scholarly journals Mechanical Properties, Permeability, and Freeze–Thaw Resistance of Pervious Concrete Modified by Waste Crumb Rubbers

2018 ◽  
Vol 8 (10) ◽  
pp. 1843 ◽  
Author(s):  
Hanbing Liu ◽  
Guobao Luo ◽  
Yafeng Gong ◽  
Haibin Wei
Keyword(s):  
Mechanical Properties ◽  
Urban Areas ◽  
Rubber Particle ◽  
Crumb Rubber ◽  
Pervious Concrete ◽  
Negative Effects ◽  
Freeze Thaw ◽  
Urban Heat ◽  
Island Phenomena ◽  
Pavement Material

Due to the negative effects that derive from large impervious surfaces in urban areas, pervious concrete has been developed, and has become an environmentally friendly pavement material. As a porous and permeable material, pervious concrete presents an overwhelming advantage in solving urban problems, such as flooding, groundwater decline, urban heat island phenomena, etc. Waste crumb rubber has been verified as a feasible modifier for pavement material. The objective of this paper is to explore the effects of rubber particle size and incorporation level on the permeability, mechanical properties, and freeze–thaw resistance of pervious concrete. Two kinds of rubbers (fine and coarse) with four incorporation levels (2%, 4%, 6%, and 8%) are used in the experiment. Permeability, compressive strength, flexural strength, flexural strain, and freeze–thaw resistance are tested. The results indicate that the addition of rubber slightly decreases strength and permeability, but significantly enhances ductility and freeze-thaw resistance. Fine crumb rubber with a suitable incorporation level could remarkably improve the ductility and freeze–thaw resistance of pervious concrete without sacrificing excessively strength and permeability.

Mechanical Properties of Surface Mortar with Waste Crumb Rubber

2014 ◽  
Vol 584-586 ◽  
pp. 917-920
Author(s):  
Gang Xue ◽  
Chun Feng Wu
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Rubber Particle ◽  
Impact Resistance ◽  
Crumb Rubber ◽  
Application Performance ◽  
Waste Rubber ◽  
Aging Properties ◽  
Rubber Particles ◽  
Waste Crumb Rubber

Applying modified waste rubber particle to surface mortar can give full play of the unique characteristics to utilize the waste and decrease environmental pollution. In order to study the application performance of crumb rubber mortar, five different mortar proportions are selected to determine the compressive strength, flexural strength, impact strength and thermal aging strength. The results show that rubber particles mortar possess excellent toughness, impact resistance and heat aging properties.

Urban Design Guidelines to Mitigate Urban Heat Island (UHI) Effects In Hot-Dry Cities

2015 ◽  
Vol 74 (4) ◽  
Author(s):  
Shima Taslim ◽  
Danial Monsefi Parapari ◽  
Arezou Shafaghat
Keyword(s):  
Thermal Comfort ◽  
Urban Heat Island ◽  
Urban Design ◽  
Urban Areas ◽  
Design Guidelines ◽  
Heat Island ◽  
Negative Effects ◽  
The Past ◽  
Urban Heat ◽  
Increasing Temperature

Global warming and undeniable climatic change in the world have led to decreasing thermal comfort for humans. Urban heat island (UHI) is the most documented phenomenon which has led to the increasing temperature in urban areas. It has received much focus in the past few decades to evaluate the main effective criteria of UHI. Street heat has negative effects on human health and will only worsen in future; these negative effects would double in hot and dry urban area. This paper investigates the effects of UHI in these cities and illustrates the important factors which make them extremely hot. The outcome of this study can be used to determine the key guidelines for urban designers, urban planners, architects and landscape designers to recline the UHI impressions in urban areas and make more thermal comfort for Burgher.

scholarly journals Urban Heat Island Mitigation Strategies: Experimental and Numerical Analysis of a University Campus in Rome (Italy)

2020 ◽  
Vol 12 (19) ◽  
pp. 7971 ◽  
Author(s):  
Gabriele Battista ◽  
Luca Evangelisti ◽  
Claudia Guattari ◽  
Emanuele De Lieto Vollaro ◽  
Roberto De Lieto Vollaro ◽  
...  
Keyword(s):  
Urban Heat Island ◽  
Urban Areas ◽  
High Performance ◽  
Energy Performance ◽  
Climatic Conditions ◽  
Mitigation Strategies ◽  
Heat Island ◽  
Negative Effects ◽  
Local Overheating ◽  
Urban Heat

The urban heat island (UHI) phenomenon is strictly related to climate changes and urban development. During summer, in urban areas, the lack of green zones and water sources causes local overheating, with discomfort and negative effects on buildings’ energy performance. Starting from this, an experimental and numerical investigating of the climatic conditions in a university area in Rome was achieved, also assessing the occurrence of the UHI phenomenon. The analyzed area was recently renewed, with solutions in contrast to each other: on one side, an old building was re-designed aiming at high performance; on the other hand, the neighboring areas were also refurbished leading to large paved surfaces, characterized by high temperatures during summer. A calibrated numerical model was generated through ENVI-met software and eight different scenarios were compared, to mitigate the overheating of this area and to analyze the influences of the proposed solutions in terms of air temperature reduction. The analysis of this case study provides information on potential mitigation solutions in the urban environment, showing that goals and priorities in the design phase should concern not only buildings but also external areas, also considering university areas.

scholarly journals Mechanical properties, permeability and freeze-thaw durability of low sand rate pervious concrete

2021 ◽  
Vol 1765 ◽  
pp. 012022
Author(s):  
H B Liu ◽  
S Zhou ◽  
H B Wei ◽  
W J Li ◽  
R Xiu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Pervious Concrete ◽  
Freeze Thaw

Rise in coincidence of extreme heat in Nevada’s largest urban areas

2019 ◽  
Vol 1 (2019) ◽  
pp. 5-28
Author(s):  
Shortridge Adora ◽  
Benjamin Hatchett ◽  
Mae Sexauer Gustin
Keyword(s):  
Urban Areas ◽  
Warm Season ◽  
Extreme Heat ◽  
Strong Correlations ◽  
Negative Effects ◽  
Mitigation And Adaptation ◽  
Energy Demands ◽  
Urban Heat ◽  
Heat Extremes ◽  
Anthropogenic Alterations

As global and regional temperatures rise, urban areas are increasingly vulnerable to heat-related impacts because of high-density populations and anthropogenic alterations to the landscape. The urban heat island (UHI) effect enhances human and environmental exposure to heat. This exposure produces human health impacts, damages ecosystems, increases water and energy demands, and strains infrastructure. Here, we assess warm season urban heat extremes in four Nevada (western USA) cities using daily temperature data between 1950-2018. Extreme heat days (nights) are defined as days when maximum (minimum) temperatures exceeded the 90th percentile of the 1981-2010 baseline. While all locations observed more frequent coincident heat extremes in the past five years, the two most urbanized cities (Las Vegas and Reno) have strong correlations between coincident events and extreme heat nights. This suggests a role for UHI effects as both cities have undergone increases in minimum temperatures. To aid Nevada cities in actively preparing climate change resilience and adaptation plans, we have identified a range of mitigation and adaptation strategies aimed at reducing negative effects from increasing regional and local temperature extremes.

scholarly journals Theory and smart practice in the reduction of negative effects of urban heat island

2018 ◽  
Vol 22 (Suppl. 4) ◽  
pp. 1011-1031
Author(s):  
Svetlana Stevovic ◽  
Dragoljub Mirjanic ◽  
Nedjo Djuric
Keyword(s):  
Objective Function ◽  
Urban Communities ◽  
Urban Environment ◽  
Urban Areas ◽  
Methodological Approach ◽  
Building Energy ◽  
Negative Effects ◽  
Heat Islands ◽  
Biotechnical System ◽  
Urban Heat

Urban environment could be considered as a complex biotechnical system. Multidisciplinary, interdisciplinary, and intradisciplinary analyses are required in order to achieve sustainable urban communities and healthier cities, especially in the era of climate changes. The main goal of this paper is to investigate, select, and review the theories and smart practices in negative effects of urban areas heat problems reduction and to define the objective function of the issue. The objective function could be treated as the force, with magnitude and direction of influence that operates in a certain space, which is considered to control certain factors and parameters, including time as a dimension. Spatial and temporal gradient of canyon effect are defined with nodes canyon effects interaction. The thermal islands are analyzed by its volume, sources of heat, thermal gradient, with the goal to select strategies to reduce the negative effects of heat islands. Positive smart practice in the world is discussed. The purpose of this study is to find, by literature review and by holistic methodological approach application, better practice and adequate solutions for building, energy, water, and carbon balance in urban environment. The results are expected in the movement towards the blue and green cities.

Problems of Development of Small and Medium Russian Towns

2019 ◽  
pp. 24-29
Author(s):  
V V. Kafidov ◽  
V. N. Filippov ◽  
I. P. Filippova
Keyword(s):  
Urban Development ◽  
Urban Areas ◽  
Negative Impact ◽  
Physical Space ◽  
Living Environment ◽  
Transport Infrastructure ◽  
Negative Effects ◽  
Conceptual Approach ◽  
Fundamental Factor ◽  
New Buildings

The presented study addresses the problems of development of small and medium towns in Russia. Aim. The study aims to examine a town as a socio-economic environment where its residents exist and as the fundamental factor for the development of society.Tasks. The authors identify key problems in the development of small and medium Russian towns, which interferes with the historical appearance and has a negative impact on the living environment.Methods. Problems in the development of small and medium towns in Russia are examined using theoretical methods: systematic approach, statistical analysis, social and philosophical analysis.Results. The study identifies the main negative effects of the existing model of development of small and medium Russian towns, such as destruction of their historical and cultural appearance, distortion of the overall architectural motif, increased load on communications, and congestion of the transport infrastructure.Conclusions. At the current stage, efficient development of small and medium towns in Russia is impossible within the framework of the existing infill development. This chaotic process cannot be stopped without a new conceptual approach and changes in the legislative and normative framework of urban development. The only factor that determines the boundaries of the existing approach to urban development is the lack of physical space for new buildings in urban areas. The authors formulate proposals that would help to solve the problems of development of small and medium towns in Russia. 

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