to the crack face. Acoustic emission (AE) is a sensitive technique for detecting...

Measurement of Restraint Moment Effect on Lab Specimens with Precast Girders Made Continuous

Typically precast girders are designed and utilized as simple supported members. Alternatively, the precast girders can be made continuous at the intermediate support using cast-in-place concrete topping. Once the girders are made continuous, time-dependent restraint moments will occur. The magnitude of the restraint moment is mainly affected by...

Challenges on the shear behavior of existing continuous precast girder bridges

There are a large number of precast girder bridges in the Netherlands that are made continuous utilizing cast in situ layers and cross beams. When controlled by the Eurocode minimum shear reinforcement requirement, the majority of these bridges that were constructed before the 1970s have insufficient amount of transverse reinforcement, which...

Geometric characteristic of flexural-shear cracks of members without shear reinforcement

For reinforced concrete members without shear reinforcement, the shear failure is characterized by the formation of a critical flexural shear crack. Recently experimental observations making use of Digital Image Correlation (DIC) by many researchers suggested the significance of geometric characteristics and kinematic conditions of critical...

Beoordelen bestaande betonnen bruggen

Om de vele bestaande betonnen bruggen – die de komende tijd het einde van hun beoogde levensduur bereiken – te beoordelen, is het belangrijk een aanpak met verschillende niveaus van beoordelen te gebruiken. Waar een handberekening niet volstaat, kunnen geavanceerde modellen, meetgegevens, belastingproeven, monitoren, inzichten van...

Quantification of the resistance modeling uncertainty of 19 alternative 2D nonlinear finite element approaches benchmarked against 101 experiments on reinforced concrete beams

Nineteen 2D nonlinear finite element analysis (NLFEA) solution strategies were benchmarked against a wide variety of 101 experiments on reinforced concrete beams failing in bending, flexural shear, or shear compression. The relatively high number of solution strategies was motivated by the conviction that choices for the constitutive models,...

Developing a new acoustic emission source classification criterion for concrete structures based on signal parameters

Acoustic emission (AE) signal parameters can be used to classify the source type in concrete structures. However, signal parameters are influenced by the wave propagation from the source to the receiver, leading to wrong source classification results, especially for monitoring large concrete structures. This paper experimentally evaluates the...

Probability density field of acoustic emission events: Damage identification in concrete structures

This paper proposes a new damage identification method, namely, the probability density field of acoustic emission (AE) events. This new method provides a different perspective to deal with the uncertainties in the source localization process. We treat the source location as a random variable, and estimate its probability density field based...

A closed-form shear resistance model for regions of prestressed beams without flexural cracks

When the shear resistance of prestressed beams with stirrups is determined with the current Eurocode, no distinction is made between regions with and without flexural cracks. This while it may be expected that a region without flexural cracks will have a higher shear resistance. This is due to the lower longitudinal strains and the narrow...

Acoustic Emission-based crack tracking for existing concrete structures: Influence of number of load cycles and loading speed

Acoustic Emission (AE)-based crack tracking is a promising approach to locate cracks in concrete structures. Different from conventional AE, this approach uses AE activities during crack closure. But, AE activities during crack closure may be influenced by the number of load cycles and loading speed. This may challenge the applicability of AE...