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1
Organic substances as corrosion inhibitors for steel in concrete – an overview
Osial M., Wiliński D.
Journal of Building Chemistry
|
2016
|
Vol. 1, iss. 1
43-53
EN
Organic inhibitors have attracted considerable attention due to their promising application as admixtures in concrete protecting against corrosion of rebars. Over the last decade the use of those inhibitors significantly raised. The inhibition efficiency depends on their physical and chemical properties. This paper gives short overview of the protection of steel in concrete against the ingress of chlorides, oxygen and carbon dioxide in concrete, as species causing the corrosion of rebars. This work involves only organic inhibitors.
2
Content available remote A cognitive approach for the multi-objective optimization of RC structural problems
Yepes V., García-Segura T., Moreno-Jiménez J. M.
Archives of Civil and Mechanical Engineering
|
2015
|
Vol. 15, no. 4
1024--1036
EN
This paper proposes a cognitive approach for analyzing and reducing the Pareto optimal set for multi-objective optimization (MOO) of structural problems by means of jointly incorporating subjective and objective aspects. The approach provides improved knowledge on the decision-making process and makes it possible for the actors involved in the resolution process and its integrated systems to learn from the experience. The methodology consists of four steps: (i) the construction of the Pareto set using MOO models; (ii) the filtering of the Pareto set by compromise programming methods; (iii) the selection of the preferred solutions, utilizing the relative importance of criteria and the Analytic Hierarchy Process (AHP); (iv) the extraction of the relevant knowledge derived from the resolution process. A case study on the reinforced concrete (RC) I-beam has been included to illustrate the methodology. The compromise solutions are obtained through the objectives of economic feasibility, structural safety, and environmental sustainability criteria. The approach further identifies the patterns of behavior and critical points of the resolution process which reflect the relevant knowledge derived from the cognitive perspective. Results indicated that the solutions selected increased the number of years of service life. The procedure produced durable and ecological structures without price trade-offs.
3
Content available remote Non-destructive investigation of corrosion current density in steel reinforced concrete by artificial neural networks
Sadowski L.
Archives of Civil and Mechanical Engineering
|
2013
|
Vol. 13, no. 1
104--111
EN
Corrosion of the steel reinforcement in concrete is an important problem for the civil engineering. Inspection techniques are needed to assess the corrosion in order to protect and repair concrete structures. Many studies were performed to establish a series of corrosion rate assessment methods. A method of providing a direct evaluation of the corrosion rate by corrosion current density measurement is Linear Polarisation Resistance (LPR). The main drawback is that it requires a localised breakout of the concrete cover. The corrosion of the steel reinforcement is monitored by measuring the resistivity of the concrete. The purpose of this paper is to use the resistivity four-probe method and galvanostatic resistivity measurement together with neural networks to assess the corrosion rate of steel in concrete without a direct connection to the reinforcement. Three parameters determined by two non-destructive resistivity methods together with the air temperature were employed as input variables, and corrosion current density, predicted by the destructive LPR method, acted as the output variable. The results shows that it is possible to predict corrosion current density in steel reinforced concrete by using the model based on artificial neural networks on the basis of parameters determined by two non-destructive resistivity measurement techniques.
4
Content available remote Interaction between bracing system and moment resisting frame in braced RC frames
Massumi A., Absalan M.
Archives of Civil and Mechanical Engineering
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2013
|
Vol. 13, no. 2
260--268
EN
One of the most suitable choices in design and improvement of reinforced concrete frames is using steel bracings. In this study the results of two experimental models of reinforced concrete frames are investigated. Both frames are designed based on old traditional codes, but one of them is strengthened with steel X-bracing. With respect to experimental results and using ANSYS software, the finite element model related to these frames is made and calibrated, and then nonlinear analyses under additive cyclic static loading are performed. For assessment of interaction between two braced- and bare-frame systems, a new numerical model is developed. The results show considerable interaction effects between two systems in enhancement of seismic characteristics of compound system, especially on increasing of energy damping.
5
Content available remote Behaviour of short polymer-high strength concrete columns under eccentric compression
Barbuta M., Toma I. O., Harja M., Toma A. M., Gavriloaia C.
Archives of Civil and Mechanical Engineering
|
2013
|
Vol. 13, no. 1
119--127
EN
Engineers have been looking for ways to combine two or more materials in order to take advantage of their strong features. This is how the hybrid materials were born. A very common type of such a construction material is the reinforced concrete. The present paper presents the results of the experimental and numerical investigations of the behaviour of short hybrid concrete columns subjected to short-time eccentric compression. The columns are made of high strength concrete, in the compression part, and polymer concrete located in the tensioned part. At the age of 28 days the columns were subjected to eccentric compression, with constant eccentricity. The influence of the second order effects, such as creep, was neglected. From the experimental results it can be concluded that the type of reinforcement can have a significant effect on the ultimate carrying capacity of the hybrid columns. The numerical simulations by means of non-linear finite element analysis are in good agreement with the experimental results.
6
Żelbetowe pale prefabrykowane. Przykład zastosowania na budowie autostrady A1
Chęcińska K.
Magazyn Autostrady
|
2011
|
Nr 4
24-26
PL
Przedmiotem artykułu jest prezentacja prefabrykowanych pali żelbetowych produkowanych w wytwórni Fabud WKB na potrzeby budowy autostrady A1 na odcinku Piekary Śląskie - Maciejów. Pale wbijane w grunt w I kwartale 2010 r. zaprojektowano jako fundamenty wzmocnienia gruntu pod obiekt inżynieryjny - wiadukt WA-440a. W treści: ogólna charakterystyka inwestycji, opis pali prefabrykowanych, technologia ich produkcji oraz etapy wbijania pali na budowie.
EN
The paper presents precast foundation piles manufactured in Fabud WKB for foundation construction of the A1 motorway between Piekary Śląskie and Maciejów. The piles were set down in the soil in the 1st quarter of 2010. The paper contains general contract presentation, precast piles characteristics, precast production technology and stages of setting piles down on site.
7
Content available remote Wsporniki zbrojone trzpieniami stalowymi
Nagrodzka-Godycka K., Seroka D., Sikorska M.
Inżynieria Morska i Geotechnika
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2010
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nr 2
313-320
PL
Wyniki eksperymentalnych badań krótkich wsporników słupa zbrojonych stalowymi trzpieniami. Porównanie efektywności tego zbrojenia ze zbrojeniem klasycznymi prętami zbrojeniowymi stosowanymi w konstrukcjach żelbetowych.
EN
The results of tests on corbels reinforced by steel studs. Comparison of its efficiency with classical reinforcement by bars in reinforced concrete constructions.
8
Content available remote Nowoczesne elementy betonowe do kanalizacji
Suligowski Z.
Inżynieria Morska i Geotechnika
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2010
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nr 4
489-493
PL
Żelbet nie jest materiałem odpowiednim do użycia w kanalizacji. W budownictwie drogowym betonowe elementy stosowane w odwodnieniach mają wystarczającą nośność, jeżeli spełniają wymagania aktualnej normy.
EN
The reinforced concrete is not a proper material for elements of sewage systems. In road construction concrete elements used in drainage systems have sufficient strength if they meet the regulations of current standard.
9
Content available remote Graniczne stopnie zbrojenia poprzecznego elementów żelbetowych według normy europejskiej i polskiej
Wesołowski M.
Inżynieria Morska i Geotechnika
|
2010
|
nr 2
320-323
PL
Analiza wyznaczania minimalnego i maksymalnego stopnia zbrojenia na ścinanie elementów żelbetowych. Porównanie zaleceń normy Eurocode 2 i normy polskiej oraz wyników ilościowych dla elementów żelbetowych o wysokościach użytecznych od 0,2 do 0,6 m.
EN
Analysis of determination of minimal and maximal reinforcement degree with respect to shear strength of reinforced concrete elements. Comparison of Eurocode 2 recommendations with Polish code and quantitative results for reinforced concrete elements of useful height range from 0.2 to 0.6 m.
10
Content available remote Close to reality methods for the structural design of towers. The basics of the relevant standards for industrial chimneys
Noakowski P.
Architecture Civil Engineering Environment
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2010
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Vol. 3, no. 3
79-84
EN
Numerous large concrete chimneys were built in many different countries in the seventies and eighties last century. Unfortunately, the professional scene had to realize that those structures were very different in their forms, wall thicknesses and reinforcements. In addition to this many of them had been impaired by wide vertical through cracks decreasing their durability and wind bearing capacity. Both findings revealed dissatisfying situation that the existing chimney standards were mostly over safe and in some cases unsafe. Due to this, efforts were undertaken to develop modern, close to reality methods for the structural design of chimneys. These new design methods became popular and as such entered the most relevant European standards on chimneys.
11
Content available remote Analysis of composite steel - reinforced concrete (SRC) columns
Gramblička Š., Valach P.
Architecture Civil Engineering Environment
|
2008
|
Vol. 1, no. 4
67-74
EN
A composite SRC column is defined as a composite member with components of concrete and structural steel. Composite SRC columns are a very important application and widespread use of them is found, particularly in high-rise buildings. The paper presents some results of theoretical and experimental analyses of steel-reinforced concrete composite columns. There is a wide variety of types of columns with various types of cross-sections. We are concerned with composite SRC columns, which are completely or partially concrete-encased steel columns. The main topic is a theoretical analysis of the design method according to EN 1994-1-1 and experimental investigations. A partially encased steel-reinforced concrete cross-section was selected for short-term laboratory tests of composite steel-reinforced concrete columns. A total of 12 columns were tested in two series. In the first series 6 columns with a length of 3 m and with eccentricities of normal compression forces of 30 and 80 mm were tested. The second series contained 6 columns with lengths of 4 m and with eccentricities of 40 and 60 mm. The evaluation of the test results is also shown in comparison with the design method according to EN 1994-1-1.
PL
Kompozytowy słup SRC jest elementem zespolonym, wykonanym z betonu i stali konstrukcyjnej. Słupy kompozytowe SRC mają bardzo ważne i szerokie zastosowanie, szczególnie w przypadku budynków wysokich. Artykuł prezentuje prace teoretyczne i eksperymentalne przeprowadzone na żelbetowych słupach kompozytowych. Istnieje szeroka gama slupów o różnych typach przekrojów. W artykule przeanalizowano słupy kompozytowe SRC będące stupami stalowymi całkowicie lub częściowo pokrytymi betonem. Głównym tematem jest teoretyczna analiza metody projektowej zawartej w normie EN 1994-1-1 oraz badania doświadczalne. W celu przeprowadzenia krótkotrwałych badań laboratoryjnych żelbetowych słupów kompozytowych wybrano częściowo zamknięty żelbetowy przekrój. Łącznie w dwóch seriach zbadano 12 słupów. W pierwszej serii zbadano 6 słupów o wysokości 3 m i sile ściskającej przyłożonej na mimośrodzie równym 30 i 80 mm. Druga seria obejmowała 6 słupów o wysokości 4 m i mimośrodach równych 40 i 60 mm. Ocena wyników badań została przedstawiona w odniesieniu do metody projektowej zawartej w normie EN 1994-1-1.
12
Content available remote Durability analysis of a reinforced concrete member using probabilistic SBRA method
Pustka D., Marek P.
Roczniki Inżynierii Budowlanej
|
2007
|
z. 7
91--94
EN
Proposed application of the SBRA (Simulation-Based Reliability Assessment) method, documented e.g. in [1], [2] demonstrates its potential in durability analysis of reinforced concrete beam situated in a such environment leading to a carbonation of the concrete. In a certain time, the carbonation front reaches the reinforcement and the corrosion process of the reinforcement starts. The reliability of the beam from the viewpoint of bending is evaluated.
CS
Článek se zabývá analýzou trvanlivosti prostě podepřeného železobetonového nosníku, jenž je umístěn v prostředí vedoucím ke karbonataci betonu. Jakmile karbonatace dosáhne výztuže, započíná korozní proces této výztuže Spolehlivost uvažovaného nosníku je vyšetřována metodou SBRA (Simulation-Based Reliability Assessment) založenou na Monte Carlo simulační technice.
13
Content available remote Effektivnost’ prmenenia uskoritela tverdenia “AC” v betone i zelezobetone
Kalgin A. A., Velicko E. G., Divnenko E. V.
Budownictwo o Zoptymalizowanym Potencjale Energetycznym
|
2007
|
nr (4)
119--122
EN
The article presents theoretical and practical aspects of using „AC” setling material in concrete and reinforced concrete.
14
Wpływ konstrukcji betonowych i żelbetowych na formy architektoniczne budynków mieszkalnych
Niebrzydowski W.
Zeszyty Naukowe Politechniki Białostockiej. Architektura
|
2002
|
Z. 19
93-110
PL
W artykule przedstawiono wpływ betonu i żelbetu na kształtowanie form architektonicznych budynków mieszkalnych. Omówiono pionierskie realizacje dziewiętnastowieczne. Szczegółowo przeanalizowano różnice w architekturze XX wieku, tworzonej pod wpływem tych tworzyw.
EN
Author of this dissertation presents the influence of concrete and reinfored concrete on architectural forms of dwelling buildings. He gives examples of early, pioneer objects of 19-th century. Author also analyses 20-th century architectural trends in which these materials were the most important.
15
Wybrane problemy zarysowania elementów żelbetowych
Kosińska A.
Zeszyty Naukowe. Budownictwo / Politechnika Łódzka
|
2002
|
Z. 53
50-60
EN
The paper presents the methods of crack width and crack spacing calculation according to few codes. The comparison is made between the methods by CEB-FIP 1990, ACJ 318-89, EC-2 and PN-B-032664. The analysis, based on own investigation is given with the calculation examples for the beam tested in bending. the selected problems of diagonal cracks are also presented and the date for service load from own tests are given. the analisys shows that the accurate prwediction of crack width is not possible.
PL
W referacie zostały przedstawione metody obliczania szerokości rozwarcia rys i ich rozstawu według kilku norm. Dokonano porównania tych metod wg CEB-FIP 1990, ACJ 318-89, EC-2 i PN-B-03264. Analizie poddano badania własne oraz przedstawiono przykłady obliczeń dla belek badanych na zginanie. Przedstawiono również wybrane problemy dotyczące zarysowania ukosnego na tle danych dla obciążenia uzytkowego zaczerpnietych róniez z badan własnych. Analiza wykazała, że dokładne obliczeniowe okreslenie szerokości rozwarcia rys jest praktycznie niemozliwe.
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