scholarly journals The effect of the addition of polypropylene fibres on improvement on concrete quality

2018 ◽  
Vol 183 ◽  
pp. 02011 ◽  
Author(s):  
Alina Pietrzak ◽  
Małgorzata Ulewicz

Concrete serves as one of the most important construction materials, which thanks to its resistance and durability, gives total freedom in using it in building industry, and by extension in defining urban areas. Despite numerous advantages (ease of handling, high compressive strength, low production cost, heat resistance) it also has many disadvantages, including low tensile strength as well as sensitivity to destructive action of chemical agents. A constant growth in expectations concerning increasing the quality of concrete led to its polymer modification, whose aim was to eliminate above-mentioned disadvantages. The scope of the present research involved designing and making of concrete mixtures modified by 19, 30, 40 and 60 mm long polypropylene fibres. For the experiment the authors used: Portland cement CEM I 42.5R, sand, gravel aggregate of the 2-8 and 8-16 fractions, water, Master Pozzolith STD plasticizer and polypropylene fibres of various length. The authors made 4 series of concrete samples modified by fibres, for which the following factors have been assigned: compression strength after 7, 28 and 56 days of maturing as well as absorptivity, volumetric density and frost resistance after 100 cycles of freezing and thawing.

2020 ◽  
Vol 7 (1) ◽  
pp. 67-71
Author(s):  
Sritharan Sahana ◽  
Sacthivel Karthigayini

Noise and visual pollution are major arising pollution in the world. These types of pollution cause negative impacts on the inhabitants of the inbuilt environment or on the outside communities. Visual pollution affects the overall wellbeing of the community and retards quality of life. Moreover, noise pollution arises mainly from transportation, construction, industrialization and electronic equipment or tools. This study was carried out to mitigate the noise and visual pollution by proposing basic design strategies that can be applicable anywhere. Proper town and building planning could be a better option with noise tolerant buildings and noise barriers. In addition, building designs and selection of suitable construction materials also have to be considered in mitigating noise and visual pollution. However, it is mainly the responsibility of the decision makers of the society to make the development look and feel better as well as of the designers and planners to implement proper methods to ensure that the community fits the regulations.


2012 ◽  
Vol 9 (2) ◽  
pp. 1
Author(s):  
Asra Hosseini

From earliest cities to the present, spatial division into residential zones and neighbourhoods is the universal feature of urban areas. This study explored issue of measuring neighbourhoods through spatial autocorrelation method based on Moran's I index in respect of achieving to best neighbourhoods' model for forming cities smarter. The research carried out by selection of 35 neighbourhoods only within central part of traditional city of Kerman in Iran. The results illustrate, 75% of neighbourhoods' area in the inner city of Kerman had clustered pattern, and it shows reduction in Moran's index is associated with disproportional distribution of density and increasing in Moran's I and Z-score have monotonic relation with more dense areas and clustered pattern. It may be more efficient for urban planner to focus on spatial autocorrelation to foster neighbourhood cohesion rather than emphasis on suburban area. It is recommended characteristics of historic neighbourhoods can be successfully linked to redevelopment plans toward making city smarter, and also people's quality of life can be related to the way that neighbourhoods' patterns are defined. 


2020 ◽  
Vol 19 (11) ◽  
pp. 2116-2135
Author(s):  
G.V. Savin

Subject. The article considers functioning and development of process flows of transportation and logistics system of a smart city. Objectives. The study identifies factors and dependencies of the quality of human life on the organization and management of stream processes. Methods. I perform a comparative analysis of previous studies, taking into account the uniquely designed results, and the econometric analysis. Results. The study builds multiple regression models that are associated with stream processes, highlights interdependent indicators of temporary traffic and pollution that affect the indicator of life quality. However, the identified congestion indicator enables to predict the time spent in traffic jams per year for all participants of stream processes. Conclusions. The introduction of modern intelligent transportation systems as a component of the transportation and logistics system of a smart city does not fully solve the problems of congestion in cities at the current rate of urbanization and motorization. A viable solution is to develop cooperative and autonomous intelligent transportation systems based on the logistics approach. This will ensure control over congestion, the reduction of which will contribute to improving the life quality of people in urban areas.


2016 ◽  
Vol 1 (1) ◽  
pp. 201
Author(s):  
Elida Kurti

This paper aims to reflect an effort to identify the problems associated with the educational learning process, as well as its function to express some inherent considerations to the most effective forms of the classroom management. Mentioned in this discussion are ways of management for various categories of students, not only from an intellectual level, but also by their behavior. Also, in the elaboration of this theme I was considering that in addition to other development directions of the country, an important place is occupied by the education of the younger generation in our school environments and especially in adopting the methods of teaching and learning management with a view to enable this generation to be competitive in the European labor market. This, of course, can be achieved by giving this generation the best values of behavior, cultural level, professional level and ethics one of an European family which we belong to, not just geographically. On such foundations, we have tried to develop this study, always improving the reality of the prolonged transition in the field of children’s education. Likewise, we have considered the factors that have left their mark on the structure, cultural level and general education level of children, such as high demographic turnover associated with migration from rural and urban areas, in the capacity of our educational institutions to cope with new situations etc. In the conclusions of this study is shown that there is required a substantial reform even in the pro-university educational system to ensure a significant improvement in the behavior of children, relations between them and the sound quality of their preparation. Used literature for this purpose has not been lacking, due to the fact that such problems are usually treated by different scholars. Likewise, we found it appropriate to use the ideas and issues discussed by the foreign literature that deals directly with classroom management problems. All the following treatise is intended to reflect the way of an effective classroom management.


1979 ◽  
Vol 10 (2-3) ◽  
pp. 171-190
Author(s):  
Pertti Lahermo ◽  
Jouko Parviainen

In this study the changes in the quality of groundwater are described on the basis of material collected at some groundwater extraction plants situated mainly in urban areas. The causes of the marked increase in the content of dissolved solids are evaluated from the 1960s onwards.


Author(s):  
José van

Platformization affects the entire urban transport sector, effectively blurring the division between private and public transport modalities; existing public–private arrangements have started to shift as a result. This chapter analyzes and discusses the emergence of a platform ecology for urban transport, focusing on two central public values: the quality of urban transport and the organization of labor and workers’ rights. Using the prism of platform mechanisms, it analyzes how the sector of urban transport is changing societal organization in various urban areas across the world. Datafication has allowed numerous new actors to offer their bike-, car-, or ride-sharing services online; selection mechanisms help match old and new complementors with passengers. Similarly, new connective platforms are emerging, most prominently transport network companies such as Uber and Lyft that offer public and private transport options, as well as new platforms offering integrated transport services, often referred to as “mobility as a service.”


Urban Science ◽  
2021 ◽  
Vol 5 (1) ◽  
pp. 22
Author(s):  
Valdemir Antoneli ◽  
Manuel Pulido-Fernández ◽  
João Anésio Bednarz ◽  
Leonardo Brandes ◽  
Michael Vrahnakis ◽  
...  

The catchment area of River das Antas (Irati, Paraná, Brazil) is of high importance both for human consumption and irrigation. Within Irati, this river passes through a rural area and through the city of Irati, crossing both poor and rich neighbourhoods. We selected three study areas downstream (a rural area, poor community, and rich neighbourhood) in which we measured turbidity, the concentration of sediments and pH during rainy days. Our results showed downstream trends of increasing turbidity and concentrations of sediments with decreasing pH. The values of turbidity and of concentration of sediments were significantly different in the rural area, while the pH values were significantly different between the three study areas. These findings highlight the effect of agricultural activities in the generation of sediments and turbidity. The—presumably expected—effects of organic urban waste from the poor neighbourhood were also detected in the pH values. We conclude that efforts should be made to ensure that land planning and training/education programmes on sustainable farming practices are undertaken by the authorities to reduce water pollution and its effects on water bodies during rainfall events, since paving streets is not a feasible option in the short term due to the high costs associated with this measure.


Author(s):  
Yu-Tzu Wu ◽  
◽  
Linda Clare ◽  
Ian Rees Jones ◽  
Sharon M. Nelis ◽  
...  

Abstract Purpose The aim of this study was to investigate the associations between quality of life and both perceived and objective availability of local green and blue spaces in people with dementia, including potential variation across rural/urban settings and those with/without opportunities to go outdoors. Methods This study was based on 1540 community-dwelling people with dementia in the Improving the experience of Dementia and Enhancing Active Life (IDEAL) programme. Quality of life was measured by the Quality of Life in Alzheimer’s Disease (QoL-AD) scale. A list of 12 types of green and blue spaces was used to measure perceived availability while objective availability was estimated using geographic information system data. Regression modelling was employed to investigate the associations of quality of life with perceived and objective availability of green and blue spaces, adjusting for individual factors and deprivation level. Interaction terms with rural/urban areas or opportunities to go outdoors were fitted to test whether the associations differed across these subgroups. Results Higher QoL-AD scores were associated with higher perceived availability of local green and blue spaces (0.82; 95% CI 0.06, 1.58) but not objective availability. The positive association between perceived availability and quality of life was stronger for urban (1.50; 95% CI 0.52, 2.48) than rural residents but did not differ between participants with and without opportunities to go outdoors. Conclusions Only perceived availability was related to quality of life in people with dementia. Future research may investigate how people with dementia utilise green and blue spaces and improve dementia-friendliness of these spaces.


Smart Cities ◽  
2021 ◽  
Vol 4 (3) ◽  
pp. 1058-1086
Author(s):  
Franklin Oliveira ◽  
Daniel G. Costa ◽  
Luciana Lima ◽  
Ivanovitch Silva

The fast transformation of the urban centers, pushed by the impacts of climatic changes and the dramatic events of the COVID-19 Pandemic, will profoundly influence our daily mobility. This resulted scenario is expected to favor adopting cleaner and flexible modal solutions centered on bicycles and scooters, especially as last-mile options. However, as the use of bicycles has rapidly increased, cyclists have been subject to adverse conditions that may affect their health and safety when cycling in urban areas. Therefore, whereas cities should implement mechanisms to monitor and evaluate adverse conditions in cycling paths, cyclists should have some effective mechanism to visualize the indirect quality of cycling paths, eventually supporting choosing more appropriate routes. Therefore, this article proposes a comprehensive multi-parameter system based on multiple independent subsystems, covering all phases of data collecting, formatting, transmission, and processing related to the monitoring, evaluating, and visualizing the quality of cycling paths in the perspective of adverse conditions that affect cyclist. The formal interactions of all modules are carefully described, as well as implementation and deployment details. Additionally, a case study is considered for a large city in Brazil, demonstrating how the proposed system can be adopted in a real scenario.


1972 ◽  
Vol 26 (2) ◽  
pp. 469-478 ◽  
Author(s):  
David A. Kay ◽  
Eugene B. Skolnikoff

In the industrialized northern hemisphere we are assaulted daily with evidence of the deteriorating quality of the human environment: Rivers are closed to fishing because of dangerous levels of contamination; the safety of important foods is challenged; the foul air that major urban areas have been forced to endure is now spreading like an inkblot into surrounding areas. Lack of early concern about the implications for the environment of the widespread application of modern technology has allowed the problem to grow rapidly into a critical domestic and international issue.


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