International Engineering Conference (IEC2023)
2023-02-22 10:00:00
 

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Static and Dynamic Load Testing in a Lifecycle of a Bridge Infrastructure

ABSTRACT

Load testing is a popular method of verifying the loadbearing capacity of bridge structures. It provides a methodology that is not restricted to understrength bridges but is also applicable to checking the performance of newly constructed ones. The assessment rating of existing bridges can be improved by using the results of the load test to modify the computer analysis and provide a more realistic FE model based on the observed load distribution. On the other hand, in the case of new bridges, load testing can provide data for the design verification, data that describes bridge in its healthy starting condition. In this case, the cyclical repetition of a load test can be a simple application of Structural Health Monitoring.

The main advantage of load testing is its non-destructive nature and the minimum impact on the structure itself. Load testing involves a wide variety of measurement techniques, including material testing. It also requires, among others the usage of signal processing, data analysis, and system identification techniques. In general, load testing subdivides into two categories - static and dynamic tests. In a static test, observation focuses on structural response to the ballast of known parameters. The dynamic trial relies on the usage of artificial excitation of structure vibrations; the goal is to assess the real dynamic properties of the bridge under study in its operational conditions. In the lecture, the main ideas of load testing in bridge engineering are presented and exemplified through the application to retrofitted and newly constructed bridges.

Bridge Management Systems with BIM and Augmented Reality Implementation

ABSTRACT
Given current trends and political decisions, it is increasingly likely that BIM technology in infrastructure, and in Bridge Management Systems (BMS), will rapidly develop in the coming decades. Advanced bridge modelling methods will be required for the efficiency of this technique in BMS will depend on the virtual model of the bridge being inspected. The BrIM (Bridge Information Model) will be the most important element of the BMS knowledge base (Fig. 1). The use of BrIM models for management and maintenance (BIM 6D and 7D) occurs only in pilot projects and still requires research. Therefore, the development of procedures for creating bridges will be necessary - models that will be used in inspections and in BMS. These procedures must consider dominant span lengths and hard-to-reach areas such as high supports and pylons, where unmanned aerial vehicles (UAV) can assist. BrIM bridge model will be the most important element of the BMS database.


Fig. 1. Basic digital components of future Bridge Management Systems with BrIM models

The paper shows details of a new concept of Cyber-Physical Systems for inspection of bridges based on BrIM and Augmented Reality (AR). This system can be the basis for a meaningful discussion on the implementation of BIM and AR technologies in the design, construction, and maintenance of bridge structures. The infrastructure managers in those countries that choose to implement modernised BMS systems with intelligent tools for inspection will be able to use them to make more transparent and uniform investment decisions

Physical Chemistry Characterization of Modified Bitumen

ABSTRACT

Bitumen is a complex solid or semisolid colloidal suspension of asphaltenes in a continuous phase of saturated paraffins, aromatic oils and resins [1, 2]. Nowadays bitumen makes up 4–7% of the road pavement and acts as a binder in-between the aggregate skeleton, giving sufficient internal cohesion to the asphalt. Bitumen is a viscoelastic material whose mechanical response is both time and temperature dependent [3]. However, because of the wide variation in geographical and climatic conditions, a careful selection of asphalt materials is required to increase the useful life of the pavement and reduce the huge cost of road maintenance.  An improvement of its mechanical response does represent an equally important factor in the design of roads. To date, a variety of chemical compounds has been tested as bitumen modifiers and evaluated in their capacity to improve the adhesion [4] of binder to the aggregates and promote an increase of the bitumen softening point, especially in warm ambient conditions. This contribution explores, for the first time, the potentialities of a class of lipophilic food grade additives, i.e., non-toxic and eco-friendly biocompatible compounds, acting both as adhesion promoters and as rheological modifiers [5]. Their effects on the high temperature mechanical performance of a tested bitumen have been investigated through time cure rheological measurements and the sol-transition.

  1. Rozeveld S.,Shin E., Bhurke A., France L., Drzal L. Network morphology of straight and polymer modified asphalt cements. Microsc ResTech 38 (1997) 529-43.
  2. Lesueur D. The colloidal structure of bitumen: Consequences on the rheology and on the mechanisms of bitumen modification. Adv Colloid Interface Sci 145 (2009) 42- 82.
  3. Loeber L., Muller G., Morel J., Sutton O. Bitumen in colloid science: a chemical, structure and rheological approach, Fuel 77 (1998) 1443-1450.
  4. Oliviero Rossi C., Caputo P., Baldino N., Lupi, F.R., Miriello, D., Angelico R. Effects of adhesion promoters on the contact angle of bitumen-aggregateinterface. Int. J. Adhes. Adhes. 70 (2016) 297–303.
  5. Baldino N., Gabriele D., Lupi F.R., Rossi Oliviero C., Caputo P., Falvo T. Rheological effects on bitumen of polyphosphoric acid (PPA ) addition. Constr. Build Mater 40 (2013) 397-404.

Using of Functionally Graded Materials in Civil Engineering

ABSTRACT

In a Functionally Graded Material (FGM) both the composition and the structure gradually change over the volume, resulting in corresponding changes in the properties of the material. The general idea of structural gradients first was advanced for composites and polymeric materials in 1972. In 1985, the use of continuous texture control was proposed in order to increase the adhesion strength and minimize the thermal stress in the ceramic coatings and joints being developed for the reusable rocket engine.
Recently, a new class of composite materials known as functionally graded materials (FGMs) has drawn considerable attention. A typical FGM, with a high bending–stretching coupling effect, is an inhomogeneous composite made from different phases of material constituents (usually ceramic and metal).
There are many potentially useful applications of the FGM concept. For example, structural walls that combine the two functions of thermal and sound insulation with good specific strength could be made by the gradation of both the porosity and the composition. Also, it might be possible to design attractive interference colors for automobiles by dispersing graded coated particles such as titanium dioxide/mica (Ti02/mica) in the body coating.

Enhancement of the Safety of Structures under Extreme Events

ABSTRACT
One of the major challenges facing the civil engineering community is to reduce the risk of catastrophic damage due to the extreme loads and enhance the resiliency of urban infrastructure. Experimental testing of large-scale structures is the most reliable means to assess and improve the resilience and performance of structural systems under extreme loads. The development and use of advanced cyber-physical systems, has paved the way to enhance the existing experimental methods in a suitable and cost-effective manner. Hybrid simulation is an innovative cyber-physical testing technique in which computational models and physical components are integrated at run-time. This method overcomes many of the limitations of conventional shaking table tests while using similar equipment used for quasi-static testing. A state-of-the-art hybrid testing facility, referred to as the Multi-Axis Substructure Testing (MAST) system, has been designed, assembled and validated that is capable of simulating the complex three-dimensional time-varying boundary effects on large-scale structural components. The MAST system is unique in Australasia and is capable to serve the research community and practice, nationally and internationally. The paper presents versatile capabilities of the MAST system that will greatly advance the current state of knowledge in large-scale experimental testing.