scholarly journals Comparison of the planned and actual course of construction of reinforced concrete monolithic structures

2021 ◽  
Vol 1209 (1) ◽  
pp. 012011
Author(s):  
R Doubek

Abstract During construction, there is often a change in contractual terms, either in advance of construction or delayed construction. This phenomenon is due to many influencing factors such as delayed subcontracting, climatic conditions, the surrounding construction site, the quality of project documentation, the solvency of the investor, the expertise of the general contractor, etc. The aim of the paper is to assess the planned and actual construction of reinforced concrete monolithic structural elements using tower cranes. The subject of the paper is to state the expected method of implementation in time and how the construction proceeded. Milestones for accelerating and slowing down construction, analyzing their causes and proposing future measures will be presented. Data are obtained by measuring real buildings.

2018 ◽  
Vol 33 ◽  
pp. 01043 ◽  
Author(s):  
Elena Anatol’evna Korol’ ◽  
Yuliya Olegovna Kustikova

As the height of the building increases, loads on load-carrying structures increase dramatically, and as a result of the development of high-rise construction, several structural systems of such buildings have been developed: frame, frame-frame, cross-wall, barrel, box-type, box-to-wall ("pipe in pipe", "Trumpet in the farm"), etc. In turn, the barrel systems have their own versions: cantilever support of the ceilings on the trunk, suspension of the outer part of the overlap to the upper carrying console "hanging house" or its support by means of the walls on the lower bearing cantilever, intermediate position of the supporting cantilevers in height to the floor, from a part of floors. The object of the study are the structural solutions of high-rise buildings. The subject of the study is the layout of structural schemes of high-rise buildings, taking into account the main parameters - altitude (height), natural climatic conditions of construction, materials of structural elements and their physical and mechanical characteristics. The purpose of the study is to identify the features and systematization of structural systems of high-rise buildings and the corresponding structural elements. The results of the research make it possible, at the stage of making design decisions, to establish rational parameters for the correspondence between the structural systems of high-rise buildings and their individual elements.


Author(s):  
Ekaterina Aleksandrovna Erdokesko

The subject of this article is the tobacco cultivation in Tauride Province in the late XIX – early XX centuries. The author provides information on the amount of land allocated for tobacco cultivation, types of tobacco, tobacco plants and their owners, manufactured tobacco products, as well as retail of tobacco products. An overview is given to the factors that affected the demand for tobacco products in this historical period and uneven level of tobacco production. The article leans on the vast array of sources, including archival materials from the State Archive of the Republic of Crimea and the Russian State Historical Archive, statistical data, as well as reference material. The scientific novelty consists in the attempt to give a broader picture of tobacco production in the territory of Tauride Province, as this topic did not receive due attention within the Russian historiography. The conclusion is made that the second half of the XIX century marks a breakthrough in the development of tobacco cultivation in Tauride Province, associated with the legislative acts on taxation, as well as construction of new transport routes. This turned tobacco cultivation into one of the leading segments of agriculture in Yalta, Simferopol and Feodosia Uyezds, which have the most favorable natural and climatic conditions for the development of this industry. However, significant decline in the number of tobacco farmers was observed by the beginning of the XX century, as well as the acres of land allocated for tobacco cultivation. This was caused by unfavorable conditions for retail of tobacco products, decrease in yield capacity, quality of tobacco, as well as excess of supply over demand for tobacco products.


2013 ◽  
Vol 59 (No. 2) ◽  
pp. 56-60 ◽  
Author(s):  
P. Findura ◽  
J. Turan ◽  
J. Jobbágy ◽  
M. Angelovič ◽  
O. Ponjican

Machines for harvesting vegetable must reliably collect the given type of vegetables at various climatic conditions, and with adequate performance, quality and low losses. Machines for harvesting of green peas must be sufficiently reliable and handling must be simple. The criteria of their work are based on harvested product quality, and the size of losses incurred depends on the rate of release of pods from the plants and on the release of grains from pods. The size of loss of grain and pods in the field and grain damages in the storage tank is directly proportional to the appropriately selected operating mode of the machine. Resistance to the damage of grain can be partly affected by selecting varieties with appropriate physical and mechanical properties and by choosing appropriate operating speed of the collector of green peas. Experimental measurements were carried out in the cooperative farm Zemné, Slovak Republic, within a conventional tillage technology, which has suitable conditions for the cultivation of this commodity. The subject of research was green peas Ploeger EPD 490.  


2018 ◽  
Vol 251 ◽  
pp. 02039
Author(s):  
Lyudmila Elshina

Design of reinforced concrete is based on assuming that applied rebar has no corrosion damages at its surface. However, conventional construction practice allows the rebar embedded into concrete to have surface rust. Being transported in open railway cars, by river or marine transports, being in warehouses of intermediate traders and then affected during this time by an atmospheric precipitation and sometimes even aggressive agents of the environment (for example, being in direct contact with remains of chlorides which are earlier transported in the same cars), rebar arrives to construction site with corrosion defects of different types and various extents. Corrosion damages are caused not only by the conditions of its transportation and storage, but also by poor quality of the steel itself. This may lead to dangerous consequences such as sudden collapses of building constructions without preliminary visible deflections and deformations. One of the reasons of sudden structure collapses related to steel quality is strong structure heterogeneity stressed out by the slag immerge at the surface from the bar’s core. The emergence of slag to a surface of the rebar is especially noticeable in rebar produced by a multilane casting method. The solution of durability problems of reinforced concrete structures is based on competent design, identification and application of necessary methods of corrosion resistance for steel rebar, quality control in producer facilities as well as on the construction site of the consumer, increase in durability of bonding of rebar with concrete, and sufficient choice of primary and secondary anticorrosive protection for rebar and concrete.


2019 ◽  
Vol 284 ◽  
pp. 07004
Author(s):  
Kamila Owczarska ◽  
Elżbieta Szmigiera ◽  
Piotr Woyciechowski

The subject of the article is the analysis of the influence of factors related to the course of concreting on the quality of the reinforced concrete element. The problem was discussed on the example of columns with an unusual narrow cross-section (18x80 cm). The characteristics of the surface defects of tested columns are presented and their causes are discussed. The basis of discussion were observations and in-situ tests of concrete mix performed during concreting similar elements in similar conditions. The potential effects of defects in terms of component durability were also considered.


2013 ◽  
pp. 77-90
Author(s):  
Yen Nguyen Thi Hoang

This paper focuses on the understanding of service quality in the context of Vietnamese universities. It proposes an approach for measuring the quality of the higher education service provided by universities in Vietnam. Firstly, an exploratory study was conducted. Then, the set of items which were generated became the subject of a questionnaire that was then administered to 675 students of a Vietnamese university to determine the dimensions of higher education service quality in this context. The obtained results permit us to appropriate a measurement scale which is slightly different from the SERVQUAL scale widely known as the standard for measuring service quality. The results also show that tangible elements, responsiveness and assurance seem to be three specific dimensions of the higher education service of Vietnamese universities.


The author analyzes the reasons that objectively reduce the importance and quality of the organizational and technological solutions of work production plans and the content of their main documents. Based on a generalization of practical experience, one of the real ways of increasing the level of work production plans is proposed as a result of the development of "The Unified Rules for Work Production on the Site" as part of the construction organization project, in the form of fundamental requirements, followed by the inclusion of this document in the work production plan as an input document. The structure and content of the Unified Rules are described with the disclosure of the main documents - calendar plans of work, construction master plans, technological schemes of works. The first section of the document contains requirements for the content of tasks for the development of the project of work execution, the order of its approval, and requirements for the quality of solutions. The second section presents principal solutions, methods of work execution and their technological schemes. The organizational and technological solutions adopted in the proposed document are specified and detailed by the General Contractor Construction Organization with due regard for the resource capabilities and the actual conditions of construction or reconstruction.


Moreana ◽  
2002 ◽  
Vol 39 (Number 149) (1) ◽  
pp. 41-60 ◽  
Author(s):  
Eugenio M. Olivares Merino
Keyword(s):  

The recent reprinting of Álvaro de Silva’s 1998 edition of a selection of More’s letters prompts the author to examine the subject of Spanish translations of More, and of de Silva’s general commentary on More’s correspondence and on his relationship to other humanists. The author reflects on aspects of More’s personality as exposed in his letters and uses what he finds as a corrective to several biographical misconceptions. He points out the strengths and weaknesses of de Silva’s work and compares it with that of other translators, particularly Elizabeth Rogers, and notes the particularly Spanish quality of de Silva’s edition.


2018 ◽  
Vol 12 (2) ◽  
pp. 1-7
Author(s):  
Sînziana Venera Morărița

Abstract Although relatively recent, peach culture has grown great in our country due to the special quality of the fruit, its very complex chemical composition and the large production that can be obtained without much effort. Peach is a species slightly adapted to our climatic conditions, suffers from winter frost, but can provide productive and long productions of 10-15 years.


2020 ◽  
pp. 26-28
Author(s):  
Н.Т. Чеботарев ◽  
Н.Н. Шергина

Пахотные угодья Республики Коми в основном представлены дерново-подзолистыми почвами с низким естественным плодородием, которые без применения удобрений быстро подвергаются деградационным процессам, что резко снижает их продуктивность. Цель исследований: оценка эффективности долговременного применения органических и минеральных удобрений при выращивании картофеля в кормовом севообороте в условиях Республики Коми. Методической основой выполнения работ были комплексные исследования дерново-подзолистых почв, клубней картофеля на участках многолетнего полевого эксперимента, заложенного на землях Института агробиотехнологий ФИЦ Коми НЦ УрО РАН в соответствии с «Методическими указаниями географической сети опытов с удобрениями». Длительный период исследований (более 40 лет) характеризовался различными климатическими условиями, которые отразились на количестве урожая и качестве клубней картофеля. Было проведено 7 ротаций (14 лет) с выращиванием картофеля. Вносили органические удобрения – торфонавозный компост (ТНК) в дозах 40 и 80 т/га (1 и 2 фон, соответственно) под картофель и минеральные удобрения – NPК в дозах 1/3; 1/2 и 1 для восполнения выноса растениями элементов питания. Установлено положительное влияние комплексного применения органических и минеральных удобрений на урожайность и качество картофеля, а также на плодородие дерново-подзолистой легкосуглинистой среднеокультуренной почвы в кормовом севообороте в почвенно-климатических условиях Республики Коми. В результате применения шестипольного севооборота и комплексного внесения удобрений с 1978 года к 2019 году в почвах снизилась обменная и гидролитическая кислотность; повысилось содержание гумуса на 0,5% (в контроле); на 0,2–0,5% (с тремя дозами минеральных удобрений); на 0,3–1,1% (с ТНК); на 0,2–1,6% (при совместном применении органических и минеральных удобрений). Наибольшие урожаи картофеля получены при совместном применении органических (80 т/га) и минеральных удобрений (1 NPК) и составили 37,1 т/га клубней (8,5 тыс/га кормовых единиц). При таком соотношении удобрений показано высокое качество клубней картофеля: содержание крахмала 15,5%, витамина С – 19,4 мг%, сырого протеина – 14,1%. Количество нитратного азота не превышало ПДК (ПДК 250 мг.с.м.). Экономические расчеты показали, что при внесении ТНК 40 т/га + 1 NPК в дерново-подзолистые почвы с.-х. использования в среднетаежной зоне Республики Коми при выращивании картофеля, условный чистый доход составит 68,4 тыс. р. с 1 га, себестоимость 1 т картофеля – 2,8 тыс. р., рентабельность 188,7%. The arable land of the Republic of Komi is mainly represented by dern-sub-ground soils with low natural fertility, which without the use of fertilizers are quickly subjected to degradation processes, which dramatically reduces their productivity. The aim of the research is to evaluate the efficiency of long-term use of organic and mineral fertilizers in the growing of potatoes in feed crop rotation in the conditions of the Komi Republic. The methodological basis for carrying out the works was comprehensive studies of dern-subhead soils, potato tubers on the sites of a multi-year field experiment laid on the lands of the Institute of Agrobiotechnology of the FRC Komi SC UB RAS in accordance with the «Methodological Instructions of the Geographical Network of Experiments with Fertilizers». A long period of research (more than 40 years) was characterized by different climatic conditions, which affected the number of crops and the quality of potato tubers. There were 7 rotations (14 years) with potato cultivation. Organic fertilizers – peat-avous compost (TNK) in doses of 40 and 80 t/ha (1 and 2 background, respectively) for potatoes and mineral fertilizers – NPK in doses of 1/3; 1/2 and 1 to replenish the carry-out of food elements by plants. The positive effect of the integrated use of organic and mineral fertilizers on the yield and quality of potatoes, as well as on the fertility of soddy-podzolic light loamy medium cultivated soil in fodder crop rotation in the soil and climatic conditions of the Komi Republic, has been established. As a result of the use of six-bed crop rotation and the integrated application of fertilizers, metabolic and hydrolytic acidity decreased in soils from 1978 to 2019; humus content increased by 0.5% (in control); 0.2–0.5% (with three doses of mineral fertilizers); 0.3–1.1% (with TNCs); 0.2–1.6% (with combined use of organic and mineral fertilizers). The largest potato yields were obtained from the combined use of organic (80 t/ha) and mineral fertilizers (1 NPK) and amounted to 37.1 t/ha tubers (8.5 thousand/ha feed units). The largest potato harvests were obtained with the combined use of organic (80 t/ha) and mineral fertilizers (1 NPK) and amounted to 37.1 t/ha of tubers (8.5 thousand/ha of feed units). With this ratio of fertilizers, the high quality of potato tubers was also determined: the starch content was 15.5%, vitamin C – 19.4 mg%, crude protein – 14.1%. The amount of nitrate nitrogen did not exceed the MPC (MPC 250 mg.s.m.). Economic calculations showed that if TNK is added 40 t/ha 1 NPK to the dern-sub-ground soils of agricultural use in the medium-sized zone of the Komi Republic when growing potatoes, the conditional net income will be 68.4 thousand rubles from 1 ha, the cost of 1 t of potatoes – 2.8 thousand rubles, profitability 188.7%.


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