bluuebunny/crossref_metadata_2025 huggingface dataset:
Las puzolanas y el ahorro energético en los materiales de construcción
Authors: Soria Santamaría Francisco
Published: July 2012

This discussion commences with some general comments on the energy crisis and its impact on the cement industry, with the corresponding coal reconversion problems. Three factors are highlighted where saving has been centered: technological process, raw materials and finished product, emphasizing the interest of latter which includes incorporating active additions in Portland cement.
A quick review then follows about pozzolanas, their origin, definitions and classification. Their chemical composition is underlined, and the concept of pozzolanic activity is described.
Later on, pozzolanic cements, their most significant properties and the advantages of using pozzolana are explained.
After a lengthy description about possible applications of pozzolanas and pozzolanic cements, the conclusion reviews current trends in international standards for such cements and possible evolution in consumption of additions by the year 2000, with a view to saving more energy, without impairing the essential properties of the cement.
Interpretación textural de dos clínkeres de cemento portland de distinta velocidad de fraguado
Authors: Rodríguez Rey Ángel
Published: July 2012

Two industrial portland cement clinkers from the same kiln, with different setting rates, were texturally characterizated by reflected light microscopy.
They showed remarkable mineralogic and textural differences which arised during their distinct cooling processes, according to the interpretation of their textures.
Determinación de la composición mineralógica del clínker por microscopía cuantitativa, disolución de fases y difracción de rayos X
Authors: Triviño F. , Blanco M. T.
Published: July 2012

A comparative study has been done about the use of three methods: Microscopic, Dissolution of Phases and X-Ray Diffraction, for the determination of the mineralogical composition of clinker, XRD appears (just as it is shown in this paper) as a complicated method which does not guarantee a good determination of C3A.
The consecutive dissolution of phases whith methanol and salicylic acid and saccharose is a simple, cheap and reliable alternative method.
The dissolution of phases with salicylic acid is a good method to determine the whole of silicates and liquid phase.
Optic microscopy (reflected light) is a method of determining bi and tricalcium silicates but the results so given are unreliable.
Varations which could improve these methods are indicated.
8.° Congreso Internacional de la Química de los Cementos (8.° CIQC) Comité Científico para Europa, Asia y África (CEAA). Reunión del 22-VI-83 en París
Authors: Calleja José
Published: July 2012

This information paper deals with the subject treated in the mentioned meeting, the third of those celebrated by the Committee. This meeting was not previously programmed and had a character merely informative.
Many questions related to the Scientific Program were treated in the meeting and a final proposal was prepared by the Committee to be sent to the President of the Latin-American Committee and Coordinator of the three Scientific Committees, Prof F. de A. Basilio.
Sulfatos en el cemento portland y su incidencia sobre el falso fraguado: Estado actual del conocimiento
Authors: De la Cruz Ignacio , Vázquez Tomás , Fernández-Peña Olga
Published: July 2012

A bibliographical study is carried out of the sulphates which may be present in the clinker and Portland cement, as likewise the effects of the aeration and temperature on the setting.
This work is a prior phase of a wide experimental investigation carried out in the IETCC, on anomalies or setting and phenomena of "lumping" in Portland cement.
Ensayos de materiales en atmósferas simuladas. III. Evaluación de un sistema de simulación
Authors: Vale J. , Martín A.
Published: July 2012

The final step in the creation of a system of simulation of the drying and purification of the air, yield answer when we attempt to produce determined conditions with it. In this article are gathered the different aspects to be borne in mind in such an evaluation efficiency of the drying and purification of the air, yield in the generation of the different pollutants, autonomy of the sections, reproduction, stability, homogeneousnness and evolution of the simulated conditions, etc.
It comprises a deeper study on the technique of generation of one of the pollutants introduced, the FH, which presents some specific problems. Special attention is also devoted to the results obtained in a series of experiments of application, which constitute the definitive proof for a system of simulation. Finally, there are carried out a series of considerations on these systems and on the alteration experiments.
Proyecto para la construcción de un precalentador de lecho fluidizado para un horno piloto de laboratorio
Authors: Palomo Sánchez Ángel
Published: July 2012

A preheater with fluidized bed is planned on a pilot scale, capable of being fitted to a rotatory furnace, also of a pilot nature, for the manufacture of Portland clinker.
With this it is intended to design a system of dynamic simulation of clinkerization, to obtain clinker of similar characteristics to those which are obtained industrially.
Determinación del agua retenida por el agregado en relación a las características superficiales y granulométricas
Authors: Grinszpan Pedro Enrique
Published: July 2012

This study covers point relating to capacity of aggregates to superficially retain part of the water used in mortar and concrete mixtures.
It relates this property with the real characteristics of the aggregates. The superficial retention capacity is a decisive factor to determine dosage of mortar and concrete mixtures. The relation between granulometry, modulus of fineness and surrounding surface has accordingly been focused in relation to superficially retained water.
Sufficiently generalized analytic expressions have been developped, and later compared with results obtained in experiments based on a process designed for this purpose.
The variables are later inter-related using expressions that permitted graphic functions to be developed for correlation with the experimental results, and finally establishing acceptance limits for this process.
Sistemas homogéneos de ecuaciones diofánticas. Resolución y aplicación al ajuste automático de reacciones químicas
Authors: Recuero Alfonso , Gutiérrez J. Pedro
Published: July 2012

An algorithm to solve systems of linear homogeneous diophantine equations is given here. Subsequently, as an example of application, a method of heuristic search for the best solution is described; this fulfils certain conditions within an infinite space of solutions of various dimensions. Finally, an application of the algorithm and of the process of heuristic search for the best solution in adjusting chemical reactions is described. The listing in BASIC of the program of application mentioned is included, for the HP-75 portable computer.
Estudio comparativo de la relación existente entre resistencia media y concentración en hormigones fabricados con portland y portland con adiciones activas
Authors: Hernández Antonio Garrido
Published: July 2012

This study attempts to show the differences found between average resistance, after 28 days, obtained in the laboratory and that predicted when the C/A relationship has been calculated using the general De la Peña formula. This difference is considered to be sufficient to justify modifying the content of the formula, though not that of its structure. It is suggested that the difference may be due to the use of PA cement, when the formula originates from the tests with pure Portland cement. If this is the case, it would simply be a question of generalizing the formula to another type of cement.
Resistencia química del hormigón. XXIII. Influencia de la adición de escoria a un cemento portland resistente al yeso. Estudio de la concentración iónica del sistema cemento 2/escoria-agua potable filtrada
Authors: Sagrera-Moreno José Luis , Gaspar-Tebar Demetrio
Published: July 2012

In this study, which follows on from others, the pH variation is examined and also that of the concentration of Ca (II) and SO4 (II) ions in the mediums (filtered potable water) in which the test samples of mortar (1: 3) made with industrial portland cement resistent to gypsum (cement 2 < > P-450-Y) and with the mixtures cement 2/slag = 85/15 - 65/35 - 40/60 and 30/70, in weight, have been submerged throughout the curing period (21 days) and, subsequently, for 56 - 90- 180 and 360 days (preservation periods), at this stage. In the same way, the chemical composition of these solid stages was determined by XRD (calcite, in both periods and, also, aragonite during the preservation period of the series of test samples made only with cement 2); an account of this was given in (2).
In this cement 2/slag-filtered potable water system, it has been shown that an increase in the content of Ca (II) occurs in dissolution and the solid stages mentioned, and also in the pH value, depending on the mixture used to make up the different series of test samples and the length of preservation time. The quantities of Ca (II) found in the different dissolutions (filtered potable water) are normally smaller than 0.1 x 10-2 moles, while in the new solid stages they are greater than this quantity and, as a general rule, exceed 0.5 X 10-2moles.
The SO4 (II) ion has not been detected in the new solid stages, but has been found in small quantities in the different liquid stages (filtered potable water). The content of these ions is normally of the same order as that of filtered potable water in those mediums in which the different series of test samples have been submerged, with the exception of those mediums which have had the test samples with greatest slag content (60 and 70%, in weight) submerged in them.
Visión panorámica actual del Ingeniero de Planta en el proceso de fabricación del cennento
Authors: Castilo Neyra Percy B. R.
Published: July 2012

The energy crisis and subsequent retraction of sales on the market have demanded a greater exigency in the productive aspect of cement, requiring lower production costs and making the quality of the product more appropriate to the nature of its use in construction.
This article focuses on the perspectives which should be considered by the Plant Engineer in order to achieve these objectives. The importance and necessity of projecting the process to the characteristics of the end product are stressed, as well as the usefulness of an adequate knowledge of the raw materials.
Other factors which could also be considered as work tools of the Plant Engineer are mentioned, always taking into consideration, however, the fact that their best use will basically depend on the criterion with which they are put to use, since each factory constitutes a different world of its own.
Estudio petrofísico de las areniscas del Palacio de Revillagigedo de Gijón (Asturias)
Authors: Esbert Rosa M. , Valdeón Luis
Published: July 2012

The petrography and physical properties of the building stones used in the construction of the Revillagigedo Palace (Gijón, Spain), 1699-1711, are studied. The physical properties more closely related to the state of alteration and to the alterability processes of these Uper Jurassic sandstones are quantified, namely: rock density, porosity, open porosity, capillarity, etc.
The pore space configuration is appreciated under optic and electronic microscopy; the size distribution and total volume of the open pores are obtained by means of mercury injection techniques.
Hidraulicidad de los silicatos cálcicos
Authors: Triviño Ana Isabel , Triviño Fernando
Published: July 2012

In spite of the largeness of this work we can consider it as a brief resume, since we have employed a little sample among all the wide bibliography existing on calcium silicates. Our aim is to connect the hydraulic properties with the crystallographic ones; to clear up the theories about the stabilization into ambient temperature of the stable composites into high temperatures and finally to describe the probable reasons of the hydraulic activity of the silicates. We are working in this subject, so, we also expose our own idea and we also think we have put up to date this confused subject.
Ensayos de laboratorio sobre el efecto inhibidor de los NO2- sobre la corrosión de las armaduras
Authors: Andrade C. , Alonso C. , González J. A.
Published: July 2012

We present the summary of several years of research about the inhibitor effect of NO2- on the corrosion of reinforcements. We have studied their inhibitor effect using galvanostatic and potentiodynamic polarization curves and we have measured the corrosion rates using the Polarization Resistance method (linear polarization).
We have verified by this last technique, Rp, that the NO2- in concrete, if they are used in sufficient proportion, are a complete inhibitor when the Cl are added during the mixing (e.g. mixing whith sea water, CaCl2 as an accelerator in inbitor).
Inssufficient amounts of NO2- have never provoked more corrosion in our experiments in concrete. The presence of NO2- always have produced a beneficial effect.
The NO2- are also beneficial in carbonated concrete, suppressing or, at least, reducing the attacked area and the corrosion rate of the reinforcements.
Preparación de muestras para análisis por difracción de rayos X con el equipo Philips PW 1700
Authors: Sagrera José Luis
Published: July 2012

In the present article the needed modifications for the very usual case of having a little quantity of samples are related. There are related in the same way the dimensional modifications of some of the pieces of the HERZOG press which allows with a full security the pressing of dust samples for the use of the automatic adapter and its rotary addition.
Finally it starts out, step by step, for the obtention of pressed samples.
Estudio teórico y experimental sobre los morteros para muros resistentes de fábrica de ladrillo para la actualización de la Norma Básica MV 201-1972
Authors: Lahuerta Vargas Javier , Monterde Comba Guillermo J.
Published: July 2012

This theoretical and experimental study on cement or lime and cement mortars brings up to date the contents of Chapter 3: MORTARS, of Norm MV 201-1972 "Resistant brick-work walls" which lost its validity when disappeared portland cement P-250, substituted by portland cement PA-350 with active additions, prescribed in the new Standard RC-75 "Standard of general technical prescriptions for cements acceptance" being obligatory its fulfilment.
Acción de las radiaciones U.V. sobre el poli (cloruro de vinilo) flexible
Authors: Ortega Juan J. , Blanco Manuel , Cuevas Ángel
Published: July 2012

The aim of this work is the study of the U.V. radiations effects on plasticized Poly (vinyl chloride) used as waterproofing membrane in Building and also in Public Works.
The ageing fact due to U.V. radiations has been followed for 3.000 hours, checking the changes produced in the composition of the material, on its mechanical characteristics and microscopic structure.
La plancha de plomo en cubiertas y fachadas
Authors: Aramburu Maqua Rocío
Published: July 2012

A description is given of the properties of lead sheet for roofing and cladding purposes. Basic rules as far as installations are concerned are given, specially with respect to dimensions of the pieces, characteristics of Joints and fixings, and watertightness conditions. Compatibility of lead with other building materials is also taken into account, as well as elementary health and safety rules for its installation. Spanish standards on the subject are also reviewed.
Un método empírico para el proporcionamiento de mezclas de Morteros de Cemento Portland para Albañilería
Authors: Salazar Alejandro
Published: July 2012

In Colombian ways and means, since the application of no traditional constructive systems is growing up, and having recourse to the new Seismic Construction Code, it is necessary to work with cement mortars of defined and reproducible characteristics.
An analysis of the variability affecting the mortars behaviour was carried out, and an experimentation which would allow to test and to correlate the interdependence between them, was expressed.
With professional stonemasons, the suitable fluidity rank was established, and the effect of the retempered on the resistance properties of the mortars, was tested.
A method of dosage is presented, which best satisfies the technical and economic aspects and considers the traditional work methods of our construction worker.
Realce textural mediante "desbaste iónico" de muestras pulidas de clínker de cemento portland para estudios por microscopía electrónica de "scanning"
Authors: Rodríguez Rey Ángel , De Llanos González Carlos
Published: July 2012

Results of using "ion thinning" techniques as final stage in the preparation of polished samples of portland cement clinker for SEM studies are showed. Under proper conditions, flat and clean surfaces are obtained which allow to discriminate textural facts (grain size, form, etc.), hardly to see on conventional polished samples due to the similarities of the secondary electron emission of the clinker minerals.
Estudio de la fluorellesteadita por difracción de rayos X: Propuesta de nuevas líneas de difracción
Authors: Puertas Maroto F. , Blanco-Varela M. T. , Sagrera-Moreno J. L.
Published: July 2012

The Ca10(SiO4)3(SO4)3F2 is synthetized and the reflexions obtained by DRX are studied, comparing them with this registered in the J.C.P.D.S. file which corresponds to the same component.
A new listing which includes 27 new reflexions is proposed.
Some values of the reflexions given in the file 23-113 are modified as well.
Restauración de la Iglesia de San Pedro, en Ávila
Authors: Fernández Suárez Jesús , Fernández Tresguerres Ramón , Somoza Arias Luis
Published: July 2012

The work have been carried out in two consecutive phases. Firstly the four wooden nave forms were sustituted by overdimensioned iron lattice girders that entered the aisles and ended in a capping hoop thus allowing the absorption of the pushes from the vaults that were ruining the church fabric. Besides a careful impermeabilization of both nave and aisles roof was undertaken.
The second phase included the restoration of pases and sacristies roofs to their original configurations, both with a re-pointing of the tower's ashlers and a reopening of blinded windows in his intermediate volume. The ruined capping body made of bricks was substituted by another made of ashlers. New windows were designed according to the existent buttress and following the double arch configuration of the reopened ones.
Refractarios: un aspecto clave en la industria del cemento
Authors: Castillo Neira Percy
Published: July 2012

To sit in judgement values of the technic level reached in a cement plant, it is surprisingly objetive to analyse work, planning and control development about Refractories subject.
Considering and recognizing the validity of this pragmatic axiom it will offer unexpected improvement perspectives of the productivity rates and production records.
This work pretends to be a contribution for this purpose, bringing some theoretic and practical accounts about de conditions offered by the Kiln-Exchanger-Cooler most diffused system, analyzing the characteristics that refractory material must have, in accordance with each zone, and finally, including some appraisals and recommendations regarding some of the manifold aspects which belongs to one of the most interesting ad complex fields of cement industry.
Obtención del hormigón apropiado a terrenos y/o aguas agresivas diversas mediante la norma TGL 11357
Authors: Talero Rafael
Published: July 2012

TGL 11357 Norm specifies the express use of the cement:
— Portland with a content between 0% and 5% of C3A, or
— Supersulphathed iron foundry (with conditions), or
— Aluminates (with conditions)
when the agressiveness of the water and/or of an agressive sulphatic ground (among others) will be touching the concrete work.
There are countries where there is not such a specific kind of cement, being unable to execute this norm. But by means of this study, which enlarge with good reason the range of those appropiate composites to defined puzzolans, it would be easier to keep the meaning o this norm, to reach identical purpose, that is, a cement concrete with appropriate puzzolanic additions (and/or appropriate iron slags) resistant to the mentioned agressiveness.
Relaciones entre porosidad, contenido en arcillas y durabilidad de areniscas
Authors: Esbert R. M. , Ordaz J. , Valdeón L.
Published: July 2012

The petrographical characterization of three spanish sandstones from Villamayor (Salamanca), Somió and Tazones (Asturias) is presented. The significance of the percentage and type of the clay minerals cementing the grains on the pore system geometry, for the rocks studied, is especially emphasized. Besides, correlations between the petrography and durability of these sandstones, evaluated by means of freeze-thawing and salt cristallisation tests, are established.
Arenas calizas para la confección de hormigones: influencia de sus finos calizos y arcillosos a nivel de morteros
Authors: Ramírez Ortiz J. L. , Barcena Díaz J. M. , Urreta Ormaechea J. I.
Published: July 2012

For the purpose to obtain data for a next revision of the Spanish Concrete Norm about the content of fines in sands fixed to date on 5 % without exceptions, an exhaustive research project has been undertaken. Following, the results of the influence of different contents of calcareous and clayey fines in mortar mechanical properties, are shown, first step to begin the study of this influence on concretes made with limestone aggregate, presently in execution phase. Before those experimental works, a general survey at all the limestone aggregate quarries in northern area of the peninsula corresponding to the Basque Country, was accomplished. By the results obtained it seems that it will be possible to enlarge the limit untill 12-15%, if only a limited presence of clay is assured.
La alveolización y otras formas de alteración desarrolladas sobre las areniscas del palacio de Revillagigedo de Gijón (Asturias)
Authors: Valdeón Luis , Esbert Rosa M. , Marcos Rosa M.
Published: July 2012

The various forms of alteration presented in the monumental sandstones of the “Palacio de Revillagigedo” (Gijón, Spain) are identified, localized and studied. Among them, the alveolation phenomena (honeycomb erosion) stand aut; the morphologically different alveoles are described and their genesis interpreted.
Contribución al estudio de la resistencia química de los cementos. Comportamiento mecánico de un cemento portland resistente al yeso (2.ª parte)
Authors: Gaspar-Tébar Demetrio , Sagrera-Moreno José Luis , González-Vila Victoriano
Published: July 2012

This work, a completion of which started in (1), studies the evolution of the mechanical flexural strain of different ranges of mortar samples of 1 X 1 X 6 cm (12 samples/ranges/age/solution) made with sulphoresistant portland cement (P-450-Y, according to RC-75), submerged in filtered drinking water and in the following aggressive solutions: saturated of CaSO4.2 H2O, saturated of CaSO4.2 H2O, of MgSO4.7 H2O (3.22 g/l), of MgSO4.7 H2O (32.2 g/l), saturated of CaSO4.2 H2O plus MgSO4.7 H2O (3.22 g/l) saturated of CaSO4.2 H2O plus MgSO4.7 H2O (32.2 g/l) and artificial ASTM D 1141-75 sea water, during 56 – 90 - 180 - 360 - 540 - 720 - 900 and 1.080 days, after the curing period (1 + 21 days).
It also studies the variation of those mechanical flexural strain and compression strain of 4 X 4 X 16 cm mortar samples (1 : 3), to centrifugal tension of 7 X 7 X 28 cm mortar samples and to flexural strain and compression strain of 10 X 10 X 40 cm concrete samples made with the mentioned cement (P-450-Y), when they are submerged in drinking water and in five agressive solutions (CaSO4.2 H2O saturated solution, Na2SO4 (2.1 g/l) solution, MgSO4.7 H2O (3.22 g/l) solution, Na2SO4 (3.5 g/l) plus NaCl (20.0 g/l) solution and artificial ASTM D 1141-75 sea water during 6 - 12 – 18 – 24 – 30 - 36- 42 - 48 - 54 and 60 months, after the curing period (1 + 30 days).
The results obtained allow to stablish a range of the studied cement according to its behaviour, against the mentioned agressive solutions.
Aditivos para hormigones, morteros y pastas. Normativa: clasificación y definiciones
Authors: Gaspar-Tébar Demetrio
Published: July 2012

In this work, classification and definitions of the additives used to produce concretes, mortars and plasters which base is cement, aim and application field of the UNE 83-200-84 norm (edited on December 1984) elaborated by Working Group n.º 2 "Additives" of the IRANOR Technical Commission n.º 83 "Concretes", are studied.
On another hand, it is carried out a study of the normative and of the documents related with the classification and the definitions of the additives of international feature, so as those of advanced technology countries.
Análisis cuantitativo por difracción de rayos X de cuarzo-alfa en una matriz de cemento portland anhidro con equipos Philips modelo PW-1710 y PW-1700
Authors: Sagrera Moreno J. L.
Published: July 2012

This article, explains the necessary steps to obtained a quartz-low quantitative analysis in an anhydrous Portland cement matrix, by means of a simple addition of a little quantity of Corydon to the sample and applying a simple mathematical formula which gives directly the crystalline compound percentage which determination is required. With this method the labour of preparation samples with internal standard, necessary to obtain a straight line, is eliminated. The need of having a pure sample of the compound which is to be analyzed is also excluded. The method is simple and rapid, offering an acceptable precision in the quantitative crystalline compounds determination.
New method for analysis of portland cements with secondary components
Authors: Gomá F.
Published: July 2012

We describe a new method for the determination of the composition of Portland cement mixtures with active additions and the identification of the type of addition.
This method enables us to classify a Portland cement or Portland with active additions, whatever this addition may be, and it is specially suitable for discriminating the type of slag when there are slags present.
IR spectroscopy of sulphates in clinkers and cements
Authors: De la Cruz I. , Vázquez T. , Fernández Peña O.
Published: July 2012

Infrared spectroscopy is a very useful technique in Cement Chemistry. This work is devoted to the study of a large number of sulphates that should have an incidence in false set phenomena, and they are qualitative and semi-quantitatlvely studied when they are in some degree in the clinker or in the portland cement.
Perspectives in the Science of Technology of Cements
Authors: Glasser F. P.
Published: July 2012

Rapid advances are being made in the science and technology of cement manufacture and use are being made. Time and space permit me to highlight only a few selected topics. However, the main stimulus for cement research arises from economic factors both in manufacture and use which in turn suggest certain lines
of research, both fundamental and applied. The topical areas which will be discussed here relate to five themes
which are summarized in Table 1.
New test for determining fundamental transverse, longitudinal and torsional frequencies of concrete specimens
Authors: Gaidis J. M. , Rosemberg A. H.
Published: July 2012

For twenty-five years The ASTM method used to determine reductions in concrete durability after freeze-thaw cycling has been C215-60. In this test the fundamental frequencies of a concrete specimen are compared. This test is time consuming, noisy and often inaccurate. In this paper a new method is proposed for measuring the fundamental frequencies of concrete to a single tap via a Fast Fourier Transform. The new test is faster, simpler and more accurate.
False set in aireated cements
Authors: De la Cruz P. I. , Vázquez T.
Published: July 2012

The influence of aireation on the appearance or elimination of the false setting in industrial portland cements is studied by means of infrared spectroscopy.
Resistencia química del hormigón XXV. Influencia de la adición de escoria a un cemento Portland. Estudio de la concentración iónica del sistema cemento 3/escoria-agua potable filtrada
Authors: Gaspar-Tebar Demetrio , Sagrera-Moreno José Luis
Published: July 2012

This work, which follows on others, study the variation of the pH, and likewise the concentrations of the ions Ca (II) and SO4 (II) of the filtered potable water in which there were submerged the test specimens of mortar (1:3) made with a Portland cement (cement 3 < > P-450) and with the mixtures cement 3/slag = 85/15 - 65/35 - 40/60 and 30/70 of weight, submerged for a curing period (21 days) and later during 56 - 90 - 180 and 360 days (conservation periods), in this stage. It also study the chemical composition of the new solid phases formed in the said means. The structural composition of the solid phases (calcite) was determined by DRX; an account of this was given in (2).
In the different studied cases it has been demonstrated that an increase of the content of Ca (II) in the solution and in the new solid phases and of the value of the pH is produced, which depends on the mixture used to manufacture the different test specimen series and on the time of conservation. The content of Ca (II) in the solution is less than 0,1 X 10-2 moles, in most of the cases, while in the new solid phases is greater, reaching 4,31 X 10-2 moles.
On the contrary the ion SO4 (II) has not been in the solid phases mentioned, being found in little quantities in the different liquid phases (filtered potable water); the greater contents correspond to the means of the mixture that have the greater mounts of slag (60 and 70 % of weight).
Theoretical and experimental investigations on fracture statistics carried out at the IDIEM (Chile)
Authors: Kittl P. , Díaz G. , León M.
Published: July 2012

The high exigencies required for some structures owing to their responsability or their high cost have originated a new discipline that can be called Reability Engineering, which main aim is to determine the probability afforded by a machine to comply a requirement.
This work contains a not fully detailed description of the topics studied by IDEM during those last years, within this field.
Within it there are Fracture Statistics, which studies the probability for some structure to undergo plastic deformations, and the probability of the causes to occur, taken into account materials fatigue.
It also includes a theoretical development of the fracture statistics, describing the specific-risk-of-fracture functions by means of integral equations, and the determination of their parameters and their uncertainties, when the functions have a known analytical form.
Experimental researches range from the most brittle bodies, such as glass, almost brittle ones such as cement paste and to others that can admit plastic deformation, such as certain weldings, enlarging the study to fibro-composites and natural materials such as granite.
Use or rice husk ash an addition in mortar
Authors: Salas Julián , Castillo Percy , Sánchez de Rojas M. Isabel , Veras Janer
Published: July 2012

With the aid of a 400-litre capacity pilot furnace, in which 40 Kg of rice husk is submitted to controlled combustion, an ash (RHA) is obtained for use as an addition, the physicochemical properties of which form the focal point of this work.
Results will also be presented for the combustion power of the husk ≃ 4000 kcal/kg, being greater than half the value for normal bituminous coals.
Conglomerates have been obtained by mixing RHA with different proportions of lime and portland cement, and their properties are studied with regard to both mortars and concretes.
The ultimate aim of the work is to demonstrate how rice husk (world production of which is estimated at 500.106 m3 per annum) may be feasibly applied as an addition, without forgetting its excellent properties as a fuel, which makes it particularly suitable for developing countries with a shortage of cement and energy resources.
Influence of the “Fire jet” finishing method of stone claddings on the mineralogical and textural characteristics and physical properties of ''pink Porriño'' granite
Authors: Rodríguez Rey Ángel , Ruiz de Argandoña Vicente G. , Calleja Escudero Lope
Published: July 2012

The effect of an industrial process of surface treatment ("fire jet") of ornamental rock slabs upon the mineralogical and textural characteristics of an igneous rock known commercially as "Pink Porriño" (Rosa Porriño) rom Galicia (NW Spain), has been studied by optical and electron microscopy. The most important physical properties of both treated and non-treated rocks have also been determined.
As a result, it may be concluded that no significant changes in the mineralogical or textural characteristics, or in the physical properties, are caused by the proper application of the process. The refrigeration of the rock is essential: without it, the properties of samples change significantly.
Clasificación de materiales de construcción
Authors: Galvan Llopis Vicente A. , Palaia Pérez Liliana
Published: July 2012

The present work pretends to give a quick answer to a professional request, which is to classificate building materials. With that purpose this work analyses some of the different existing systems of classification, creating an operating system to choose a building material attending its specific properties as a constuction element.
Finally, all the information about each material is summarized in a preformated fiche.
Stability of the calcium hydroxyzincate protective layer developed on galvanized reinforcements after a further increase of the pH value
Authors: Macías A. , Andrade C.
Published: July 2012

In previous works on galvanized reinforcements in contact with Ca- containing highly alkaline media, the authors have reported the existence of a threshold pH of 13,3 ± 0,1, below which the Zn in contact with such a medium is passivated by formation of a continuous layer of calcium hydroxyzincate, but at pH values above this it corrodes continuously until it totally disappears.
The investigation on the stability of the calcium hydroxyzincate layer after an increase of the pH to very high alkaline values, is the aim of the present paper.
It has been establised that if the calcium hydroxyzincate is perfectly developed, a later increase of the pH does not affect the stability.
Effect of MgO on compositions of the system CaO-Al2O3-Fe2O3. Solubility
Authors: Palomo Ángel , Blanco M. Teresa , Vázquez Tomás
Published: July 2012

Five different compositions belonging to the equilibrium system CaO-Al2O3-Fe2O3 were dopep with a fixed quantity of MgO (6,5% wt).
The compositions, which lie in different primary fields of crystallization and in different triangles of compatibility, were submitted to several thermal treatments. Each composition, which had previously been melted, originates in its solidification the aluminates and ferrites which are usual in the interstitial phase of clinker Portland, although they are in different microstructural arrangements.
The effect of MgO on the generated microstructures has been shown. Also, the solubility of MgO on the aluminic and ferritic phases has been measured.
Resistencia química del hormigón XXVI. Influencia de la adición de escoria a un cemento Portland. Estudio de la concentración iónica (del sistema cemento 3/escoria-agua) de mar artificial
Authors: Gaspar-Tebar Demetrio , Sagrera-Moreno José Luis
Published: July 2012

This work, which is a follow-up of others, studies the development of the solid-stage quantity formed in ASTM D 1141-75 artificial seawater, in which the series of samples of mortar (1:3), made up of a portland cement (cement 3 < > P-450) and the mixtures cement 3/slag = 85/15 - 65/35 - 40/60 and 30/70, in weight, were submerged during 56 - 90 - 180 and 360 days (periods of conservation-attack) in this stage, after the curing period (1 day in a curing chamber and 21 days under drinking filtered water). The changes in the pH value and the concentration of Ca (II), Mg (II), SO4 (II) and Cl (I) ions in this ASTM artificial sea-water are likewise studied, so as the content of Ca (II), Mg (II) and SO4 (II) ions of the new solid phase formed.
In the studied cases it has been shown that an increase of Ca (II) in the solution and of the pH value is produced, the Mg (II), SO4 (II) and Cl (I) content is reduced and a solid phase is formed, these being a function of the mixture used for making the series of samples mentioned and of the conservation-attack period. Furthermore, it has been proved that the evolution in the Ca (II) and Mg (II) content is closely linked: when it increases in the first one, that of the second decreases and vice versa, being there a point which corresponds to the Ca (II) ↔ Mg (II) ionic equilibrium.
Quantities of Ca (II) into the solution and in the new solid phase, from the compounds of hydrated cement, show an increase, in accordance with the conservation-attack period of each serie of samples made up with a cement 3/slag mixture, and decrease sharply in accordance with the reduction of cement 3 content in the mixture. If moreover the Ca (II) content in the ASTM artificial sea-water is taken into account, the dissolving process of the Ca (II) compounds of the cement (average values) may be added.
The Mg (II) ion has practically disappeared from the artificial sea-water where the series of mortar samples made up of cement 3 and the mixture which has 15% slag in weight, have been submerged; in these means it has precipitated, in a part, as brucite. In the other means this ion is found in diverse quantities, according to the mixture and to the conservation-attack time.
The content of SO4 (II) and Cl (I) in the artificial sea-water has, in likewise experience, a decrease which depends on the mixture used in the manufacture of the mortar samples and the time of conservation-attack. The greatest quantities that have disappeared correspond to the means containing the mortar samples made with cement 3 and the mixtures with 15% and 35% slag, in weight, for the SO4 (II) ions and the mixtures with 35%, 60% and 70% slag for the Cl (I) ions.
Application of the fluorescence light microscopy in the textural study of portland cement clinker
Authors: Rodríguez Rey Ángel , Montoto San Miguel Modesto , Calleja Escudero Lope , Gómez Ruiz de Argandoña Vicente , Suárez del Río Luis Miguel
Published: July 2012

The application of fluorescence light microscopy in the textural study of Portland cement clinker, specially its porosity, is presented. Principles and types of the technique are commented and the suggested sample preparation method is described. The use of fluorescence microscopy allows an easier study of the clinker porosity, and very proper images for automated quantification can be obtained. Besides, the samples can also be observed by reflected-light polarizing microscopy.
Modifications clinker phase and mechanical strength in relation to type of quenching
Authors: Puertas F. , Triviño F.
Published: July 2012

The effect of quenching in the stability of the phases of different commercial clinkers and so its flexotraction and compression strength at 7 and 28 days curing time have been studied. The clinkers were reheated at 1.576 ºC, for a period of thirty minutes, and were quenched in two different ways:-outside at air temperature and water submersion. The samples were studied by the techniques: XRD, optical microscopy and dispersive X-ray analysis. All the water quenched clinker had always a trigonal structured alite, which has Mg and Al is solid solution. The air quenched clinkers had a monoclinic alite.
The flexotraction and compression strength at 7 and 28 days of the water quenched clinkers were always lower to those of the air quenched ones. This is due to that the trigonal structured alita hydrates with much more difficulty than the monoclinic alite.
Resistencia química del hormigón. XXVII. Contribución al estudio del sistema: cemento P-550-ARI hidratado-agua desionizada
Authors: Bermejo-Muñoz M. Francisca , Sagrera-Moreno José Luis , Gaspar-Tébar Demetrio
Published: July 2012

In this work, which is the following of others, the performance of a portland cement of a high initial resistance (P-550-ARI) —with a calculated content (Bogue) of 39,2% of C3S, of 25,7% of C2S, of 9,9% of C3A, of 12,0% of C4AF and of 6,9% of CaSO4 — is studied when it is submitted to the action of deionized water running across the beds of granulated cement, made with this hydrated cement cured during 7 or 28 days, determining:
a) the evolution of the content on ions Ca (II) and SO4 (II) on the taken diverse fractions of deionized water which have ran across those beds, so as this of the pH and of the conductivity,
b) the variation in the amount of these ions that are forming the correspondent compounds, in the hydrated cement from the beds that have been submitted before and after to the action of the deionized water, and
c) the structural modification undergone by the crystalline compounds of the hydrated cement from the beds submitted to the action of the deionized water.
Modificación de Betún-Venezuela por reacción de Friedel y Crafts
Authors: Blanco Manuel , Cuevas Ángel , Ortega Juan J.
Published: July 2012

In this work, a Venezuelan-bitumen of newtonian nature was modified by Friedel and Crafts reaction, changing it in new materials that present pseudoplastic characteristics, with very different properties from the original product. These new materials are harder and have less thermical susceptibility and allow us to use them in many applications such as paving and roofing. The modifications have been made with rubbers, PVC, phtalic anhydride, maleic anhydride, 1, 2-propyleneglycol, hexamethylenediisocyanate and toluylene-2,4-diisocyanate.
Laboratory studies on the consolidation and protection of calcareous materials in the Cathedral of Oviedo. Part I
Authors: Esbert Rosa M. , Grossi Carlota , Marcos Rosa M.
Published: July 2012

The suitability of some consolidating and protecting products, to be applied to the deteriorated calcareous stones of the Cathedral of Oviedo, is presented. A proposed procedure and methodology for evaluating that suitability is also described.
The studied stones, limestones and dolomites, have been experimentally subjected in laboratory to some treatment products: ethyl silicate, oligomeric silane and silicon resin.
Some physical properties of those stones were evaluated before and after the treatments with the mentioned products. Those properties (porosity, water absorption, compressive strength and deformability, mechanical microfissuration threshold, acoustic emission, etc.) were selected according to the significative role they play on the process of stone alteration or in supporting the proposed conclusions.
Cemento aluminoso: cómo evitar la pérdida de las resistencias mecánicas
Authors: Triviño F.
Published: July 2012

Not available
Revisión crítica del ensayo de cristalización de sales
Authors: Alonso F. J. , Ordaz J. , Valdeón L. , Esbert R. M.
Published: July 2012

The salt crystallisation test is, for its simplicity and aggressivity, one of the most suitable ageing tests to evaluate the durability of rock materials. However the results of this test could be conditioned by differences in their experimental procedure.
In this article the principal variables involved in the salt crystallisation test are reviewed: concentration of the solution, type of immersion, temperature and time of drying of the specimens, etc.; as well as the criteria used in the evaluation of induced damages.
The knowledge and control of these factors facilitates the optimization of the test, and the correct interpretation of the obtained data.
Resistencia química del Hormigón. XXVIII. Contribución al estudio del sistema Cemento P-550-ARI hidratado-disolución de sulfato de sodio
Authors: Bermejo-Muñoz M. Francisca , Sagrera-Moreno José L. , Gaspar-Tébar Demetrio
Published: July 2012

In this work, which is the following of the others, the performance of a portland cement of a high initial resistance (P-550-ARI) —with a calculated content (Bogue) of 39,2 - 25,7 - 9,9 - 12,0 and 6,9% of C3S - C2S - C3A - C4AF and CaSO4, respectively— is studied when it is submitted to the action of an sodium sulfate solution [2,1 g/l of Na2S04 < > 1,42 g/l of SO4 (II) < > 1,48 X 10-2 moles/litre of SO4 (II)] running across the beds of granulated cement, made with this hydrated cement cured during 7 or 28 days, determining:
a) The evolution of the content on ions Ca (II) and SO4 (II) on the taken diverse fractions of sodium sulfate solution which have run across those beds, so as this of the pH and of the conductivity,
b) the variation in the amount of these ions that are forming the correspondents compounds, in the hydrated cement from the beds that have been submitted before and after to the action of the sodium sulfate solution, and
c) the structural modifications undergone by the crystalline compounds of the hydrated cement from the beds submitted to the action of the sodium sulfate solution.
Approach to the effect of concrete resistivity in the corrosion of rebars in concrete
Authors: Alonso C. , Andrade C. , González J. A.
Published: July 2012

The concrete resistivity has been considered as a factor which affects the corrosion rate of the rebars. Untill now the only relation found has been stablished between potentials and resistivity for steel embedded in Chloride contaminated concrete.
In this paper a comparison between corrosion rate of rebars, determined from Polarization Resistance method, and Electrical Resistance data measured through the electronic compensation of the ohmic drop are given.
The results of icorr and Rohm has been measured for rebars embedded in mortar made with three different types of cement. The specimens were submited to an accelerated carbonation.
The relation between icorr and Rohm is quite similar in all the cases and suggests that the concrete electrical resistivity may be a controling factor of the corrosion rate of the rebars.
Puzzolanic cements of greater resistance at the attack of selenitic waters than the high sulfate resistance portland cements, and viceverse
Authors: Talero Rafael
Published: July 2012

This work confirms the certainty of the predictions of useful service given by Kaluosek and al. for the sulphate resistant portland cements (type V, USA), subject to severe selenitic attack.
Two sulphate resistant portland cements, were tested by means of the Le Chatelier Anstett method. The tarts were destroyed at ages of three years, having detected in them the presence of thaumasite by XRD.
Even so, the impossibility and possibility thaumasite formation was confirmed in pozzolanic cements tarts, which either had or did not have adequate amount of pozzolana (diatomite) for such purpose.
Comparación del comportamiento de dos escayolas amasadas con aguas contaminadas
Authors: Peris Mora E. , Millán González M. C. , Bonilla Salvador M.
Published: July 2012

Not available
Influence of Ba2+ and Sr2+ ions on the hydration process of portland cement and blended cements
Authors: Živanović B. M. , Petrašinović Lj. , Milovanović T. , Karanović Lj. , Krstanović I.
Published: July 2012

This study concerns the influence of the concentration of Sr2+ and Ba2+ ions in mortar batch waters upon the hydration process of various Portland and additive cements.
An increase in the mechanical resistence of said cements is observed, after 28 days, when the concentration of Ba2+ and Sr2+ ions in the mortar batch waters increases. This suggests a possible microstructural explanation of said phenomenon.
Laboratory studies on the consolidation and protection of calcareous materials in the Cathedral of Oviedo. Part II
Authors: Esbert Rosa M. , Grossi Carlota , Marcos Rosa M.
Published: July 2012

We have carried out a series of accelerated artificial ageing tests to study the evolution of the silico-organic treatment products applied to calcareous materials of the Catedral of Oviedo.
Test valoration has been made both by visual examination and weight loss measuring.
We conclude by comparing different behaviours of treated stones with diverse products in the tests monitored.