Concrete Level Research Articles

Micromechanics based multi-level model for predicting the coefficients of thermal expansion of hybrid fiber reinforced concrete

This study is involved with presenting a multi-level micromechanical model for predicting the coefficients of thermal expansion (CTE) of randomly distributed and oriented short hybrid fiber reinforced concrete (HFRC), which includes the cement paste level, concrete level, and HFRC level. In this micromechanical model, the inner products (IP), outer products (OP), calcium hydroxide (CH), unhydrated clinker, sands, aggregates and hybrid fibers are comprehensively considered. A substepping homogenization framework is presented to realize the upscaling from the microstructure to macro HFRC, based on which the overall CTE of HFRC is determined. In addition, the volume fractions of phases at each level are also presented to facilitate the prediction of CTE. Comparisons with experimental data from previous studies are implemented level by level. Subsequently, the influences of the water-cement ratio, the hydration degree, the aggregate property and the fiber property on the CTE are discussed carefully.

Cultural influences on brand extension judgments: Opposing effects of thinking style and regulatory focus

Asians are more likely than Westerners to have both a relational (vs. analytic) thinking style and a prevention (vs. promotion) focus. These two chronic dispositions can have opposite effects on their evaluations of brand extensions, the relative magnitude of which depends on whether the extensions are construed at a concrete or abstract level. Results of three experiments demonstrate that when an extension is psychologically close and construed at a concrete level, Asians' disposition to engage in relational thinking leads them to perceive the extension to be relatively more similar to the parent, leading them to evaluate the extension more favorably than do Westerners. On the other hand, when the extension is psychologically distant and construed at an abstract level and thus Asians are unlikely to engage in relational processing, their prevention focus leads them to perceive the extension to be riskier and evaluate it less favorably than do Westerners.

De Sitter vs Quintessence in String Theory

AbstractDe Sitter solutions have been recently conjectured to be incompatible with quantum gravity. In this paper we critically assess the progress and challenges of different mechanisms to obtain de Sitter vacua in string compactifications and compare them to quintessence models. We argue that, despite recent criticisms, de Sitter models reached a level of concreteness and calculational control which has been improving over time. On the other hand, building string models of quintessence appears to be more challenging and requires additional fine‐tuning. We discuss the tension between the swampland conjecture and the Higgs potential and find examples which can evade fifth‐force bounds even if they seem very hard to realise in string theory. We also comment on the tension with low‐redshift data and explore ultra‐light axions from string theory as dark energy candidates.

Représentations de l’eau dans les essais yourcenariens

<p>Adept of metamorphosis, Marguerite Yourcenar repeatedly uses in her essays the image of water, fluid elements related to the idea of transformation and rebirth; sea, ocean, artificial fountain – water takes various aspects and forms; from motif in the analyzed paintings to the biological functions it exercises, water crosses the yourcenarian essays. Established in the United States of America after the Second World War, did the writer study the ecology lesson testified by her texts about water? Or do these writings rather go beyond the concrete and circumstantial level of existence to talk about a global philosophy of life, as it seems to acknowledge the title of her trilogy: As the Water That Flows?</p>

Combination of the Wenner resistivimeter and Torrent permeameter methods for assessing carbonation depth and saturation level of concrete

Assessing carbonation depth is of great interest for the diagnosis of reinforced concrete structures because carbonation is one of the origins of steel corrosion. The assessment of carbonation depth is usually performed by a simple and reliable semi-destructive test consisting in spraying a colored indicator on a sample extracted from the structure. When the structure is large, this test must be reproduced many times if an assessment of the variability of carbonation depth is required. In this case, the extraction of multiple samples can be prohibitive from the technical and economic points of view. So, in this case, a non-destructive testing (NDT) method could be relevant. However, even when NDT methods can be used, there is a need to improve the interpretation of their results. In this study, the use of two usual NDT methods is proposed: resistivity measurement by a Wenner probe and surface permeability assessment by a Torrent permeameter. Both techniques are implemented on carbonated slabs having different carbonated depths and at different saturation degrees. The results show that the two techniques are sensitive to moisture and carbonation. For a given saturation level, resistivity increases when the carbonated depth increases and resistivity decreases when the saturation level increases. Torrent permeability decreases when the saturation degree and carbonated depth increase. Good repeatability is observed for resistivity measurements while a larger scatter is obtained for Torrent permeability. Empirical laws are built for the relationships between resistivity or permeability and saturation degree and carbonated depth. For resistivity, either a linear model between resistivity and saturation degree is used or Archie’s law is adapted to take the effect of carbonation into account. Following the same idea, a linear law between Torrent permeability and saturation degree is adapted to the effect of carbonation. Because resistivity can be measured only if the saturation degree is rather high, i.e. if there is a continuity of the interstitial solution, and because permeability assessment is impossible if the concrete is fully saturated, these laws are limited to saturation degrees in the 40–83% range.Then, these laws are used to predict carbonation depth and saturation degree on a wall designed with the same concrete but stored in different conditions. The results show that resistivity and Torrent permeability can be used for the combined assessment of carbonation depth and saturation degree in laboratory conditions.

Smartphones in Order to Measure the Correlation between Speed of Reading and Logical Reasoning of Future Preschool Teachers

Teacher training is an important key of education, although some authors consider the training is not helpful in order to improve learning science of the future teachers. Understanding scientific and mathematics concepts is necessary to develop the logical or abstract reasoning. Most commonly used, the PISA test is a basis in the scientific and mathematics education. In this research, it measures the logical reasoning with the test of logical reasoning and the reading speed and comprehension have been measured by a science PISA test. The students are 109 years old studying to be kindergarten teachers. They use Socrative and their smartphones in order to answer the questions. The results show that the logical reasoning is in the lowest level, the concrete level. The older students have better results than the younger students and there is a correlation between the reading speed and logical reasoning.

Experimental and analytical study on behavior of pull‐out failure of reinforcing bar embedded in concrete blocks

The bond between concrete and steel reinforcing bars is a very important functional requirement of reinforced concrete as a composite building material. This paper focuses on the comparison between the outcomes of the investigation dealing with bond strength at different levels of depth of concrete. The levels of concrete can be found in reinforced concrete columns, walls, and slabs. This paper presents an experimental and analytical analysis of the pull‐out test on 32 concrete specimens. In the experimental part, eight concrete specimens grouped into normal self‐compaction concrete (SCC) and lightweight SCC, as well as mixtures between them, were tested. In each sample, four steel bars were embedded in concrete at different locations: at the top, two samples in the middle, and at the bottom of the sample. Moreover, the slip and bond strength of each steel bar was measured using the pull‐out test. It was found that, in all the studied mixes, the average bond strength is greater in normal SCC than in lightweight SCC. This study recorded about 27.86% difference for mix CM compared with mix MCF100. An analytical analysis of nonlinear finite element (FE) was conducted for 12 reinforced concrete specimens; three different mixes are considered. A nonlinear FE analysis has been carried out to analyze the specimens that were tested experimentally. The results obtained from the experimental analyses and FE are compared with each other. The results revealed that the FE failure behavior indicates a good agreement with the test behavior.

Innovation, Strategy, and Design: Design Thinking as a Dynamic Capability

This paper explores an emerging perspective on the intersection of strategy making and design thinking. It hypothesizes that one driver of the increasing popularity of design thinking approaches, and their relevance to strategy making processes, is changes underway in how innovation itself is viewed, with innovation increasingly aspired to as an organization-wide strategic capability essential for competitive advantage, rather than a particular area of functional expertise. We hypothesize that design thinking, when viewed as a set of organizational routines, has the potential to accomplish the creation of a dynamic capability for innovation by accelerating progress on critical imperatives in the strategy making process: identifying new opportunities, specifying the new behaviors needed at a concrete level, engaging and aligning stakeholders who must implement them, prioritizing capabilities and potentially, aiding in transforming business models.

Where Fisher, Neyman and Pearson went astray: On the logic (plus some history and philosophy) of Statistical Tests

Every scientific endeavour consists of (at least) two components: A hypothesis on the one hand and data on the other. There is always a more or less abstract level - some theory, a set of concepts, certain relations of ideas - and a concrete level, i.e., empirical evidence, experiments or some observations which constitute matters of fact. The focus of this contribution is on elementary models connecting both levels that have been very popular in the social sciences - statistical tests. Going from simple to complex we will examine four paradigms of statistical testing (Fisher, Likelihood, Bayes, Neyman & Pearson) and an elegant contemporary treatment. In a nutshell, testing is an easy problem that has a straightforward mathematical solution. However, it is rather surprising that the statistical mainstream has pursued a different line of argument. The application of the latter theory in psychology and other fields has brought some progress but has also impaired scientific thinking.

An analysis of long-term forest management plans for Forest Management Units in Sumatra, Indonesia

Indonesia has been developing Forest Management Units (FMUs) as on-site forest managers that undertake actual forest management activities at the field level. Previous studies have identified a critical lack of various resources, particularly human and financial, in FMU development, and yet the types of forest management activities and official planning procedures are less frequently reported. The present study examines forestry planning aspects of the FMU policy and forest management activities planned by FMUs to fill this information gap. The author analyzed relevant laws and regulations and the long-term forest management plans of 22 FMUs in Sumatra. For the latter, the author explored basic characteristics of FMUs, quantitatively summarized planned activities focusing on four aspects of forest management (i.e., utilization, conservation, empowerment of local people, and supervision of concession holders), and qualitatively assessed the levels of concreteness of plan descriptions related to the above-mentioned four aspects. The FMUs listed various kinds of activities in their long-term plans, particularly those related to utilization and conservation. However, a large number of the sample FMUs simply listed or described what they would like to do, or what FMUs are supposed to do, with little concrete detail or deliberation of feasibility. The results of the study can be attributable to a lack of focus on policy formulation, as well as the vulnerability and unpredictability of FMUs themselves. Qualitative enhancement and quantitative increase of human resources and policy options to reduce unpredictability and uncertainty in financial and institutional dimensions are desirable to promote substantive planning for FMUs.

An Analysis of Long-Term Forest Management Plans of Forest Management Units in Sumatra, Indonesia

Indonesia has been developing Forest Management Units (FMUs) as on-site forest managers that undertake actual forest management activities at the field level. Previous studies have identified a critical lack of various resources, particularly human and financial, in FMU development, and yet the types of forest management activities and official planning procedures are less frequently reported. The present study examines forestry planning aspects of the FMU policy and forest management activities planned by FMUs to fill this information gap. The author analyzed relevant laws and regulations and the long-term forest management plans of 22 FMUs in Sumatra. For the latter, the author explored basic characteristics of FMUs, quantitatively summarized planned activities focusing on four aspects of forest management (i.e., utilization, conservation, empowerment of local people, and supervision of concession holders), and qualitatively assessed the levels of concreteness of plan descriptions related to the above-mentioned four aspects. The FMUs listed various kinds of activities in their long-term plans, particularly those related to utilization and conservation. However, a large number of the sample FMUs simply listed or described what they would like to do, or what FMUs are supposed to do, with little concrete detail or deliberation of feasibility. The results of the study can be attributable to a lack of focus on policy formulation, as well as the vulnerability and unpredictability of FMUs themselves. Qualitative enhancement and quantitative increase of human resources and policy options to reduce unpredictability and uncertainty in financial and institutional dimensions are desirable to promote substantive planning for FMUs.

Mechanics analysis for the main bearing of the rotating drum in the concrete mixing truck

The main bearing of the rotating drum (MBRD) used in a concrete mixing truck is usually a double row spherical roller bearing. The forces of the bearing are affected by many factors when working, and it is difficult to calculate the roller load. In the past, the researches on the mechanical properties of this specially used bearing are few. In this paper, the main bearing of the rotating drum of a certain type of concrete mixing truck is studied. A method for calculating the concrete distribution pattern in the rotary drum is developed with considering the different rotating speeds, incline angles and concrete liquid levels. Then, the force balance equations are established to get the radial load and axial load acting on the main bearing. A mechanical model for MBRD has been derived with considering bearing’s radial load, axial load and inner ring tilting angle. The effects of mixing drum’s rotating speed and inner ring tilting angle on the radial displacement, axis center orbit and rollers loads of MBRD are studied when the mixing drum is empty. The effects of mixing drum’s rotating speed, concrete liquid level, rotating drum’s incline angle and bearing’s inner ring tilting angle on MBRD’s radial displacement, axis center orbit, rollers loads are also studied when the mixing drum is filled with concrete. A series of relationship curves are obtained and analyzed.

Indefeasible Family Rights: A Comparative View on the Restrictions of Testamentary Freedom

Testamentary freedom and family protection in succession law are often described as contradictory principles. Nonetheless, in most European legal systems both principles coexist. This article focuses on three conceptions of this coexistence: legal rights in Scotland, compulsory portion in Germany and family provision in England. All three systems must accommodate changing values of family life in modern society. Most recently, the timeliness of traditional solutions has been a controversial topic of the debate leading to the Succession (Scotland) Act 2016, and it continues to be an issue of debate, because regarding legal rights no final solution has been found. A comparative analysis can demonstrate the interconnectedness between social values and legal concepts, and it can further identify potential for legal innovation. Family rights, especially in Germany, have been contextualised with a historic notion of family property. In the present law of all three countries the contextual emphasis shifts towards familial solidarity and a moral duty to provide for family members. On a concrete level, there is a discernible connection between matrimonial property relationships and spousal rights to the estate in Germany and England, which in Scotland is no longer present. Further, the English system can also accommodate cohabitants as potential claimants. Scots law has at least in the case of intestacy incorporated a similar provision, while German law thus far does not provide any legal concept for cohabitation.

Calculating method of the fatigue life for the main supporting bearing of mixing drum in concrete mixing truck when considering drum’s vibration

It has been observed that there are many studies focusing on the vibration properties of bearings caused by manufacturing errors, assembly related errors, out-of-balance rotor rotation, cage instability, etc. But there are fewer research studies on the effect of rotor’s vibration on double-row rolling element bearings’ mechanical properties. In this paper, a calculating method has been established for bearing’s roller load and fatigue life when considering rotor’s vibration. And this model is applied to study the main supporting bearing of the mixing drum of a certain type of concrete mixing truck with the consideration of the mixing drum’s vibration. The effects of rotating speed, inclination angle, concrete liquid level, and rolling wheels’ supporting position on the roller load and bearing’s fatigue life are studied with a specific example with and without considering the mixing drum’s vibration. Results show that with the increase in the rotating speed, the bearing roller’s maximum load decreases, while the fatigue life of main supporting bearing increases. With the decrease of the concrete liquid level, there is increase in the inclination angle and the movement of rolling wheel from left to right, and the bearing roller’s maximum load increases, while the fatigue life of main supporting bearing decreases. The changes of the mixing drum’s inclination angle have tremendous effect on bearing’s fatigue life, while the change in the rolling wheel’s supporting position has little influence on the fatigue life of the main supporting bearing. When considering the mixing drum’s vibration, the roller’s maximum load is larger than that without considering mixing drum’s vibration, while the fatigue life of the main supporting bearing is shorter than that without considering mixing drum’s vibration.

Self-compacting concrete incorporating sugarcane bagasse ash

The aim of the current study is to assess the feasibility of incorporating sugarcane bagasse ash (SBA) from the sugar and ethanol industry as a filler material in the production of self-compacting concrete (SCC). For this purpose, paste composition was designed in the first stage of this study by conducting an experimental plan at the mortar level. During the second stage, SCC mixture properties were evaluated by considering the paste mixture proportions defined in the first stage. The study at the mortar level was conducted based on a statistical factorial design approach, which offers a valid basis for developing empirical models that allow determination of optimal settings of the design variables to satisfy all performance requirements. At the concrete level, the impact of three optimised paste mixtures on SCC properties was assessed. Fresh state, mechanical, and durability properties were evaluated. Mortar and concrete test results revealed that SBA can be used successfully in powder-type SCC as a filler material, and it exhibits good self-compacting ability and strength levels, which are adequate for many current civil engineering applications.

ANALYSIS OF COST CONTROL, TIME, AND QUALITY ON CONSTRUCTION PROJECT

This research aims to analyze the relationship of delay time and costs with estimated that causes increased costs from perspective of management fees project with earned value method and to analyze the influence of the variables associated with the quality control at each stage of the work concreting. Secondary data collection i.e. the draft budget, the curve S, financing and weekly reports the progress of the project. Primary data i.e. questionnaires to 30 respondents. The cost control and time used earned value methods, and quality control with multiple linear regression. The results of the research project performance until the 27th week of aspects of cost and time projects implementation are not experiencing excess costs, but suffered delays. Regression analysis a very influential determinant variables of each job of making concrete to install formwork: concrete level marking and dimensions for formwork, ironing: the connection reinforcement iron and iron a clean free from rust, oil, and dry concrete, for concreting: checking of slump test and the amount of labor, and to uninstall the formwork: concrete age and concrete level according to plan.

Investigation on the Rheological Behavior of Fly Ash Cement Composites at Paste and Concrete Level

Towards developing sustainable concrete, nowadays, high volume replacement of cement with fly ash (FA) is more common. Though the replacement of fly ash at 20–30% is widely accepted due to its advantages at both fresh and hardened states, applicability and acceptability of high volume fly ash (HVFA) is not so popular due to some adverse effects on concrete properties. Nowadays to suit various applications, flowing concretes such as self compacting concrete is often used. In such cases, implications of usage of HVFA on fresh properties are required to be investigated. Further, when FA replacement is beyond 40% in cement, it results in the reduction of strength and in order to overcome this drawback, additions such as nano calcium carbonate (CC), lime sludge (LS), carbon nano tubes (CNT) etc. are often incorporated to HVFA concrete. Hence, in this study, firstly, the influence of replacement level of 20–80% FA on rheological property is studied for both cement and concrete. Secondly, the influence of additions such as LS, CC and CNT on rheological parameters are discussed. It is found that the increased FA content improved the flowability in paste as well as in concrete. In paste, the physical properties such as size and shape of fly ash is the reason for increased flowability whereas in concrete, the paste volume contributes dominantly for the flowability rather than the effect due to individual FA particle. Reduced density of FA increases the paste volume in FA concrete thus reducing the interparticle friction by completely coating the coarse aggregate.

Sustainable consumption

PurposeWhile there has been a great deal of research to distinguish the factors that promote the adoption of sustainable consumption, however there has been a very little attention given to the contribution of justice, coping appraisal, and psychological distance. The purpose of this paper is to explore the potential role of deontic justice, protection motivation, and construal level theories to elucidate the green purchase intention.Design/methodology/approachData were collected from 471 participants in a laboratory experiment. Then, structural equation modeling was carried out to analyze the data.FindingsProtection motivation theory is valuable to apply specifically since it introduces the concept of coping appraisal. The findings demonstrate that deontic justice theory (DJT) is a suitable framework that can be employed to shed more light on sustainable consumption. The study shows that consumer can conceptualize a green product at different levels of concreteness or abstraction.Originality/valueThis study is a pioneering effort to look at sustainable consumption within the context of DJT. It departs from the more traditional research by repositioning moral obligation as the primary driver of green purchase intention and by elucidating when green purchase intention is elevated in investigating the moderating role of mindset.

Asthma: personalized and precision medicine.

In this review, we herein describe the progress in management of severe asthma, evolving from a 'blockbuster approach' to a more personalized approach targeted to the utilization of endotype-driven therapies. Severe asthma characterization in phenotypes and endotypes, by means of specific biomarkers, have led to the dichotomization of the concepts of 'personalized medicine' and 'precision medicine', which are often used as synonyms, but actually have conceptual differences in meaning. The recent contribute of the omic sciences (i.e. proteomics, transcriptomics, metabolomics, genomics, …) has brought this initially theoretic evolution into a more concrete level. This step-by-step transition would bring to a better approach to severe asthmatic patients as the personalization of their therapeutic strategy would bring to a better patient selection, a more precise endotype-driven treatment, and hopefully to better results in terms of reduction of exacerbation rates, symptoms, pulmonary function and quality of life.

Formal foundations for software model to model transformation operation

Software model transformation operations are central operations in Model-Driven approaches. In order to represent software models, graphical modeling notations, for example UML, are used. Quality of software model, obtained after transformation, influences on further operations with this model. Thus, it is important to design formal approaches for model to model transformation that are grounded on analytical and mathematical tools. These approaches should provide a background for flexible adopting software model transformational techniques for peculiarities of specific software development lifecycle model. Challenges to mathematical tools and transformation rules that are involved to designing of model to model transformation approaches are formulated in this paper. The ground of mathematical tools choice that is based on these challenges is performed. An approach for performing model to model transformation, which is based on graph transformation, is presented in this paper. Transformational operations are considered on meta-level and concrete level. On meta-level choosing of mathematical tools for representing of transformation stages and transformational artifacts are grounded. Software models are represented as graphs. Initial information for transformation is represented as a set of sub-graphs. Transformation rules are composed using second and first order logics. On the level of the first-order logic all software model elements that participate in transformation are considered. In the level of second-order logic transformation rule considers types of software model element that are participate in the transformation. Proposed approach is extensible and may be used for extend functionality of model to model tools that process software models. For example in MEDINI QVT there is no direct ways to compose a model to model transformation rule that considers those software models elements that have no direct links. Problems in programming 2018; 2-3: 124-131