Our researchers

José María Fernández Álvarez

Department
Química
Facultad de Ciencias. Universidad de Navarra
Research lines
Contribución de los complejos metálicos al color del vino, Estabilización/inmobilización de metales en matrices cementicias, Electroanálisis de biomoléculas, Metales en aguas estuáricas, Incorporación de aditivos fotocatalíticos en matrices cementicias
H-Index
19, (Google Scholar, 21/09/2019)

Most recent scientific publications (since 2010)

Authors: Pérez, María; J. Plank; Ruiz-Izuriaga, D.; et al.
Journal: CONSTRUCTION AND BUILDING MATERIALS
ISSN 0950-0618  Vol. 162  2018  pp. 628 - 648
Coatings made with water dispersions of different nano-particles of photocatalytic additives (titania and titania doped with iron and vanadium) were prepared with diverse superplasticizers, SPs, to optimize the atmospheric NO removal efficiency when applied onto cement- and air-lime mortars. The use of different polycarboxylate-based superplasticizers (52IPEG, 23APEG and 45PC6) prevented nano-particles from agglomeration. The steric hindrance, provided by a large density and length of side chains, was ascertained as the most effective repulsion mechanism and 52IPEG was the most efficient SP. In PC- and air-lime mortars, the coatings with polycarboxylate-based SPs improved the NO removal rates as compared with the SP-free coating: an average increase of NO degradation by 15% under UV and by 76% under solar light was found. This finding was related to the drop in the agglomeration of the photocatalysts, with more exposed active sites and a decrease of the electron-hole recombination rates. Capillary water absorption and water vapour permeability values showed that the coatings did not alter the performance of the mortars. SEM examination showed that the use of SPs enhanced the distribution of the photocatalysts yielding thinner coating layers and boosting the percolation of the active material within the mortars. Accelerated weathering showed a moderate reduction of NO removal efficiency. Coating with 52IPEG was the most efficient in preserving the activity. Measurements of Ti content showed a low washout of the TiO2 nano-particles, supporting the long-run activity of these coatings.
Authors: Duran, A.; Fernández, J.M.; et al.
Journal: POLYMERS
ISSN 2073-4360  Vol. 10  Nº 8  2018  pp. 824
A new range of grouts prepared by air lime and metakaolin (MK) as a pozzolanic admixture has been obtained by using as dispersing agents two polymers, namely poly-naphthalene sulfonate (PNS) and lignosulfonate (LS), with the aim of improving the fluidity of the fresh grouts. Fluidity and setting times of the grouts were assessed. Differences in the molecular architecture and in the anionic charge density explained the different adsorption of the polymers and the different performance. The higher anionic charge of PNS and its linear shape explained its better adsorption and effectiveness. The pozzolanic reaction was favoured in grouts with PNS, achieving the highest values of compressive strength (4.8 MPa after 182 curing days). The addition of PNS on lime grouts slightly decreased the frost resistance of the grouts (from 24 freeze-thaw cycles for the polymer-free samples to 19 or 20 cycles with 0.5 or 1 wt % of PNS). After the magnesium sulphate attack, grouts were altered by decalcification of hydrated phases and by formation of hexahydrite and gypsum. A protective role of portlandite against magnesium sulphate attack was clearly identified. Accordingly, the polymer LS, which preserves a significant amount of Ca(OH)2, could be an alternative for the obtaining of grouts requiring high sulphate attack resistance.
Authors: Pérez, María; Navarro-Blasco, I.; Fernández, J.M.; et al.
Journal: NANOMATERIALS
ISSN 2079-4991  Vol. 7  Nº 10  2017  pp. 329
Mortars with two different binders (Portland cement (PC) and high alumina cement (HAC)) were modified upon the bulk incorporation of nano-structured photocatalytic additives (bare TiO2, and TiO2 doped with either iron (Fe-TiO2) or vanadium (V-TiO2)). Plastic and hardened state properties of these mortars were assessed in order to study the influence of these nano-additives. Water demand was increased, slightly by bare TiO2 and Fe-TiO2, and strongly by V-TiO2, in agreement with the reduction of the particle size and the tendency to agglomerate. Isothermal calorimetry showed that hydration of the cementitious matrices was accelerated due to additional nucleation sites offered by the nano-additives. TiO2 and doped TiO2 did not show pozzolanic reactivity in the binding systems. Changes in the pore size distribution, mainly the filler effect of the nano-additives, accounted for the increase in compressive strengths measured for HAC mortars. A complex microstructure was seen in calcium aluminate cement mortars, strongly dependent on the curing conditions. Fe-TiO2 was found to be homogeneously distributed whereas the tendency of V-TiO2 to agglomerate was evidenced by elemental distribution maps. Water absorption capacity was not affected by the nano-additive incorporation in HAC mortars, which is a favourable feature for the application of these mortars.
Authors: Pérez, María; Navarro-Blasco, I.; Fernández, J.M.; et al.
Journal: CONSTRUCTION AND BUILDING MATERIALS
ISSN 0950-0618  Vol. 149  2017  pp. 257 - 271
Mortars made with Portland cement, two different calcium aluminate cements and air lime were chosen to incorporate photocatalytic additives, because they have large exposed surfaces that boost the photochemical oxidation (PCO) of atmospheric pollutants such as nitrogen oxides. TiO2 as reference catalyst, and two doped titania, Fe-TiO2 and V-TiO2, which were expected to increase the sensitivity of the additives towards the visible light, were studied. Cementing matrices, particularly air lime and high alumina cement mortars, yielded significant amounts of NO removal under the three illumination conditions studied (UV, solar and visible light), with high selectivity response for NO abatement (up to 60 to 80%) and low NO2 release. The presence of calcium carbonate has been shown to have a synergistic effect, enhancing the PCO of these mortars under different light sources.
Authors: Duran, A.; Sirera, R; Pérez, María; et al.
Journal: CEMENT AND CONCRETE RESEARCH
ISSN 0008-8846  Vol. 81  2016  pp. 1 - 15
The effect of chlorides and nitrates of Li(I), Cr(III), Zn(II), Cu(II), Pb(II) nitrate and Cr(VI) (chromate) on the early hydration of ternary cement system of calcium aluminates (CA, CA2, C12A7) was reported. Li(I) and Cr(III) caused a strong acceleration of the hydration, while Zn(II) as well as chromate gave rise to a slight acceleration. On the contrary, Pb(II) and Cu(II) retarded the hydration. A clear formation of AFm phases during the first hydration stages was found and related to the acceleration ability. Anions (nitrate or chloride as counterions or even chromate) were able to be incorporated into the interlayer space of AFm, yielding insoluble and stable compounds. A balance between the insolubility of the metal hydroxides (dependant on the low amphoteric character of the compound) and the ability of the formation of AFm hydrates seems to be very important to lean the equilibrium towards the retarding of the hydration or towards the acceleration, respectively.
Authors: Pérez, María; Duran, A.; Navarro-Blasco, I.; et al.
Journal: CEMENT AND CONCRETE RESEARCH
ISSN 0008-8846  Vol. 82  2016  pp. 11 - 22
Polynaphtalenesulfonate (PNS) and lignosulfonate (LS) were tested as superplasticizers in pastes and mortars of pure air lime and air lime with a pozzolanic additive, nanosilica (NS). LS showed a better plasticizing effect than PNS: the flowability of the samples with LS as well as the slump retention over time was larger. LS strongly hindered carbonation due to its ability to form Ca2+ complexes. In mortars with NS, PNS was seen to interfere with the C-S-H formation, resulting in lower mechanical strengths. Adsorption isotherms and zeta potential showed that PNS was more adsorbed than LS onto lime and C-S-H particles. PNS acted mainly through electrostatic repulsion owing to its high anionic charge density and flat adsorption. However, LS was more efficient as superplasticizer in air lime media, steric hindrance being the main mechanism responsible for avoiding flocculation. Furthermore, LS yielded high compressive strengths in mortars with NS.
Authors: Navarro-Blasco, I.; Duran, A.; Pérez-Nicolás, M.; et al.
Journal: JOURNAL OF ENVIRONMENTAL MANAGEMENT
ISSN 0301-4797  Vol. 159  2015  pp. 288 - 300
Phosphate coating hazardous wastes originated from the automotive industry were efficiently encapsulated by an acid¿base reaction between phosphates present in the sludge and calcium aluminate cement, yielding very inert and stable monolithic blocks of amorphous calcium phosphate (ACP). Two different compositions of industrial sludge were characterized and loaded in ratios ranging from 10 to 50 wt.%. Setting times and compressive strengths were recorded to establish the feasibility of this method to achieve a good handling and a safe landfilling of these samples. Short solidification periods were found and leaching tests showed an excellent retention for toxic metals (Zn, Ni, Cu, Cr and Mn) and for organic matter. Retentions over 99.9% for Zn and Mn were observed even for loadings as high as 50 wt.% of the wastes. The formation of ACP phase of low porosity and high stability accounted for the effective immobilization of the hazardous components of the wastes.
Authors: Pérez-Nicolás, M; Balbuena, J.; Cruz-Yusta, M.; et al.
Journal: CEMENT AND CONCRETE RESEARCH
ISSN 0008-8846  Vol. 70  2015  pp. 67 - 76
Photocatalytic activity of TiO2 was studied in two types of calcium aluminate cement (CAC) under two different curing regimes. The effect of the TiO2 addition on the setting time, consistency and mechanical properties of the CACs was evaluated. The abatement of gaseous pollutants (NOx) under UV irradiation was also assessed. These cementitious matrices were found to successfully retain NO2: more abundant presence of aluminates in white cement (w-CAC, iron-lean) helped to better adsorb NO2, thus improving the conversion performance of the catalyst resulting in a larger NOx removal under UV irradiation. As evidenced by XRD, SEM, EDAX and zeta potential analyses, the presence of ferrite in dark cement (d-CAC, iron-reach) induced a certain chemical interaction with TiO2. The experimental findings suggest the formation of new iron titanate phases, namely pseudobrookite. The reduced band-gap energy of these compounds compared with that of TiO2 accounts for the photocatalytic activity of these samples.
Authors: Duran, A.; Navarro-Blasco, I.; Fernández, J.M.; et al.
Journal: CONSTRUCTION AND BUILDING MATERIALS
ISSN 0950-0618  Vol. 58  2014  pp. 147 - 158
The performance of air lime mortars modified by the incorporation of large amounts of nanostructured colloidal silica ¿ nanosilica, NS - (6, 10 and 20 wt.% with respect to lime) was the main objective of this work. Fresh mixture properties (water demand, setting time and plastic shrinkage), mechanical strengths up to one year and specimens¿ durability after accelerated ageing conditions (climatic chamber, freeze-thaw cycles and sulfate attack by MgSO4 corrosion test) were evaluated. NS was seen to have a strong pozzolanic activity in air lime media. Although the addition of NS gave rise to an increase in volume contraction, the superficial cracking caused by the drying shrinkage was reduced. A noticeable increase in the compressive strength values was observed in the NS-bearing mortars owing to the NS filler effect and the C-S-H formation, as proved by SEM examination and MIP analysis. A honeycomb-shaped network of C-S-H phases appeared as the prevailing microstructure in mortars with large NS additions. In the face of accelerated ageing processes, the presence of NS made the mortars more durable, delaying the progress of decay.
Authors: Sirera, R; Álvarez, J.I.; Duran, A.; et al.
Journal: REVISTA INTERNACIONAL DE EDUCACIÓN Y APRENDIZAJE
ISSN 2255-453X  Vol. 2  Nº 1  2014  pp. 83 - 92
Los medios audiovisuales son herramientas adecuadas hoy en día para ilustrar el desarrollo de las clases magistrales impartidas por el profesor universitario. El alumno se desenvuelve con soltura en estos soportes, y la utilización de estos medios es un óptimo complemento para una buena comprensión del tema. Particularizando esta acción en estudios experimentales, como la Química, las ventajas que aporta el empleo de estos materiales son claras, tanto en el entendimiento de los temas como en el propio acercamiento del alumno a aspectos más prácticos y relacionados con el ejercicio profesional al que se dedicarán cuando finalicen los estudios. El presente trabajo evalúa los resultados de aplicar las nuevas tecnologías en la enseñanza de la Química a estudiantes de la Universidad de Navarra. Se pretende identificar elementos propios del ejercicio profesional del químico y relacionar los contenidos teórico-prácticos de las asignaturas con el mismo, consiguiendo además con ello un mejor conocimiento de la materia objeto de estudio. La percepción de los alumnos ha sido ciertamente positiva en términos de un incremento de interés por las materias implicadas y de una mejora en la comprensión de las mismas.
Authors: Navarro-Blasco, I.; Pérez-Nicolás, M.; Fernández, J.M.; et al.
Journal: CONSTRUCTION AND BUILDING MATERIALS
ISSN 0950-0618  Vol. 73  2014  pp. 1 - 12
Two polycarboxylate ether copolymers were assessed as superplasticizers (SPs) for hydrated lime pastes modified with two reactive compounds, nanosilica (NS) and ceramic metakaolin (MK). Characterization of the molecular structure of the SPs by Size Exclusion Chromatography, XRD, FTIR and MALDI-TOF (Matrix Assisted Laser Desorption Ionization Time-of-Flight) mass spectrometry was performed. The structures of the polymers were seen to be star- and worm-like shapes. A close relationship was found between the molecular architecture and the flowability of the pastes, being the star-shaped plasticizer the most efficient. Zeta potential assessment allowed us to elucidate a steric hindrance as the main action mechanism for these polymers. The large specific surface area of nanosilica led to a large SPs consumption as compared with metakaolin with lower surface area. However, SPs in MK¿lime samples were attached favourably on the C¿S¿H and aluminate hydrates, so that the dispersing action was greater with respect to NS¿lime suspensions.
Authors: Fernández, J.M.; Navarro-Blasco, I.; Duran, A.; et al.
Journal: JOURNAL OF ENVIRONMENTAL MANAGEMENT
ISSN 0301-4797  Vol. 140  2014  pp. 1 - 13
Polyphosphate-modified calcium aluminate cement matrices were prepared by using aqueous solutions polluted with toxic metals as mixing water to obtain waste-containing solid blocks with improved management and disposal. Synthetically contaminated waters containing either Pb or Cu or Zn were incorporated into phosphoaluminate cement mortars and the effects of the metal¿s presence on setting time and mechanical performance were assessed. Sorption and leaching tests were also executed and both retention and release patterns were investigated. For all three metals, high uptake capacities as well as percentages of retention larger than 99.9% were measured. Both Pb and Cu were seen to be largely compatible with this cementitious matrix, rendering the obtained blocks suitable for landfilling or for building purposes. However, Zn spoilt the compressive strength values because of its reaction with hydrogen phosphate anions, hindering the development of the binding matrix.
Authors: Álvarez, J.I.; Fernández, J.M.; Navarro-Blasco, I.; et al.
Journal: MATERIALS CHARACTERIZATION
ISSN 1044-5803  Vol. 80  2013  pp. 36-49
The addition of a pozzolanic nanosized material, nanosilica (NS), onto lime binding materials was carried out with the aim of assessing the microstructural modifications attained by its presence that were related to the mechanical behavior. Simultaneously, a comparative study between five different drying methods for water removal was reported, and their influence on the pore structure evaluation is discussed. Solvent-exchange with isopropanol and freeze-drying methods were shown to remove the excess of free water efficiently, allowing us to measure the gel pores (< 10 nm) of the calcium silicate hydrated (C-S-H) phases and yielding the largest surface area values. By using vacuum drying, oven drying at 60ºC or oven drying at 105ºC macro-, meso- and micropores could not be properly measured. On the other hand, the addition of NS dramatically altered the mesopore range. As a result of the intercalation of NS particles between lime particles, a drop in the population of large and medium capillary pores (in the range of 20-100 nm) was observed, leading to reduced overall porosity. The NS was clearly proven to act as nanofiller. Finally, this filling effect of NS together with the development of C-S-H gel, as a consequence of the pozzolanictype reaction proved by the increase of population in the micropore range, notably enhanced the compressive strength of the lime binding materials, yielding values more than twice those of the NS-free materials.
Authors: Navarro-Blasco, I.; Fernández, J.M.; Duran, A.; et al.
Journal: CONSTRUCTION AND BUILDING MATERIALS
ISSN 0950-0618  Vol. 48  2013  pp. 218 - 228
The recycling of WFS in calcium aluminate cement mortars at high level of replacement (50%) was studied. Consistency and setting time were measured in fresh mortars. Two different curing conditions were used, the second one with the aim of enhancing the formation of stable cubic calcium aluminate hydrates. Compressive strength, pore size distribution and SEM examination were carried out to assess the effectiveness of CAC matrix in the recycling of WFS. The effect of the incorporation of a polymeric admixture - a chitosan derivative - was also explored. Leaching studies on hardened mortars of three target pollutants of the WFS (toxic metals Pb, Cr and Zn) were also done to evaluate their immobilization. By comparison with OPC mortars, the use of CAC showed several advantages, improving the compressive strength and the toxic metal retention.
Authors: Fernández, J.M.; Duran, A.; Navarro-Blasco, I.; et al.
Journal: CEMENT AND CONCRETE RESEARCH
ISSN 0008-8846  Vol. 43  Nº 1  2013  pp. 12 - 24
The effect of individual and combined addition of both nanosilica (NS) and polycarboxylate-ether plasticizer (PCE) admixtures on aerial lime mortars was studied. The sole incorporation of NS increased the water demand, as proved by the mini-spread flow test. An interaction between NS and hydrated lime particles was observed in fresh mixtures by means of particle size distribution studies, zeta potential measurements and optical microscopy, giving rise to agglomerates. On the other hand, the addition of PCE to a lime mortar increased the flowability and accelerated the setting process. PCE was shown to act in lime media as a deflocculating agent, reducing the particle size of the agglomerates through a steric hindrance mechanism. Mechanical strengths were improved in the presence of either NS or PCE, the optimum being attained in the combined presence of both admixtures that involved relevant microstructural modifications, as proved by pore size distributions and SEM observations.
Authors: Navarro-Blasco, I.; Duran, A.; Sirera, R; et al.
Journal: JOURNAL OF HAZARDOUS MATERIALS
ISSN 0304-3894  Vol. 260  2013  pp. 89-103
The ability of calcium aluminate cement (CAC) to encapsulate toxic metals (Pb, Zn and Cu) was assessed under two curing conditions. Changes in the consistency and in the setting time were found upon the addition of the nitrates of the target metals. Both Pb and Cu caused a delay in CAC hydration, while Zn accelerated the stiffening of the mortar. Compressive strengths of the metal-doped mortars, when initially cured at 60ºC / 100%RH, were comparable with that of the free-metal mortar. Three different pore size distribution patterns were identified and related to the compounds identified by XRD and SEM. Sorbent capacities of CAC for the toxic metals were excellent: a total uptake was achieved for up to 3 wt.% loading of the three metals. In this way, CAC mortars were perfectly able to encapsulate the toxic metals, allowing the use of CAC for waste management as proved by the leaching tests.
Authors: Navarro-Blasco, I.; Fernández, J.M.; et al.
Journal: JOURNAL OF HAZARDOUS MATERIALS
ISSN 0304-3894  Vol. 233-234  2012  pp. 7 - 17
Cement mortars loaded with Cr, Pb and Zn were modified by polymeric admixtures [chitosans with low (LMWCH), medium (MMWCH) and high (HMWCH) molecular weight and hydroxypropylchitosan (HPCH)]. The influence of the simultaneous presence of the heavy metal and the polymeric additive on the fresh properties (consistency, water retention and setting time) and on the compressive strength of the mortars was assessed. Leaching patterns as well as properties of the cement mortars were related to the heavy metals-bearing solid phases. Chitosan admixtures lessened the effect of the addition of Cr and Pb on the setting time. In all instances, chitosans improved the compressive strength of the Zn-bearing mortars yielding values as high as 15 N mm¿2. A newly reported Zn phase, dietrichite (ZnAl2(SO4)4·22H2O) was identified under the presence of LMWCH: it was responsible for an improvement by 24% in Zn retention. Lead-bearing silicates, such as plumalsite (Pb4Al2(SiO3)7), were also identified by XRD confirming that Pb was mainly retained as a part of the silicate network after Ca ion exchange. Also, the presence of polymer induced the appearance and stabilization of some Pb(IV) species. Finally, diverse chromate species were identified and related to the larger leaching values of Cr(VI).
Authors: Navarro-Blasco, I.; Fernández, J.M.; et al.
Journal: CEMENT AND CONCRETE COMPOSITES
ISSN 0958-9465  Vol. 34  Nº 8  2012  pp. 964 - 973
The effect of two non-ionic chitosan derivatives (hydroxypropyl (HPCH) and hydroxyethyl (HECH) chitosans) and one ionic derivative (carboxymethylchitosan, CMCH) on the fresh-state properties of cement mortars was studied. Zeta potential measurements and particle size distribution were carried out in order to elucidate the action mechanism of the admixtures. Results were seen to be strongly dependent on substituents of the chitosan. Non-ionic derivatives had a weak dosage-related influence on the fresh-state properties. The ionic CMCH showed the more marked effect: it was found to act as a powerful thickener and to reduce the workable life of the fresh mixtures, whereas it caused a delay in the hydration of the cement particles. CMCH reduced the slump by 50% while commercial viscosity enhancers exhibiting larger molecular weights (hydroxypropylmethylcellulose, HPMC, and hydroxypropyl guaran, HPG) only reduced it by ca. 25%. The negative values of zeta-potential and the strong flocculating effect point to an adsorption of CMCH onto the positively charged cement particles. Optical microscopy and TEM observations showed the polymer giving rise to interlinking between cement particles.
Authors: Navarro-Blasco, I.; Fernández, J.M.; et al.
Journal: JOURNAL OF APPLIED POLYMER SCIENCE
ISSN 0021-8995  Vol. 120  Nº 1  2011  pp. 242 - 252
Authors: Santamaría, C; Fernández, J.M.;
Journal: REVUE D'OENOLOGUES ET DES TECHNIQUES VITI-VINICOLES ET OENOLOGIQUES
ISSN 0760-9868  Vol. 38  Nº 141S  2011  pp. 56 - 58
Authors: Navarro-Blasco, I.; Álvarez, J.I.; et al.
Journal: JOURNAL OF HAZARDOUS MATERIALS
ISSN 0304-3894  Vol. 194  2011  pp. 223 - 231
Authors: Valle, EMA ; Santamaría, C; Machado, SAS; et al.
Journal: JOURNAL OF THE BRAZILIAN CHEMICAL SOCIETY
ISSN 0103-5053  Vol. 21  Nº 6  2010  pp. 1052 - 1059
The affinity of two widely used pesticides of diverse specificities, i.e., the fungicide Thiram and the herbicide Picloram, for lead ions has been studied by an electrochemical approach. The anodic stripping voltammetric profile of the studied metallic ion was significantly affected by the chemical nature of pesticide (ligand) used and new light has been shed on the nature, strength and possible stoichiometry of formed complexes. Thiram caused a pronounced effect on the stripping signals of Pb. Linearization algorithms of titration data with the metal allowed the conditional stability constant to be calculated for Thiram (log K' = 6.8) and Picloram (log K' = 6.0). It was found that both pesticides contribute to the formation of the respective 1:1 complexes with Pb in a high percentage (ca. 83%).
Authors: Tasci, B.; Martínez-de-Tejada, Guillermo; et al.
Book title:  RILEM Proceedings PRO 130
2019  pp. 359 - 372
Different rendering mortars were prepared by mixing air lime and air lime-pozzolanic nanosilica with TiO2 and sodium oleate as, respectively, photocatalytic and water repellent agents, added in bulk. The aim of the work was to design and obtain new rendering mortars with improved durability focusing in the reduction of the water absorption of these materials and in their self-cleaning and biocide effect. To achieve a better distribution of the TiO2 particles, which was expected to enhance their efficiency, different dispersing agents were also incorporated to the fresh mixtures. Four diverse polycarboxylate ethers superplasticizers and a poly-naphthalene-sulfonate were tested. Workability and fluidity of the fresh rendering mortars were determined to guarantee the applicability of the final products. Water contact angle was monitored with the aim of assessing the hydrophobicity of the mortars lent by the water repeller. The biocide effect was studied by means of the culture of a strain of Pseudomonas fluorescens. The colonization of the mortars¿ surface was analyzed by determining the number of colonies forming units (CFU) after several days subjecting the samples to suitable T and RH conditions. At the same time, the surface of the mortars was irradiated with solar light to activate the photocatalyst. Results showed the efficiency of the sodium oleate in reducing the water uptake of the rendering mortars.
Authors: Navarro-Blasco, I.; Duran, A.; et al.
Book title:  Proceedings PRO 130 : 5th Historic Mortars Conference
2019  pp. 330 - 345
This work reports the obtaining of lime-based grouts as repairing materials. Microsilica was added as pozzolanic additive to enhance the compressive strength of the hardened grouts. Sodium oleate, as water repellent admixture, and different superplasticizers (SPs) were also incorporated to reduce the water absorption and to enhance the injectability of the grouts. Polycarboxylate ether (PCE), polynaphthalene sulfonate (PNS), melamine sulfonate (MMS) and polyacrylic acid (PA) were tested as SPs. Regarding the fluidity of the grouts, PCE was seen to improve the injectability, followed by PNS, MMS and PA. However, PCE addition was also accompanied by a severe delay in the setting time. The other three superplasticizers did not provoke significant delays in the hardening of the samples. The water contact angle underwent an increase pointing to an effective hydrophobization of the surface as a consequence of the water repellent admixture. The combination with PCE was the most effective in keeping the water repellency in comparison with the control sample (lime grout + oleate). MMS yielded high compressive strengths and durability of the mortars, in the face of freezing-thawing cycles, was enhanced.
Authors: Speziale, A.; Navarro-Blasco, I.; et al.
Book title:  Proceedings PRO 130 : 5th Historic Mortars Conference
2019  pp. 155 - 168
Active coatings to be applied onto hardened surfaces of lime rendering and masonry mortars and stones of the Built Heritage were developed. Nano-heterostructures of TiO2/ZnO (50:50 and 10:90) were obtained by Flame Spray Pyrolysis as photocatalytic agents with expanded sensitivity towards solar light, instead of the restricted UV dependence of the pure TiO2 or ZnO. A superhydrophobic medium was simultaneously prepared and photocatalytic nanoparticles were added to obtain the coatings. The active products were expected to prevent the water absorption of the substrates and the subsequent degradation effects as well as to allow the stones and mortars to act as self-cleaning materials, reducing the dirt deposition and the biological colonization. Dispersions were applied onto the surface of lime mortars and siliceous stone. Measurements of the photocatalytic oxidation activity of the coatings were carried out by means of the NO degradation, showing a very good efficiency of the nanoparticles even at long term tests (values of NO oxidation of ca. 35%). Water contact angle assessment evidenced a strong hydrophobization of the treated surfaces, with WCA values higher than 140º. The results proved the synergistic effect of these coatings with respect to the durability of the treated substrates, giving rise to a promising way of preventive conservation for building materials of the Cultural Heritage.
Authors: Pérez, María; Navarro-Blasco, I.; Fernández, J.M.; et al.
Book title:  Tradición, versatilidad e innovación en la cal: un material de excelencia
2018  pp. 268 - 279
Diferentes morteros de cal fueron modificados por la incorporación en masa de aditivos fotocatalíticosnanoestructurados (TiO2 o TiO2 dopado con hierro (Fe-TiO2) o vanadio (V-TiO2)). Las propiedades plásticas y endurecidas de estos morteros han sido evaluadas para estudiar la influencia de estos nanoaditivos. Los retrasos en la demanda de agua observados en las pastas de cal se atribuyeron al impedimento de la difusión de CO2 dentro de la pasta. El TiO2 y el TiO2 dopado no mostraron reactividad puzolánica alguna. El examen por microscopía electrónica de barrido de los morteros de cal mostró que las fases predominantes en la microestructura eran placas hexagonales de portlandita y las aglomeraciones gruesas escalenoédricas de calcita. Se encontró que el Fe-TiO2 se distribuía homogéneamente, mientras que el análisis EDS demostró la tendencia al aglomeramiento del V-TiO2. La capacidad de absorción de agua no se vio afectada por la incorporación de nanoaditivos, lo cual es una característica favorable para la aplicación de estos morteros.
Authors: Duran, A.; Navarro-Blasco, I.; et al.
Book title:  Tradición, versatilidad e innovación en la cal: un material de excelencia
2018  pp. 228 - 240
El presente trabajo tiene como principal objetivo estudiar las interacciones que se producen cuando se adicionan separadamente dos superplastificantes (PNS ¿sulfonato de polinaftaleno- y LS ¿lignosulfonato-) a un conglomerante aéreo (cal aérea Cl 90-S) y a uno hidráulico formado por cal aérea a la que se le ha añadido metacaolín como material puzolánico, y los efectos que dichas adiciones tienen en las propiedades de los sistemas. Para la fabricación de los morteros, se empleó árido calcáreo. Adicionalmente, se efectuaron ensayos de durabilidad en morteros con la composición citada, sometiéndolos a ciclos de hielo-deshielo y a ataque con sulfatos. Aunque se realizaron algunas medidas con las pastas en estado fresco, la mayoría de los experimentos (resistencia a compresión y a flexión, TG-ATD, DRX, FTIR-ATR, porosimetría de intrusión de mercurio) se realizaron tras períodos de fraguado del mortero de 7, 28, 91, 182 y 365 días. Se detectaron fases silicatadas y silicoaluminatadas en los morteros estudiados, a pesar de que las experiencias se realizaron a temperatura ambiente y con un bajo porcentaje de material puzolánico (¿20 %). La presencia de LS impidió el proceso de carbonatación, lo que a su vez provocó un decrecimiento en los valores de resistencia mecánica cuando se trataba de morteros hidráulicos. Se observó asimismo una mayor porosidad y un mayor tamaño medio de poro en el caso de sistemas con LS. La durabilidad (ciclos hielo-deshielo) de los morteros mejoró notable
Authors: Navarro-Blasco, I.; Duran, A.; et al.
Book title:  Tradición, versatilidad e innovación en la cal: un material de excelencia
2018  pp. 251 - 262
Los morteros de relleno o inyección, especialmente destinados a reparación de cavidades y defectos de albañilería, deben fluir adecuadamente en estado fresco y combinar resistencia y durabilidad. Para conseguir algunas de estas características pueden utilizarse aditivos químicos: superplastificantes, para mejorar la fluidez; adiciones puzolánicas, para conseguir resistencias adecuadas en ambientes con limitado acceso de CO2 y una mejora de la durabilidad; e hidrofugantes, de manera que, sin perjudicar la permeabilidad de estos materiales al vapor de agua, se evite la penetración de agua por capilaridad mejorando la durabilidad. Sin embargo, en la mayor parte de los casos, toda la información disponible se circunscribe al efecto de un único aditivo, sin contemplar el posible efecto conjunto o incluso sinérgico de las combinaciones más interesantes de dos o más aditivos y/o adiciones puzolánicas. El estudio de las sinergias entre estos componentes ofrece posibilidades muy interesantes de avance científico-técnico. Precisamente este es el objetivo del trabajo: diseño de nuevos morteros de inyección de cal que puedan ser utilizados para la restauración del Patrimonio Edificado mediante combinación adecuada de aditivos superplastificantes (éteres de policarboxilato, condensados de naftaleno-formaldehído, sulfonato de melamina y ácido poliacrílico), hidrofugante (oleato sódico) y adiciones minerales puzolánicas (microsílice y metacaolín).
Authors: Fernández, J.M.; Pérez, María; Duran, A.; et al.
Book title:  Proceedings of the 4th Historic Mortars Conference HMC 2016
2016  pp. 721 - 728
This contribution dealt with the design of different air lime mortars and pastes by combining a nanostructured pozzolanic additive, nanosilica, and different dispersing agents, superplasticizers (two different polycarboxylate ethers (PCE), a polynaphthalene sulfonate-based polymer (PNS) and a lignosulfonate (LS)). In pure air lime systems, the highest effectiveness was shown by the PCE1, whereas the PNS was the less effective superplasticizer. In samples with nanosilica, the PCE1 was also the most effective superplasticizer. LS was seen to be effective at low dosages. In the presence of the pozzolanic additive, there was a high consumption of polycarboxylates. Nanosilica provided no ¿active¿ adsorption sites, resulting in a slight decrease of the zeta potential values. PCE1 showed low adsorbed amounts, better dispersing action and required lower dosage of plasticizing agent. There was a positive combination between lime mortars with nanosilica and polycarboxylates, which resulted in a mechanical strength improvement. Also the combined presence of nanosilica, for example, with PNS or with LS yielded better compressive strengths, being LS more effective than PNS: SEM images showed the better formation of C-S-H phases in LS-mortars.
Authors: Duran, A.; Sirera, R; Pérez, María; et al.
Book title:  Proceedings of the 4th Historic Mortars Conference HMC 2016
2016  pp. 383 - 390
A new range of repair lime mortars were obtained by using as superplasticizer a polynaphthalene sulfonate-based polymer (PNS) and metakaolin as pozzolanic addition. Adsorption isotherms showed that PNS exhibited a high affinity for air lime particles with 52.08 mg¿g-1 as maximum sorption capacity in pure air lime media. Mathematical treatment of experimental data showed an optimal adjustment to a Freundlich model, in which interactions arising from multilayer adsorption are taken into account. The experimental results suggested a great interaction of PNS with air lime media (pure air lime or air lime with MK). Zeta potential curves of air lime systems titrated with PNS showed a larger zeta potential reduction, giving rise to a charge reversal, as a consequence of the high anionic charge density of this polymer (2.44 meq of anionic charge¿g-1). A flat adsorption was proposed as the attachment model of this admixture, owing to its higher anionic charge density and to its linear shape. The electrostatic repulsion was then the main action mechanism to explain the PNS function. In the hardened state, the combination of PNS and MK resulted sometimes in moderate mechanical strength increases and in a clear enhancement of the durability in the face of freezing-thawing cycles.
Authors: Pérez, María; Duran, A.; Sirera, R; et al.
Book title:  Proceedings of the 4th Historic Mortars Conference HMC 2016
2016  pp. 375 - 382
A superplasticizing admixture of natural origin, lignosulfonate (LS), was incorporated to air lime mortars sometimes modified with a pozzolanic additive, metakaolin, to obtain a new range of repair mortars to be applied in Built Heritage. LS improved the flowability of the air lime samples and showed good slump retention over time: for example, after 150 minutes of the air lime pastes preparation, blends with LS lost only ca. 13% of the slump value. Experimental results showed that LS interfered with the carbonation due to its ability to form Ca2+ complexes. Adsorption isotherms and zeta potential measurements showed that LS was scarcely adsorbed onto lime and C-S-H particles. Due to its branchy structure, LS exhibited an adsorption mechanism leading to steric hindrance as the main responsible mechanism for avoiding flocculation. The presence of free LS molecules in the dispersion was seen to improve the plasticizing effect of this polymer. Flexural and compressive strengths as well as the durability in the face of freezing-thawing cycles of these mortars were also determined to assess the applicability of these repair mortars.
Authors: Pérez, María; Navarro-Blasco, I.; Duran, A.; et al.
Book title:  Proceedings of the 4th Historic Mortars Conference HMC2016
2016  pp. 688 - 695
The obtaining of self-cleaning mortars is very interesting to apply them in Built Heritage. Atmospheric pollutants, mainly carbonaceous particles and gases like NOx and SO2 can lead to severe aesthetic and functional damages in artworks. In the case of mortars and renders, the use of photocatalysts -usually based on TiO2- can be worthy of consideration. Photocatalysts, after being activated by light, are able to oxidize pollutants avoiding their deposition onto building materials. In this work, different air lime mortars modified upon the addition of TiO2-based photocatalysts were obtained and studied. Photocatalysts can be incorporated in bulk and the changes in fresh state properties were studied as well as the effect of the presence of the photocatalysts on the pore structure and mechanical resistance. Finally, the photocatalytic efficiency of these materials was carried out by means of a NOx abatement test. Results showed that the presence of the photocatalysts had a positive impact on the preservation of the lime mortars characteristics.
Authors: Pérez, María; Navarro-Blasco, I.; Duran, A.; et al.
Book title:  Proceedings of the 14th International Congress on the Chemistry of Cement (CD): Section 4: Admixtures
2015  pp. 1 - 14
Although CAC is used in many building as well as industrial structures, its modification upon addition of photocatalytic additives has not yet been addressed and that is precisely the purpose of the present work. We intend to obtain for the first time depolluting CAC mortars modified with different amounts of TiO2. The effect of the TiO2 incorporation on setting time, compressive strength and mineralogical composition of the CAC mortars will be assessed. PCO efficiency of these TiO2-bearing CAC mortars will be also measured by means of the NOx abatement. The modified depolluting mortars could be then applied in different tunnels, industrial floors and urban areas in which CACs are usually applied.
Authors: Duran, A.; Navarro-Blasco, I.; Pérez, María; et al.
Book title:  Proceedings of the 14th International Congress on the Chemistry of Cement (CD): Section 4, Admixtures
2015  pp. 1 - 8
The behaviour of different superplasticizers admixtures was assessed for hydrated lime pastes and mortars. Sometimes, air lime pastes and mortars were modified with two supplementary cementing materials (SCMs), namely nanosilica (NS) and metakaolin (MK). Two different polycarboxylate ethers, a lignosulfonate and a naphthalene condensed sulfonate superplasticizer were added to lime pastes and mortars and their effects on fresh-state properties as well as on the mechanical strengths were evaluated. A close relationship was found between the molecular architecture of the plasticizers and the flowability of the pastes. Zeta potential assessment allowed us to elucidate the main action mechanisms for these admixtures. In the case of polycarboxylate ethers, the large specific surface area of nanosilica led to a large SPs consumption as compared with metakaolin with lower surface area. However, polycarboxylate ethers in MK-lime samples were attached favourably to the C-S-H and aluminate hydrates, so that the dispersing action was greater with respect to NS-lime suspensions.
Authors: Navarro-Blasco, I.; Sirera, R; Pérez, María; et al.
Book title:  Proceedings of the 14th International Congress on the Chemistry of Cement (CD): Section 6, Alternative binders
2015  pp. 1 - 11
The rationale is that polyphosphate-CAC matrices have shown interesting potential to solidify/stabilize heavy metals, owing to the aforementioned acid-base reaction that yields a compact and low porous matrix mainly composed of ACP - amorphous calcium phosphate -, which can be able to retain hazardous compounds. We aimed to take advantage of the reactivity of one of the sludge components: the sludges with relatively large concentrations of phosphate are expected to act themselves as reactants that, interacting with the CAC, could result in a very effective retaining system of the sludge constituents. Sludge samples from two locations have been incorporated in high proportion within the mix. We discussed the effects of the sludge on the CAC mortar and a possible interaction mechanism is provided.
Authors: Álvarez, J.I., (Editor); Fernández, J.M., (Editor); Navarro-Blasco, I., (Editor); et al.
2019 
Proceedings of the 5th Historic Mortars Conference (HMC 2019) held at the University of Navarra in Pamplona from the 19th to the 21st June 2019.
Authors: Álvarez, J.I., (Editor); Fernández, J.M., (Editor); Navarro-Blasco, I., (Editor); et al.
2019 
This book collects the abstracts of the communications presented in the 5th Historic Mortars Conference (HMC 2019) organized by the Heritage, Materials & Environment (MIMED) Research Group of the Chemistry Department of the University of Navarra at the School of Sciences in Pamplona from 19 to 21 June 2019.
Authors: Álvarez, J.I., (Editor); Fernández, J.M., (Editor); Navarro-Blasco, I., (Editor); et al.
2018 
El Fórum Ibérico de la Cal, FICAL, es una asociación sin ánimo de lucro cuyo objetivo es el desarrollo de la investigación, la formación y la difusión de la producción y el uso de la cal. Después de las exitosas V Jornadas celebradas en el LNEC de Lisboa, la Universidad de Navarra toma el relevo y organizará en Pamplona, en la Facultad de Ciencias, las VI Jornadas FICAL, del 28 al 30 de mayo de 2018. Estas Jornadas están abiertas a participantes de distintas procedencias e intereses: restauradores, arquitectos y arquitectos técnicos, químicos, geólogos, ingenieros civiles y de materiales, historiadores, científicos, profesionales del sector industrial, estudiantes, empresas productoras¿ con el común denominador de conocer más posibilidades de aplicación, características, comportamiento y aspectos innovadores y tecnológicos en relación con la cal. Se conocen aplicaciones de la cal desde tiempos inmemoriales, particularmente en construcción: morteros, soportes decorativos y pictóricos. La cal es un material íntimamente ligado al Patrimonio Histórico-Artístico y se sigue produciendo a partir de las mismas materias primas. Destacan, entre sus características, la plasticidad de las argamasas que utilizan cal, su capacidad higroscópica y desinfectante, sus propiedades aislantes y su durabilidad. La cal es perfectamente compatible con estructuras antiguas, es idónea para procesos de restauración y rehabilitación, pero también tiene interés en obra nueva porque aporta estabilidad,

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