Real Case: Assessing Sulfate Resistance of Coastal Protection Precast Elements

2016 ◽  
Vol 711 ◽  
pp. 327-334
Author(s):  
Francisco Aracil ◽  
Gaetan Dufour ◽  
Peter Wauters ◽  
Geert de Schutter ◽  
Roberto Torrent
Keyword(s):  
Precast Concrete ◽  
Initial Period ◽  
Field Investigation ◽  
Air Permeability ◽  
Coastal Protection ◽  
High Quality ◽  
Sulfate Resistance ◽  
Precast Elements ◽  
Concrete Elements

As part of a new harbor development, a new offshore breakwater will be constructed, for which the use of coastal protection plain precast concrete elements (AccropodesTM II) is required. The applicable exposure class is S1 (ACI 318). Over 4'000 elements have been produced. The owner required guarantees on the sulfate resistance of the elements before accepting them for usage in the project. For this, a revision of the documentation available was conducted, complemented by a thorough field investigation, measuring the coefficient of air-permeability kT (Swiss Standard SIA 262/1) of preselected elements (damaged during transportation) and elements representing the 28 weeks of production. The site NDTs confirmed a high quality of the majority of elements that were judged fit for the purpose. However, the NDTs confirmed the questionable quality of those cast during the initial period, requiring further evaluation before acceptance.The paper presents the results of: water aggressiveness, cement chemistry, strength quality control and air-permeability kT, and the criterion used to assess sulfate resistance of the elements.

scholarly journals Evaluación de elementos premoldeados de hormigón utilizados en instalaciones de crianza de ganado porcino en ambiente agresivo. Recomendaciones de fabricación

2013 ◽  
Vol 3 (2) ◽  
pp. 140-148
Author(s):  
M. Positieri ◽  
C. Baronetto ◽  
B. Raggiotti
Keyword(s):  
Ultrasonic Wave ◽  
Precast Concrete ◽  
Capillary Absorption ◽  
Aggressive Environment ◽  
Compression Speed ◽  
Intensive Rearing ◽  
Service Conditions ◽  
Precast Elements ◽  
Concrete Elements

RESUMENLas modernas instalaciones destinadas a la crianza intensiva de ganado porcino se construyen con elementos premoldeados de hormigón ensamblados in situ en grandes superficies techadas; están sujetas a un ambiente agresivo por los excrementos y vapores que el ganado porcino produce, produciéndose un recambio prematuro de piezas por la escasa durabilidad de las mismas. El trabajo presenta los resultados del estudio realizado sobre elementos premoldeados de hormigón (sin uso) que conforman la estructura, con el objetivo de verificar su comportamiento en las condiciones de servicio y realizar recomendaciones para asegurar su correcto desempeño. Se extrajeron testigos de las piezas y se midieron la resistencia a compresión, velocidad de pasaje de onda ultrasónica, absorción capilar, absorción y permeabilidad al aire. Los resultados obtenidos permiten calificar al hormigón entre regular y bueno y se presentan las recomendaciones que deberían considerarse al fabricar los elementos premoldeados para asegurar su durabilidad.Palabras Clave: hormigón; premoldeados; durabilidad; calidad; testigos.ABSTRACTThe modern installations for the intensive rearing of pigs are constructed based on precast concrete elements that are assembled on site in large areas covered and which are subject to an aggressive environment and in the feces they produce vapors, causing a premature replacement of parts by the low durability of the same. The paper presents the results of a study on precast concrete (unworn) that make up the structure in order to verify its performance in service conditions and make recommendations to assure its correct performance. Witnesses were extracted from the parts and measured the resistance to compression, speed of passage of the ultrasonic wave, capillary absorption, absorption and permeability to air. The results obtained allow us to qualify to the concrete between regular and good and presents the recommendations should be considered when manufacturing the precast elements to ensure their durability.Keywords: concrete; precast; durability; quality; witnesses.

scholarly journals ANÁLISIS DE LA ADMINISTRACIÓN DEL TALENTO HUMANO EN EL CENTRO DE EDUCACIÓN BÁSICA FISCO-MISIONAL “CRISTO REY” DE LA CIUDAD DE ESMERALDAS

2017 ◽  
Vol 2 (4) ◽  
pp. 03
Author(s):  
Abraham Tiverio Romero Morales ◽  
Leoaysa Priscila Ortiz Delgado ◽  
Karina Yadira Barrezueta Maldonado
Keyword(s):  
Basic Education ◽  
Strategic Plan ◽  
Field Investigation ◽  
High Quality ◽  
Institutional Strengthening ◽  
Palabras Clave ◽  
Recursos Humanos ◽  
The City ◽  
Cristo Rey

RESUMEN La investigación en el Centro de Educación Básica Fiscomisional “Cristo Rey” de Esmeraldas sobre el “Análisis de la Administración del Talento Humano en el centro de educación básica Fisco misional “Cristo Rey” de la ciudad de Esmeraldas.”, tuvo como objetivo establecer las posibles tendencias para alcanzar altos niveles de calidad, y se propone un Modelo de Administración que organice de mejor manera los procesos, vigile permanentemente el buen desarrollo, donde esté inmerso un Plan de Selección y un Plan Estratégico de Fortalecimiento Institucional, para involucrar a todos los actores y apuntalar al objetivo del Centro Educativo. Con el desarrollo de esta propuesta se beneficiarán la Comunidad Esmeraldeña, los Directivos, personal Docente, Administrativo y de Servicio que laboran en la institución, porque permitirá elevar la calidad de servicio ofertado. La investigación reviste de gran importancia para las administraciones de instituciones educativas tanto en el posible diseño como la divulgación de estas. La investigación bibliográfica realizada reveló la interrelación del talento como también de los recursos humanos donde se genere el conocimiento, la innovación, y la responsabilidad para la integración de factores en la calidad de servicios administrativos. PALABRAS CLAVE: administración; talento humano; educación básica. ANALYSIS OF THE ADMINISTRATION OF HUMAN TALENT IN THE FISCO-MISIONAL BASIC EDUCATION CENTER "CRISTO REY" OF THE CITY OF ESMERALDAS ABSTRACT The present project of investigation has been realized in the Center of Basic Education Fiscomisional "Cristo Rey" of Emeralds on the "Analysis of the Administration of the Human Talent in the Center of Basic Education Fiscomisional "Cristo Rey " of the City of Emeralds", developed across the field investigation, applying survey to Family Parents, Executives, Personal Teacher, Administrative officer and of Service, which they work and are linked to the institution. This investigation there demonstrated a model of administration of the Human Talent, obsolete who opposite to the changes and requirements of the current world, is an obstacle to reach quality levels and undertakes the institutional competitiveness. With the aim to reach high quality levels, a Model of Administration proposes to organize of better way the processes and to monitor permanently the good development, where there is immersed a Plan of Selection and a Strategic Plan of Institutional Strengthening, to involve all the actors and to support to the aim of the Educational Center. With the development of this offer they were benefiting the Esmeralda Community, the Executives, personal Teacher, and Administrative officer and of Service, that work in the institution, because it will allow raising the quality of offered service. KEYWORDS: administration; human talent; basic education.

scholarly journals Recycled Aggregates from Construction and Demolition Waste in the Manufacture of Urban Pavements

Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6605
Author(s):  
Manuel Contreras-Llanes ◽  
Maximina Romero ◽  
Manuel Jesús Gázquez ◽  
Juan Pedro Bolívar
Keyword(s):  
Precast Concrete ◽  
Breaking Load ◽  
Construction And Demolition Waste ◽  
Recycled Aggregates ◽  
Waste Streams ◽  
Demolition Waste ◽  
Class 1 ◽  
Natural Aggregates ◽  
Precast Elements ◽  
Concrete Elements

Construction and Demolition Waste (CDW) is among the largest waste streams in the world. Therefore, within the Circular Economy concept, there is a growing interest in its reuse. The purpose of this work was to study the use of recycled aggregates (RAs) obtained by a specific separation method from CDW, replacing natural aggregates (NAs) in the manufacture of precast concrete elements, such as kerbstones and paver blocks. The physical and technological properties of precast products formulated with RAs were analysed in accordance with current regulations, comparing them with those of commercial products manufactured with NAs. The results indicated that partial or total substitution of NAs by RAs increased the water absorption and apparent porosity values of the precast elements while reducing the bulk density and compressive strength. However, all units manufactured with RAs showed breaking load values higher than the minimum required by EN 1338 and, in some cases, slightly higher average tensile strength values than the reference material. In addition, some of the compositions including RAs gave rise to pieces that, according to their flexural strength, were classified as class 1 and marked S in accordance with EN 1340. According to abrasion resistance, in most cases, the precast elements are classified as Class 4 and I (≤20 mm). Finally, precast concrete produced from RAs satisfies the tolerance requirements for classification as class 3 (≤1.5 kg m−2). Therefore, it could be suitable for use in high pedestrian or traffic areas.

scholarly journals Industrial Low-Clinker Precast Elements Using Recycled Aggregates

2020 ◽  
Vol 10 (19) ◽  
pp. 6655
Author(s):  
Carlos Thomas ◽  
Ana I. Cimentada ◽  
Blas Cantero ◽  
Isabel F. Sáez del Bosque ◽  
Juan A. Polanco
Keyword(s):  
Mechanical Properties ◽  
Coarse Aggregate ◽  
Precast Concrete ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Slight Reduction ◽  
Construction And Demolition Wastes ◽  
Precast Elements ◽  
The Impact ◽  
Concrete Elements

Increasing amounts of sustainable concretes are being used as society becomes more aware of the environment. This paper attempts to evaluate the properties of precast concrete elements formed with recycled coarse aggregate and low clinker content cement using recycled additions. To this end, six different mix proportions were characterized: a reference concrete; 2 concretes with 25%wt. and 50%wt. substitution of coarse aggregate made using mixed construction and demolition wastes; and others with recycled cement with low clinker content. The compressive strength, the elastic modulus, and the durability indicator decrease with the proportions of recycled aggregate replacing aggregate, and it is accentuated with the incorporation of recycled cement. However, all the precast elements tested show good performance with slight reduction in the mechanical properties. To confirm the appropriate behaviour of New Jersey precast barriers, a test that simulated the impact of a vehicle was carried out.

PASTURE FOR YOUNG DAIRY STOCK: III. EFFECT OF PREPASTURE RATION, AGE, AND GRAIN SUPPLEMENTATION ON GROWTH OF CALVES ON PASTURE

1964 ◽  
Vol 44 (1) ◽  
pp. 8-15 ◽  
Author(s):  
K. A. Winter ◽  
V. S. Logan ◽  
Vern Miles ◽  
W. J. Pigden
Keyword(s):  
Growth Rate ◽  
Body Weight ◽  
Chemical Composition ◽  
Initial Period ◽  
Growth Patterns ◽  
High Quality ◽  
Feeding Regime ◽  
Treatment Comparisons

The growth of pastured calves, as affected by supplementary grain feeding, moderate and high prepasture planes of nutrition, and age on going to pasture (56, 112, or 168 days), was compared with growth of calves on a standard barn feeding regime. Seventy-two Holstein heifer calves were involved with treatment comparisons based on gains in body weight, withers height, heart girth, and barrel circumference.Over-all gains of pastured calves were not affected by either prepasture plane of nutrition or age to pasture and were similar to gains of barn-fed controls. Calves fed supplemental grain (crushed oats) showed no increase m growth rate. This was attributed to a lower intake of forage by the supplemented animals and the relatively high quality of the forage as indicated by chemical composition and digestibility.Seasonal growth patterns of pastured calves showed a depression during the initial period on pasture. However, this was overcome by greater gains than barn-fed controls during the later pasture periods.

Structural grouting of load-bearing precast concrete elements: Issues and solutions

PCI Journal ◽  
2022 ◽  
Vol 67 (1) ◽  
Author(s):  
Keyword(s):  
Construction Industry ◽  
Precast Concrete ◽  
Concrete Columns ◽  
The United States ◽  
Poor Quality ◽  
Building Codes ◽  
Concrete Walls ◽  
Load Bearing ◽  
Concrete Elements

The purpose of this paper is to raise construction industry awareness regarding structural grouting of precast concrete projects in the United States. Incidents related to structural grouting have occurred with both precast concrete systems and other building systems. Designers, architects, owners, insurance carriers, and the construction industry in general are becoming increasingly aware of deficient grouting installation methods and verification procedures. Concerns include the timeliness of grout installation during the erection process, the lack of grout on some components of finished projects, and the poor quality of installed grout. These concerns pertain to horizontal connection joints of critical load-bearing elements between foundations and precast concrete columns and walls, stacked precast concrete columns, and stacked precast concrete walls. Current building codes and standards provide no requirements and limited guidance for the installation or special inspection of these critical horizontal joints. In an effort to address this gap in building codes and standards, as it specifically relates to precast concrete structural products, some precast concrete producers and erectors are implementing several strategies and new procedures, as noted and further developed in this paper.

scholarly journals Degradation of architectural precast concrete elements on the facade of St. Michael the Archangel church in Warsaw

2019 ◽  
Vol 284 ◽  
pp. 07001
Author(s):  
Grzegorz Adamczewski ◽  
Piotr Woyciechowski
Keyword(s):  
Ground Penetrating Radar ◽  
Precast Concrete ◽  
Radar Method ◽  
Precast Elements ◽  
Ground Penetrating ◽  
Concrete Elements

The paper presents the case study of the degradation of architectural precast concrete elements on the facade of St. Michael the Archangel church in Warsaw. The background of the contemporary precast non-standard prefabrication was presented with the examples of polish recent applications. The GPR (ground penetrating radar) method was used in determining the location of reinforcement in the precast elements in the degraded façade. The conceptions of repair were analyzed and the reasons of the destructions of the precast elements.

scholarly journals Defining High-Quality Answers on a Chinese Tourism Q&A Platform in Terms of Information Needs

2021 ◽  
Vol 13 (24) ◽  
pp. 13884
Author(s):  
Lei Li ◽  
Xue Song ◽  
Shujun Liu ◽  
Kun Huang
Keyword(s):  
User Satisfaction ◽  
Information Needs ◽  
Emotional Expressions ◽  
High Quality ◽  
Exchange Information ◽  
Types Of Information ◽  
Concrete Elements ◽  
Positive Effect ◽  
Tourist Information

Travel Question and Answer (Q&A) platforms are widely used by travelers to exchange information online. This paper examined one such platform, Ctrip Q&A, to better understand the features of high-quality answers. The questions were first categorized into four types of information required by tourists (knowledge, efficiency, risk, and hedonic types) and then subdivided into more concrete elements, such as accommodation, food, and climate. The characteristics of high-quality answers on the platform were identified and a regression analysis was conducted to determine their importance. The study found that negative emotional expressions negatively impacted the quality of answers while the usefulness, richness, and amount of information had a positive effect. The usefulness of the answer content and quantity of information consistently predicted high-quality answers, whereas richness and conciseness were inconsistently related. Finally, the characteristics of high-quality answers to questions about different elements of tourism in the same category of tourist information varied significantly. This study may help travelers select and provide high-quality answers on tourism Q&A platforms. It may also assist platform operators in optimizing the features of their platforms, thereby improving user satisfaction and overall quality.

Influence of technology parameters of free-cutting steel continuous casting on the billet internal structure

2020 ◽  
Vol 76 (2) ◽  
pp. 139-142
Author(s):  
A. T. Kunakbaeva ◽  
A. M. Stolyarov ◽  
M. V. Potapova
Keyword(s):  
Regression Analysis ◽  
Continuous Casting ◽  
Internal Structure ◽  
Sulfur Content ◽  
Manganese Content ◽  
High Quality ◽  
Correlation And Regression Analysis ◽  
Cutting Steel ◽  
Continuously Cast

Free-cutting steel gains specific working properties thanks to the high content of sulfur and phosphorus. These elements, especially sulfur, have a rather high tendency to segregation. Therefore, segregation defects in free-cutting steel continuously cast billets can be significantly developed. The aim of the work was to study the influence of the chemical composition of freecutting steel and casting technological parameters on the quality of the macrostructure of continuously cast billets. A metallographic assessment of the internal structure of cast metal made of free-cutting steel and data processing by application of correlation and regression analysis were the research methods. The array of production data of 43 heats of free-cutting steel of grade A12 was studied. Steel casting on a five-strand radial type continuous casting machine was carried out by various methods of metal pouring from tundish into the molds. Metal of 19 heats was poured with an open stream, and 24 heats – by a closed stream through submerged nozzles with a vertical hole. High-quality billets had a cross-sectional size of 150×150 mm. The macrostructure of high-quality square billets made of free-cutting steel of A12 grade is characterized by the presence of central porosity, axial segregation and peripheral point contamination, the degree of development of which was in the range from 1.5 to 2.0 points, segregation cracks and strips – about 1.0 points. In the course of casting with an open stream, almost all of these defects are more developed comparing with the casting by a closed stream. As a result of correlation and regression analysis, linear dependences of the development degree of segregation cracks and strips both axial and angular on the sulfur content in steel and on the ratio of manganese content to sulfur content were established. The degree of these defects development increases with growing of sulfur content in steel of A12 grade. These defects had especially strong development when sulfur content in steel was of more than 0.10%. To improve the quality of cast metal, it is necessary to have the ratio of the manganese content to the sulfur content in the metal more than eight.

Experience of clinical testing of personal telemedicine system ‘Obereg’ for remote monitoring of patients in intensive care units

2020 ◽  
pp. 52-58 ◽  
Author(s):  
A. A. Eryomenko ◽  
N. V. Rostunova ◽  
S. A. Budagyan ◽  
V. V. Stets
Keyword(s):  
Intensive Care ◽  
Intensive Care Units ◽  
Remote Monitoring ◽  
Clinical Testing ◽  
Transportation Of Patients ◽  
High Quality ◽  
Telemedicine System ◽  
Accuracy Of Measurements ◽  
Hospital Equipment

The experience of clinical testing of the personal telemedicine system ‘Obereg’ for remote monitoring of patients at the intensive care units of leading Russian clinics is described. The high quality of communication with the remote receiving devices of doctors, the accuracy of measurements, resistance to interference from various hospital equipment and the absence of its own impact on such equipment were confirmed. There are significant advantages compared to stationary patient monitors, in particular, for intra and out-of-hospital transportation of patients.

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