scholarly journals Developing a modern thermal strengthening technique for regulated fishplate cooling

2014 ◽  
Author(s):  
Y. G. Yaroshenko ◽  
Y. I. Lipunov ◽  
M. V. Startseva ◽  
K. Y. Eysmondt ◽  
E. V. Nekrasova ◽  
...  
Keyword(s):  
Strengthening Technique

scholarly journals Experimental Characterization of the FRCM-Concrete Interface Bond Behavior Assisted by Digital Image Correlation

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1154
Author(s):  
Dario De Domenico ◽  
Antonino Quattrocchi ◽  
Damiano Alizzio ◽  
Roberto Montanini ◽  
Santi Urso ◽  
...  
Keyword(s):  
Digital Image Correlation ◽  
Digital Image ◽  
Mechanical Tests ◽  
Image Correlation ◽  
Front Face ◽  
Full Field ◽  
Bond Behavior ◽  
Externally Bonded ◽  
Strengthening Technique ◽  
Concrete Interface

Digital Image Correlation (DIC) provides measurements without disturbing the specimen, which is a major advantage over contact methods. Additionally, DIC techniques provide full-field maps of response quantities like strains and displacements, unlike traditional methods that are limited to a local investigation. In this work, an experimental application of DIC is presented to investigate a problem of relevant interest in the civil engineering field, namely the interface behavior between externally bonded fabric reinforced cementitious mortar (FRCM) sheets and concrete substrate. This represents a widespread strengthening technique of existing reinforced concrete structures, but its effectiveness is strongly related to the bond behavior between composite fabric and underlying concrete. To investigate this phenomenon, a set of notched concrete beams are realized, reinforced with FRCM sheets on the bottom face, subsequently cured in different environmental conditions (humidity and temperature) and finally tested up to failure under three-point bending. Mechanical tests are carried out vis-à-vis DIC measurements using two distinct cameras simultaneously, one focused on the concrete front face and another focused on the FRCM-concrete interface. This experimental setup makes it possible to interpret the mechanical behavior and failure mode of the specimens not only from a traditional macroscopic viewpoint but also under a local perspective concerning the evolution of the strain distribution at the FRCM-concrete interface obtained by DIC in the pre- and postcracking phase.

Enhancement of flexural performance of RC beams with steel wire rope by external strengthening technique

2021 ◽  
pp. 1-11
Author(s):  
Yanuar Haryanto ◽  
Ay Lie Han ◽  
Hsuan-Teh Hu ◽  
Fu-Pei Hsiao ◽  
Banu Ardi Hidayat ◽  
...  
Keyword(s):  
Steel Wire ◽  
Wire Rope ◽  
Rc Beams ◽  
Flexural Performance ◽  
External Strengthening ◽  
Strengthening Technique

scholarly journals Using internal in-plane k-shape steel bracing as a simple strengthening technique for RC box beams failed in torsion

2021 ◽  
Vol 1076 (1) ◽  
pp. 012092
Author(s):  
Ali Hameed Aziz ◽  
Muhammad Hussein Abdallah
Keyword(s):  
Steel Bracing ◽  
Box Beams ◽  
Strengthening Technique

scholarly journals Investigation of a New Strengthening Technique for RC Deep Beams Using Carbon FRP Ropes as Transverse Reinforcements

Fibers ◽  
2018 ◽  
Vol 6 (3) ◽  
pp. 52 ◽  
Author(s):  
Constantin Chalioris ◽  
Parthena-Maria Kosmidou ◽  
Nikos Papadopoulos
Keyword(s):  
Shear Failure ◽  
Structural Behaviour ◽  
Deep Beams ◽  
Near Surface ◽  
Lap Splices ◽  
Rectangular Beam ◽  
Rc Deep Beams ◽  
Carbon Fibre Reinforced Polymer ◽  
Strengthening Technique ◽  
The Web

The effectiveness of a new retrofitting technique to upgrade the structural behaviour of reinforced concrete (RC) deep beams without steel stirrups using carbon fibre-reinforced polymer (CFRP) ropes as the only transverse shear reinforcement is experimentally investigated. Five shear-critical beams with rectangular and T-shaped cross-section are tested under monotonic loading. The strengthening schemes include (a) one vertical and one diagonal single-link CFRP rope that are internally applied through the web of the rectangular beam using an embedded through-section (ETS) system and (b) two vertical U-shaped double-link ropes that are applied around the perimeter of the web of the flanged beam using a near-surface-mounted (NSM) system. In both cases, the free lengths of the CFRP ropes have been properly anchored using epoxy bonded lap splices of the rope as NSM at (a) the top and the bottom of the web of the rectangular beam and (b) the top of the slab of the T-beam. Promising results have been derived, since the proposed strengthening technique enhanced the strength and altered the brittle shear failure to a ductile flexural one. The experimental results of this study were also used to check the validity of an analytical approach to predict the strength of shear strengthened deep beams using FRP ropes as transverse link reinforcement.

scholarly journals Strengthening technique on firestop system of valve hall for existing UHVDC converter stations

2020 ◽  
Vol 461 ◽  
pp. 012036
Author(s):  
Bo Zhong ◽  
Chang-Zheng Zhao ◽  
Ze-Jiang Zhang ◽  
Ya-Qiang Jiang ◽  
Jia-Qing Zhang ◽  
...  
Keyword(s):  
Strengthening Technique

scholarly journals Flexural Behavior of Fire-Damaged Prefabricated RC Hollow Slabs Strengthened with CFRP versus TRM

Materials ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2556
Author(s):  
Zheng-Ang Sui ◽  
Kun Dong ◽  
Jitong Jiang ◽  
Shutong Yang ◽  
Kexu Hu
Keyword(s):  
Failure Modes ◽  
Early Stage ◽  
Load Capacity ◽  
Peak Load ◽  
Flexural Behavior ◽  
Masonry Building ◽  
Fire Exposure ◽  
Standard Fire ◽  
Four Point Bending ◽  
Strengthening Technique

In this paper, carbon fiber reinforced polymer (CFRP) and textile reinforced mortar (TRM) strengthening techniques were proposed to retrofit and strengthen fire-damaged prefabricated concrete hollow slabs. A total of six slabs, from an actual multi-story masonry building, were tested to investigate the flexural performance of reinforced concrete (RC) hollow slabs strengthened with TRM and CFRP. The investigated parameters included the strengthening method (CFRP versus TRM), the number of CFRP layers, and with or without fire exposure. One unstrengthened slab and one TRM strengthened slab served as the control specimens without fire exposure. The remaining four slabs were first exposed to ISO-834 standard fire for 1 h, and then three of them were strengthened with CFRP or TRM. Through the four-point bending tests at ambient temperature, the failure modes, load and deformation response were recorded and discussed. Both CFRP and TRM strengthening methods can significantly increase the cracking load and peak load of the fire-damaged hollow slabs, as well as the stiffness in the early stage. The prefabricated hollow slabs strengthened by CFRP have better performance in the ultimate bearing capacity, but the ductility reduced with the increase of CFRP layers. Meanwhile, the TRM strengthening technique is a suitable method for the performance improvement of fire-damaged hollow slabs, in terms of not only the load capacity, especially the cracking load, but also the flexural stiffness and deformation capacity.

scholarly journals Effects of Defects on Bond Behavior of Fiber Reinforced Cementitious Matrix Materials

Materials ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 164 ◽  
Author(s):  
Antonio Bilotta ◽  
Gian Piero Lignola
Keyword(s):  
High Strength ◽  
Epoxy Adhesive ◽  
Fiber Reinforced ◽  
Bond Behavior ◽  
The Matrix ◽  
Low Sensitivity ◽  
Strengthening Technique ◽  
Geometrical Defects ◽  
Bond Tests

High-strength fibers embedded in inorganic matrix i.e., Fiber Reinforced Cementitious Mortar materials (FRCM) are commonly used as strengthening technique for existing masonry structures, due to the low sensitivity to debonding phenomena between substrate and matrix. Nevertheless, the use of lime or cement-based matrix instead of epoxy adhesive implies that attention has to be paid to the bond behavior between the fibers and the matrix, since sliding phenomena and cohesive failures in the mortar matrix can occur. The paper aims to investigate the effect of the mechanical properties of fiber and matrix on the FRCM efficiency, and potential geometrical defects, typical of real applications. The aim is to analyze the mechanical behavior of the FRCM system by simulating hypothetical bond tests, as they are usually performed in laboratories. The bond test has a significant role, as it is used for the qualification of the material, providing sometimes very scattered results. Hence, it is particularly important and greatly discussed in the scientific community and among manufactures and practitioners. The purpose is to understand where this variability could derive from and possibly how to contain it, to improve the characterization of FRCM systems. A mechanical model has been proposed to simulate the usual bond test to focus and stress the way in which each fiber slips out of the matrix as the load increases; and this has been recognized as the main reason for scattered results in bond tests. The model was then applied to the typical cases of PBO-FRCM and Glass-FRCM, hence considering different ratios for the fiber and matrix properties.

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