Wireless low-cost corrosion sensors for reinforced concrete structures

2005 ◽  
Author(s):  
Nathan P. Dickerson ◽  
Jarkko T. Simonen ◽  
Matthew M. Ardringa ◽  
Sharon L. Wood ◽  
Dean P. Neikirk
Keyword(s):  
Reinforced Concrete ◽  
Low Cost ◽  
Concrete Structures ◽  
Reinforced Concrete Structures

scholarly journals Lumped damage mechanics as a diagnosis tool of reinforced concrete structures in service: case studies of a former bridge arch and a balcony slab

2021 ◽  
Vol 15 (58) ◽  
pp. 21-32
Author(s):  
Rafael Cunha ◽  
Camila Vieira ◽  
David Amorim
Keyword(s):  
Reinforced Concrete ◽  
Case Studies ◽  
Damage Mechanics ◽  
Low Cost ◽  
Concrete Structures ◽  
Structural Condition ◽  
Numerical Analyses ◽  
Engineering Practice ◽  
Reinforced Concrete Structures ◽  
Diagnosis Tool

Reinforced concrete structures may need repair in order to ensure the designed durability. Such necessity vary in cause and effect, but the structural diagnosis serves as the basis for adopting intervention measures. The assessment of the structural condition usually is made in loco, but sometimes numerical analyses are required as a low cost and effective preliminary diagnosis. In general, numerical analyses use hundreds or thousands of finite elements and nonlinear theories that are not often used in engineering practice. As an alternative, lumped damage mechanics (LDM) uses key concepts of classic fracture and damage mechanics in plastic hinges throughout well-known quantities such as ultimate moment and cracking moment. Such theory describes the concrete cracking by a damage variable, which can be used as a diagnosis criterion. Therefore, this paper presents LDM as a diagnosis tool to analyse actual structures. The case studies presented in this paper are a former bridge arch tested in China and a balcony that collapsed in Brazil. The results show that LDM numerical response of those structures are quite close to laboratory observations (former bridge arch) and in loco measurements (balcony).

scholarly journals Development of low cost packaged fibre optic sensors for use in reinforced concrete structures

Measurement ◽  
2019 ◽  
Vol 135 ◽  
pp. 617-624 ◽  
Author(s):  
Richard H. Scott ◽  
Sanjay Chikermane ◽  
Miodrag Vidakovic ◽  
Brett McKinley ◽  
Tong Sun ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Low Cost ◽  
Concrete Structures ◽  
Reinforced Concrete Structures ◽  
Fibre Optic

scholarly journals Analysis of reinforced concrete structures through the ultrasonic pulse velocity: technological parameters involved

2017 ◽  
Vol 10 (2) ◽  
pp. 358-385 ◽  
Author(s):  
D.S. ADAMATTI ◽  
A. LORENZI ◽  
J. A. CHIES ◽  
L.C.P. SILVA FILHO
Keyword(s):  
Reinforced Concrete ◽  
Low Cost ◽  
Concrete Structures ◽  
Ultrasonic Pulse Velocity ◽  
Correct Choice ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Reinforced Concrete Structures ◽  
Technological Parameters ◽  
Surface Mapping

Abstract The application of Nondestructive Testing methods (NDT) may be an interesting strategy to monitor the condition state of reinforced concrete structures, especially when there are problems related to mixing, conveying or placing the concrete. Among the NDT methods, the Ultrasonic Pulse Velocity (UPV) has been one of the most used in various fields of civil engineering, due to the ease of operation, low cost, test velocity and low level of damage to the surface analyzed. This work aims to study the influence of certain technological variables in the results obtained through UPV tests. With this aim two large blocks were cast at the laboratory, with dimensions close to real concrete elements. One of the elements was reinforcement with steel meshes on both sides while the other was cast without reinforcement. Inside these elements objects were introduced to reproduce internal concrete flaws. To facilitate the analysis the results were represented by means of a surface mapping image technique and were also subjected to statistical analysis. Through the study it was demonstrated that the correct choice of test parameters is crucial to obtain a right interpretation of UPV results from real structures.

Application of Polymer-Mortar Composites as a Sustainable Building Material

2015 ◽  
Vol 650 ◽  
pp. 21-28 ◽  
Author(s):  
A.S. Benosman ◽  
Y. Senhadji ◽  
M. Mouli
Keyword(s):  
Energy Efficiency ◽  
Reinforced Concrete ◽  
Composite Materials ◽  
Tap Water ◽  
Low Cost ◽  
Concrete Structures ◽  
Sound Intensity ◽  
Reinforced Concrete Structures ◽  
Destructive Testing ◽  
Polymer Mortar

In a number of countries, important research projects are nowadays carried out and are mainly devoted to developing original approaches to sustainability in order to improve the lifetime of reinforced concrete structures. This paper describes an innovative use of plastic bottle waste as cement-substitution within composite materials for preventing chemical attacks, energy efficiency in buildings or repairing various reinforced concrete structures. So, experiments were accomplished on polymer-mortar composite materials where the cement was partially replaced by various volume fractions of waste polyethylene terephthalate (PET) particles (0%, 6%, 12% and 17%). The specimens were tested by destructive and non-destructive testing and for chemical resistance to acid solutions at different concentrations. From this study, it was found that the PET-modified mortars exposed to aggressive environments showed better resistance to chemical attack than unmodified one without substantially affecting the mechanical strength in tap water and UPV values decrease as the proportion of PET waste in the mix increases. The addition of PET to the modified mortars, means reducing the penetration of aggressive agents. The formations which appear such as different calcium salts were determined by TG/dTG analysis. So, these composite materials are often used as low-cost materials for energy efficiency in buildings, preventing chemical attacks or repairing various reinforced concrete structures exposed to aggressive environments where high resistance to acid is required and to both reduce sound intensity and dampen vibrations.

A low-cost version of electro-mechanical impedance technique for damage detection in reinforced concrete structures using multiple piezo configurations

2016 ◽  
Vol 20 (8) ◽  
pp. 1247-1254 ◽  
Author(s):  
Naveet Kaur ◽  
Lingfang Li ◽  
Suresh Bhalla ◽  
Yong Xia
Keyword(s):  
Reinforced Concrete ◽  
Health Monitoring ◽  
Low Cost ◽  
Concrete Structures ◽  
Mechanical Impedance ◽  
Metal Wire ◽  
Reinforced Concrete Structures ◽  
Experimental Scheme ◽  
Impedance Technique ◽  
Lcr Meter

The electro-mechanical impedance technique has developed rapidly during the past few decades as a reliable health monitoring component of civil structures. However, the high cost of impedance analyzer/LCR meter conventionally used for data acquisition in the electro-mechanical impedance technique restricts its wide use in real applications. This article provides a comprehensive study of exploring the low-cost electro-mechanical impedance technique for health monitoring of concrete under destructive testing using multiple piezo configurations. The experimental scheme ensures separate acquisition of both the real and the imaginary components of the electro-mechanical impedance signature for detailed analysis, a feature not available in some previous low-cost adaptations. The piezo configurations covered here for comparison are the surface-bonded piezo configuration, the embedded piezo configuration, and the metal wire piezo configuration. The repeatability of the proposed low-cost electro-mechanical impedance technique is checked and the results are compared with the traditional counterpart utilizing conventional LCR meter. The two electro-mechanical impedance approaches show similar trends of the conductance signature for all configurations. In particular, the metal wire piezo configuration can be adopted as an excellent alternative in practice for reinforced concrete structures when the direct surface bonding is not feasible. Overall, the low-cost version of the electro-mechanical impedance technique is effective to detect the presence of the damage.

Design of precast reinforced concrete structures of frame buildings: a new set of rules

2019 ◽  
pp. 4-9 ◽  
Keyword(s):  
Reinforced Concrete ◽  
Concrete Structures ◽  
Reinforced Concrete Structures ◽  
Building Frames ◽  
Fine Grained ◽  
Rigid Frame ◽  
Floor Slabs ◽  
Frame Buildings ◽  
Spatial System ◽  
Precast Elements

Currently, prefabricated reinforced concrete structures are widely used for the construction of buildings of various functional purposes. In this regard, has been developed SP 356.1325800.2017 "Frame Reinforced Concrete Prefabricated Structures of Multi-Storey Buildings. Design Rules", which establishes requirements for the calculation and design of precast reinforced concrete structures of frame buildings of heavy, fine-grained and lightweight structural concrete for buildings with a height of not more than 75 m. The structure of the set of rules consists of eight sections and one annex. The document reviewed covers the design of multi-story framed beam structural systems, the elements of which are connected in a spatial system with rigid (partially compliant) or hinged joints and concreting of the joints between the surfaces of the abutting precast elements. The classification of structural schemes of building frames, which according to the method of accommodation of horizontal loads are divided into bracing, rigid frame bracing and framework, is presented. The list of structural elements, such as foundations, columns, crossbars, ribbed and hollow floor slabs and coatings, stiffness elements and external enclosing structures is given; detailed instructions for their design are provided. The scope of the developed set of rules includes all natural and climatic zones of the Russian Federation, except seismic areas with 7 or more points, as well as permafrost zones.

Improvement Of Curvilinear Diagrams Of Concrete Deformation

2019 ◽  
pp. 99-104
Keyword(s):  
Reinforced Concrete ◽  
Peak Load ◽  
Experimental Studies ◽  
Concrete Structures ◽  
Deformation Model ◽  
Reinforced Concrete Structures ◽  
Significant Difference ◽  
Deformation Diagrams

Problems when calculating reinforced concrete structures based on the concrete deformation under compression diagram, which is presented both in Russian and foreign regulatory documents on the design of concrete and reinforced concrete structures are considered. The correctness of their compliance for all classes of concrete remains very approximate, especially a significant difference occurs when using Euronorm due to the different shape and sizes of the samples. At present, there are no methodical recommendations for determining the ultimate relative deformations of concrete under axial compression and the construction of curvilinear deformation diagrams, which leads to limited experimental data and, as a result, does not make it possible to enter more detailed ultimate strain values into domestic standards. The results of experimental studies to determine the ultimate relative deformations of concrete under compression for different classes of concrete, which allowed to make analytical dependences for the evaluation of the ultimate relative deformations and description of curvilinear deformation diagrams, are presented. The article discusses various options for using the deformation model to assess the stress-strain state of the structure, it is concluded that it is necessary to use not only the finite values of the ultimate deformations, but also their intermediate values. This requires reliable diagrams "s–e” for all classes of concrete. The difficulties of measuring deformations in concrete subjected to peak load, corresponding to the prismatic strength, as well as main cracks that appeared under conditions of long-term step loading are highlighted. Variants of more accurate measurements are proposed. Development and implementation of the new standard GOST "Concretes. Methods for determination of complete diagrams" on the basis of the developed method for obtaining complete diagrams of concrete deformation under compression for the evaluation of ultimate deformability of concrete under compression are necessary.

SEISMIC ANALYSIS OF MULTISTOREY REINFORCED CONCRETE STRUCTURES

2019 ◽  
Vol 9 (1) ◽  
pp. 61
Author(s):  
SINGH RAVIKANT ◽  
KUMAR SINGH VINAY ◽  
YADAV MAHESH ◽  
◽  
◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Seismic Analysis ◽  
Concrete Structures ◽  
Reinforced Concrete Structures
Sign in / Sign up

Export Citation Format

Share Document