scholarly journals APPLICATION OF THE MODIFIED MAGNETOELASTIC METHOD AND AN ANALYSIS OF THE MAGNETIC FIELD

2018 ◽  
Vol 15 ◽  
pp. 46-50 ◽  
Author(s):  
Tomáš Klier ◽  
Tomáš Míčka ◽  
Michal Polák ◽  
Tomáš Plachý ◽  
Milan Hedvábný ◽  
...  
Keyword(s):  
Prestressed Concrete ◽  
Concrete Beam ◽  
Structural Elements ◽  
Practical Application ◽  
New Approach ◽  
Knowledge Based ◽  
Axial Forces ◽  
Magnetoelastic Properties ◽  
Prestressed Reinforcement ◽  
The Magnetic Field

In the technical praxis there is very often a need of axial force determination in the important structural elements of a building during its construction or operational state. The paper presents practical application of the new approach based on the magnetoelastic principle, especially aimed on experimental evaluation of the axial forces in the prestressed reinforcement on prestressed concrete structures. Described approach is usable not only for newly built structures but in particular for existing ones. The experiment was realized on a prestressed concrete beam dismantled from a bridge that was put out of operation. The influence of a simulated defect of the reinforcement on its magnetoelastic properties has also been investigated. During result evaluation, the knowledge based on the theoretical analysis of the electromagnetic field was used.

scholarly journals New information about practical application of the modified magnetoelastic method

2020 ◽  
Vol 310 ◽  
pp. 00026
Author(s):  
Tomáš Klier ◽  
Tomáš Míčka ◽  
Michal Polák ◽  
Tomáš Plachý ◽  
Milan Hedbávný ◽  
...  
Keyword(s):  
Prestressed Concrete ◽  
Experimental Evaluation ◽  
Engineering Practice ◽  
Structural Elements ◽  
Practical Application ◽  
New Approach ◽  
Axial Forces ◽  
Technical Practice ◽  
New Information ◽  
Prestressed Reinforcement

In the technical practice there is very often a need of axial force determination in the important structural elements of a building during its construction or operational state with adequate precision. The magnetoelastic method is one of the five experimental techniques usually used for that purpose in civil engineering practice. The modified magnetoelastic method is especially aimed on experimental evaluation of the axial forces in the prestressed steel reinforcements on prestressed concrete structures and it is usable not only for newly built structures but in particular for existing ones. New information and knowledge about practical application of the new approach based on the magnetoelastic principle is introduced in the paper. The results of three experiments are summarized, which were realized on the full locked cable PV 150 standardly used as a cable stay strand, on the MUKUSOL threadbar 15FS 0000 generally applied as a temporary prestressed reinforcement and on some prestressed tendons of an existing concrete road bridge, which is about thirty years old.

Bending Capacity of T Beam with Prestressed Concrete-Filled Steel Tube

2013 ◽  
Vol 368-370 ◽  
pp. 1048-1051
Author(s):  
Wen Yu Hou ◽  
Lian Guang Wang ◽  
Peng Liu
Keyword(s):  
Prestressed Concrete ◽  
Steel Tube ◽  
Superposition Method ◽  
Practical Application ◽  
Concrete Filled Steel Tube ◽  
Circular Steel Tube ◽  
Bending Capacity ◽  
Prestressed Reinforcement ◽  
T Beam ◽  
Theoretical Analyses

The prestressed composite T beam with concrete-filled steel tube is made through welding with half I-beam to connect the concrete-filled circular steel tube. The prestressed reinforcement was equipped on the T-beam. The load-bearing capacity and rigidity of the composite beam was enhanced by using prestressed force. In consideration of applying prestress, the corresponding parts stress and strain from the beginning of applying prestress to the phase of elimination of the pressure is calculated through the process of applying prestress; establish the equation of elastic flexural capacity with different location of neutral axis according to the theoretical analyses. Also use the superposition method to build the equation of the deflection. The computational results show that applying prestress reduces the deformation of the composite structure and the mechanic performance has improved which provide important theoretical basis with practical application in engineering.

Experimental Study on Mechanical Performance of Unbonded and Bonded Prestressed Concrete Beams

2012 ◽  
Vol 178-181 ◽  
pp. 2387-2392
Author(s):  
Jian Su ◽  
Nan Gai Yi ◽  
Zong Guang Sun ◽  
Yang Bai ◽  
Ai Guo Zhang
Keyword(s):  
Prestressed Concrete ◽  
Concrete Beam ◽  
Mechanical Performance ◽  
Concrete Beams ◽  
Stress And Strain ◽  
Strain Variation ◽  
Yield Strain ◽  
Prestressed Concrete Beam ◽  
Bearing Load ◽  
Prestressed Reinforcement

The experiment which based on the stress performance of unbonded and bonded prestressed concrete beam, has made a systematically research on the stress and strain variation law of pretressing tendon in the aforementioned reinforcement prestressed concrete structure. When the bonded prestressed concrete beam bearing load, there is a larger variation in stress and strain of prestressing reinforcement along the length. The maxima of stress and strain of prestressing reinforcement in bonded prestressed concrete beam appears in midspan, it is achieved the yield stress and yield strain, the minima appears in bearing, the stress and strain of prestressing reinforcement in bonded prestressed concrete beam is proportional to the distortion. The stress and strain of prestressed reinforcement in unbonded prestressed concrete beam is almost the same along the length.

Prestressed Concrete Beam Bridge Design and Main Parameters of Prestressed Steel Beam Calculations and Arrangement

2014 ◽  
Vol 496-500 ◽  
pp. 2501-2504
Author(s):  
Xi Jun Yin
Keyword(s):  
Cross Section ◽  
Prestressed Concrete ◽  
Concrete Beam ◽  
Steel Beam ◽  
Prestressed Concrete Beam ◽  
Steel Welds ◽  
Prestressed Reinforcement ◽  
Edge Cracking ◽  
Beam Bridge ◽  
Beam Edge

Prestressed concrete beam bridge cross-section using T-shaped cross-section. Anti-shrinkage reinforcement requirements adopted under the dense arrangement of all the memorial steel welds are double-sided welding, using a special form of prestressed reinforcement arranged in assembly is completed, tension on the deck to prevent the beam edge cracking.

Study on a New Linear Arrangement of Prestressed Concrete Beam

2011 ◽  
Vol 94-96 ◽  
pp. 1471-1475
Author(s):  
Chun Bao Li ◽  
Qing Wang
Keyword(s):  
Prestressed Concrete ◽  
Concrete Beam ◽  
Concrete Beams ◽  
Fundamental Principle ◽  
Torsional Moment ◽  
Linear Arrangement ◽  
Prestressed Concrete Beam ◽  
Torsion Moment ◽  
Load Tests ◽  
Prestressed Reinforcement

A new kind of prestressed concrete beams with spiral broken line cables subjected to torsions is present based on the fundamental principle of equivalent loads of prestressed reinforcement. It carried out the emulation analyses and load tests of the beams on spiral broken line cables and the general prestressed concrete beams with longitudinal cables. The results showed that the spiral broken line cables effectively postpone the cracking of the beam and increased both crack torsional moment and ultimate torsion moment, and kept some ductility.

scholarly journals Overview of the modified magnetoelastic method applicability

ACTA IMEKO ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 167
Author(s):  
Tomáš Klier ◽  
Tomáš Mícka ◽  
Michal Polák ◽  
Milan Hedbávný
Keyword(s):  
Prestressed Concrete ◽  
Concrete Structures ◽  
Engineering Practice ◽  
Structural Elements ◽  
Engineering Structures ◽  
Advantages And Disadvantages ◽  
Axial Forces ◽  
Technical Practice ◽  
Tensile Forces

<p class="Abstract">A requirement of axial force determination in important structural elements of a building or engineering structure during its construction or operational state is very frequent in technical practice. In civil engineering practice, five experimental techniques are usually used for evaluation of axial tensile forces in these elements. Each of them has its advantages and disadvantages. One of these methods is the magnetoelastic method, that can be used, for example, on engineering structures for experimental determination of the axial forces in prestressed structural elements made of ferromagnetic materials, e.g., prestressed bars, wires and strands. The article presents general principles of the magnetoelastic method, the magnetoelastic sensor layout and actual information and knowledge about practical application of the new approach based on the magnetoelastic principle on prestressed concrete structures. Subsequently, recent results of the experimental verification and the in-situ application of the method are described in the text. The described experimental approach is usable not only for newly built structures but in particular for existing ones. Furthermore, this approach is the only one effectively usable experimental method for determination of the prestressed force on existing prestressed concrete structures in many cases in the technical practice.</p>

scholarly journals FINITE ELEMENT MODELING OF CAMBER OF PRESTRESSED CONCRETE BEAMS

2017 ◽  
Vol 13 (4) ◽  
pp. 58-65
Author(s):  
Peter P. Gaigerov
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Prestressed Concrete ◽  
Numerical Experiments ◽  
Concrete Beam ◽  
Concrete Beams ◽  
Reinforced Concrete Beam ◽  
Prestressed Reinforcement ◽  
The Impact ◽  
Relief Efforts

For large-span reinforced concrete beam structures developed by the method of determining the camber due to the prestressing of a steel rope on the concrete. Performed numerical experiments to study the impact of various schemes layout prestressed reinforcement without bonding with concrete on the distribution of the relief efforts along the path of the reinforcement.

Study on the Dynamic Response of Prestressed Concrete Beam under Explosive Load

2014 ◽  
Vol 672-674 ◽  
pp. 1890-1893
Author(s):  
Yu Lan Wang ◽  
Yan Zhao Li
Keyword(s):  
Finite Element ◽  
Dynamic Load ◽  
Prestressed Concrete ◽  
Concrete Beam ◽  
Dynamic Performance ◽  
Explosive Load ◽  
Element Analysis ◽  
Prestressed Concrete Beam ◽  
Stress And Deformation ◽  
Prestressed Reinforcement

The dynamic performance of the 12m span prestressed concrete beam is analyzed by finite element method. Based on the finite element analysis, with the change of the peak dynamic load, the risetime of dynamic load and the reinforcement ratio of prestressed reinforcement, the change laws of mid-span maximum deflection and the maximum stress of prestressed reinforcement in prestressed concrete beam are studied. At the same time, have further understanding to the stress and deformation of the prestressed concrete beam under explosive load. It can provide references for study on dynamic performance of the prestressed concrete beam under explosive load.

Analysis of loss in flexural stiffness of in-service prestressed hollow plate beam

2019 ◽  
Vol 10 (4) ◽  
pp. 534-547
Author(s):  
Guanhua Zhang ◽  
Jiawei Wang ◽  
Jinliang Liu ◽  
Yanmin Jia ◽  
Jigang Han
Keyword(s):  
Prestressed Concrete ◽  
Concrete Beam ◽  
Human Life ◽  
Calculation Model ◽  
Flexural Stiffness ◽  
Loading Test ◽  
Content Type ◽  
Prestressed Concrete Beam ◽  
Non Linear ◽  
Prestressed Reinforcement

Purpose During service, cracks are caused in prestressed concrete beams owing to overload or other non-load factors. These cracks significantly affect the safety of bridge structures. The purpose of this paper is to carry out a non-linear iterative calculation for a section of a prestressed concrete beam and obtain the change in stiffness after the section cracks. Design/methodology/approach The existing stress of prestressed reinforcement was measured by performing a boring stress release test on two pieces of an in-service 16 m prestressed concrete hollow plate. Considering the non-linear effects of materials, the calculation model of the loss in the flexural stiffness of the prestressed concrete beam was established based on the existing prestress. The accuracy of the non-linear calculation method and the results obtained for the section were verified by conducting a bending destruction test on two pieces of the 16 m prestressed concrete hollow plate in the same batch and by utilising the measured strain and displacement data on the concrete at the top edge of the midspan section under all load levels. Findings The flexural stiffness of the section decreases rapidly at first and then gradually, and structural rigidity is sensitive to the initial cracking of the beam. The method for calculating the loss in the flexural stiffness of the section established with the existing stress of prestressed reinforcement as a parameter is accurate and feasible. It realizes the possibility of assessing the loss in the rigidity of a prestressed concrete structure by adopting the existing stress of prestressed reinforcement as a parameter. Originality/value A method for quickly determining the loss in the stiffness of structures using existing prestress is established. By employing this method, engineers can rapidly determine whether a bridge is dangerous or not without performing a loading test. Thus, this method not only ensures the safety of human life, but also reduces the cost of testing.

Formation Of An Estimate For A State Contract With A Firm Price In The Construction Sector

2020 ◽  
pp. 47-57
Keyword(s):  
Construction Projects ◽  
Cost Of Capital ◽  
Federal Budget ◽  
The State ◽  
Structural Elements ◽  
Construction Sector ◽  
Construction Process ◽  
Practical Application ◽  
Stage Of Development ◽  
Capital Construction

The issues of determining the estimated cost of capital construction projects with the involvement of Federal budget funds at the stage of development of project documentation, during verification of the accuracy of determining the estimated cost and the initial (maximum) contract price are considered. On the basis of the assessment of amendments to urban planning legislation for the purpose of implementing a state contract by the contractor ( based on the results of competitive procedures or without competitive procedures by decision of state authorities), the procedure for forming the estimate as part of a state (municipal) contract, the price of which is firm, is presented. For the purpose of mutual settlements between the customer and the contractor for the work performed, the formation of primary accounting documentation, as well as for checking the work performed by regulatory authorities, an example of drawing up an estimate of the state (municipal) contract on the basis of grouping costs according to structural elements and complexes of work is given. The result of the research conducted was the development of regulations and the formation of criteria for their practical application by state bodies, institutions, organizations and other participants in the investment-construction process, as well as recipients of budget funds, who perform the functions of the state (municipal) customer, developer and technical customer.

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