Oscar Galao

University of Alicante | UA · Departamento de Ingeniería Civil

En esta investigación se ha estudiado el uso de nanoadiciones conductoras, como los nanotubos de carbono (NTC) y productos de grafito (PG), en probetas de cemento para desarrollar las funciones de percepción de la deformación y calefacción. Para ello, se han fabricado probetas de pasta de cemento con adición de 1% NTC y 5% PG y se han realizado ens...

Most regulations on the manufacturing of concrete for reinforced concrete structures rest on durability models that consider the corrosion of reinforcements. Those models are based on factors such as humidity, frost, presence of chlorides, and internal characteristics of the concrete itself, like resistance, porosity, type of cement, water/cement r...

In this study, CNTs and graphite have been incorporated to provide electrical conductivity and self-heating capacity by Joule effect to an epoxy matrix. Additionally, both types of fillers, with different morphology, surface area and aspect ratio, were simultaneously incorporated (hybrid CNTs and graphite addition) into the same epoxy matrix to eva...

The European transport infrastructure sector is facing challenges to develop in a sustainable way, improving consumer safety and providing reliable performance in all conditions. A solution towards creating safer, more durable roads is investigated as part of the EU Horizon 2020 funded MASTRO project, which aims to develop intelligent bulk material...

Cement composites with hybrid conductive fillers carbon nanotubes (CNT) and graphite products (GP), have been tested as strain sensors under varying temperatures (0 °C–60 °C), and moisture conditions (0%–100% saturation degree (SD)). Cement pastes with 1% CNT and 5% GP (purified expanded graphite) presented resistivity values between 50 and 75 Ohm·...

This paper aims to study the viability of conductive cement paste and conductive concrete with the hybrid addition of carbon nanotubes (CNT) and graphite powder (GP) as a self-heating material for heating, ice formation prevention and de-icing in pavements. Different heating tests, ice-preventing tests and de-icing tests were performed with cement...

This paper proposes binary and ternary combinations of sewage sludge ash (SSA) with fly ash (FA), marble dust (MD) and rice husk ash (RHA) as partial replacements of Portland cement in concretes with a similar dosage to that used in precast blocks, with very dry consistency. Several physical-mechanical tests were carried out on concrete specimens w...

Different studies in the literature indicate the effectiveness of CNTs as reinforcing materials in cement–matrix composites due to their high mechanical strength. Nevertheless, their incorporation into cement presents some difficulties due to their tendency to agglomerate, yielding a non-homogeneous dispersion in the paste mix that results in a poo...

The electrical resistivity of carbon fiber reinforced cement composites (CFRCC) has been widely studied for the functional applications of these composites. CFRCC with enhanced electrical properties can be used as strain or damage sensor, heating or deicing material, or anode in different electrochemical techniques, like chloride extraction or cath...

Cement composites with nano-additions have been vastly studied for their functional applications, such as strain and damage sensing. The capacity of a carbon nanofiber (CNF) cement paste has already been tested. However, this study is focused on the use of CNF cement composites as sensors in regular concrete samples. Different measuring techniques...

Stainless steel is a corrosion resistant metal that has now wide record of good performance in several aggressive media, in spite of which is not fully immune to different types of attack. In present work is presented the performance of 304 stainless steel as forming part of the tubes of a tank that has been operating from 1964 for Liquefied Natura...

Resumen La adición de fibras de carbono en materiales cementicios permite, además de mejorar sus prestaciones mecánicas, su utilización en otras funciones no estructurales, p. ej., sensor de deformaciones. Al incluir adiciones crecientes de fibras en pastas de escoria de alto horno activada alcalinamente se consiguió mejorar su resistencia a compre...

La función de calefacción que poseen los materiales cementantes conductores presenta un importante campo de aplicación en las infraestructuras de transporte. La adición de fibras de carbono (FC) en bajas cantidades al hormigón mejora sustancialmente su conductividad eléctrica, lo que puede ser aprovechado para acometer actuaciones de prevención y c...

Alkaline activation has become a useful procedure to obtain high strength cement composites without Portland cement. Different industrial byproducts can be activated using this technique, e.g. blast furnace slag, fly ash or metakaolin. Thus a new generation of more sustainable composites is being developed. However, the main disadvantage of these c...

This paper aims to study the feasibility of highly conductive carbon fiber reinforced concrete (CFRC) as a self-heating material for ice formation prevention and curing in pavements. Tests were carried out in lab ambient conditions at different fixed voltages and then introduced in a freezer at -15°C. The specimens inside the freezer were exposed t...

Additions to concrete may change some of its basic properties in several ways depending on the nature of these additions. The addition of fibers, in particular, has enabled new concrete characteristics, making standard concrete a very modern composite material. If the fibers are electrical conductors, the properties that change in addition to the m...

This research studies the self-heating produced by the application of an electric current to conductive cement pastes with carbonaceous materials. The main parameters studied were: type and percentage of carbonaceous materials, effect of moisture, electrical resistance, power consumption, maximum temperature reached and its evolution and ice meltin...

This paper proposes binary and ternary combinations of sewage sludge ash (SSA) with fly ash, marble dust and rice hull ash, as partial replacement or addition relative to Portland cement in concretes with a similar dosage to that used in the manufacture of precast blocks, with very dry consistency given its manufacturing process in plant. Several p...

Binary and ternary combinations of sewage sludge ash (SSA) with marble dust (MD), fly ash (FA) and rice husk ash (RHA) as replacement in Portland cement pastes, were assessed. Several tests were carried out at different curing ages: thermogravimetry, density, water absorption, ultrasonic pulse velocity and mechanical strengths. Pozzolanic effects o...

The viability of carbon nanofiber (CNF) composites in cement matrices as a self-heating material is reported in this paper. This functional application would allow the use of CNF cement composites as a heating element in buildings, or for deicing pavements of civil engineering transport infrastructures, such as highways or airport runways. Cement p...

In the present paper, changes in mechanical properties of Portland cement-based mortars due to the addition of carbon nanotubes (CNT) and corrosion of embedded steel rebars in CNT cement pastes are reported. Bending strength, compression strength, porosity and density of mortars were determined and related to the CNT dosages. CNT cement paste speci...

The electrical resistivity of carbon fiber reinforced cement composites (CFRCCs) has been widely studied, because of their utility as multifunctional materials. The percolation phenomenon has also been reported and modeled when the electrical behavior of those materials had to be characterized. Amongst the multiple applications of multifunctional c...

In recent years, several researchers have shown the good performance of alkali activated slag cement and concretes. Besides their good mechanical properties and durability, this type of cement is a good alternative to Portland cements if sustainability is considered. Moreover, multifunctional cement composites have been developed in the last decade...

This paper is focused on the assessment of sewage sludge ash added on precast concrete blocks, therefore, based on a matrix of Portland cement with particular characteristics (dry consistency). A pilot experience was performed, by manufacturing commercial concrete blocks at an industrial local plant, using mixes in which sand replacements of 5, 10...

In this research, strain-sensing and damage-sensing functional properties of cement composites have been studied on a conventional reinforced concrete (RC) beam. Carbon nanofiber (CNFCC) and fiber (CFCC) cement composites were used as sensors on a 4 m long RC beam. Different casting conditions (in situ or attached), service location (under tension...

In the application of the electrochemical chloride extraction (ECE) technique, traditionally, the Ti-RuO2 wire netting has been used as the external anode. This article provides the results of the research based on the use of conductive cement paste with addition of carbon nanofibers (CNF) as anodes and its application in ECE. The tests were develo...

The changes in mechanical properties of Calcium Aluminate Cement (CAC) mortars due to the addition of carbon fibers (CFs) to the mix have been studied. Compressive and flexural strengths have been determined in relation to the amount of CF added to the mix, water/cement ratio (w/c), curing time and porosity. The relationship between the values of u...

This paper reports on recent work that is directed at studying the changes in the mechanical properties of Portland cement based mortars due to the addition of carbon nanofiber (CNF). Both flexural and compression strength has been determined and related to the CNF addition to the mix, to the curing time and to the porosity and density of the matri...

RESUMEN En este artículo se presentan resultados obtenidos en distintas propiedades relacionadas con la durabilidad y características resistentes de morteros de cemento parcialmente sustituidos con diferentes residuos agrícola e industriales que presentan actividad puzolánica: ceniza de lodo de depuradora (CLD), ceniza volante (CV), residuo de cat...

In the application of the electrochemical chloride extraction (ECE) technique, traditionally, the Ti-RuO2 wire netting has been used as the external anode. This article provides the results of the research based on the use of conductive cement paste with addition of carbon nanofibers (CNF) as anodes and its application in ECE. The tests were develo...

Fiber reinforced concretes (FRC) are technologically important due to their combination of good structural properties, durability and multifunctional properties. The behavior of a structure under dynamic actions is determined by its dynamic mechanical properties and its total overall damping. In this work the influence of the steel fiber (SF) and c...