scholarly journals Defects systematization of reinforced concrete bridges of ukrainian railways as the result of their inspection

2021 ◽  
pp. 18-28
Author(s):  
Liudmyla Trykoz ◽  
Ruslan Yurchenko
Keyword(s):  
Reinforced Concrete ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Concrete Bridges ◽  
Reinforced Concrete Bridges ◽  
Condition Evaluation ◽  
Immediate Recovery ◽  
Railway Operation ◽  
Train Vibration

Visual inspection is the important part of the bridges management. Many defectscan be detected that determine the traffic conditions, service life, and operation cost. Thedeterioration of bridges calls for effective methods for condition evaluation and maintenance as wellas suitable methods of their repair and recovery. This article aims defects systematization ofreinforced concrete bridges to define the effective method for recovering of their technical state. Morethan 100 reinforced concrete bridges in Ukrainian railways were inspected from 2017 to 2021.Ultrasonic pulse velocity, penetration resistance, reinforcement corrosion tests, and rebar locatingwere performed on beams, bed block, and piers of reinforced concrete bridges. It is shown that themost probable reasons of defects are natural impacts (freezing-thawing, moisturizing-drying),technogenic factors (train vibration, leakage current), and technological disadvantages(unsatisfactory production or setting). During the inspection, there are three categories of defectswere defined. The first one does not influence the train traffic (for example, deficient protectiveconcrete layer). The second one can limit the train traffic (for instance, crack width more than 0.3mm). The third category endangers the safe railway operation (such as an intense leaching of cementstone at an area more than 2 m2). It is made a proposal to match external signs of damage withreasons their appearance and methods of recovery. Three main types of repairs are used in Ukrainianrailways: torkret process, steel hooping, waterproof layer. However, the relationship between thetype of defect and the method of recovery has not been estimated before. It is important that themethods of repair and protection will be assigned according to their operation state (a disabled staterequires immediate recovery of the structures) as well as the reasons of appearance (destructiveacts). These methods must prevent a future destruction or protect of the structures.

scholarly journals About the Possible Limitations in the Usage of the Non-Destructive Ultrasonic Pulse Velocity Method for Assessment of Cracks in Reinforced Concrete Structures, Subjected to Direct Environmental Exposure

Buildings ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 202 ◽  
Author(s):  
Ivan Ivanchev ◽  
Veselin Slavchev
Keyword(s):  
Reinforced Concrete ◽  
Experimental Studies ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Reinforced Concrete Beams ◽  
Safety And Reliability ◽  
External Conditions ◽  
Maximum Crack ◽  
Non Destructive

Failures occur in the structures of reinforced concrete buildings and facilities during their continuous exploitation, without being overloaded or exposed to extreme impacts, the most common being cracks. Their detection and change in time are related to the assessment of the state of the structures, their safety, and reliability during their construction and especially for their safety exploitation. This paper describes the results of the experimental studies conducted by authors aiming to verify the possibility of using the non-destructive ultrasonic pulse velocity method (NDUPVM) for detection and evaluation of cracks. Results of an experimental study of 12 reinforced concrete beams are presented. In previous experiments, some of them were subjected to bending until the maximum crack width of 0.3 mm was reached and others until yielding of the longitudinal reinforcement. The results obtained from the measurements of the depths of the normal cracks with different widths with NDUPVM were compared with the visually measured ones. In the present research cracks with the same width and with a similar depth were chosen. The influence of extreme external conditions to the accuracy of the measured crack depths by the NDUPVM was investigated. Non-destructive ultrasonic research was done by a portable device Proceq TICO.

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.

scholarly journals Structural health assessment of reinforced concrete structure

2021 ◽  
Vol 1197 (1) ◽  
pp. 012019
Author(s):  
A A Raut ◽  
P D Pachpor ◽  
D P Mase
Keyword(s):  
Reinforced Concrete ◽  
Service Life ◽  
Chloride Content ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Chloride Ingress ◽  
Commercial Building ◽  
Reinforced Concrete Structure ◽  
Chemical Test

Abstract There is a magnificent rise in repair, retrofitting and rehabilitation in construction industry in recent years. Concrete is a major used material in construction for various structures mainly because it deteriorates at a low rate. Concrete alone is durable but for structural application, Reinforced concrete is used. Reinforced concrete structures are not that durable because of number of reasons such as variation in construction methods, loading condition in service life and subsequent attack by environmental factors. The external symptoms range from cracking to spalling of concrete. In maximum field cases the main cause of deterioration are penetration of water and aggressive chemicals attack. Carbonation, Chloride ingress, leaching, sulphate attack, alkali-silica reaction are known responsible causes. Due to these reasons, during service life the structure deteriorates, and hence monitoring is required. If the condition of structure is below acceptable limit considering various parameters considered, the structure requires repair and retrofitting. For the study, we have considered G+3 Storey commercial building with a basement. Non-Destructive and Chemical Test. The Rebound hammer, Ultrasonic Pulse Velocity Test, Cover Meter Test, pH Test, Carbonation Test and Chloride Content Test are carried out to understand and analyze the current condition of the structure. The result computed from field and lab test were used as parameters for analyzing the structure in STAAD PRO Software. After assessing, the strengthening scheme for reinforced concrete structural components such as beams, columns and slab is discussed and suggested to increases the service life of structure.

scholarly journals ULTRASONIC PULSE VELOCITY TEST OF REINFORCED CONCRETE WITH INDUCED CORROSION

2017 ◽  
Vol 7 (2) ◽  
pp. 9-17 ◽  
Author(s):  
Jason Maximino Co Ongpeng
Keyword(s):  
Reinforced Concrete ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Reinforcing Bars ◽  
Accelerated Corrosion ◽  
Steel Bar ◽  
Significant Damage ◽  
Steel Bars ◽  
Reinforced Steel

Non-destructive test has been applied to measure damage in structures. Common structures are assessed with the use of practical and easy application of ultrasonic pulse velocity (UPV). In this paper, the damage brought by corrosion was investigated using Proceq Punditlab having 54 kHz transducers oriented in direct transmission under the UPV. Fifty-four reinforced concrete of size 150 mm x 250 mm x 300 mm with two 10mm diameter reinforcing bars (Grade 40) and one 6mm diameter stainless steel bar (Type 304) was cast and tested. It had varying water cement ratio of 45%, 50%, and 55%with two conditions at day 0 (after curing), day 14, and day 28: non-accelerated condition under air-drying and accelerated condition using impressed current technique (ICT). The UPV test was conducted in each layer where reinforced steel bars were present and absent. It was found out that UPV test results was insignificant to all non-accelerated concrete, while it indicated significant damage for accelerated corrosion rate of more than 8 mm per year. In accelerated condition, the decrease in strength under UPV test was more than 20% for all specimens along the reinforced bars, and less than 15% for all specimens along the layer with no steel bars. This showed that the effect of corrosion greatly affects the entirety of structures near and far from the placement of reinforcing steel bars.

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