scholarly journals Experimental and Analytical Study on Torsional Behaviour Of RC Flanged Beams Strengthened With Glass FRP

2019 ◽  
pp. 361-368
Author(s):  
K. Gowthami ◽  
D. Mohammed Rafi ◽  
K. Mohammed Rasheed
Keyword(s):  
Cross Sections ◽  
Construction Materials ◽  
High Strength ◽  
Reinforced Concrete Beams ◽  
Seismic Retrofitting ◽  
Analytical Models ◽  
Experimental Result ◽  
Existing Structures ◽  
Torsional Behavior ◽  
T Beam

Environmental degradation, increased service loads, reduced capacity due to aging, degradation owing to poor construction materials and workmanships and conditional need for seismic retrofitting have demanded the necessity for repair and rehabilitation of existing structures. Fibre reinforced polymers has been used successfully in many such applications for reasons like low weight, high strength and durability. Many previous research works on torsional strengthening were focused on solid rectangular RC beams with different strip layouts and different types of fibres. Various analytical models were developed to predict torsional behavior of strengthened rectangular beams and successfully used for validation of the experimental works. But literature on torsional strengthening of RC T- beam is limited. In the present work experimental study was conducted in order to have a better understanding the behavior of torsional strengthening of solid RC flanged T-beams. An RC T-beam is analyzed and designed for torsion like an RC rectangular beam; the effect of concrete on flange is neglected by codes. In the present study effect of flange part in resisting torsion is studied by changing flange width of controlled beams_ The other parameters studied are strengthening configurations and fiber orientations. The objective of present study is to evaluate the effectiveness of the use of epoxy-bonded GFRP fabrics as external transverse reinforced to reinforced concrete beams with flanged cross sections (T-beam) subjected to torsion. Torsional results from strengthened beams are compared with the experimental result of the control beams without FRP application. The study shows remarkable improvement in torsional behavior of all the GFRP strengthen beams. The experimentally obtained results are validated with analytical model presented by A.Deifalla and A. Ghobarah and found in good agreement.

scholarly journals Pilot Demonstration of a Strengthening Method for Steel-Bolted Connections Using Pre-Formable Carbon Fiber Cloth with VaRTM

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2184
Author(s):  
Takahiro Matsui ◽  
Kohei Suzuki ◽  
Sota Sato ◽  
Yuki Kubokawa ◽  
Daiki Nakamoto ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Carbon Fiber ◽  
Axial Stress ◽  
Steel Structures ◽  
High Strength ◽  
Seismic Retrofitting ◽  
Gusset Plates ◽  
Stepped Surfaces ◽  
Existing Structures ◽  
Stepped Surface

In recent years, many seismic retrofitting methods have been performed to improve the structural performance and prevent the brittle failure of structural members. In the case of steel structures, slender seismic braces have been widely used for buildings, towers, and bridges. The brace connections should resist the full plastic axial tension load to ensure adequate plastic deformation performance for vibration energy absorption. However, certain connections do not satisfy these requirements. Recently, carbon fiber reinforced plastic (CFRP) has been used extensively to strengthen existing structures because of its high-strength, high elastic modulus, and light-weight characteristics. In this paper, we investigate the applicability of CFRP strengthening for brace connections and gusset plates with stepped surfaces using the vacuum-assisted resin transfer molding technique as a pilot demonstration. Stepped surfaces can be eliminated by using alternative CFRP layers to straighten the structural CFRP layers in order to effectively transfer the axial stress. Eventually, it is shown that CFRP strengthening can improve the connection strength and plastic deformation with 3% elongation, even if the CFRP is molded on the stepped surface.

Laboratory tests on strengthening steel and concrete elements with high-strength concrete

2021 ◽  
Author(s):  
Marina Traykova ◽  
Lazar Georgiev ◽  
Emad Abdulahad ◽  
Stoyan Ivanov
Keyword(s):  
High Strength Concrete ◽  
Laboratory Tests ◽  
High Strength ◽  
Reinforced Concrete Beams ◽  
Strength Concrete ◽  
Existing Structures ◽  
Additional Layer ◽  
Orthotropic Bridge Deck ◽  
Strengthening Technique ◽  
The University

<p>In the University of Architecture, Civil Engineering and Geodesy in Sofia a research project has started in 2018 aiming to investigate the possibilities of local production and application of high- strength concrete (or even UHPFRC) for strengthening existing structures in Bulgaria. Under this project laboratory tests of steel orthotropic bridge deck specimens as well as reinforced concrete beams, strengthened with high-strength concrete are performed. All elements are strengthened with an additional layer of high-strength concrete with thickness of 50mm on top.</p><p>The results obtained from the tests are summarized in this article. Comparative analysis showing the effect of this strengthening method is also presented. At the end summary and conclusions are drawn. Future steps for enhancing and promoting this strengthening technique in Bulgaria are outlined.</p>

scholarly journals Results of experimental studies of high-strength fiber reinforced concrete beams with round cross-sections under combined bending and torsion

2020 ◽  
Vol 16 (4) ◽  
pp. 290-297
Author(s):  
Vladimir I. Travush ◽  
Nikolay I. Karpenko ◽  
Vladimir I. Kolchunov ◽  
Semen S. Kaprielov ◽  
Alexey I. Demyanov ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Cross Sections ◽  
Concrete Beams ◽  
High Strength ◽  
Fiber Reinforced Concrete ◽  
Reinforced Concrete Beams ◽  
Reinforced Concrete Structures ◽  
Fiber Reinforced ◽  
High Strength Fiber ◽  
Round Cross

The aim of the work - experimental investigation on crack propagation and deformation in high-strength fiber reinforced concrete beams with round cross-sections under combined bending and torsion for the development of practical methods of crack resistance, deformation and strength analysis of such structures, and also for the accumulation of new experimental data on resistance under combined loading. Method is experimental-theoretical. Results. Deflection plots and force-deformation relationships for high-strength fiber reinforced concrete beams with round cross-sections under combined bending and torsion are determined experimentally. Principal deformations in terms of elongation and compression of concrete for the experimental beam structures with high torsion to bending moment ratio are determined. It is established that for high-strength fiber reinforced concrete structures of circular cross-section, generally, development of one-two discrete cracks is observed, therefore the circular shape of the cross-section slightly reduces the concentration defined by the material structure of high-strength concrete. On the basis of the conducted investigation on high-strength fiber reinforced concrete structures with circular sections, new experimental data on the combined stress-strain state in the studied areas of resistance is obtained, such as: values of generalized cracking, and failure, load, its level relative to the ultimate load; distance between the cracks at different stages of crack propagation; crack widths at principal reinforcement axis level, at a double diameter distance from the principal rebar axes and also along the entire crack profile at various stages of loading; coordinates of nonplanar crack formations; patterns of crack formation, development and opening in reinforced concrete structures under combined bending and torsion.

scholarly journals Effectivenes of Strengthening Loaded RC Beams with FRCM System

2018 ◽  
Vol 64 (3) ◽  
pp. 3-13 ◽  
Author(s):  
Z. Blikharskyy ◽  
K. Brózda ◽  
J. Selejdak
Keyword(s):  
Composite Materials ◽  
Concrete Beams ◽  
High Strength ◽  
Reinforced Concrete Beams ◽  
Fiber Reinforced Polymers ◽  
Rc Beams ◽  
Aramid Fibers ◽  
Reinforced Polymers ◽  
Existing Structures ◽  
Synthetic Matrix

AbstractThe composite materials as FRP (Fiber Reinforced Polymers), which are characterized by benefits resulting from the combination of high strength reinforcement (as carbon, glass, steel or aramid fibers) with synthetic matrix are increasingly used to reinforce existing structures. Reinforcing System as FRCM (Fibre Reinforced Cementitious Matrix), which includes, among others, Ruredil X Mesh Gold System, is much less commonly used. However, the uniform and practical methods for calculating composite reinforced structures are not determined. Especially when considering the real conditions of structure exploitation, which requires further research in this field. In the paper the initial loading level influence on the efficiency of reinforced concrete beams strengthen using system Ruredil X Mesh Gold was investigated.

Torsional Behavior of Reinforced Concrete Beams with High-Strength Steel Bars

2019 ◽  
Vol 116 (6) ◽  
Author(s):  
Changhyuk Kim ◽  
Seungeun Kim ◽  
Kil-Hee Kim ◽  
DongIk Shin ◽  
Muhammad Haroon ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
High Strength Steel ◽  
Concrete Beams ◽  
High Strength ◽  
Reinforced Concrete Beams ◽  
Steel Bars ◽  
Torsional Behavior

CREDO RADON UA – INFORMATION MODEL FOR CALCULATION OF ROAD CONSTRACTION

2019 ◽  
pp. 34-42
Author(s):  
Volodymyr Karedin ◽  
Nadiya Pavlenko
Keyword(s):  
Design Process ◽  
Static Loading ◽  
Computer Aided Design ◽  
Experimental Studies ◽  
Construction Materials ◽  
Residual Deformation ◽  
Road Construction ◽  
Information Support ◽  
Existing Structures ◽  
Road Pavement

CREDO RADON UA software provides an automated calculation of the strength of the pavement structures of non-rigid and rigid types, as well as the calculation of the strengthening of existing structures. In the article, one can see the main features and functionality of the CREDO RADON UA software, the main points in the calculations according to the new regulations. Information support of the design process includes necessary databases, informational and helping materials that make up the full support of the pavement design process. The concept of CREDO RADON UA 1.0 software is made on the use of elasticity theory methods in calculations of initial information models of pavements. Performing optimization calculations, the roadwear in CREDO RADON UA is designed in such a way that no unacceptable residual deformation occurs under the influence of short-term dynamic or static loading in the working layer of the earth bed and in the structural layers during the lifetime of the structure. The calculation algorithms were made in accordance with the current regulatory documents of Ukraine. CREDO RADON UA software allows user to create information bases on road construction materials and vehicles as part of the traffic flow for calculations. The presented system of automated modeling makes it easier for the customer to control the quality of design solutions, to reasonably assign designs to layers of reinforcement, to quickly make comparisons of calculations of different designs for the optimal use of allocated funds. Prospects for further improvement of the program should be the results of theoretical and experimental studies on filling the databases, which are used as information support for automated design of road structures. Keywords: CREDO RADON UA, road, computer-aided design, repair project, road pavement, strengthening, construction, rigid pavement, elasticity module, a transport stream, calculation method, information support, dynamic or static loading.

Bamboo Waste-based Bio-composite Substance: An application for Low-cost Construction Materials

2020 ◽  
Vol 4 (1) ◽  
pp. 41-48
Author(s):  
Teodoro Astorga Amatosa ◽  
Michael E. Loretero
Keyword(s):  
Composite Materials ◽  
Sea Water ◽  
Raw Materials ◽  
Low Cost ◽  
Construction Materials ◽  
Single Layer ◽  
High Strength ◽  
Green Technology ◽  
Experimental Medium ◽  
Natural Treatment

Bamboo is a lightweight and high-strength raw materials that encouraged researchers to investigate and explore, especially in the field of biocomposite and declared as one of the green-technology on the environment as fully accountable as eco-products. This research was to assess the technical feasibility of making single-layer experimental Medium-Density Particleboard panels from the bamboo waste of a three-year-old (Dendrocalamus asper). Waste materials were performed to produce composite materials using epoxy resin (C21H25C105) from a natural treatment by soaking with an average of pH 7.6 level of sea-water. Three different types of MDP produced, i.e., bamboo waste strip MDP (SMDP), bamboo waste chips MDP (CMDP) and bamboo waste mixed strip-chips MDP (MMDP) by following the same process. The experimental panels tested for their physical-mechanical properties according to the procedures defined by ASTM D1037-12. Conclusively, even the present study shows properties of MDP with higher and comparable to other composite materials; further research must be given better attention as potential substitute to be used as hardwood materials, especially in the production, design, and construction usage.

scholarly journals Study on the Bending and Joint Performances of Reinforced Concrete Beams Using High-Strength Rebars

2021 ◽  
Vol 13 (6) ◽  
pp. 3482
Author(s):  
Seoungho Cho ◽  
Myungkwan Lim ◽  
Changhee Lee
Keyword(s):  
Yield Strength ◽  
High Strength ◽  
Reinforced Concrete Beams ◽  
High Yield ◽  
Performance Tests ◽  
Reinforcing Bars ◽  
Joint Performance ◽  
Lap Splice ◽  
Reinforcing Bar ◽  
Nominal Strength

High-strength reinforcing bars have high yield strengths. It is possible to reduce the number of reinforcing bars placed in a building. Accordingly, as the amount of reinforcement decreases, the spacing of reinforcing bars increases, workability improves, and the construction period shortens. To evaluate the structural performance of high-strength reinforcing bars and the joint performance of high-strength threaded reinforcing bars, flexural performance tests were performed in this study on 12 beam members with the compressive strength of concrete, the yield strength of the tensile reinforcing bars, and the tensile reinforcing bar ratio as variables. The yield strengths of the tensile reinforcement and joint methods were used as variables, and joint performance tests were performed for six beam members. Based on this study, the foundation for using high-strength reinforcing bars with a design standard yield strength equal to 600 MPa was established. Accordingly, mechanical joints of high-strength threaded reinforcing bars (600 and 670 MPa) can be used. All six specimens were destroyed under more than the expected nominal strength. Lap splice caused brittle fractures because it was not reinforced in stirrup. Increases of 21% to 47% in the loads of specimens using a coupler and a lock nut were observed. Shape yield represents destruction—a section must ensure sufficient ductility after yielding. Therefore, a coupler and lock nut are effective.

scholarly journals The zooarchaeological identification of a ‘Morisco’ community after the Christian conquest of Granada (Spain, early 16th century): sociocultural continuities and economic innovations

2021 ◽  
Vol 13 (3) ◽  
Author(s):  
Marcos García-García ◽  
Guillermo García-Contreras ◽  
Michelle M. Alexander ◽  
Rowena Y. Banerjea ◽  
Aleks Pluskowski
Keyword(s):  
Middle Ages ◽  
Distribution Systems ◽  
Construction Materials ◽  
Meat Products ◽  
Early Modern Period ◽  
16Th Century ◽  
Existing Structures ◽  
Production And Distribution ◽  
Surrounding Landscape ◽  
The Middle Ages

AbstractThis article presents the results of the zooarchaeological analysis of an assemblage dating to the second quarter of the 16th century that was discovered on the current university campus of Cartuja, on the outskirts of Granada (Andalusia, Spain). During the Middle Ages, this area was largely used for agricultural purposes, including as estates owned by high officials of the Nasrid dynasty, the last Islamicate polity in the Iberian Peninsula. The Castilian conquest of Granada in 1492 brought significant changes to the area, with the construction of a Carthusian monastery and the transformation of the surrounding landscape, including changes in property structures, different agrarian regimes and the demolition of pre-existing structures. Among these transformations was the filling up of a well with construction materials, and its further use as a rubbish dump. This fill yielded an interesting and unique zooarchaeological assemblage, the study of which is presented here. The results advance our understanding of changing patterns in animal consumption during the formative transition from the Middle Ages to the Early Modern period at the heart of the former Nasrid Kingdom of Granada, and indicate the continuity of some Andalusi consumption patterns along with specialised production and distribution systems of meat products that have no archaeological precedent in the region, suggesting that the bones were dumped by a possible ‘Morisco’ community (autochthonous Muslims forced to convert to Christianity in 1502).

Sign in / Sign up

Export Citation Format

Share Document