Virginia Mendizabal

@upc.edu

Strength of Materials and Structures in Engineering Department
Universitat Politècnica de Catalunya

Virginia Mendizabal


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https://researchid.co/virginiamendi

RESEARCH, TEACHING, or OTHER INTERESTS

Mechanics of Materials, Mechanical Engineering, Civil and Structural Engineering, Building and Construction
17

Scopus Publications

Scopus Publications

  • Self-Sensing Natural Hydraulic Lime-Based Mortars with Carbon Microfibers
    Ali Dalalbashi, Virginia Mendizabal, Anastasios Drougkas, Vasilis Sarhosis
    Rilem Bookseries, 2026
  • Interpreting and modelling the high piezoresistive sensing performance of cementitious materials
    Anastasios Drougkas, Virginia Mendizábal, Borja Martínez, Ernest Bernat-Maso, Lluís Gil
    Procedia Structural Integrity, 2026
    Self-sensing cementitious materials are set to play a crucial part in structural health monitoring operations on buildings and infrastructure due to the ubiquitous presence of cement-based materials in the built environment, their ease of modification for enhanced sensing capabilities and the low cost of application. It is therefore of prime importance to fundamentally understand the physical mechanisms behind their self-sensing performance. One of the salient characteristics of cementitious materials is their notably high piezoresistive sensitivity under compression, reaching an order of magnitude above what would be expected from simple coupled electrical-mechanical analysis, even before modification with electrically conductive inclusions. While widely observed in the lab and tentatively attributed to various micro-or nano-scale material features and phenomena, this remarkable characteristic has not been sufficiently modelled and explained. This paper offers a micro-mechanical interpretation of the physical mechanisms behind the high piezoresistive gauge factor of cementitious materials. By accounting for the distortion of the shape of the different phases of the material, such as the paste, pores and aggregates, the resulting shifts in effective volume fractions as well as the closure of cracks perpendicularly oriented with respect to the load direction, the gauge factor of the material is able to reach the experimentally-derived values. The proposed model is used to evaluate the influence of various mechanical, electrical and loading parameters on the piezoresistive behaviour of cementitious materials, indicating potential future areas of focus for further experimental and numerical simulation work.
  • Artificial reef based ecosystem design and monitoring
    M. Francescangeli, D.M. Toma, V. Mendizabal, M. Carandell, E. Martinez, D. Martin, M.P. Mura, J. Aguzzi, L. Gil Espert, J. Del Rio
    Ecological Engineering, 2025
  • Electromechanical and piezoresistive behaviour of hydraulic lime mortar incorporating carbon microfibers for self-sensing applications
    Ali Dalalbashi, Virginia Mendizabal, Anastasios Drougkas, Vasilis Sarhosis
    Construction and Building Materials, 2025
    Self-sensing mortars, a type of smart material capable of monitoring structural behaviour under mechanical loading, have recently attracted significant attention. Although most research in this area has focused on cement-based systems, lime-based mortars remain relatively underexplored despite their importance in sustainable construction and heritage preservation. This study investigates the impact of carbon microfibers (CMFs) as a functional filler on the mechanical, electrical, and piezoresistive properties of hydraulic lime-based mortars. Mortar and paste mixes were prepared with different dosages of CMF (0 %, 0.05 %, 0.1 %, and 0.2 % by weight of the binder), both with and without silica fume as a pozzolanic additive. Mechanical tests, including flexural and compressive strength, as well as electrical resistivity measurements and electromechanical (piezoresistivity) evaluations, were performed. The results show that while silica fume enhances compressive strength, it tends to lower flexural strength, likely due to increased brittleness. The addition of CMF exhibited a nonlinear influence on the mechanical properties of the mixes, with strength decreasing up to 0.1 % CMF, followed by a slight increase at 0.2 % CMF. Similarly, the electrical properties (particularly piezoresistivity) also followed a nonlinear trend, showing enhanced sensitivity up to 0.1 % CMF and a reduction beyond that point. These trends suggest the presence of a percolation threshold around 0.1 % CMF The piezoresistive performance, assessed through gauge factor and linearity, also reached its peak at this dosage. The formulation of 0.1 % conductive material mixed with silica fume achieved a gauge factor of 311, which is 34 % higher than the mix containing 0.0 % CMF. This mix also displayed a coefficient of determination (R 2 ) of 0.97. In contrast, the mix without silica fume attained a gauge factor of 339, representing a 79 % increase compared to the mix with 0.0 % CMF, with an R 2 of 0.94. These results confirm that the sensing response was stable and highly reliable. Overall, 0.1 % CMF was identified as the optimal amount for improving the self-sensing behaviour of lime-based mortars. These findings confirm that CMF can effectively enhance the electromechanical response of traditional lime matrices without compromising their structural performance or their suitability for heritage materials. • Silica fume improved compressive strength but reduced flexural strength. • CMF addition showed a nonlinear effect on mechanical and sensing performance. • 0.1 % CMF showed best strength, lowest resistivity, and highest sensitivity. • A balance of matrix density and fibre connectivity governed piezoresistivity.
  • Experimental assessment of shear connectors for sandwich hemp insulation panels with FRCM and 3D printed wythes
    Ernest Bernat-Maso, Virginia Mendizábal, Borja Martinez, Luís Mercedes, Lluís Gil
    Construction and Building Materials, 2025
    This study investigates a novel enclosure solution comprising an inner FRCM (Fabric Reinforced Cementitious Matrix) structural layer and an outer 3D-printed mortar layer, connected to a hemp-based insulation panel via flexible connectors. The sandwich solution requires a proper shear transmission between layers. Two surface adaptations of the insulation panel—bonded particles and bonded mesh—and two types of punctual connectors—shredded yarn and closed staples—are analysed for their performance under direct shear, flexural, and pull-out (adherence) tests. Results show that connectors do not improve flexural response, but closed staples effectively resist shear when mortar penetration is manually ensured. Among surface adaptations, bonding a hemp mesh enhances strength across all tested efforts. Consequently, the combination of no connectors and a bonded hemp mesh emerges as the most viable solution for further research. A global mechanical assessment confirms that this connection method supports handling and installation of panels up to 900 mm in length • Bonding a mesh on the insulation layer improves the connection with mortar. • Manually applied mortar assures connector interaction. • Closed staple connectors improve shear and adherence performance. • 3D printed mortar is not penetrating mechanical shear connectors.
  • Thermal performance and durability of hemp shiv and recycled cardboard fibers
    B. Martínez, V. Mendizábal, E. Bernat-Masó, L. Gil
    Advances in Bio Based Materials for Construction and Energy Efficiency, 2025
  • RC beams strengthened with hemp-FRCM and cotton-FRCM under cyclic bending loads
    Virginia Mendizabal, Borja Martínez, Ernest Bernat-Maso, Lluís Gil
    Engineering Structures, 2024
    Fiber Reinforced Cementitious Matrices (FRCM) is an interesting solution to retrofit structures, due its compatibility with the substrate and its versatility. This paper presents the application of vegetal-FRCM for strengthening RC beams. Two types of vegetal fibers, cotton and hemp, were coated with epoxy and polyester resin and were embedded into a mortar matrix to retrofit RC-beams subjected to cyclic bending loads. Additionally, FEA simulation analyses of the cyclic bending tests were conducted. Modal analysis was performed on both pre- and post-strengthened RC beams to assess the impact of FRCM on their vibrational modes. The application of FRCM increased the frequency of the 1st bending vibrational mode, enhanced the maximum load-bearing capacity of the specimens between a 4 and a 22 %, and delayed the appearance of cracking in the substrate. The numerical simulation proved to be reliable until the yield point, therefore it is suitable for determining design parameters.
  • Experimental Assessment of Hemp Shiv and Green Adhesives to Produce a Biocomposite Material
    Borja Martínez, Virginia Mendizabal, Ernest Bernat-Masó, Lluís Gil
    Materials, 2024
    This study investigated the utilization of innovative green composites made from hemp shiv, a waste by-product of hemp cultivation, with the aim of promoting sustainability within the construction industry. The manufacturing method involved the application of pressure in a mold to create the samples. These materials were produced using an environmentally friendly binder consisting of colophony, arabic gum, and corn starch. Moreover, white glue and bioepoxy were also used to compare with the green resins. Three different binder compositions were used for the specimens. The samples underwent mechanical testing through tensile and bending assessments, and their performance was compared to that of non-green binders to validate the effectiveness of the manufacturing processes. The study revealed that decreasing the moisture content during the curing process was crucial for improving the mechanical properties. The best results were achieved when using arabic gum as a binder, yielding a tensile strength of 2.16 MPa and a bending strength of 5.25 MPa, with a composition of 62.5% hemp shiv and a manufacturing process involving a pressure of 5 MPa.
  • Experimental assessment of yarns and coatings for mesh production to strengthen earthen elements
    Ernest Bernat-Maso, Borja Martinez, Virginia Mendizábal, Luís Mercedes, Lluís Gil
    Construction and Building Materials, 2024
    Earthen construction has gained attention during the last decade because of its sustainability. Nevertheless, increasing its strength properties is still a challenge that is faced herein by including vegetal meshes with different coatings as internal reinforcement. An experimental campaign oriented to characterise the bending response of little scale earth beams in simply supported configuration was carried out including three different mesh materials (jute, hemp and cotton) and three different coatings (arabic gum, colophony and white glue). The results as failure mode, maximum load/stress and absorbed energy are presented and discussed. Results indicated that it is feasible to strengthen earthen materials with vegetal meshes. Colophony was too stiff to be combined with the chosen vegetal meshes with the goal of strengthening deformable earth. In addition, greater yarn thickness and smaller yarn separation were associated to premature debonding failure. Using cotton meshes with arabic gum coating brought the more promising results. In this case, the strength was slightly increased by 6 % but the absorbed energy was increased by 25 times respect to the control case.
  • Towards sustainable building solutions: Development of hemp shiv-based green insulation material
    Borja Martínez, Virginia Mendizabal, M. Blanca Roncero, Ernest Bernat-Maso, Lluis Gil
    Construction and Building Materials, 2024
    There is currently a growing need for sustainable and environmentally friendly materials. One promising candidate is hemp shiv, which is considered waste material. hemp shiv exhibits lightweight properties and high insulation capabilities. This study focuses on the development of a material based in hemp shiv, recycled cardboard fibers is used as binder material, with the addition of a vegetable coating (colophony and arabic gum) for moisture protection and citric acid to enhance cellulose crosslinking. Thermal insulation properties were assessed measuring the heat transfer through the material. Acoustic insulation properties were evaluated using a Kundt tube within a frequency range of 100–6500 Hz. Mechanical tests, including compression, shear, and bending, were performed to assess the material’s strength. Additionally, moisture and fire resistance properties, as well as microstructure analysis, were examined. The influence of citric acid in the cellulose crosslinking was verified using FTIR-ATR spectroscopy. Results demonstrated that a higher percentage of hemp shiv content led to improved insulation performance, achieving attenuation values greater than 0.85–0.95 dB/dB and a thermal conductivity of 0.02–0.03 W/m K. These findings indicate a great performance compared to commercial materials. The coating shields the material from external factors. It was observed that the citric acid does not react with hemp shiv.
  • Shear Performance of the Interface of Sandwich Specimens with Fabric-Reinforced Cementitious Matrix Vegetal Fabric Skins
    Lluís Gil, Luis Mercedes, Virginia Mendizabal, Ernest Bernat-Maso
    Applied Sciences Switzerland, 2024
  • Energy harvester based on low cost piezoelectric membrane for road traffic application
    Ernest Bernat-Maso, Borja Martínez, Luis Mercedes, Virginia Mendizábal
    Microsystem Technologies, 2023
  • Vegetal-FRCM Failure under Partial Interaction Mechanism
    Virginia Mendizabal, Borja Martínez, Luis Mercedes, Ernest Bernat-Maso, Lluis Gil
    Applied Sciences Switzerland, 2022
  • Debonding of Vegetal FRCM from Concrete Beams Subjected to Bending Loads
    Virginia Mendizabal, Luis Mercedes, Ernest Bernat-Maso, Lluis Gil
    Key Engineering Materials, 2022
  • MECHANICAL CHARACTHERISATION OF VEGETAL FRCM COMPOSITES: EXPERIMENTAL AND ANALYTICAL APPROACH
    Rehabend, 2022
  • Performance of hemp-FRCM-strengthened beam subjected to cyclic loads
    L. Mercedes, V. Mendizábal, E. Bernat-Maso, L. Gil
    Materiales De Construccion, 2022
  • Experimental comparison of two testing setups for characterizing the shear mechanical properties of masonry
    Jorge Segura, Ernest Bernat, Virginia Mendizábal, Luca Pelà, Pere Roca, Lluís Gil
    Journal of Building Engineering, 2021