Fernando Martínez Abella

University of A Coruña | UDC · Department of Construction Technology

In a research project, Biovalvo Project, developed in the University of A Coruña, mussel shells by-products of the local canning industry were converted into a building material. The main milestone of the project was the construction of an experimental building as a real case application. This building used heat-treated and grinded mussel shells in...

To obtain analytical models for the compressive behaviour of masonry structures, it is crucial to accurately measure the compressive strengths of its constituents, i.e., brick and mortar. The mechanical properties and the stress-strain relationship under uniaxial compression are essential for thoroughly investigating and evaluating masonry structur...

This study analyzed the performance of self-compacting concrete with a paste composition that includes limestone filler and metakaolin replacing cement to design binary (75% cement and 25% limestone filler) and ternary binders (60% cement, 25% limestone filler and 15% metakaolin). Furthermore, to analyze the effect of the solid volume fraction (vol...

The purpose of this research is to analyse the long-term deformations of reinforced concrete beams made of recycled coarse aggregates (RCA), using four different replacement ratios, 0%, 20%, 50% and 100%. For said purpose, three different loading stages were carried out: firstly, loading and sustained load for 1300 days, secondly, unloading and rec...

Air lime coating mortars with mussel shells exhibit useful hygrothermal properties related to humidity and temperature regulation. Introducing mussel shell sand produces a significant increase in pore volume, changing mortar’s microstructure and reducing density. This is attributed to the flaky and irregular shape of the shell particles that presen...

The effect of two different mixing protocols on the fresh-state behaviour of self-compacting mortars with and without recycled sand was compared. For this purpose, the mortar mixes were designed considering three solid volume fractions, while maintaining the water to cement ratio and superplasticiser dosage constant. The results conclude that the i...

Strain measurement and mapping of cracks are essential tasks when load-testing concrete and masonry structures to assess the structure’s safety in service and ultimate states. The Point-wise sensors (PWS), e.g. strain gauges and LVDTs that are usually employed for this purpose, suffer a draw-back on the quality of information collected, i.e. data a...

Coal power stations generate huge amounts of wastes, mainly ash. Approximately 80% of this residue is the so-called fly ash, a fine powder that has been used as a supplementary cementitious material for decades and has been deeply studied. However, the remaining 20% of the ash produced in coal power plants, the so-called bottom ash, has not been st...

The carbonation process is studied from young ages up to 2 years in mortars with fine mussel shell aggregate. Mussel shell aggregate affects lime mortars due to its shape (angular and flaky) and texture (smooth), and also its microstructure consisting of 2% organic matter in the form of protein and polysaccharides (chitin). Its effect is analysed i...

This review collates the results obtained in more than 100 scientific publications regarding the performance of concrete with granular coal combustion products (GCCP, commonly referred to as coal bottom ash in literature) as a partial substitute for conventional aggregate. The effects of this by-product on the workability, density and mechanical an...

This document introduces a general view of some results obtained in ALFILLER PROJECT (2018-2020), development by EXTRACO, SA, Galaicontrol SL and Prefhorvisa SL, with gCONS Group-University of A Coruña (Spain), founded by Axencia Galega de Innovación-GAIN-Xunta de Galicia. This is a first approach to design of sustainable solutions for concrete blo...

Mussel shells, composed of calcium carbonate (>95%) and organic matter, are suitable alternatives to conventional sand in mortar. In addition, the use of lime instead of cement as a binder has also been considered for sustainable construction materials as well as in restorative applications. This study aims to contribute to the knowledge of air li...

Given the rising societal pressure towards sustainable waste management and resource efficiency, in a more circular economy, an increased use and diversification of supplementary cementitious materials (SCM) will be necessary to achieve the CO2 mitigation goals. The current study addresses the development of self-compacting concrete, replacing part...

The production of farmed mussels amounts to millions of tonnes across over 40 countries. Shell waste resulting from this production has a very significant environmental impact. In Galicia, mussel shell waste is transformed, using low impact heat treatment, into a by-product that can be used as an aggregate. This research investigates cement-coating...

In Galicia, the 35% mussel culture is intended for canning. This industry has a residue (shells) derived with a volume of 25 thousand tons per year of waste that end mainly in landfills or in the bottom of the sea, producing an important environmental impact. After a heat treatment mussel shells become a by-product suitable for different uses (poul...

Aquaculture and cannery industry are important economic sectors in different countries. It generates big profits and create thousands of employment. However, it also produces lots of waste, being bivalve shells remarkable because of their volume. Shell residue usually is disposed in dump sites producing a great environmental impact. Nevertheless, s...

Galician "Rias" conditions enable the cultivation of excellent quality mussels, as well as extension. This leads Spain to be the third producer country on the world, just after China. The 35% of this production means 25,000 tons of mussel shell waste per year. Hence, it is necessary to find a sustainable use for this material. The bioconstruction h...

Galician “Rías”·conditions (extension, water temperature ….) enable the production of excellent quality cultured mussels. This leads Spain to be the third producer country in the world. Cannery industry (35% of the total cultured mussel production) generates 25000 tons of mussel shell waste per year. Hence, it is necessary to find a sustainable use...

Reducing both the energy consumption and CO2 emissions of buildings is nowadays one of the main objectives of society. The use of heating and cooling equipment is among the main causes of energy consumption. Therefore, reducing their consumption guarantees such a goal. In this context, the use of adaptive setpoint temperatures allows such energy co...

This work studies the proportioning and the effects in fresh state rheology of the use of fine recycled aggregates (FRA) to produce self-compacting concrete (SCC). The recycled sand was incorporated in percentages of 0%, 20%, 50% and 100%. The mix proportioning was supported with tests on mortars, in which workability was measured from 10 min to 90...

The use of self-compacting recycled concrete appears as to be a very interesting technology for the sustainable construction future. However, one of the major obstacles to a more widespread use of self-compacting concrete is to obtain a robust material. Therefore, the emphasis of this work is placed on analysing both practice and theory to understa...

The aim of this study is to investigate the behaviour of recycled aggregate concrete subjected to sustained loading. For the tests, eight reinforced concrete beams were manufactured with recycled coarse aggregate, using water-to-cement ratios of 0.50 and 0.65, and four replacement percentages: 0%, 20%, 50%, and 100%. First, the basic concrete prope...

The construction field has contributed to environmental degradation, producing a high amount of construction and demolition waste (C&D waste) and consuming large volumes of natural resources. In this context, recycled concrete (RC) has been recognised as a means to preserve natural resources and reduce space for waste storage. During the last decad...

Connecting reinforcement bars in their longitudinal direction is often needed in reinforced concrete structures. These connections must guarantee a correct stress transmission between bars without excessive cracking or inadmissible slips, and they are commonly executed by overlapping the reinforcement bars in a procedure known as a lap splice. In t...

Este trabajo se centra en el análisis de la influencia de las variaciones de materiales en el comportamiento reológico de los hormigones autocompactantes fabricados con árido grueso reciclado. Se diseña un hormigón autocompactante patrón y tres reciclados con porcentajes de sustitución del 20%, 50% y 100% en volumen. Asimismo, en cada una de estas...

En este trabajo se diseñan siete hormigones autocompactantes convencionales y de cada uno de ellos se obtienen tres hormigones autocompactantes con árido grueso reciclado de hormigón (utilizando sustituciones del 20%, 50% y 100% en volumen). Las mezclas recicladas se fabrican utilizando el árido reciclado seco y con un 3% de humedad natural, añadie...

This work is focused on assessing the thixotropy of self-compacting recycled concrete (SCRC) and on evaluating the interlayer bond strength. To do so, four SCRC mixes with 0%, 20%, 50%, and 100% of recycled coarse aggregate (by volume) were studied. This aggregate was used in dry-state conditions and an extra quantity of water was added during mixi...

This work deals with the flexural performance of recycled concrete subjected to increasing loads up to failure. For this purpose, eight reinforced concrete beams were made with recycled coarse aggregates using two different water to cement ratios (0.50 and 0.65) and four replacement percentages (0%, 20%, 50% and 100%). Firstly, the basic concrete p...

This work is focused on understanding the origin of the lower robustness detected in self-compacting recycled concretes and on identifying the parameters affecting this property to a greater extent. A reference concrete (0%) and three recycled concretes were studied. The replacement percentages of natural with recycled coarse aggregate were 20, 50...

The behaviour of fresh and hardened alkali-activated slag (AAS) and OPC concretes was compared and the effect of mixing time assessed. OPC and AAS concrete slump and rheological results proved to differ, particularly when the slag was activated with waterglass (WG). The nature of the alkaline activator was the key determinant in AAS concrete rheolo...

The use of fine recycled aggregates from recycled concrete is limited due to the high absorption of the material and the subsequent reduction in mechanical performance. At the same time, Self-Compacting Concrete (SCC) uses large amounts of fines to ensure its flowability. Therefore, this type of concrete could allow the use of fine recycled aggrega...

This research focuses on studying the fresh state behaviour of self-compacting recycled concrete (SCRC) using rheology as a fundamental tool. For said purpose, a reference self-compacting concrete (SCC) was designed and it was modified to obtain other two SCCs with different water to cement ratios. Lastly, the natural coarse aggregate of each SCC w...

Valorisation of thermal plant bottom ashes in construction: materials and products for the eco-construction in civil works and architecture

This paper studies the bond stress-slip curve of recycled concretes and the influence of recycled coarse aggregate, which leads to the determination of bond behavior at serviceability. In order to perform this analysis, a study of the compressive strength of the recycled aggregate concretes is required, due to the relationship between the bond stre...

An only suitable type of self-compacting recycled concrete (SCRC) for all applications does not exist, as happens with conventional self-compacting concrete (SCC). An experimental program was carried out to evaluate workability and rheology of 49 mixes of self-compacting concrete made replacing the natural coarse aggregate by recycled concrete coar...

En los últimos años el campo de las técnicas de refuerzos de estructuras de hormigón ha estado sujeto a importantes innovaciones debido al desarrollo de una línea de investigación basada en la utilización aleaciones con memoria de forma (AMF). Dentro de estas nuevas técnicas de refuerzos existe una tipología basada en el pretensado del elemento apr...

Resumen En este documento se recogen los resultados de una campaña experimental en la que se han estudiado los principales parámetros geométricos que definen un solapo de barras: diámetro de la armadura, recubrimiento, separación entre barras solapadas y distancia entre familias de barras solapadas. Para realizar esta investigación se recurrió a un...

The research on shape memory alloys (SMAs) has attracted a lot of attention in recent years for different structural engineering applications. In this paper the performance of relatively large-diameter Ni-Ti SMA cables is depicted for their use in reinforced concrete applications. The cable was characterized through a complete experimental program,...

11 The number of fluidized bed power plants is growing rapidly due to economic and environmental 12 benefits. These facilities produce larger quantities of bottom ash than conventional boilers. This ash ex-13 hibits pozzolanic activity once ground, but due to regulation limitations this by-product is nowadays des-14 tined to landfill. Blended cemen...

This work studies with the influence of recycled coarse aggregates features on the mechanical properties of structural concrete. Recycled concrete is characterised by replacing different percentages of natural coarse aggregate with recycled coarse aggregate (0, 20, 50 and 100%) and two different water-to-cement ratios .50 and .65. The experimental...

In this work the performance of mussel shell as aggregate in plain concrete has been studied. The mussel shell used came from the cannery industry, which produces more than 1 million tonnes of shell by-product a year worldwide. The mussel shell has been heat-treated at 135. C for 30. min and then crushed and sieved into sand and gravel. The new agg...

This work studies the physical and mechanical properties of recycled concrete aggregate (recycled aggregate from concrete waste) and their influence in structural recycled concrete compressive strength. For said purpose, a database has been developed with the experimental results of 152 works selected from over 250 international references. The pro...

This work studies the effect of incorporating fine recycled aggregates on the rheology of self-compacting concrete over time (at 15, 45 and 90 min). The fine fraction of the natural aggregates was replaced at 0%, 20%, 50% and 100% with recycled sand. The fresh-state properties were studied by empirical tests (slump-flow, J-Ring, L-Box) and fundamen...

En este estudio se plantea el uso de árido fino procedente de concha de mejillón en morteros de revestimiento. Los ligantes utilizados han sido, por un lado, el cemento, por tratarse éste del ligante más utilizado en la construcción convencional y, por otro la cal aérea en pasta y la arcilla, ligantes acordes con principios de bioconstrucción. Se h...

En este proyecto se plantea el uso de la concha de bivalvo, específicamente concha de mejillón, como árido para hormigones. Se trabajó con un hormigón de limpieza (HL) y un hormigón en masa estructural (HM) orientado al uso en cimentaciones y zonas portuarias para bloques de espaldón de diques. Se diseñó la dosificación patrón de ambos hormigones c...

In this research coating mortars with partial replacement of conventional sand with mussel shell sand are investigated. Three different binders have been used to study the influence of mussel shell sand: cement, aerial lime paste and clay. The cement binder has been used because it is the most use done in conventional construction. On the other han...

In this project the use of mussel shell as fine and coarse aggregate in concrete is studied. Two different conventional concretes were designed, a non-structural concrete (NSC) and a plain structural one (SC). Then, the conventional fine and coarse aggregate was partially replaced with seashell. Initially, each size fraction (fine or coarse) was re...

This paper presents the improvement of the EC-2 and EHE-08 shear strength formulations for concrete beams with shear reinforcement. The employed method is based on the genetic programming (GP) technique, which is configured to generate symbolic regression from a set of experimental data by considering the interactions among precision, accuracy, saf...

VAMDEF: Sistema de visión artificial para a medición de deformacións (VAMDEF: Computer vision system to measure deformations). Sistema óptico para medir las deformaciones que se producen en materiales de construcción (como el hormigón o el acero). Este nuevo sistema se basa en el análisis de los procesos de deformación en un material sin utilizar s...

The objective of this research was to evaluate the feasibility of producing structural lightweight concrete prestressed girders with load-bearing capacities similar to conventional concrete girders. The methodology consisted of comparing the results of the production and monitoring of scaled prestressed concrete beams at a precasting plant and the...

This article discusses an analytical model that relates the transfer length and the prestressing strand draw-in immediately after transfer; the model is based on the elastic confinement hypothesis of the prestressing strand using concrete and/or confining reinforcement. Two expressions are proposed to estimate upper and lower bounds on the transfer...

Starting from the FIB database, this work is aimed to analyze the current equations which predict the main datum that can be provided by bond tests: the ultimate bar stress when the failure is reached. Furthermore, Genetic Programming (GP) techniques are also applied in order to enhance the expression of the FIB, which achieves the best adjustment...

This paper presents the results of an experimental program developed to study the feasibility of producing prestressed concrete girders using lightweight concrete. During the experimental campaign, bond tests were performed in push-in (TL bond test) and pull-out (FB bond test) types of specimens. To-scale prestressed concrete elements were produced...

This paper reports on a study of the behavior of plain concrete made with mixed recycled coarse aggregate, i.e., recycled aggregate with a high percentage of fired clay (brick and similar) waste. The parameters studied were: workability, density, compressive strength, longitudinal modulus of deformation, Poisson ratio, depth of water penetration un...

One of the main issues in civil engineering is to analyze the behavior of materials in strength tests. Traditionally, information about displacements and strains in the materials is carried out from these tests using physical devices such as strain gauges or other transducers. Although these devices provide accurate and robust measurements in a wi...

A method based on Genetic Programming (GP) to improve previously known empirical equations is presented. From a set of experimental data, the GP may improve the adjustment of such formulas through the symbolic regression technique. Through a set of restrictions, and the indication of the terms of the expression to be improved, GP creates new indivi...

In this work the influence of the substitution of 100% of natural coarse aggregate with recycled coarse aggregate has been analysed in order to know the behaviour of the structural concrete in one particular aspect: that is, the behaviour of the recycled concretes under sustained load.To know the behaviour under sustained load, tests under very low...

Soft computing techniques are applied to a huge quantity of problems spread in several areas of science. In this case, Evolutionary Computation (EC) techniques are applied, in concrete Genetic Programming (GP), to a temporary problem associated to the field of Civil Engineering. The case of study of this technique has been centered in the predictio...

This study evaluates the possibility of measuring the damage of the recycled concrete. In this way, two conventional concretes with a w/c ratio of 0.55 and 0.65 were designed. Based on them, six recycled concretes with different percentages of replacement of natural coarse aggregates with recycled coarse aggregate (20, 50 and 100%) were obtained. T...

DistiClustPG: Sistema distribuido de programación genética con técnicas coevolutivas

Knowing the strain response of materials in strength tests is one of the main issues in construction and engineering fields. In these tests, information about displacements and strains is usually carried out using physical devices attached to the material. In this paper, the suitability of Computer Vision techniques to analyse strength tests withou...

In this work the stress–strain curve of the recycled concretes was determined by replacing different percentages of the natural coarse aggregate with recycled coarse aggregate (20%, 50% and 100%). The results made it possible to establish the differences between the stress–strain relationship of a conventional concrete and this relationship for a r...

Soft computing techniques are applied to a huge quantity of problems spread in several areas of science. In this case, Evolutionary Computation (EC) techniques are applied, in concrete Genetic Programming (GP), to a temporary problem associated to the field of Civil Engineering. The case of study of this technique has been centered in the predictio...

This paper presents the improvement of the EC-2 shear strength formulation for concrete beams without shear reinforcement. The method used is based on the modification of the Genetic Programming (GP) technique configured to generate symbolic regression from a set of experimental data. Starting from the EC-2 formulation, several points of the equati...

The aim of this research was to determine the behavior of recycled concrete in response to the phenomenon of shear transfer. To perform it, a conventional control concrete and a concrete with 50% recycled coarse aggregate were designed. An additional goal was to shed light on how this behavior is modified with a pozzolanic addition, silica fume. Th...

The aim of this research was to determine the behavior of recycled concrete in response to the phenomenon of shear transfer. To perform it, a conventional control concrete and a concrete with 50% recycled coarse aggregate were designed. An additional goal was to shed light on how this behavior is modified with a pozzolanic addition, silica fume. Th...

The techniques using Artificial Intelligence are more and more widespread in different engineering fields. Specifically, those based on Connectionist Systems and on Evolutionary Computation have been applied successfully in the analysis of big experimental data bases which were obtained in civil engineering. In this paper it is presented an approac...

One of the key aspects that must be taken into consideration within the framework of Sustainable Construction is the management of Construction and Demolition (C&D) Debris. As for other types of waste, specific handling procedures are required to manage C&D Debris; these include reduction, reuse, recycling, and if all other possibilities fail, reco...

En el marco actual de la Construcción Sostenible destaca la gestión de los Residuos de Construcción y Demolición, cuyo correcto desarrollo exige, primeramente, una cuantificación y una composición suficientemente precisas de los residuos, para así poder realizar una estimación sobre la producción de áridos reciclados y analizar la repercusión que t...