scholarly journals Mechanical Behavior of the Extraction Mud Dam for Use in the Manufacture of CEB

2021 ◽  
Vol 7 (10) ◽  
pp. 1774-1786
Author(s):  
Benaicha Amar Cherif ◽  
Fourar Ali ◽  
Mansouri Tarek ◽  
Fawaz Massouh

The aim of this work is to study the mechanical behavior of the sediments extracted from the Koudiet Meddaouar, Timgad dam (Algeria), for a possible valorization in the field for building works in order to minimize this phenomenon which is currently a concern for the operators and the persons in charge of the mobilization of the water resources. This siltation therefore severely limits its storage capacity and consequently it’s operating life. The extraction of the sediments accumulated in the dam's reservoir is therefore imperative, on the pain of seeing it perish in the medium term. These sediments are, however, of great geotechnical and mechanical value. The results of the tests conducted in the laboratory have enabled us to identify the different sediments from a physical and geotechnical point of view In front of the difficulties noted in the control of the silting up of the dams in Algeria, a very important quantity of silt being deposited annually in the dams. In order to achieve our objective, different mixtures of silt with or without lime treatment, cement glass fibers and powdered fibers were studied for the possible manufacture of Compressed Earth Bricks (CEB). The results obtained show that some of the mixtures present very interesting results in the different tests (compression and bending), verifying the conditions of the standards in force and thus allowing their use in the field of the manufacture of building materials. Doi: 10.28991/cej-2021-03091759 Full Text: PDF

1973 ◽  
Vol 12 (4) ◽  
pp. 438-439
Author(s):  
G. M. Radhul

The book under review deals with economic integration among deve¬loping countries from the point of view of planning. The author believes that it is useful to approach economic integration from a planning point of view and to develop planning models for it, because the theory of economic integration relevant for developing countries should be directed towards the impact of integration on future investments and future production. The type of models used in the book are the multisector linear programming models and the method of analysis is essentially a comparison of two situations; one with economic integration and the other without. For each prospective partici¬pant a medium term planning model is drawn up taking account of its economic situation in some base year. The results of these single country planning models are analysed and compared to those of a similar planning model for the integration area as a whole. The consequences of the integration policy are then evaluated.


2011 ◽  
Vol 63 (6) ◽  
pp. 1099-1110 ◽  
Author(s):  
R. Giné Garriga ◽  
A. Pérez Foguet

The Water Poverty Index (WPI) has been recognized as a useful tool in policy analysis. The index integrates various physical, social and environmental aspects to enable more holistic assessment of water resources. However, soundness of this tool relies on two complementary aspects: (i) inadequate techniques employed in index construction would produce unreliable results, and (ii) poor dissemination of final outcome would reduce applicability of the index to influence policy-making. From a methodological point of view, a revised alternative to calculate the index was developed in a previous study. This paper is therefore concerned not with the method employed in index construction, but with how the composite can be applied to support decision-making processes. In particular, the paper examines different approaches to exploit the index as a policy tool. A number of alternatives to disseminate achieved results are presented. The implications of applying the composite at different spatial scales are highlighted. Turkana District, in Kenya has been selected as initial case study to test the applicability and validity of the index. The paper concludes that the WPI approach provides a relevant tool for guiding appropriate action and policy-making towards more equitable allocation of water resources.


2021 ◽  
Vol 13 (24) ◽  
pp. 13607
Author(s):  
Alexey N. Beskopylny ◽  
Sergey A. Stel’makh ◽  
Evgenii M. Shcherban’ ◽  
Levon R. Mailyan ◽  
Besarion Meskhi ◽  
...  

Improving the efficiency and quality of construction mainly depends on the cost of building materials, which is about 55–65% of total capital-construction costs. The study aimed to obtain geopolymer fine-grained concrete with improved quality characteristics that meet the construction field’s sustainable development criteria and that have environmental friendliness, economic efficiency, and advantages over competing analogues. The dependences of strength characteristics on various compositions of geopolymer concrete were obtained. It was found that the most effective activator is a composition of NaOH and Na2SiO3 with a ratio of 1:2. The increase in the indicators of the obtained geopolymer concrete from the developed composition (4A) in relation to the base control (1X) was 17% in terms of compressive strength and 24% in tensile strength in bending. Polynomial equations were obtained showing the dependence of the change in the strength characteristics of geopolymer concrete on the individual influence of each of the activators. A significant effect of the composition of the alkaline activator on the strength characteristics of geopolymer fine-grained concrete was noted. The optimal temperature range of heat treatment of geopolymer concrete samples, contributing to the positive kinetics of compressive strength gain at the age of 28 days, was determined. The main technological and recipe parameters for obtaining geopolymers with the desired properties, which meet the ecology requirements and are efficient from the point of view of economics, were determined.


Author(s):  
Aysem Berrin Cakmakli

There is a growing universal awareness of protecting the living and non-living environment and making enlightened decisions to achieve a sustainable development without destruction of the natural resources. In this point of view, selecting building materials according to their energy and health performances gains importance in sustainable design. 3Rs (reducing, reusing, recycling), and supplying a healthy, non-hazardous indoor air for building occupants are two important parameters of environmental life-cycle assessment for materials. Information on exposure to gases and vapors from synthetic materials made from petrochemicals, to heavy metals and pesticides, and to some combustion pollutants that cause acid rain should be determined by analyzing environmental product declarations or material specifications. After studying on building materials individually, they are analyzed in the form of tables for four different stages; manufacturing, application, usage, demolition phase. Consequently, this chapter can guide the designer and engineer to think on the elements of design and construction activity.


Author(s):  
Aleksey Shebeko ◽  
Natalia Konstantinova ◽  
Olga Krivoshapkina

Проанализирована роль декоративно-отделочных, облицовочных материалов и покрытий полов в формировании опасных факторов пожара (ОФП). Проведены расчеты распространения ОФП в модельном помещении с учетом вклада облицовочного материала стен и потолка. Показана возможность применения рассмотренного подхода для моделирования условий (стандартных и нестандартных) испытаний строительных материалов и конструкций на пожарную опасность (например, фасадных систем) и гибкого нормирования при использовании декоративно-отделочных, облицовочных материалов и покрытий полов в зданиях и сооружениях.Article presents the study of the possibility to describe thermal decomposition and thermal oxidation processes of fire load finishing materials by means of the kinetic parameters. These parameters are defined by results of termogravimetric analysis for modeling the dynamics of fire development. Nowadays the problem of modeling the distribution of hazardous fire factors (HFF) in buildings and constructions has wide practical application, however techniques of HFF modeling do not take into account as fire load finishing and facing materials of building and construction premises in development of a fire, so they are not considered at an estimation of safe evacuation of people from buildings and constructions as well as at calculation of fire risk, too. When describing a seat of fire there are used fire hazard indicators having essential uncertainty according to the technical literature sources and experimental data while formation should be based on the possibility of their thermodestruction and thermooxidation under the influence of heat loads of various intensity. At the same time, the speed of the specified processes should be interconnected with values of heat loads. The presented work is of current importance because it is necessary to describe thermodestruction and thermooxidation processes of fire load material at modeling the dynamics of HFF distribution in buildings and constructions by means of kinetic parameters received as the results of thermogravimetric analysis. On the example of calcium silicate and wood composition there are carried out calculations of HFF distribution in a test premise taking into account the contribution of wall and ceiling facing material. There is shown the prevailing, in comparison with a seat of fire, contribution of wall and ceiling facing material to HFF formation at its initial stage which is especially important from the point of view of ensuring safe evacuation of people at fire in buildings and constructions. On the basis of the conducted analysis of research results there are developed proposals for applying the considered approach to model conditions for (standard and non-standard) tests of building materials and structures for fire hazard (for example, front systems) and flexible rationing of use of decorative - finishing and facing materials as well as floor coverings in buildings and structures.


Coatings ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 288 ◽  
Author(s):  
José A. Orosa ◽  
Diego Vergara ◽  
Ángel M. Costa ◽  
Rebeca Bouzón

Research from the International Energy Agency about indoor ambiences and nearly zero energy buildings (nZEB) in the past has been centred on different aspects such as the prediction of indoor conditions as a function of the weather using laboratory material properties for simulations and real sampled data for validation. Thus, it is possible to use real data for defining behavioural groups of indoor ambiences as a function of real vapour permeability of internal coverings. However, this method is not suitable for modelling it and predicting its behaviour under weather changes, which is of interest to improve the method of selection and use of building construction materials. In this research, artificial intelligence procedures were employed as the first model of permeable coverings material behaviour to provide a newer understanding of building materials and applications for the generation of new control procedures between the mechanical and electronic point of view of building construction materials.


2018 ◽  
Vol 276 ◽  
pp. 248-253
Author(s):  
Jiří Zach ◽  
Jitka Peterková ◽  
Vítězslav Novák

The paper deals with the possibilities of using secondary raw materials in the development of new advanced lightweight plasters. It was about fibers from recycled waste materials (waste paper, PET bottles, tyres) and recycled insulation (stone wool). The aim of adding fibers to these lightweight building materials was improvement of mechanical properties, improvement thermal insulation properties and reduction of crack sensitivity. It can be stated, based on the evaluation of the selected measurements, that both types of cellulose fibers and fibers from recycled tyres had positive influence on the mechanical properties, namely in the case of compressive strength. From the point of view of thermal insulating properties, it can be said that only 2 types of fibers have reduced the value of the thermal conductivity. They were mixtures with stone fibers and with recycled tyres fibers. Both of these mixtures also showed the lowest average values of bulk density. Based on the carried out research works can be it concluded that the use of recycled tyres fibers show as optimal.


Hydrology ◽  
2019 ◽  
Vol 6 (4) ◽  
pp. 93 ◽  
Author(s):  
Winfred Kilonzo ◽  
Patrick Home ◽  
Joseph Sang ◽  
Beatrice Kakoi

Urbanization has caused limitations on water resources, while climate change has reduced amounts of surface water in some parts of the world. Kikuyu, a suburban area in Kiambu county, Kenya, is facing this challenge. The major challenge in the study is scarcity of potable water, resulting in inadequate water supply to Kikuyu residents. Currently, only 63.6% of the population is being supplied with water by Kikuyu Water Company, the company mandated to supply water to the area. Water demand was 2972 m3/day in 2015 and was projected to be 3834 m3/day by 2025. This has put pressure on the already exploited clean water resources, making it necessary to seek additional sources of domestic water. Storage capacity and water quality of surface water bodies, especially small reservoirs whose water can be used to ease the demand, need to be assessed for supplemental water supply. This study aimed at assessing the suitability of the abandoned quarry reservoir as a source of potable urban water by determining its storage capacity characteristics and water quality status. Volume characteristics were determined using bathymetry survey in January 2019. Water samples were collected in January and August 2019 and analyzed for chemical, physical, and bacteriological quality, as per the American Public Health Association (APHA) standard methods for water and wastewater. Parameters were evaluated based on World Health Organization (WHO) and Kenya Bureau of Standards (KEBS) guidelines for drinking water, and rated based on the drinking water quality index (WQI). The reservoir’s maximum storage capacity was found to be 128,385 m3, the surface area was 17,699 m2, and the maximum depth was 15.11 m. Nineteen of the twenty-five investigated parameters were within the acceptable standards. However, the concentrations of manganese (Mn), cadmium (Cd), iron (Fe), turbidity, total coliforms, and Escherichia coli (E. coli) were above the acceptable limits. Manganese and iron levels increased with depth. The overall WQI of the reservoir was 82.51 and 85.85 in January and August, respectively. Therefore, based on WQI rating, the water scored a good quality rating and could be used for domestic supply upon treatment. The original achievement of this study is establishment of the volume of the water in the quarry as an additional source of water to the nearby community, along with water quality status.


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