scholarly journals Analysis of applicability of porous concrete containing recycled ceramic aggregates for communication pedestrian routes forming surface rainwater drainage

2017 ◽  
Vol 8 (3) ◽  
pp. 3-7
Author(s):  
Paweł Ogrodnik ◽  
Bartosz Zegardło

This work is a continuation of the authors' research conducted to develop innovative concrete mixtures containing recycled ceramic aggregates formed after crushing of waste ceramic sanitary elements. The article presents the problem of utilization of ceramic waste, there are listed factors of waste generating and the main characteristics of the waste material. Based on available literature, there are presented the results of research work on successfully using ceramic waste aggregates in the production of concrete composites. The main aim of this work was to design innovative concrete containing sanitary waste which would be permeable to water. The composite presented in the work showed total water permeability. The tested strength parameters allowed us to propose using it for the communication substrates carrying the load from pedestrian traffic. In this type of communication substrates the authors see a remedy for the problem of utilizing rainwater. Especially in urban areas where is no rain water sewer system this solution would have a legitimate benefit. Totally permeable communication routes could directly transfer water to the substrate under their surface which would effectively increase the chance of natural rainwater absorption.

2021 ◽  
Vol 1895 (1) ◽  
pp. 012027
Author(s):  
Hussein J. Almansori ◽  
Adnan Al-Sibahy ◽  
Basim Al-Humeidawi

Water ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 1171 ◽  
Author(s):  
Mitja Janža ◽  
Joerg Prestor ◽  
Simona Pestotnik ◽  
Brigita Jamnik

The assurance of drinking water supply is one of the biggest emerging global challenges, especially in urban areas. In this respect, groundwater and its management in the urban environment are gaining importance. This paper presents the modeling of nitrogen load from the leaky sewer system and from agriculture and the impact of this pressure on the groundwater quality (nitrate concentration) in the urban aquifer located beneath the City of Ljubljana. The estimated total nitrogen load in the model area of 58 km2 is 334 ton/year, 38% arising from the leaky sewer system and 62% from agriculture. This load was used as input into the groundwater solute transport model to simulate the distribution of nitrate concentration in the aquifer. The modeled nitrate concentrations at the observation locations were found to be on average slightly lower (2.7 mg/L) than observed, and in general reflected the observed contamination pattern. The ability of the presented model to relate and quantify the impact of pressures from different contamination sources on groundwater quality can be beneficially used for the planning and optimization of groundwater management measures for the improvement of groundwater quality.


2016 ◽  
Vol 74 (10) ◽  
pp. 2280-2296 ◽  
Author(s):  
Ekkehard Christoffels ◽  
Andrea Brunsch ◽  
Jens Wunderlich-Pfeiffer ◽  
Franz Michael Mertens

Micropollutant pathways were studied for the Swist river basin (Western Germany). The aim was to verify the effectiveness of a monitoring approach to detect micropollutants entering the river. In a separate sewer system, water was frequently found to be contaminated with micropollutants. Improper connections of sewage canals to the stormwater network seemed to be the cause of pollution. Wastewater treatment plants (WWTPs) exerted the largest influence on micropollutants for the receiving river. During a flu outbreak, antibiotics in the Swist stemming from WWTPs increased remarkably. Elevated levels of pharmaceuticals were measured in discharges from a combined sewer overflow (CSO). The study showed that the pharmaceutical load of a CSO was significantly reduced by advanced treatment with a retention soil filter. Painkillers, an anticonvulsant and beta blockers were the most often detected pharmaceuticals in the sewage of urban areas. Herbicides, flame retardants and industrial compounds were also observed frequently. On cropland, Chloridazon and Terbuthylazine compounds were often found in landscape runoff. Fungicides and insecticides were the most frequent positive findings in runoff from orchards. The paper shows that a coherent approach to collecting valid information regarding micropollutants and to addressing relevant pathways as a basis for appropriate management strategies could be established.


2008 ◽  
Vol 569 ◽  
pp. 233-236
Author(s):  
Z. X. Yang ◽  
Kyu Hong Hwang ◽  
Jeong Bae Yoon ◽  
J.O. Kim ◽  
M.C. Kim

Porous concretes with continuous voids have been gaining more interest as an ecological material because of their useful functions such as water permeability and adsorption ability. Especially, to make porous concrete much more environmentalized, micropores play a role of nest for microorganism and germs to live in. So micropore distribution and the size of micropores especially open pores are the key point . In this study, the size and distribution of micropores of porous concrete were effected by the AE agents to the cement pastes and then by the treating types, treating times, treating temperatures, and the vacuum pressure during the treating. And another group specimens were added sodium bicarbonate and alum. And then physical properties were examined, digital microscope was also used to observe the micropores sizes and distributions. Cracks were observed on the cement-aggregate joint when the amount and vacuum pressure increased. And high treating temperature shows no good on the bonding of cement paste and aggregate.


GeoScape ◽  
2017 ◽  
Vol 11 (1) ◽  
pp. 16-24 ◽  
Author(s):  
Marek Obrębalski

Abstract The article presents the population problem of urban functional area around selected medium-sized cities in Poland and the Czech Republic. Research work refers to six cities (on the Polish side - Jelenia Góra, Legnica and Wałbrzych – located in Lower Silesia region; on the Czech side - Hradec Králové, Liberec and Ústí nad Labem). These core cities with suburban areas co-create the functional urban areas with varied demographic structure and development dynamics. In the analysed period, the population growth was observed only in Liberec. The largest total population among studied areas refers also to Liberec functional urban area. The population in suburban areas of the examined Polish and Czech cities is relatively younger than in the core cities. Functional approach for development of urban areas founding depart from perception of demographic problem and challenges only by prism of administrative borders becomes more important.


2018 ◽  
Vol 39 (1) ◽  
pp. 39
Author(s):  
Cristiano De Assumpção Santos ◽  
Elisandro Pires Frigo ◽  
Késia Damaris de Azevedo Frigo ◽  
Caroline Thaís Eckert ◽  
Jonathan Dieter ◽  
...  

Urbanization and disorderly occupation of urban areas have created several environmental problems, such as floods. Among the main causes of these problems is soil sealing associated with urban sprawl. Impervious surfaces provide less precipitation to recharge catchment basins by diverting water that should be restored in that region to other basins. This study compares two existing paving systems: concrete pavers with permeable joints and porous concrete pavers. Our objective was to learn which system better promotes the recovery of catchment basins and, consequently, mitigate problems caused by increasing surface runoff in urban areas. In order to reach the results, precipitations were simulated using lysimeters and a rainfall simulation infiltrometer at rainfall rates of 45, 60, and 90 mm h-1. The analyzed paving systems represented characteristics of public sidewalks. This experiment indicates that porous concrete pavers (99.86%) and concrete pavers (99.59%) present mean infiltration similar to that of grass cover (100%) and thereby can promote water infiltration into soil and the recovery of catchment basins in urban areas.


2020 ◽  
Vol 10 (1) ◽  
pp. 83-88
Author(s):  
Touqeer Ali Rind ◽  
Hemu Karira ◽  
Shahzad Ali Mirani ◽  
Ali Khan Mari

AbstractIn developing countries like Pakistan, Due to rapid growth and population, an increase in the production of industrial waste is rising significantly day by day. Stabilization of soil using those industrial wastes not only gives proper usage of waste materials but also increases the cost-benefit ratio as a whole. In this research work, an attempt was made to use Ground granulated blast furnace slag (GGBFS) in the stabilization of District Khairpur Mirs’ soil. Generally, while dealing with building construction industry such as foundations for buildings, highways such as subgrades as a foundation and in earthen dams as landfills sometimes there exist naturally occurring unsuitable soils. District Khairpur Mirs’ soil is accounted for the different laboratory tests and the concerned District Khairpur Mirs’ soil found to be relatively unsuitable; therefore, various percentages of ground granulated blast furnace slag were added to make it suitable. To improve the concerned soil different percentages of slag are used, and samples thus formed so for were tested in the laboratory for this research work. Various laboratorial tests like particle size distribution, Atterberg limits, Modified Proctor test, AASHTO soil classification, and CBR test were performed on controlled and stabilized soil samples. The aim of this research study was to examine the influence of ground granulated blast-furnace slag (GGBFS) on the index, Compaction and mechanical strength parameters of natural Khairpur Mirs’ soil. Finally, based on laboratorial tests, it was observed that stabilization of soil by GGBFS made favourable changes on the index, compaction and strength parameters of District Khairpur Mirs’ soil.


Author(s):  
Igor V. Polyakov ◽  
Mikhail V. Barannikov ◽  
Ekaterina A. Stepanova

The effect of a complex additive containing superplasticizer C-3 on the properties of heavy concrete has been investigated. The efficiency of the plasticizing action of the specified additive at the stage of preparation of the concrete mixture and subsequent molding of concrete products has been revealed. It is proved that at the stage of concrete hardening, the investigated additive promotes to the formation of a more homogeneous colloidal-crystalline structure and the formation of dense crystalline hydrate complexes of cement stone by the time of completion of concrete hardening. The objects of investigation were samples of grade B22.5 concrete without additives; containing a monoadditive - superplasticizer S-3; containing the complex additive. When designing the composition of additives for heavy concrete, we proceeded from the fundamental provisions of construction science that the complexity of the action of additives lies in the optimal combination of two main opposite processes in time and volume of the concrete matrix. The use of the caprolactam oligomer synthesized in the course of this investigation makes it possible to solve the problem of involving concentrated wastes of caprolactam production in the production turnover. The obtained caprolactam oligomers can be used in construction as plasticizers of concrete mixtures, as inhibitors of corrosion of steel reinforcement in the production of reinforced concrete products. Water-soluble oligomers of caprolactam, which reduce the time of dissolution of the superplasticizer C-3 and the dispersion of low-temperature catalyst in the volume of the concrete mixture being mixed, were synthesized. It was found that in the presence of the oligomer caprolactam in an amount of 10 to 20% of the mass. the dissolution rate of S-3 superplasticizer in water at a temperature of 20-21 °C increases by 2.0-2.2 times. This contributes to a better mixing of the components of the concrete mixture, primarily to improve the dispersion of the complex additive in the volume of the concrete mixture. The caprolactam oligomer used in this research work is an effective water-soluble wetting agent for the surface of particles of cement, sand, and crushed stone, which is very important for activating hydration and sorption processes during mixing of a concrete mixture. The increased wetting properties of the caprolactam oligomer are characterized by a wetting angle of 19.6 °.


Muzikologija ◽  
2018 ◽  
pp. 15-48
Author(s):  
Biljana Milanovic

In the text I deal with the period of establishment and the beginnings of the work of the Institute of Musicology of the Serbian Academy of Sciences, which is marked by the role of composer and music writer Petar Konjovic (1883- 1970), who founded and was the first director of the Institute (1947-1954). I examined and problematized Konjovic?s efforts to establish and manage the institution, which were inseparable from his role of Fellow of the Academy and Secretary of the Department of Fine Arts and Music of the Serbian Academy of Sciences (1948-1954), through the analysis of archival documentation. The basic assumption that I started from was related to the interdependence between (1) the establishment of an institutional order and (2) the disciplining of scientific research in the direction of the emergence of musicology and ethnomusicology in the local context. In particular, issues related to the Institute?s relationship with the wider organizational environment and research policy of the SAN, as well as the role and support of its significant individuals in the process of the institutionalization of music science were especially highlighted. The problem of acquiring legitimacy in clearly hierarchical relationships proved to be very complex, since the Institute represented, on the one hand, a scientific unit of the Academy of Arts, that is, the Department of Fine Arts and Music, which, on the other hand, was marked by the inheritance of marginalized status of artists in comparison to other entities within the SAN. The formation of scientific tasks and objectives and the questions related to their realization were shaped in such a context. I analyzed these problems within three subchapters. The first of them provides basic information on the reorganization of the Serbian Academy of Sciences within the framework of the cultural policy of the new regime and deals with the aspects of the formal establishment of the Institute (1947) and the contextualization of the first programmatic projections of its work. The second question relates to the diverse problems that accompanied the delay of the start of the Institute?s activities, while the final subchapteris dedicated to the period from hiring the first associates to the end of Konjovic?s directorship (1948-1954). Konjovic?s strategies pointed to his simultaneous stability and flexibility in the design of thematic areas and methodological approaches. The policy of the scientific-research work of the Institute of Musicology from Konjovic?s time can be outlined in several general aspects: reliance on pre-war experiences, without the destruction of inherited value canons, but with constant changes in the direction of widening the scope of processed material through research of hitherto neglected creative personalities, performing practices and institutions; melographed and studied folklore material from various rural and urban areas, including different national and ethnic communities; the establishment of completely new thematic areas in the local context that destabilize the concept of purely national science; the emphasis on interdisciplinarity and openness to communication and exchange of scientific and methodological experiences in the international context. Konjovic?s position at the Serbian Academy of Sciences, his experience in managing various institutions, persistence and strategically planned actions, his high criteria and consideration in the selection of associates, managing without ideological divergences from his position of the bourgeois pre-war intellectual, but also his patient waiting for certain decisions of the competent instances, were crucial for the constitution and survival of the Institute of Musicology, within which the platform of musicological and ethnomusicological disciplines in Serbia was established in just a few years.


Author(s):  
Robert T. Hintersteiner

The Paper Will Address The Crisis Of Railroad-Highway Grade Crossing Accidents In The United States. A Railroad-Highway Grade Crossing Is Where A Public Or Private Roadway Crosses Railroad Tracks. Over The Years, There Have Been Many Studies And Programs To Warn The General Public Of The Hazards Of Crossing Railroad Tracks. However, The Same Types Of Railroad-Highway Crossing Accidents Continue To Occur, Despite Attempts To Educate The Public. As Will Be Discussed, Communication Between Transportation Professionals And Coordination Of Railroad And Highway Operations Also Contributes To The Crisis. The Most Effective Way To Eliminate Grade Crossing Accidents Is To Provide Grade Separation Of The Railroad From Vehicle And Pedestrian Traffic. This Has Been Completed At 39,68 1 Locations. It Is A Very Expensive Proposition. Therefore, It Has Been Done Only In Urban Areas, And Along Limited Access Highways And Arterials. The Cost Of Constructing A Grade Separated Crossing Is Estimated To Be Five Million Dollars Per Location.


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