Emilio Zornoza

• Professor
• University of Alicante

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...

The impedance spectroscopy technique has been used to study the microstructure of the binder resulting from the alkaline activation of SiMn slag. Two alkaline activators were used: waterglass and NaOH. Three different concentrations were analysed for both activators: 3.0, 3.5 and 4.0% Na2O for NaOH; and 4.0, 4.5 and 5.0% Na2O for waterglass with a...

The influence of the type and concentration of the activator on the composition of the products formed and the microstructural development of alkali activated SiMn slag pastes and their evolution with curing time are studied. About 15–17 million tons of SiMn slag is produced per year, so valorising this residue is interesting for the economic and e...

In the present work, the composition of a corroded reinforcing steel surface is studied at different pH values (related to different degrees of development in the corroding zones of the corrosion process) in solutions simulating chloride-contaminated environments. The media considered consist of saturated calcium hydroxide solutions, progressively...

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...

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 corrosion process of steel reinforcements embedded in alkali activated SiMn slag mortars was investigated. NaOH and waterglass were used as alkali activators of SiMn slag. The steel reinforced mortars were subjected to two aggressive environments: carbonation and chloride ingress. Carbonation progressed quicker for the binder activated with NaO...

This research investigates the mechanical performance and dimensional stability of mortars whose binder is prepared by alkali activation of ground granulated SiMn slag. Two types of activators have been used: NaOH and waterglass solutions. Three different types of aggregates have been tested: silica sand, limestone sand, and recycled sand obtained...

The objective of this paper is to report the improvement of sustainability through the increase of reinforced concrete corrosion resistance by using a blended cement and fly ash. Different reinforced concrete mixtures were prepared with partial substitution of a manufactured blended cement with fly ash from a thermal power plant in Andorra (Teruel,...

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...

The viability of using a SiMn slag as raw material for the preparation of alkali activated binder has been analysed. The slag has been characterized from the physical, chemical, mineralogical and microstructural point of view. The solution used for the alkali activation process was waterglass, which was prepared by the mix of a sodium silicate solu...

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...

Se evalúan las propiedades mecánicas y de durabilidad de hormigones de bajo impacto ambiental con sustituciones de cemento por subproductos industriales (35% cenizas volantes y 15% catalizador de craqueo catalítico) y de áridos gruesos por áridos reciclados (20% y 100%). Los hormigones estudiados se han sometido a ensayos de caracterización mecánic...

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...

Strain-sensing functions of Portland cement pastes with different dosages of carbon nanotubes (CNT) are systematically studied. This is one of the relevant functions that multifunctional composites are able to develop when a conductive addition is included in the cement matrix. Strain sensing refers to the ability of a structural material to sense...

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...

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...

The main strategy to reduce the environmental impact of the concrete industry is to reuse the waste materials. This research has considered the combination of cement replacement by industrial by-products, and natural coarse aggregate substitution by recycled aggregate. The aim is to evaluate the behavior of concretes with a reduced impact on the en...

The present study explored the technological feasibility of re-using sewage sludge ash (SSA) as a Portland cement replacement in commercially manufactured pre cast concrete blocks. The blocks analysed were made to the guidelines laid down in Spain’s National Plan for Waste Water Treatment Plant Sludge, 2001–2006, and European Union specifications (...

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...

This article summarizes research on the application of a conductive cement paste as an anode in the now classical technique of electrochemical extraction of chlorides applied to a concrete structural element by spraying the paste on the surface of a concrete structural element, a pillar. Sprayed conductive cement paste, by adding graphite powder, i...

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...

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 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...

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...

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...

Measurements of corrosion rate of reinforcing steels have been carried out in solutions simulating electrolytic chloride environments in corrosion pits in the propagation period with sodium nitrite. A significant corrosion inhibition has been observed at relatively low chloride contents of 0.045M due to the presence of nitrite in these systems, but...

The construction of concrete structures using silica fume (SF) additions is a common practice because it is well known that this pozzolanic material improves the compressive strength of concrete, among many other mechanical and physical properties. The response of a structure under dynamic actions is highly determined by the dynamic mechanical prop...

When chloride-induced corrosion takes place, a local acidification occurs at the corrosion pit. Therefore, it is necessary to study the performance of corrosion inhibitors in low-pH environments. Reinforcing steel bars have been exposed to solutions that simulate the electrolytic environment of concrete micropores during the corrosion propagation p...

Reaction between a spent fluid cracking catalyst (FC3R) residue and portlandite has been monitored over 56 days using several materials characterisation techniques. Results show that the residue is heterogeneous and composed of reactive and nonreactive fractions -both fractions contain silicon and aluminium. After 56 days, the development of C-S-H...

In this work, cement paste samples with 1% (by cement mass) of a conductive carbon fiber admixture have been studied under uniaxial compression. Three different arrangements were used to measure the resistivity of the samples. According to the results obtained, the resistance should be measured using the four wire method in order to obtain good sen...

The present research investigates how the addition of processed carbon materials affects the mechanical properties of cement mortars. Five types of oxidation treatments (air at 250°C, air at 410°C, ozone, H2O2, and HNO3) were applied to graphite powder, powdered carbon fiber, and short carbon fiber to assess the influence of the modification of the...

The study described in this article explored the effect of adding different types of carbon materials (graphite powder and three types of carbon fibre), fly ash (with 5.6%, 15.9% and 24.3% Fe2O3), and a mix of both on electromagnetic interference (EMI) shielding in Portland cement pastes. The parameters studied included the type and aspect ratio of...

The study described in this article explored the effect of adding different types of carbon materials (graphite powder and three types of carbon fibre), fly ash (with 5.6%, 15.9% and 24.3% Fe₂O₃), and a mix of both on electromagnetic interference (EMI) shielding in Portland cement pastes. The parameters studied included the ty...

The electrical resistivity of carbon fiber (CF) reinforced concrete with electrical continuity within the cement paste and sand/cement ratio 0.75 depends on the CF content and gravel/sand (g/s) ratio. For resistivity ≤500 Ω.cm, the mortar must exceed 62 vol.% and the cement paste must exceed 44 vol.%. The minimum resistivities provided by double pe...

This paper deals with the study of corrosion level of reinforcing steel bars embedded in Portland cement mortars containing different types of fly ash. Fly ashes used were obtained by physico-chemical treatments of an original F class fly ash to modify their magnetic properties and reduce their particle size. An original fly ash (T0) and three type...

The addition of short carbon fibers (CF) in concrete leads to changes of both the mechanical and electrical properties of the hardened product. The addition of silica fume (SF) to concrete mixtures with CF facilitates an even distribution of fibers within the mixture volume and improves the strength and multifunctional properties of the product. In...

Several durability properties of reinforced mortars of cement partially substituted with spent catalytic cracking catalyst (FC3R) in quantities up to 20% by cement mass are presented. Carbonation resistance of FC3R-OPC mortars under accelerated conditions mainly depends on the water/binder (w/b) ratio, but also the substitution level can affect thi...

Accelerated carbonation tests have been carried out on Portland cement mortars and pastes, partially substituted with a spent fluid catalytic cracking catalyst (FC3R). This study has revealed that the incorporation of FC3R on mortars produces a significant reduction of the alkaline reserve. Furthermore, it has been observed that this pozzolan also...

The influence of the incorporation of spent cracking catalyst (FC3R) on the chloride ingress resistance has been evaluated. Thermogravimetric analyses have shown that the pozzolanic reaction of FC3R yields higher contents of hydrated calcium aluminates and silicoaluminates, so chloride binding capacity of mortars was highly improved. Mercury intrus...

Accelerated carbonation tests have been carried out on Portland cement pastes and pastes partially substituted with a spent fluid catalytic cracking catalyst (FC3R) to investigate possible differences between the composition of FC3R/cement and plain cement matrices. Cement/FC3R pastes have been tested by thermogravimetry and X-ray diffraction analy...

Carbonation kinetics of mortars of normal Portland cement partially substituted by spent fluidised bed catalytic cracking catalyst (FC3R) and fly ash were studied for accelerated test conditions. It has been noted that the main limiting factor for the penetration of carbonation front is the mortar porosity, and only if this porosity is high, would...

This paper reports on a study of the corrosion levels in steel bars embedded in mortars made with a blend of Portland cement and (0-20%) spent fluid catalytic cracking catalyst residue (FC3R), with a variable (0.3-0.7) water/binder (w/b) ratio. The specimens were stored in the following conditions: relative humidity of 40, 80 or 100% and CO2 concen...

This paper reports on a study of the corrosion levels in steel bars embedded in mortars made with a blend of Portland cement and (0-20%) spent fluid catalytic cracking catalyst residue (FC3R), with a variable (0.3-0.7) water/binder (w/b) ratio. The specimens were stored in the following conditions: relative humidity of 40, 80 or 100% and CO<sub>2</...

Stationary and non-stationary chloride diffusion coefficients of mortars prepared with ordinary Portland cement partially substituted by spent cracking catalyst (FC3R) and fly ash (FA) have been determined. An accelerated test of chloride migration through the mortar has been performed in order to determine these coefficients. The results show that...

Inhibitors in concrete are usually used to be effective in alkaline or neutral solutions, however, when corroding by chlorides, there is a local acidification and therefore it is necessary to study the effect of the inhibitor in acid pH values. Measurements of the corrosion rate of corrugated steel bars have been carried out in solutions simulating...

Different types of carbonaceous materials have been added to concrete mixes and their effect on the corrosion of embedded steel has been studied. Using a constant water/cement ratio of 0.42 and different amounts of carbonaceous materials and different curing periods the evolution of the corrosion process in the embedded reinforced bars has been det...

Zeolitic catalysts are widely used in petrochemical refining. When the catalytic properties of this product are degraded, the deactivated catalyst must be replaced. Its chemical composition, based in silicoaluminates, together with its zeolitic structure, can be used in concrete, due to its high pozzolanic activity. Mortars were prepared using fauj...

This paper presents an analytical, numerical and experimental approach to detect, measure, locate and track moving loads in a structural element using discrete strain measures. An analytical model considering an Euler-Bernoulli beam was first studied in simple supported beam. Then a computer algorithm was implemented by using numerical models to au...

FCC is a waste material from petrochemical plants which has interesting properties for preparing binders. FCC is lightly grey in color, and white FCC-portland cements with L*≥85 can be prepared. FCC reactivity is enhanced by grinding and it is attributed to pozzolanic reaction towards lime. Stratlingite is the main hydrated product from pozzolanic...

El principal problema que afecta a la vida útil de las estructuras de hormigón armado es la corrosión de las armaduras. Los riesgos más importantes para dicha corrosión son la carbonatación del recubrimiento de hormigón y el ingreso de iones cloruro. Por estas razones, la investigación en nuevos conglomerantes que favorezcan la resistencia a la cor...