scholarly journals NONDESTRUCTIVE EVALUATION OF CORROSIO IN REINFORCED CONCRETE BY THERMAL BEHAVIOR ON CONCRETE SURFACE DUE TO ELECTRO-MAGNETIC HEATING

2009 ◽  
Vol 65 (1) ◽  
pp. 76-92 ◽  
Author(s):  
Hideki OSHITA ◽  
Hiroaki HORIE ◽  
Shingo NAGASAKA ◽  
Osamu TANIGUCHI ◽  
Shinjiro YOSHIKAWA
Keyword(s):  
Reinforced Concrete ◽  
Thermal Behavior ◽  
Nondestructive Evaluation ◽  
Concrete Surface ◽  
Magnetic Heating ◽  
Electro Magnetic

scholarly journals Study of the reinforcement of structure members by polypropylene fibres waste

2018 ◽  
Vol 149 ◽  
pp. 01022 ◽  
Author(s):  
Khadra Bendjillali ◽  
Mohamed Chemrouk
Keyword(s):  
Reinforced Concrete ◽  
Significant Contribution ◽  
Concrete Beams ◽  
Average Diameter ◽  
Concrete Surface ◽  
Point Of View ◽  
Reinforced Concrete Beams ◽  
Polypropylene Fibres ◽  
Steel Bars ◽  
Material Durability

The valorisation of industrial waste in the field of construction became a very interesting axis of research from scientific, economic and environmental point of view. We have conducted this work to study the effect of the addition of polypropylene fibres waste on the mechanical behaviour of reinforced concrete beams subjected to a simple flexural loading, with and without transversal reinforcement. The used fibres are coming from the waste of the fabrication of domestic brushes and sweeps; they have an average diameter of 0.47 mm and a length between 40 and 60 mm. Two weight dosages of fibres are used, 0.25 and 0.5 %. The experimental results showed that the incorporation of polypropylene fibres waste into the concrete affects negatively its workability, but its flexural and compressive strength are improved. The fibers have presented a significant contribution on the shear behavior and the cracking of beams, particularly in absence of transversal bars. The waste used in this work as fibrous reinforcement has not only increased the ductility of reinforced concrete beams, but it have also provided a perfect cracking distribution on the concrete surface and it has participated in a considerable way in the reduction of cracks number and dimensions, which allows to ensure the material durability and then the structure longevity. The reinforcement of concrete beams with 0.5 % of polypropylene fibers waste with a minimal steel bars can ensure an excellent mechanical behavior in shear, as in flexion.

scholarly journals Damage Source Identification of Reinforced Concrete Structure Using Acoustic Emission Technique

2013 ◽  
Vol 2013 ◽  
pp. 1-5
Author(s):  
Alireza Panjsetooni ◽  
Norazura Muhamad Bunnori ◽  
Amir Hossein Vakili
Keyword(s):  
Acoustic Emission ◽  
Reinforced Concrete ◽  
Nondestructive Evaluation ◽  
Analysis Method ◽  
Reinforced Concrete Structure ◽  
Acoustic Emission Technique ◽  
Rc Structures ◽  
Rc Frames ◽  
Damage Monitoring ◽  
Investigation Process

Acoustic emission (AE) technique is one of the nondestructive evaluation (NDE) techniques that have been considered as the prime candidate for structural health and damage monitoring in loaded structures. This technique was employed for investigation process of damage in reinforced concrete (RC) frame specimens. A number of reinforced concrete RC frames were tested under loading cycle and were simultaneously monitored using AE. The AE test data were analyzed using the AE source location analysis method. The results showed that AE technique is suitable to identify the sources location of damage in RC structures.

The Reinforced Concrete Durability and Rebar Erosion Monitoring

2012 ◽  
Vol 446-449 ◽  
pp. 3252-3258
Author(s):  
Jin Yang Zhang ◽  
De Mi Cui ◽  
Lie Min Lv ◽  
Zhi Yang
Keyword(s):  
Reinforced Concrete ◽  
Service Life ◽  
Protective Layer ◽  
Concrete Surface ◽  
Monitor System ◽  
Concrete Durability ◽  
Information Feedback ◽  
Starting Time ◽  
Cast Concrete

On the basis of the advantages of low construction cost, remarkable dynamics property, easy cast moulding and more controllable construction, the reinforced concrete construct are widely applied in buildings and main structures of constructions in China. However, the reinforced concrete is found more or less aging after many years’ utilization and erosion from the environment, which will lead to a hidden risk to affect its functions. After technical development for decades, the concrete can assure its durability under normal situation, yet the function would be deteriorated due to the erosion from the complex and harsh environment to make it hardly reach its designed service life. With the assist of CorroWatch erosion monitor system, the concrete structures’ erosion can kept watched on to obtain the depassivation development and information feedback of some key data dynamically and in long term so as to foresee precisely the erosion starting time. The newly cast concrete depassivation frontline is located on concrete surface and will tend to go through the protective layer and penetrate towards rebar as time goes on. Its structure service life can be enhanced with the re-designed durability in terms of the mentioned characters and do well the erosion proof measures.

scholarly journals Analysis of the behavior of reinforced concrete columns strengthened with sleeve wedge bolts and a self compacting concrete layer

2015 ◽  
Vol 8 (2) ◽  
pp. 88-99
Author(s):  
M. G. Marques ◽  
A. P. A. R. Liserre ◽  
R. B. Gomes ◽  
G. N. Guimarães
Keyword(s):  
Reinforced Concrete ◽  
Cross Section ◽  
Rectangular Cross Section ◽  
Concrete Columns ◽  
Concrete Surface ◽  
Self Compacting Concrete ◽  
Reinforced Concrete Columns ◽  
Concrete Layer ◽  
Strength Capacity ◽  
Strengthening Technique

Strengthening of reinforced concrete columns by jacketing is one of the most common structural rehabilitation techniques in Brazil. For adequate performance, it is necessary, among others, to avoid detachment of the new concrete layer (strengthening material) from the old concrete substrate when the strengthened member is again in service conditions. This paper describes the test results of eight reinforced concrete rectangular columns subjected to combined compression and one-axis bending to evaluate the efficiency of using sleeve wedge bolts across the new concrete/old concrete interface to avoid detachment. The strengthening technique, in this case, consists of adding a layer of self-compacting concrete to one face of the column. Two columns tested were monolithic and named PO (original column) e PR (reference column). The other six columns were strengthened using a new 35 mm thick self-compacting concrete layer attached to the column face subjected to highest compressive stresses. Column PO had a 120mm by 250 mm rectangular cross section and its results gave information about column behavior without the use of strengthening. Column PR had a 155mm by 250 mm rectangular cross section and its cross section dimensions matched the strengthened columns but it was cast monolithically. To improve bond conditions between the existing concrete and the new concrete, the concrete surface was roughened and the outermost aggregate was exposed using hydro jetting. Holes along the concrete surface were made to insert the wedge bolts responsible for increasing the bond between the two concrete surfaces. The difference among the six strengthened columns was the position and amount of bolts used. Results indicate that the position and amount of the bolts alters significantly the strength capacity of the columns, since premature rupture by concrete detachment was delayed.

Investigation the influence of spacer yarns orientation angle on the thermal behavior of 3D textile reinforced concrete (TRC)

2021 ◽  
pp. 095440622110473
Author(s):  
Sayyed Behzad Abdellahi ◽  
Sayyed Mahdi Hejazi ◽  
Hossein Hasani
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Finite Element ◽  
Reinforced Concrete ◽  
Thermal Behavior ◽  
Three Dimensional ◽  
Orientation Angle ◽  
Element Model ◽  
Textile Reinforced Concrete ◽  
Cementitious Matrix

Thermal behavior such as heat transfer is an important parameter for construction composites. Three-dimensional textile reinforced concrete (TRC) is one of the construction composites which is recently being used in the building industry. Therefore, in this study, the thermal behavior of three different TRC samples was investigated by a heat transfer test using an infrared method. The cementitious matrix was reinforced by 3D fabric with three different spacer yarn orientation angles. The cementitious matrix was fabricated by cement and waste stone powder. The TRC sample was put on the hot plate of the heat transfer apparatus and the temperature variations of the top surface of the sample were obtained. According to the test results, increasing the orientation angle of spacer yarns leads to a decrease in the thermal conductivity of the TRC sample and reduces heat transfer. On the other hand, a theoretical model was used to calculate the thermal conductivity and resistance coefficients of sandwich samples. Furthermore, a 3D finite element model was used to predict the heat transfer of TRC specimens. A unit cell of the TRC model was created in Abaqus software and finite element (FE) analysis was carried on a created model. Thermal conductivity and thermal resistance of samples according to FE results were calculated and compared with experimental results. FE results showed good agreement with the experimental data.

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