In-Situ Verification of Rehabilitation and Repair of Reinforced Concrete Bridge Bents under Simulated Seismic Loads

2001 ◽  
Vol 17 (3) ◽  
pp. 507-530 ◽  
Author(s):  
Chris P. Pantelides ◽  
Janos Gergely ◽  
Lawrence D. Reaveley
Keyword(s):  
Reinforced Concrete ◽  
High Strength ◽  
In Situ Tests ◽  
Shear Strengthening ◽  
Displacement Ductility ◽  
Frp Composites ◽  
Frp Composite ◽  
Pile Cap ◽  
Bridge Bents

Three in-situ tests were performed on two bents of a reinforced concrete (RC) bridge under quasi-static cyclic loads. The bridge was built in 1963 and did not possess the necessary reinforcement details for ductile performance. The tests included an as-built bent, a bent rehabilitated with carbon fiber reinforced polymer (FRP) composite jackets, and a damaged bent repaired with epoxy injection and carbon FRP composite jackets. Two new concepts of strengthening bridge bents with FRP composites were implemented in this study. The first involves shear strengthening and confinement of a beam cap-column joint through an FRP composite “ankle-wrap.” The second is an FRP composite “U-strap” to improve the anchorage of column longitudinal steel reinforcement extending into the joint. FRP composite jackets were also implemented in the columns and beam cap. An additional rehabilitation measure was that of anchorage of the piles to the pile cap using epoxied high strength steel bars. The performance of the bent in the as-built condition and that of the rehabilitated and repaired bents is described in terms of strength, stiffness, displacement ductility, and energy dissipation.

Elimination of Debonging of FRP Strips in Shear Strengthened Beams Using Grooving Method

2011 ◽  
Vol 250-253 ◽  
pp. 1077-1081 ◽  
Author(s):  
Davood Mostofinejad ◽  
Amirhomayoon Tabatabaei Kashani
Keyword(s):  
Reinforced Concrete ◽  
Experimental Studies ◽  
High Strength ◽  
Concrete Surface ◽  
Reinforced Concrete Beams ◽  
Small Scale ◽  
Shear Strengthening ◽  
Flexural Strengthening ◽  
Frp Composites ◽  
Frp Strips

One of the methods of retrofitting reinforced concrete structures is use of FRP sheets to increase the flexural and shear strength of concrete elements. Use of FRP materials is in rapid progress because of their high strength, light weight and easy installation of FRP composites. Poisson’s ratio mismatch between FRP sheets and concrete is resulted premature debonding of FRP strips. Hence, the use of ultimate strength of FRP sheets is difficult if EB (External bonded) is applied in installation of FRP. Therefore, debonding has been repeatedly reported in most experimental studies. Recent studies in Isfahan University of Technology (IUT) show that use of grooving method (GM) to attach the FRP sheet to concrete surface for flexural strengthening is much more effective compared to conventional methods. In present experimental study, small scale reinforced concrete beams were strengthened with FRP strips for shear. Comparison between the ultimate load and deflection of the test beams demonstrates that grooving method was effective and led to elimination of debonding of FRP strips used for shear strengthening.

scholarly journals Digital Image Correlation for Evaluation of Cracks in Reinforced Concrete Bridge Slabs

2021 ◽  
Vol 6 (7) ◽  
pp. 99
Author(s):  
Christian Overgaard Christensen ◽  
Jacob Wittrup Schmidt ◽  
Philip Skov Halding ◽  
Medha Kapoor ◽  
Per Goltermann
Keyword(s):  
Reinforced Concrete ◽  
Digital Image Correlation ◽  
Crack Initiation ◽  
Laboratory Test ◽  
Digital Image ◽  
Crack Detection ◽  
Image Correlation ◽  
In Situ Tests ◽  
Stop Criterion

In proof-loading of concrete slab bridges, advanced monitoring methods are required for identification of stop criteria. In this study, Two-Dimensional Digital Image Correlation (2D DIC) is investigated as one of the governing measurement methods for crack detection and evaluation. The investigations are deemed to provide valuable information about DIC capabilities under different environmental conditions and to evaluate the capabilities in relation to stop criterion verifications. Three Overturned T-beam (OT) Reinforced Concrete (RC) slabs are used for the assessment. Of these, two are in situ strips (0.55 × 3.6 × 9.0 m) cut from a full-scale OT-slab bridge with a span of 9 m and one is a downscaled slab tested under laboratory conditions (0.37 × 1.7 × 8.4 m). The 2D DIC results includes full-field plots, investigation of the time of crack detection and monitoring of crack widths. Grey-level transformation was used for the in situ tests to ensure sufficient readability and results comparable to the laboratory test. Crack initiation for the laboratory test (with speckle pattern) and in situ tests (plain concrete surface) were detected at intervals of approximately 0.1 mm to 0.3 mm and 0.2 mm to 0.3 mm, respectively. Consequently, the paper evaluates a more qualitative approach to DIC test results, where crack indications and crack detection can be used as a stop criterion. It was furthermore identified that crack initiation was reached at high load levels, implying the importance of a target load.

Seismic Performance of High Titanium Heavy Slag High Strength Concrete Columns

2012 ◽  
Vol 174-177 ◽  
pp. 455-459 ◽  
Author(s):  
Xiao Wei Li ◽  
Xue Wei Li ◽  
Xin Yuan
Keyword(s):  
Reinforced Concrete ◽  
Seismic Performance ◽  
High Strength Concrete ◽  
Load Ratio ◽  
High Strength ◽  
Scale Model ◽  
Transverse Reinforcement ◽  
Reinforced Concrete Column ◽  
Displacement Ductility ◽  
Strength Concrete

For expedite the development of high titanium heavy slag concrete, eight high titanium heavy slag high strength reinforced concrete (HTHS-HSRC) scale model column are studied. The eight HTHS-HSRC model columns are tested under reversed horizontal force. Primary experimental parameters include axial load ratio varying from 0.3 to 0.5, volumetric ratios of transverse reinforcement ranging from 1.38% to 1.56%, strength of high titanium heavy slag high strength concrete varying from 55.9 to 61.6 N/mm2 and configurations of transverse reinforcement. It is found from the test result that HTHS-HSRC model columns provides comparable seismic performance to those usually used reinforced concrete column in terms of member ductility, hysteretic and energy dissipation capacity. Primary Factors of Displacement Ductility of Model Columns are also discussed.

Current Situation and Prospect of the Application of FRP in Material Engineering

2014 ◽  
Vol 898 ◽  
pp. 375-377
Author(s):  
Xiao Lin Dong
Keyword(s):  
Composite Material ◽  
Fatigue Resistance ◽  
Civil Engineering ◽  
Temperature Stability ◽  
High Strength ◽  
Current Situation ◽  
Light Weight ◽  
Wood Structure ◽  
Frp Composites ◽  
Frp Composite

The FRP composite material can replace the traditional under certain conditions, the wood structure of steel and reinforced materials, with high strength, light weight, resistance to corrosion and fatigue resistance, temperature stability and good special, because by civil engineeringcircles. This paper introduces the characteristics of FRP composites, the application of FRP composites in civil engineering are discussed, finally, the prospect of FRP materials are introduced.

Seismic Strengthening of Reinforced-Concrete Multicolumn Bridge Piers

2007 ◽  
Vol 23 (3) ◽  
pp. 635-664 ◽  
Author(s):  
Chris P. Pantelides ◽  
Jeffrey B. Duffin ◽  
Lawrence D. Reaveley
Keyword(s):  
Reinforced Concrete ◽  
Bridge Pier ◽  
Fiber Reinforced Polymer ◽  
Bridge Piers ◽  
Seismic Rehabilitation ◽  
Frp Composite ◽  
Reinforced Polymer ◽  
Pile Caps ◽  
Rehabilitation Measures

The analysis, seismic rehabilitation measures, and in-situ performance of a reinforced-concrete (RC) bridge pier subjected to quasi-static loads are presented. The bridge was built in 1963 and was designed for gravity and wind but not seismic loads. The reinforcement details are compared with AASHTO requirements for seismic zones 3 and 4. The bridge pier was rehabilitated with steel dowels connecting the piles to the pile caps and RC grade beam connecting the three pile caps; carbon Fiber-Reinforced-Polymer (FRP) composite jackets were used to rehabilitate the columns, cap beam, and T-joints. An analytical model is presented that includes the effects of soil-pile-structure interaction and the seismic rehabilitation measures. Critical events in the experimental performance of the bridge pier are identified. Comparisons are made between the pier's performance and that of other piers tested in situ at the same site that were rehabilitated with incremental measures.

INTERFACIAL AND TENSILE PROPERTIES OF HYBRID FRP COMPOSITES USING DNN STRUCTURE WITH OPTIMIZATION MODEL

2019 ◽  
Vol 27 (02) ◽  
pp. 1950099 ◽  
Author(s):  
AHMED ABDUL BASEER ◽  
D. V. RAVI SHANKAR ◽  
M. MANZOOR HUSSAIN
Keyword(s):  
Tensile Properties ◽  
Natural Fiber ◽  
Hybrid Composites ◽  
Research Work ◽  
Composite Plates ◽  
High Strength ◽  
Fiber Reinforced ◽  
Reinforced Concrete Structure ◽  
Shear Strengthening ◽  
Frp Composites

Fiber reinforced polymer (FRP) composites are appealing for use in structural building applications because of their high strength-to-weight and stiffness-to-weight proportions, corrosion resistance, lightweight, possibly high durability, along with free design characteristics. The aim of this research work was to develop high strength natural fiber-based composite plates for the possible application in the shear strengthening of the reinforced concrete structure. In the experimental modeling, the composites were fabricated using glass, flax and kenaf fibers in treated and untreated conditions. This paper studied and analyzed the interfacial and tensile properties of fiber reinforced hybrid composites such as flax/glass and kenaf/glass by using the simulation approach, i.e. Deep Neural Network (DNN) with weight optimization. For optimizing the weights in DNN, Oppositional based FireFly Optimization (OFFO) is proposed. All the optimal results exhibit in the way that the accomplished error values between the output of the experimental values and the predicted qualities are firmly equivalent to zero in the designed system.

Contribution à l'étude du renforcement en cisaillement des poutres en béton armé à l'aide de matériaux composites avancés

2005 ◽  
Vol 32 (2) ◽  
pp. 339-351 ◽  
Author(s):  
Abdelhak Bousselham ◽  
Omar Chaallal
Keyword(s):  
Experimental Investigation ◽  
Resistance Mechanism ◽  
Steel Reinforcement ◽  
Rc Beams ◽  
Shear Strengthening ◽  
Frp Composites ◽  
Frp Composite ◽  
Fibre Reinforced Polymer ◽  
The Subject ◽  
Transverse Steel

This paper presents results of an investigation on the shear strengthening of reinforced concrete (RC) beams with externally applied fibre reinforced polymer (FRP) composites. The first part of the study reviews and synthesizes the state of the art in the subject. Also, the requirements and recommendations specified in the Canadian CSA S806-02 standards, the American ACI-440 guidelines, as well as the European fib TG9.3 recommendations are compared with the test results reported in the literature so far. This part of the study indicates that the major parameters involved in the behaviour of RC beams strengthened in shear with FRP were not fully investigated. This can explain the observed discrepancies between the resistance values predicted by the codes and guidelines, and those obtained by tests. This has been the main impetus to carry out an experimental investigation, which is the subject of the second part of this paper. The objective of this experimental investigation was to study the influence of the following parameters on the performance of RC beams strengthened in shear with FRP composites: (i) the FRP ratio, (ii) the transverse steel reinforcement ratio, and (iii) the type of beam (deep versus slender). Results clearly showed the interaction between the FRP composite and the internal transverse steel reinforcement in the shear resistance mechanism. Results also showed the influence of the type of beam on the gain due to FRP on the carrying capacity of the beam.Key words: shear, reinforcement, concrete, composites, experimental, parameters.

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