scholarly journals Relationships between Functional Properties of Pervious Concrete

2020 ◽  
Vol 12 (16) ◽  
pp. 6318
Author(s):  
Alena Sičáková ◽  
Marek Kováč
Keyword(s):  
Grain Size ◽  
Water Cycle ◽  
High Reliability ◽  
Size Composition ◽  
Pervious Concrete ◽  
Void Content ◽  
Conventional Concrete ◽  
Research Activities ◽  
Wide Range ◽  
The Individual

Pervious concrete is characterized by its open-void structure, which gives it a number of specific properties and allows specific applications, including pervious pavements, residential roads, alleys, sidewalks, parking lots, patios, and so on. Permeable areas are extremely important for the creation of sustainable cities in terms of the water cycle. Due to its high void content and low cement/mortar content, pervious concrete generally may have significantly reduced strength when compared with conventional concrete. That is why a wide range of research activities is devoted to the balance between acceptable void content, strength, as well as other significant properties. Knowledge of the relationships between the individual properties is very important for understanding this specific material. In this paper, a wide range of 38 different composition variants has been tested to determine the dependencies between the essential properties of pervious concrete. The variables related to the type of aggregate, maximum grain size, the grain-size composition, the amount of binder, and the kind (composition) of binder. The dependencies reported in the article are defined with high reliability R2 ranging from 0.75 to 0.95. On the basis of the dependencies thus determined, it can be predicted that a density of min. 1740 kg/m3 must be reached to meet the requirement of min. 10 MPa for nonpavement applications, while a density of min. 1960 kg/m3 must be achieved to meet min. 20 MPa for pavement applications. The criteria of the void ratio for pavement applications can be set at 20 ± 3%, while the criteria for nonpavement applications can be set at 28 ± 6%.

scholarly journals Evaluation of mechanical properties of concrete produced with binary and ternary mixtures of aggregate

2021 ◽  
Vol 10 (1) ◽  
pp. e43410111948
Author(s):  
Fernanda Cavalcanti Ferreira ◽  
Yane Coutinho ◽  
Arnaldo Manoel Pereira Carneiro
Keyword(s):  
Grain Size ◽  
Compressive Strength ◽  
Size Composition ◽  
Ternary Mixtures ◽  
Metropolitan Region ◽  
Unit Weight ◽  
Lower Amount ◽  
Mechanical Resistance ◽  
Conventional Concrete ◽  
Grain Size Composition

Cement is the costlier component of concrete, and its productive process causes considerable environmental impact. Thus, alternatives are studied to reduce the amount of cement used. An option is the use of optimized grain size curves of aggregates, aiming to achieve a higher compactness of concrete. An ideal grain size distribution results in a higher mechanical resistance of concrete, providing a reduction in cost and consumption of materials, and, consequently, in environmental impacts. Therefore, the present study aims to improve the properties of conventional concrete through optimized grain size distributions. In this research, concrete was produced with binary mixtures with rolled pebbles from Belém region, in Pará state, and ternary mixtures of granitic crushed stone from the metropolitan region of Recife, in Pernambuco state, and concrete properties in the hardened state were studied. The mix design IPT/EPUSP method was used and grain size composition, unit weight, water absorption by capillarity, and compressive strength tests were performed. It was observed an increase in compressive strength with for higher fine contents. Furthermore, for both aggregates studied, there was no loss in strength with the lower amount of cement used, due to the increased compactness of the concrete, indicated by the unit weight of the aggregate mixture. Therefore, the optimization of the grain size composition of the coarse aggregate provided a reduction in the cement consumption for the same required strength and for both analysed aggregates.

scholarly journals Psychological Analysis of Occupational Conditions in Extreme Environments and the Structure of Non-Standard Situations

2020 ◽  
Vol 11 (4) ◽  
pp. 132-148
Author(s):  
Oksana KHURTENKO ◽  
◽  
Kseniia BEREZIAK ◽  
Roman KHAVULA ◽  
Oksana VDOVICHENKO ◽  
...  
Keyword(s):  
Problem Solving ◽  
Behaviour Problem ◽  
Psychological Analysis ◽  
Research Activities ◽  
Wide Range ◽  
Professional Coaching ◽  
Different Types ◽  
Human Psyche ◽  
The Individual

Professional coaching career is associated with a wide range of issues and problems which need to be solved and are directly or indirectly determined by creative activity. Therefore, an appropriate training process of students, in particular prospective coaches, is an essential scientific and practical problem. The article presents a thorough psychological analysis of the structure of decision-making in extreme situations and identifies different types of non-standard situations in a coaching job. Also, it clarifies such concepts as “situation”, “non-standard situation” and “extreme situation” in the activity of the individual. It describes different types of non-standard situations which can be manifested in professional coaching and their impact on the human psyche. It analyzes extreme conditions in the activities of athletes and coaches and the role of various mental functions and personality traits in problem-solving. Importantly, the article emphasizes the role of the coach’s reflection and self-regulation in solving non-standard tasks under non-standard conditions. It indicates that two theoretical views on the nature of the human psyche and thinking correspond to two approaches to studying this particular problem. According to the first one, that is an adaptive approach, creative thinking as a form of behaviour is the result of learning, and only some individuals have creative ability. To teach creativity, however, one needs to include the elements of creative behaviour (problem-solving) and heuristics in the educational material. Another approach assumes that thinking is a productive process emerging as a result of a certain problematic situation. Prerequisites for the creative process are cognitive abilities and research activities of the individual.

Study of the mineralogical and grain size composition of the regenerated grain from bearing sludge

2021 ◽  
Vol 87 (8) ◽  
pp. 29-33
Author(s):  
I. Yu. Orlov ◽  
S. A. Kryukov ◽  
N. V. Baidakova
Keyword(s):  
Grain Size ◽  
Cutting Tool ◽  
Size Composition ◽  
Solid Particles ◽  
Metal Particles ◽  
Abrasive Particles ◽  
Grain Size Composition ◽  
Abrasive Grain ◽  
Processed Material ◽  
The Individual

The composition of sludges (wastes of bearing industry enterprises) is determined by the characteristics of the abrasive tool used upon manufacturing, grade of the processed material, cutting-tool lubricant (CTL) and modes of treatment. We present the results of studying the mineralogical and grain size composition of the regenerated grain from bearing sludges. The material under study is shown to have the following composition, %: abrasive particles — 5 – 8, metal particles — 50 – 90, binder — 2 – 5, balance — SOG, oil and various pollutants. The dispersion of solid particles ranges within 0.1 – 0.3 mm. The abrasive grains have a predominantly splintery shape, the individual binder particles being observed on their surface. The interlayer-cemented aggregates of two — three crystals and a large number of small splintery particles are also present. It is shown that the samples with a regenerated material containing fine abrasive grain and metal particles as a filler exhibit the highest mechanical strength and thermal conductivity. The results obtained can be used when using regenerated abrasive grain from sludge for manufacturing, e.g., grinding wheels, preparation of a molding abrasive mixture, etc.

Microstructure-Property Relationships in Wear Resistant Alumina/SiC 'nanocomposites' the Importance of Plastic Deformation in Ceramics

2006 ◽  
Vol 977 ◽  
Author(s):  
Richard Ian Todd ◽  
Apichart Limpichaipanit ◽  
Jose Ortiz Merino
Keyword(s):  
Plastic Deformation ◽  
Grain Size ◽  
Brittle Fracture ◽  
Wear Rate ◽  
Wear Behaviour ◽  
Alumina Matrix ◽  
Pure Alumina ◽  
Sic Nanoparticles ◽  
Wide Range ◽  
The Individual

AbstractAlumina/SiC “nanocomposites" consist of a dispersion of submicron SiC particles in an alumina matrix. The resistance to severe wear of the nanocomposites and the surface finish produced by a given grinding treatment are strikingly superior to those of pure alumina with the same grain size. We have explored the reasons for this by correlating a wide range of variations in the basic microstructure with the wear behaviour observed, including both the wear rate, and quantitative surface fractography of the worn surfaces. These improved properties of the nanocomposites are shown to be a consequence of a reduction in surface grain pullout by brittle fracture. In “dilute” nanocomposites (<10% SiC), this is due largely to a reduction in size of the individual pullouts. With 10% SiC nanoparticles, however, there is also evidence that the SiC directly suppresses the nucleation of cracking by plastic deformation of the surface. The origin of these effects will be discussed.

scholarly journals Development of Pervious Concrete with Different Void Contents

2019 ◽  
Vol 8 (4S2) ◽  
pp. 1-3
Keyword(s):  
Pervious Concrete ◽  
Storm Water ◽  
Experimental Investigations ◽  
Void Content ◽  
Concrete Pavements ◽  
Work Effort ◽  
Conventional Concrete ◽  
Porous Concrete ◽  
Concrete Mixtures ◽  
Fine Aggregates

Pervious or Porous concrete pavements are an alternative to rigid conventional concrete pavement surfaces. The main purpose of pervious pavements is to reduce the stagnation of rain water on the surface during rainy season by permitting the storm water percolate downwards into the ground. It is obtained by completely or partially eliminating the fine aggregates in the mixture proportions. In this work, effort has been taken to develop pervious concrete mixtures with different void contents and evaluating its mechanical properties at 28 days. From the experimental investigations performed, it was found that mix P1 with 15% void content has attained a maximum strength of 15 MPa. It was also observed from this study that the properties of pervious concrete mainly depend on the void content of the concrete mixtures.

scholarly journals APPROACH FOR THE AUTOMATED AND DATA-BASED DESIGN OF MECHANICAL JOINTS.

2021 ◽  
Vol 1 ◽  
pp. 521-530
Author(s):  
Christoph Zirngibl ◽  
Benjamin Schleich ◽  
Sandro Wartzack
Keyword(s):  
Expert Knowledge ◽  
Reference Model ◽  
High Reliability ◽  
Experimental Tests ◽  
Cold Forming ◽  
Mechanical Joints ◽  
Wide Range ◽  
The Individual ◽  
Transfer Of Information ◽  
Selection Of

AbstractAs a result of the increasing challenges in the field of lightweight constructions, the demand for efficient joining technologies is continuously rising. For this purpose, cold forming processes offer an environmental friendly and fast alternative to established joining methods (e.g. welding). However, to ensure a high reliability, not only the selection of an appropriate procedure, but also the dimensioning of the individual joint is essential. While product designers can rely on a wide range of design principles for thermal processes, the dimensioning and evaluation of mechanical joining processes is mainly based on expert knowledge and a few experimental tests. Although few studies already investigated the numerical analysis of mechanical joints, an approach for the sustainable and consistent optimization of the strength and reliability of joining connections for varying use-cases is not available yet. Motivated by this lack, this paper presents an approach for the automated transfer of information within the process chain and the data-based analysis of mechanical joints by using clinching as an example. Therefore, the CRISP-DM reference model is used for the systematic data mining.

Grain size composition of broken rocks under different conditions of blasting

2019 ◽  
Vol 8 ◽  
pp. 83-94 ◽  
Author(s):  
B.R. Rakishev ◽  
◽  
A.A. Orynbay ◽  
A.M. Auezova ◽  
A.E. Kuttybaev ◽  
...  
Keyword(s):  
Grain Size ◽  
Size Composition ◽  
Grain Size Composition

ANALYSIS OF THE MODERN GRAIN-SIZE COMPOSITION VARIABILITY OF THE ANAPA BAY-BAR BEACH SEDIMENTS

2018 ◽  
Author(s):  
В. Крыленко ◽  
V. Krylenko ◽  
Р. Косьян ◽  
R. Kos'yan ◽  
М. Крыленко ◽  
...  
Keyword(s):  
Grain Size ◽  
Bottom Sediments ◽  
Size Structure ◽  
Size Composition ◽  
Potential Danger ◽  
Grain Size Composition ◽  
Beach Sediments ◽  
Sediment Particles ◽  
Sand Material

The results of realized in 2010 field researches of the spatial and time grain-size structure variability of beach and bottom sediments of the bay-bar Anapskaya southern part are presented in this paper. Irretrievable carrying out of sediment particles to depths more than 7 m intensifies with their size decrease to 0,1 mm. As over 70 % bottom and about 60 % beach sediments are presented by fractions less 0,16 mm on bay-bar Anapskaya southern part, namely at this part there is sand material massive carrying out to depth. Potential danger of the investigated site geosystem degradation is revealed.

THE VALUE OF LOVE IN THE SYSTEM OF FORMATION OF THE PROFESSIONAL MATURITY OF THE EDUCATOR

2020 ◽  
Vol 1 (10(79)) ◽  
pp. 12-18
Author(s):  
G. Bubyreva
Keyword(s):  
Russian Federation ◽  
The State ◽  
Educational Process ◽  
Wide Range ◽  
The Family ◽  
The Russian Federation ◽  
The Government ◽  
The Individual ◽  
The Right

The existing legislation determines the education as "an integral and focused process of teaching and upbringing, which represents a socially important value and shall be implemented so as to meet the interests of the individual, the family, the society and the state". However, even in this part, the meaning of the notion ‘socially significant benefit is not specified and allows for a wide range of interpretation [2]. Yet the more inconcrete is the answer to the question – "who and how should determine the interests of the individual, the family and even the state?" The national doctrine of education in the Russian Federation, which determined the goals of teaching and upbringing, the ways to attain them by means of the state policy regulating the field of education, the target achievements of the development of the educational system for the period up to 2025, approved by the Decree of the Government of the Russian Federation of October 4, 2000 #751, was abrogated by the Decree of the Government of the Russian Federation of March 29, 2014 #245 [7]. The new doctrine has not been developed so far. The RAE Academician A.B. Khutorsky believes that the absence of the national doctrine of education presents a threat to national security and a violation of the right of citizens to quality education. Accordingly, the teacher has to solve the problem of achieving the harmony of interests of the individual, the family, the society and the government on their own, which, however, judging by the officially published results, is the task that exceeds the abilities of the participants of the educational process.  The particular concern about the results of the patriotic upbringing served as a basis for the legislative initiative of the RF President V. V. Putin, who introduced the project of an amendment to the Law of RF "About Education of the Russian Federation" to the State Duma in 2020, regarding the quality of patriotic upbringing [3]. Patriotism, considered by the President of RF V. V. Putin as the only possible idea to unite the nation is "THE FEELING OF LOVE OF THE MOTHERLAND" and the readiness for every sacrifice and heroic deed for the sake of the interests of your Motherland. However, the practicing educators experience shortfalls in efficient methodologies of patriotic upbringing, which should let them bring up citizens, loving their Motherland more than themselves. The article is dedicated to solution to this problem based on the Value-sense paradigm of upbringing educational dynasty of the Kurbatovs [15].

Punk as Folk: Continuities and Tensions in the UK and Beyond

2020 ◽  
Author(s):  
Pete Dale
Keyword(s):  
Folk Music ◽  
Music Making ◽  
Collective Creativity ◽  
Living Tradition ◽  
Wide Range ◽  
The Us ◽  
The Common ◽  
The Individual ◽  
The Uk

Numerous claims have been made by a wide range of commentators that punk is somehow “a folk music” of some kind. Doubtless there are several continuities. Indeed, both tend to encourage amateur music-making, both often have affiliations with the Left, and both emerge at least partly from a collective/anti-competitive approach to music-making. However, there are also significant tensions between punk and folk as ideas/ideals and as applied in practice. Most obviously, punk makes claims to a “year zero” creativity (despite inevitably offering re-presentation of at least some existing elements in every instance), whereas folk music is supposed to carry forward a tradition (which, thankfully, is more recognized in recent decades as a subject-to-change “living tradition” than was the case in folk’s more purist periods). Politically, meanwhile, postwar folk has tended more toward a socialist and/or Marxist orientation, both in the US and UK, whereas punk has at least rhetorically claimed to be in favor of “anarchy” (in the UK, in particular). Collective creativity and competitive tendencies also differ between the two (perceived) genre areas. Although the folk scene’s “floor singer” tradition offers a dispersal of expressive opportunity comparable in some ways to the “anyone can do it” idea that gets associated with punk, the creative expectation of the individual within the group differs between the two. Punk has some similarities to folk, then, but there are tensions, too, and these are well worth examining if one is serious about testing out the common claim, in both folk and punk, that “anyone can do it.”

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