•Direct pouring of SCHPC provides bond strengths comparable to the other treatments.•Cohesive failure is obtained in asphalt substrates without interfacial treatment.•No correlation exists between ...roughness level, pure tension and shear strengths.
A bonded concrete overlay consists of a concrete layer poured over a deteriorated pavement. Its mechanical performance depends on the quality of the bond between the lower and the uppermost layers. This paper reports an extensive experimental program to evaluate bond strength between Conventional Concrete (CC) and Asphalt Concrete (AC) substrates and Self-Compacting High-Performance Concrete (SCHPC) overlays. In all, 8 interface treatments are tested under Direct Tension, pure shear “LCB”, and compressive Slant Shear tests. The results show that direct pouring of the SCHPC overlay over CC and AC substrates produces similar or higher strengths than the other treatments analyzed.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
The Barcelona Test has proved to be very suitable for the systematic control of the tensile properties of Fibre Reinforced Concrete (FRC). Nevertheless, the need to measure the total circumferential ...opening displacement (TCOD) of the specimen entails the use of an expensive circumferential extensometer. In order to simplify the test, studies from the literature propose the use of the axial displacement of the press (δ) instead of the TCOD, obtaining empirical equations to correlate the energy estimated with both measurements. However, these equations are only valid for δ ranging from 1 to 4 mm and were adjusted based on the test results of just a few types of FRC. The verification of this formulation for other types of FRC shows an average error of 51.1%, thus limiting the simplification proposed for the test. In this paper, a new analytical model to convert the δ into the TCOD is developed and validated for a wide range of FRC. Besides being applicable to the whole range of δ, the new model provides a clear physical understanding of the main mechanism observed during the test and shows an average error of only 6.7%, making it possible to simplify the Barcelona test.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
► The constitutive models for FRC in the European codes are reviewed. ► The models are used in the numerical simulation of an experimental program. ► The capacity of the models to reproduce the ...response of FRC elements is analyzed. ► Satisfactory predictions of the mechanical response obtained with the models. ► Models are applicable to steel fiber and polypropylene macro-fiber reinforcement.
The recent publication of codes for the design of FRC is a major step towards extending the use of the material. An in depth analysis indicates several differences between the constitutive models proposed in the existing codes. In this study, these models are compared and a numerical simulation is performed to evaluate their differences in terms of the structural behavior predicted and measured in an experimental program of RC–FRC elements. The predictions provided by the models fit satisfactorily the experimental results for elements with steel fibers and with plastic fibers.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Several constitutive models for fibre reinforced concrete (FRC) have been reported in the past years based on the flexural performance obtained in a bending test. The Barcelona test was presented as ...an alternative to characterise the tensile properties of FRC; however, no constitutive model was derived from it. In this article, a formulation to predict the tensile behaviour of FRC is developed based on the results of the Barcelona test. The constitutive model proposed is validated by simulating the results of an experimental program involving different types of fibres and fibre contents by means of finite element software. Moreover, the simplified formulation proposed is compared with constitutive models from European codes and guidelines.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Concrete bonded whitetoppings and overlays usually fail due to a loss of bond between the layers as a consequence of direct actions (traffic loads) or indirect actions (temperature differences or ...shrinkage in the layers). These actions generate stresses in the interface that may exceed the strength capacity of the union between layers. This paper proposed an innovative solution for this problem that consisted of placing mechanical connectors in the overlay interfaces to provide them with post-cracking strength and maintaining the monolithic response of the pavement. Three experimental programs on real-scale pavements with two types of mechanical connectors were studied under heavy traffic in terms of structural performance. Findings reveal that this technique might be an excellent solution to the problem of interfacial debonding.
Steel fibers are ferromagnetic and they have the property of altering the magnetic field around them. This paper discusses a method and gives a practical example to measure, non-destructively, the ...amount and orientation of fibers from cubic concrete specimens (150 mm). This is possible because the fibers affect inductance of a sensor (an inductive coil) that is wrapped around the specimen.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The combination of fibers with traditional reinforcement may be a very interesting design solution to achieve more durable and economical structures. This paper deals with the analysis of the ...aforementioned solution through the study at serviceability and ultimate limit states. For this purpose, a total of eighteen concrete slabs were produced (3 × 1 × 0.2 m) with different reinforcement configurations, types of fibers (steel and plastic) and the fiber dosage used (0.25 and 0.50%). These slabs were tested under the configuration of a four point bending test. The results of this experimental campaign were used in the study of the cracking and deflection of the various types of concrete, tackling the analysis from several points of view.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
This paper aims to provide a detailed account of our experience in implementing a negotiation module in an optional course of Management Skills in the Master's Degree in Structural & Construction ...Engineering program at the Universitat Politècnica de Catalunya and critically evaluate its effectiveness and impact on students' personal and professional development by triangulating experiences, surveys, and interviews. Based on an analysis of university curricula, the research explores effective teaching strategies, including Role-Play Simulation and Multi-Disciplinary Case Studies, which were highly valued by students. Video Recording and Playback, Peer Feedback, and Facilitator-led Discussions emerged as the most effective evaluation methods.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
•A novel consensus method has been developed for multi-agent decision systems.•The method is specially designed to allow large groups of decision-makers.•Social rules and component division are ...introduced to improve the method response.•The method allows to manage previous influence.•HIVES can be applied beforehand to obtain group decisions for any MCDM method.
Aggregating multiple opinions or assessments in a decision has always been a challenging field topic for researchers. Over the last decade, different approaches, mainly based on weighting data sources or decision-makers (DMs), have been proposed to resolve this issue, although social choice theory, focused on frameworks to combine individual opinions, is generally overlooked. To resolve this situation, a novel methodology is developed in this paper based on social choice theory and statistical mathematics. This method innovates by dividing the assessment into components which provides a multiple assessment analysis, assigning weights to each source regarding their position compared to the group for each considered criteria. This multiple-weighting process maximises individual and group satisfaction. Furthermore, the method makes it possible to manage previously assigned influence. An example is given to illustrate the proposed methodology. Additionally, sensitivity analysis is performed and comparisons with other methods are made. Finally, conclusions are presented.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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