scholarly journals Current issues of improving the pricing system in construction in the transition period

Vestnik MGSU ◽  
2020 ◽  
pp. 518-532
Author(s):  
Vladimir P. Korolyov ◽  
Galina A. German
Keyword(s):  
Structural Steel ◽  
Corrosion Protection ◽  
Online Monitoring ◽  
Load Capacity ◽  
Structural Elements ◽  
Regulatory Requirements ◽  
Protection Measures ◽  
Reliability Indices ◽  
Constitutive Parameters ◽  
Corrosion State

Introduction. In the world practice, promotion of structural steel for execution of new effective projects for building and installation construction is linked with innovative introduction of new materials and technologies. This process is specified by the regulatory requirements for reliability of building facilities including indices of load capacity, serviceability and durability. At the same time, the priority is to prevent corrosion damages based on the analysis of the design consideration and assurance of quality of corrosion protection measures. However, for today the possibilities of the concept of limit states as the main instrument for eliminating uncertainty of corrosion protectability parameters are not fully unveiled. The aim of the study is to justify the technical and economic parameters of corrosion protectability in the course of structural steel designing taking into account the required level of structural steel reliability. Materials and methods. The regulatory requirements for means and methods of corrosion protection of structural steel are analyzed on the basis of limit state design principles. Considered are the features of the process approach for affirming compliance of corrosion protectability indices of structural steel. Established are the conditions that allow carrying out the static check and mathematical modeling of design criteria for load capacity, serviceability and durability. Determined are the nomenclature, indices and methods of offline and online monitoring of the constitutive parameters of corrosion state of structural elements. Results. The regulations in force based on the interval estimation of indices of corrosion resistance and life of protective coatings describe conditions of protective means designing as a state or case linked with corrosion hazard. Corrosion protectability defines conditions for designing the corrosion protection measures based on the specified design criteria for serviceability and durability. At that, design decisions of primary and secondary protection are justified by means of computational or computational-measuring verification of compliance of quality and reliability indices of protection means Conclusions. Design characteristics of corrosion resistance and durability obtained by offline and online monitoring of the constitutive parameters of corrosion state of structural elements provide engineering of corrosion protection quality. Management of quality and reliability indices based on corrosion protectability signs lays the groundwork for robust designing measures for the long-term technical and economic protection of building facilities

scholarly journals ASSURANCE OF STRUCTURAL STEEL SURVIVABILITY BASED ON RESERVATION OF PRODUCTION FACILITIES CORROSION PROOFNESS

2017 ◽  
Vol 2 (49) ◽  
pp. 277-284
Author(s):  
I. V. Kuschenko
Keyword(s):  
Structural Steel ◽  
Corrosion Protection ◽  
Structural Strength ◽  
Protective Coatings ◽  
Steel Structures ◽  
Competitive Advantages ◽  
Process Safety ◽  
Reliability Indices ◽  
Protection Systems ◽  
Reliability And Availability

The paper deals with the task of selecting quality and reliability indices of means and methods of corrosion protection considering structural strength requirements. Systematized description of standard (basic, characteristic) impacts and representative values of negative corrosiveness factors is provided. For corrosion protection design, classification features of steel structures and their protective coatings based on criticality rating are specified. Design indices of structural steel durability are discussed. The developed methodology involves an analytical–experimental estimate of reliability and availability factors of corrosion protection. Logistical system has been generated for reserve planning of survivability of structure on the basis of corrosion proofness signs. A method is proposed for calculating compensation for corrosion losses when comparing competitive advantages of corrosion protection systems. The index of corrosion protection level is specified for managing process safety on the basis of risk reduction.

Sustainable and environmentally friendly zinc coatings for protecting steel bridges in Europe

2021 ◽  
Author(s):  
M. C. van Leeuwen ◽  
P. M. Gangé ◽  
B. Duran ◽  
F. Prenger
Keyword(s):  
Corrosion Protection ◽  
Life Cycle Cost ◽  
Zinc Coating ◽  
Environmentally Friendly ◽  
Cost Effective ◽  
Steel Bridges ◽  
Metallic Zinc ◽  
Protection Measures ◽  
Paint Systems ◽  
Zinc Coatings

<p>Metallic zinc coatings are well established as cost-effective corrosion protection for steel bridges. The zinc coating acts first as barrier protection, isolating the base steel from corrosive elements, and secondly by cathodic protection, acting as a sacrificial anode to protect the steel should the coating be compromised. Bridge operators can be confronted by disproportional high maintenance costs for bridges in use as removal of (in)organic paint systems with hazardous and toxic compounds require expensive waste disposal and environmental protection measures. Metallic zinc coatings are recognized as environmentally friendly, sustainable, and low maintenance, providing the lowest life cycle cost corrosion protection. Various case studies with bridges protected with metallic zinc coatings in and outside Europe are illustrated.</p>

scholarly journals Assessment of a steel bridge corrosion degree

2018 ◽  
Vol 49 ◽  
pp. 00098 ◽  
Author(s):  
Jacek Selejdak ◽  
Mariusz Urbański ◽  
Marek Winiarski
Keyword(s):  
Structural Steel ◽  
General Condition ◽  
Load Capacity ◽  
Technical Condition ◽  
Steel Bridge ◽  
Railway Line ◽  
Railway Tracks ◽  
The Subject ◽  
Corrosion Assessment ◽  
National Road

The subject of this analysis is connected with the verification of the load capacity of the span structure taking into account the degree of corrosion of the railway viaduct components located at 41.446 km, on the railway line no. 301 of "Kotlarnia" SA Sand Mine built over the national road DK88 and railway tracks PKP-PLK near T. Kościuszki street in Zabrze The general condition of the structure with regard to the corrosion assessment of structural steel is presented in the paper. Static and strength calculations were carried out to determine the load capacity class, and as a result of the analysis it was found that the technical condition of the facility steel girders is suitable for repair.

Adaption of active boundary conditions in structural fire testing

2019 ◽  
Vol 10 (4) ◽  
pp. 504-528
Author(s):  
Ramla Karim Qureshi ◽  
Negar Elhami-Khorasani ◽  
Thomas Gernay
Keyword(s):  
Boundary Conditions ◽  
Structural Steel ◽  
Test Specimen ◽  
Fire Test ◽  
Structural Elements ◽  
Fire Testing ◽  
Content Type ◽  
Steel Columns ◽  
History Of ◽  
Force Displacement

Purpose This paper aims to investigate the need for active boundary conditions during fire testing of structural elements, review existing studies on hybrid fire testing (HFT), a technique that would ensure updating of boundary conditions during a fire test, and propose a compensation scheme to mitigate instabilities in the hybrid testing procedure. Design/methodology/approach The paper focuses on structural steel columns and starts with a detailed literature review of steel column fire tests in the past few decades with varying axial and rotational end restraints. The review is followed with new results from comparative numerical analyses of structural steel columns with various end constraints. HFT is then discussed as a potential solution to be adapted for fire testing of structural elements. Challenges in contemporary HFT procedures are discussed, and application of stiffness updating approaches is demonstrated. Findings The reviewed studies indicate that axial and rotational restraints at the boundaries considerably influence the fire response of steel columns. Equivalent static spring technique for simulating effect of surrounding frame on an isolated column behavior does not depict accurate buckling and post-buckling response. Additionally, numerical models that simulate fire performance of a column situated in a full-frame do follow the trends observed in actual test results up until failure occurs, but these simulations do not necessarily capture post-failure performance accurately. HFT can be used to capture proper boundary conditions during testing of isolated elements, as well as correct failure modes. However, existing studies showed cases with instabilities during HFT. This paper demonstrates that a different stiffness updates calculated from the force-displacement response history of test specimen at elevated temperature can be used to resolve stability issues. Originality/value The paper has two contributions: it suggests that the provision of active boundary conditions is needed in structural fire testing, as equivalent static spring does not necessarily capture the effect of surrounding frame on an isolated element during a fire test, and it shows that force-displacement response history of test specimen during HFT can be used in the form of a stiffness update to ensure test stability.

Structural Steel Performance Following Severe Earthquake Loading

2011 ◽  
Vol 25 (31) ◽  
pp. 4149-4153
Author(s):  
W. G. Fergusona ◽  
C. K. Seal ◽  
M. A. Hodgson ◽  
G. C. Clifton
Keyword(s):  
Plastic Strain ◽  
Structural Steel ◽  
Central Business District ◽  
Steel Structures ◽  
Earthquake Loading ◽  
Structural Elements ◽  
Steel Buildings ◽  
Structural Element ◽  
Tension And Compression ◽  
Business District

The second Christchurch earthquake on February 22, 2011, Magnitude 6.35, generated more intense shaking in the Central Business District than the September 4, 2010 Darfield earthquake, Magnitude 7.1. The second earthquake was closer to the CBD and at shallow depth, resulting in peak ground accelerations 3 times higher. There was significant failure of unreinforced masonry buildings and collapse of a few reinforced concrete buildings, leading to loss of life. Steel structures on the whole performed well during the earthquake and the plastic, inelastic deformation was less than expected given the strength of the recorded ground accelerations. For steel buildings designed to withstand earthquake loading, a design philosophy is to have some structural elements deform plastically, absorbing energy in the process. Typically elements of beams are designed to plastically deform while the columns remain elastic. In the earthquake some of these elements deformed plastically and the buildings were structurally undamaged. The question which then arises is; the building may be safe, but will it withstand a further severe earthquake? In other words how much further plastic work damage can be absorbed without failure of the structural element? Previous research at Auckland on modern structural steel, where the steel was prestrained various levels, to represent earthquake loading, the toughness was determined, as a function of prestrain for the naturally strain-aged steel. Further research, on the same steel, investigated life to failure for cyclic plastic straining in tension and compression loading at various plastic strain amplitudes. This work has shown that provided the plastic strain in the structural element is in the range 2 – 5% the steel will still meet the relevant NZ Standards. To determine the remaining life the plastic strain must be determ ined then the decision made; to use the building as is, replace the structural element or demolish.

scholarly journals High-performance water-based barrier coatings for the corrosion protection of structural steel

2017 ◽  
Vol 10 (3) ◽  
pp. 254-259 ◽  
Author(s):  
Véronique Dehan ◽  
Elodie Bourgeat-Lami ◽  
Franck D'Agosto ◽  
Brendan Duffy ◽  
Andrea Fortini ◽  
...  
Keyword(s):  
Structural Steel ◽  
Corrosion Protection ◽  
High Performance ◽  
Barrier Coatings ◽  
Water Based

Aircraft Joints: the Interaction between Corrosion Protection and Structural Performance

2011 ◽  
Vol 275 ◽  
pp. 101-104 ◽  
Author(s):  
Graham Clark ◽  
Ung Hing Tiong ◽  
Aditya Jaya
Keyword(s):  
Fatigue Life ◽  
Corrosion Protection ◽  
Protective Coatings ◽  
Fatigue Cracking ◽  
Lap Joints ◽  
Structural Performance ◽  
Large Strains ◽  
Strain Effect ◽  
Protection Measures ◽  
Coating Degradation

Aircraft joints feature prominently in aircraft structural degradation. Fatigue cracking and corrosion damage can reduce joint strength and degrade service life. Corrosion management can include use of paints and sealants and, increasingly, the application of Corrosion Inhibiting Compounds (CICs) which retard corrosion, by penetrating into crevices and cracks, and displacing water. A combination of coatings and CIC use can provide effective corrosion protection, but both interact - in different ways - with structural performance and overall system durability. This paper discusses the interaction between these two corrosion protection measures and fatigue performance of joints. The first issue relates to a reduction in the fatigue life of mechanically-fastened joints after application of CICs (or other lubricants) The lubricating properties of the CICs reduce the friction at the faying surface, which may change the load transfer characteristics of the joint. The paper discusses results from a test program assessing the fatigue life and failure mode of riveted lap joints; the results show a marked reduction in fatigue life for joints containing CICs, and the paper discusses the changes which may be responsible for the reduction. The second issue discussed is the degradation of protective coatings in service. Joints are key locations for coating cracking and failure, since areas such as sheet ends and fastener heads, where displacements are concentrated, will produce concentrated strain in coatings. So far, however, the potential influence of aircraft loading on coating degradation prognostics has received little attention. The paper discusses the role of joint displacement in service as a factor contributing to early degradation of aircraft coatings, and argues that this local strain effect, and indeed structural loading history, needs to be considered in predicting and assessing rates of coating degradation. It describes initial analyses of displacements in aircraft joints, to identify the levels of coating strain and the roles and relative contributions of the various deflections in the joints. The results indicate the potential for very large strains in coatings.

scholarly journals Comportamiento mecánico de secciones de hormigón y mortero = Mechanical behavior of concrete-mortar sections

2018 ◽  
Vol 4 (3) ◽  
pp. 10
Author(s):  
O. Pérez Casal ◽  
Alfonso Cobo Escamilla ◽  
M.E. Moreno Fernández ◽  
M.I. Prieto Barrio
Keyword(s):  
Portland Cement ◽  
Cement Mortar ◽  
Load Capacity ◽  
Good Alternative ◽  
Structural Elements ◽  
Repair Mortar ◽  
In Series ◽  
Initial Fracture ◽  
Repair Mortars ◽  
Polymer Modified Concrete

ResumenEl objetivo del presente trabajo es comparar el comportamiento de los elementos estructurales sometidos a flexión o compresión después de haber sido reparados, mediante la sustitución del hormigón deteriorado por mortero de cemento Portland o mortero modificado con polímeros. En primer lugar, las probetas cúbicas se fabricaron con diferentes proporciones de reparación de mortero de cemento para ensayar a compresión, con los materiales colocados tanto en serie como en paralelo. Del análisis de resultados, se puede concluir que los sistemas mixtos - mortero de hormigón modificado con polímeros sometido a compresión pueden soportar cargas mayores que la reparación del mortero de cemento Portland, aunque en ningún caso pueden restaurar la capacidad de carga del hormigón. En los elementos sometidos a flexión, las vigas reparadas pueden alcanzar la resistencia inicial a la fractura de las vigas y soportar cargas aún mayores. Por lo tanto, la reparación de estructuras de cemento deterioradas con morteros de reparación es una buena alternativa, especialmente en elementos estructurales sometidos a flexión, y se realizan con morteros de cemento Portland. En las estructuras sometidas a compresión, es mejor utilizar morteros de reparación modificados con polímeros que aumentan la ductilidad cuando el mortero de reparación se ubica en serie con respecto a la carga.AbstractThe aim of the present work is to compare the behavior of structural elements subjected to bending or compression after having been repaired, by substituting the deteriorated concrete by Portland cement mortar or mortar modified with polymers. Firstly, cubic specimens were manufactured with different repair concrete-mortar proportions to be tested to compression, with the materials placed both in series and in parallel. From the results analysis, it can be concluded that mixed systems - polymer-modified concrete mortar subjected to compression can withstand greater loads than the repair Portland cement mortar, although they are in no case able to restore the load capacity of concrete. In elements subjected to bending, the repaired beams are able to achieve the initial fracture strength of the beams, and support even higher loads. Therefore, repairing deteriorated concrete structures using repair mortars is a good alternative, especially in structural elements subjected to bending, and performed using Portland cement mortars. In structures subject to compression, it is better to use repair mortars modified with polymers which increase the ductility when the repair mortar is located in series regarding the load

scholarly journals Structural system based on tensioned wood panels: experimental and numerical validation

2021 ◽  
Vol 11 (23) ◽  
pp. 01-12
Author(s):  
Scarlet Karina Montilla Barrios ◽  
Ricardo Picon ◽  
Mauricio Vargas ◽  
Maylett Uzcategui
Keyword(s):  
Industrial Development ◽  
Numerical Models ◽  
Load Capacity ◽  
Frame Structure ◽  
Sustainable Construction ◽  
Experimental Program ◽  
Structural Elements ◽  
Structural System ◽  
Wood Panels ◽  
Technology Processes

Housing in modern societies is a priority need. In the countries of industrial development, there are very sharp contrasts with respect to the housing deficit, affecting the great majority of the families with lower economic resources that solve their problem through subhuman constructions, elaborated, mostly, with residues of construction and disassembly of old buildings, highlighting the importance of the economy, from the financial point of the house built on the architectural quality and comfort. The need to create new building systems based on wood for homes arises when considering the few existing alternatives in developing countries that guarantee an economic, massive and fundamentally sustainable construction. In this sense, this research aims to make a contribution to the implementation of new structural elements for the sustainable construction of wooden houses, which can be manufactured by low technology processes, allowing easy use and appropriation by the general population. The system is called TENSO-WOOD, which is conceived as a system of solid wood plates of Caribbean pine, developed by means of low technology processes that allow an easy appropriation by the population in general. This paper presents a frame structural system using tensioned wood panels as structural elements. It is a lightweight prefabrication system for the construction of two-storey wooden houses. The system consists of bolted wood elements, creating different structural panels such as beam and column. An experimental program was carried out, which allowed knowing the mechanical behavior of each panel of the frame structure. In addition, it permits to know their maximum stress and deformations. The numerical models were compared with the experimental tests to validate and calibrate some parameters in the simulations. Therefore, the numerical models can be able to compute the load capacity and deformation of the wooden elements, obtaining behavior curves.

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