LITERATURE WORK STUDY OF PRECAST CONCRETE BEAM -BEAM CONNECTIONS WITH CAST-IN-SITU JOINTS PDF

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LITERATURE WORK STUDY OF PRECAST CONCRETE BEAM - BEAM CONNECTIONS WITH CAST-IN-SITU JOINTS V.Ashokkumar B S Abdur Rahman Crescent Institute of Science & Technology, Chennai, 600048, India, [email protected] Abstract This study was performed as one phase of an extensive research program foc...

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LITERATURE WORK STUDY OF PRECAST CONCRETE BEAM BEAM CONNECTIONS WITH CAST-IN-SITU JOINTS Ashok Kumar

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LITERATURE WORK STUDY OF PRECAST CONCRETE BEAM - BEAM CONNECTIONS WITH CAST-IN-SITU JOINTS V.Ashokkumar B S Abdur Rahman Crescent Institute of Science & Technology, Chennai, 600048, India, [email protected]

Abstract This study was performed as one phase of an extensive research program focusing on the behavior of precast connections and use of precast concrete is known to improve productivity, quality control, and cost efficiency in reinforced concrete structure. The primary objective of the research program was to observe and investigate the behavior of the connection detail and the specimens with improved details, in order to develop a “Shear resisting precast concrete beam-to-beam connection”. In this study, beam–beam connection subassemblies were tested under cyclic loading simulating severe earthquake action. All of the specimens were identical in dimensions. All test specimens were 1/2 scaled models of the improved connection details used in the highly critical earthquake zones. The behavior of the precast members was compared with that of the reference one and with the others. In order to improve the seismic performance of the connection, several recommendations for future research and practices are also given in the context of the paper.

Keywords

Earthquake Cyclic loading Beam-to-beam connection Precast concrete structures

1 INTRODUCTION Precast concrete structural elements (e.g., beams, columns, wall panels, and floor units) are fabricated, transported to construction sites, lifted and assembled in place. Precast concrete structures widely used in some countries with high seismicity. In India, most of the construction utilises cast-in-situ technique. Precast concrete construction is still in its early stage. Generally, precast concrete construction is more preferred for construction of flyovers. As India is a fast developing country, there is a large scope for improvement in the construction sector, especially towards development and utilization of factory made quality controlled precast units that provides for faster construction leading to economy. A large number of studies related to the earthquake-resistant structural system have carried in the United States, New Zealand, Japan and elsewhere. The first part of this study focuses on the development of emulative connections, which aims to ensure that the precast concrete structures would be comparable to equivalent monolithic reinforced concrete structures. The introduction of jointed systems has shifted towards this connection concept and offers betterperforming concrete structures [1]. The main advantages of precast concrete structures are the possible increase in construction speed and improve productivity, quality control, and cost efficiency. Noteworthy is an economical and effective way of combining precast concrete

elements to resist seismic forces, needs to be done with small tolerances, high-quality control, and increased crane capability to lift heavy precast concrete units. Meanwhile a precast concrete element is of a finite size and must therefore connect with other elements to form a complete structure. When two elements are connected, problems such as shrinkage, thermal or load will induced strains and cause volumetric changes. The volumetric changes cause movement between the two elements and internal friction between the two elements surface is provided by using various methods such as inserting dowel between beam to column connection. Apart from that, local crushing at the top of column occurs due to the flexural rotation ofthe beam. Therefore, a bearing pad is provided to overcome this problem. Another factor need to be considered is the narrow bearing of the suspended element on the vertical element. Consideration for the overall stability of the structure is important too. Precast concrete structure refers to the combination of precast concrete elements and the structure is able to sustain vertical and horizontal loads or even dynamic loads. So the design and construction of the joints and connections is important to ensure the stability and robustness of the overall structure. 2. LITERATURE REVIEW 1. Noorhidana, VA and Forth, JP (2016) An Experimental Study on Precast Concrete Beam-to-Column Connection Using Interlocking Bars. In: II International Conference on Concrete Sustainability - ICCS16. ICCS16, 13-15 Jun 2016, Madrid, Spain. International Center for Numerical Methods in Engineering (CIMNE) A new type of precast concrete exterior beam-to-column connection is introduced in this paper. The connection consists of a precast U-beam, precast column with corbel, and interlocking bars to connect the precast column and precast beam; these bars, act as the flexural reinforcement to withstand the hogging and sagging moment subjected during testing. The beam-column joint was designed according to the strong column-weak beam Principle. In this test two specimens are tested . The length of the members was determined by the contra-flexure points resulting from a computer analysis The test setup used in this study is explained as following; both the column ends were restrained by steel plates which were bolted on to the test rig, while the beam end is free , The static-monotonic loading was applied to the first specimen (P1) and to absorb the initial crack, final failure and Deflection at peak load. while a quasistatic loading based on displacement control was applied on the second specimen (P2). Tip deflection and specimen cracking were monitored during the tests. 2. Bindurani, P, A. Meher Prasad, Amlan K. Sengupta, Analysis of Precast Multistoreyed Building - A Case Study, International Journal of Innovative Research in Science, Engineering and Technology (ICEE 2013), 2013: This study presents the modelling of connections in a wall type precast building system. A case study on a 23storeyed building, made up of precast wall panels and slabs, to study the modelling of vertical joints in terms of shear transfer, is presented in the paper. Two computational models were investigated to find the effect of modelling the vertical joints between the wall panels, on the drifts and the generated forces in the walls. It was observed that the model, which was not considering any shear transfer through the vertical joints, tend to provide conservative results in terms of amount of steel requirement. The emulative monolithic wall system seems to be adequate in moderate seismic zones. The provisions of tie reinforcements, reinforced shear keys and dowel bars provide the required structural integrity for the precast system to avoid

progressive collapse. The emulative monolithic wall system seems to be adequate in moderate seismic zones. The provisions of tie reinforcements, reinforced shear keys and dowel bars provide the required structural integrity for the precast system. 3.Can Akogul and Oguz C. Celik, Effect of Elastomeric Bearing Modelling Parameters on the Seismic Design of Highway Bridges with Precast Concrete Girders, The 14th World Conference on Earthquake Engineering, October 12-17, 2008, Beijing, China, 2008: Parameters affecting the seismic design and behavior of reinforced concrete (RC) highway bridges with precast prestressed concrete girders are numerically investigated. Igirders of these bridges are often supported at the ends by elastomeric bearing pads. The bearing pad-bridge girder interface defines support boundary conditions and may affect the seismic performance of the bridge. AASHTO design principles are followed throughout this work. A previously designed and constructed real bridge example (the Akcaova Bridge) which is located on the third earthquake zone in Turkey is considered for the analysis. SAP2000 is used to model the bridge. Although numerical investigations reveal that elastomeric pads may positively affect the seismic response of such bridges, this effect highly depends on geometry of bridge, especially the pier rigidities. Other conclusions include that elastomeric bearings may add extra stiffness to the system when tall and flexible piers are used. Shear forces at pier bases decrease by 50% since the lateral loads are more appropriately shared between the piers and abutments. Elastomeric bearings become more effective in bridges with short and rigid columns. 4. Patrick Tiong Liq Yee, Azlan Bin Adnan, Abdul Karim Mirasa and Ahmad Baharuddin Abdul Rahman , Performance of IBS Precast Concrete Beam-Column Connections Under Earthquake Effects: A Literature Review, American J. of Engineering and Applied Sciences 4 (1): 93-101, 2011, ISSN 1941-7020,2010 Science Publications, 2011: The main objective of this study was to identify the most appropriate type of beam-column connections to be introduced to precast concrete industry, particularly for regions of low to moderate seismicity. Hence, this study presented a comprehensive literature overview of the findings from studies conducted to analyze and investigate the behavior of precast concrete systems assembled with typical connections or joints under simulated earthquake loading. The seismic performance of precast concrete structure very much depended on the ductility capacity of the connectors jointing each precast components, especially at critical joints such as the beam-tocolumn connections. It was learnt from the review that (1) hybrid post-tensioned beam-column connection and (2) Dywidag Ductile Connector were among the most widely used connectors for precast construction in seismic prone regions. Future refinement and research could be carried out in order to optimize these connections to be used in low seismicity regions. Proposed connection type should be practical and well-accepted to avoid further impediment of the precast system. 5. G. Metelli and P. Riva, Behaviour of a Beam to Column “DRY” Joint for Precast Concrete Elements, The 14th World Conference on Earthquake Engineering October 12-17, 2008, Beijing, China, 2008: In Italy, precast concrete structures are traditionally designed as moment resisting frames with plastic hinges occurring at the column base and beams hinged to the columns. A ductile moment resisting connection between the column and the beam can provide the advantage of designing a seismic resisting frame which can develop plastic hinges at the beam-column joints, besides those at the column base. This paper aims at presenting the results of experimental tests concerning the cyclic behaviour of a particular beam column“dry” connection for precast concrete elements. The joint is characterized by the use of high strength steel bars and of a fibre reinforcedgrout pad in the

“Z” shaped beam-column interface, increasing the shear resistance of the connection. The experimental results show a good performance of the joint, in term of resistance, ductility and energy dissipation, with little damage observed in the connected members. The joint is featured by an obvious assembling ease due to the lack of reinforcement across the column of reinforced concrete brackets supporting the beam. Development of the joint detail on the column side is required in order to obtain an effective bar anchorage system allowing the bar yield which should provide the ductility. 6. M. N. KATAOKA, M. A. FERREIRA, A. L. H. C. EL DEBS, A study on the behavior of beam-column connections in precast concrete structures: experimental analysis, Ibracon Structures and Materials Journal, Volume 5, Number 5, 2012: Due to the large increase in the 42 use of precast concrete structures in multistory buildings, this work covers a study on the behavior of beam-column connection with emphasis on the continuity provided by the slab reinforcement. Two prototypes were tested, each one with a different detail of the continuity reinforcement distribution. In both connections, the steel area used on the concrete cover of the hollow core slab was the same, varying the amount of bars that passed through the column and the ones that were placed adjacent to the column. The experimental results showed that the connection with bars adjacent to the column presented stiffness increase and a better cracking control. According to the classification the two tested connections can be considered semi-rigid. Based on this research, with two tests of connections, it was possible to analyze the behavior of the beam-column connection between precast concrete elements which is widely used on sites and also to test an experimental methodology which is not standardized in Brazil. The method used to measure the rotation which employed the transducers placed on the corbels was very satisfactory. 7. M.J.Gopinathan et. High Performance and Efficiency of Joints in Precast Members al International Journal of Engineering and Technology (IJET) ISSN : 0975-4024 Vol 5 No 5 Oct-Nov 2013 Oct-Nov 2013 This research paper focuses on the study of performance and efficiency of connections in members of a 3-bay G+5 storeyed precast frame with various connections subjected to lateral cyclic loading and to compare the results with that of a control frame. Two types of concrete mixes M20 and M60 were adopted. In this precast frame model the following two types of joints were studied experimentally. 1. Joints in beam column junction 2. Joints in beam to beam connection. In above mentioned, the connection is strengthened by the help of Steel bolts and L- Angles by welding and bolting. The two different types of models were cast and tested by applying lateral cyclic load. The load deflection behaviour as well as the modes of failure was studied. The results are compared with the model cast by monolithic construction. To study the behaviour of prefabricated frame under lateral loading, a series of two frames were cast. Out of two frames, one of the frames is control frame and the other one is prefabricated frame. 8 Ancilet Sabu and Renny Vargheese, “Analysis of beam-column joint in a prestressed concrete structure under reverse cyclic loading,” International Research Journal of Advanced Engineering and Science, Volume 3, Issue 2, pp. 147-150, 2018. The objectives of the study are to analyse behaviour of pre-stressed concrete beam column joint using finite element method, To find the hysteresis property of prestressed beam column joint, Compare the results of convensional beam column joint with prestressed beam column joint and prestressed beam –CFST column joint for different tendon pattern, To find out which configuration for joint is more efficient. Finite Element Analysis is conducted to develop models for the analysis of different types of beam column joints of prestressed structures. The

structural response of the selected and designed prestressed beam-column connection of jointed systems under reverese cyclic load was compared 9. Sarakot Asaad Hasan, BEHAVIOUR OF DISCONTINUOUS PRECAST CONCRETE BEAM-COLUMN CONNECTIONS, University of Nottingham, 2011: The study investigates experimentally and theoretically the behaviour of an internal precast concrete beam-column connection, where both the column and beam are discontinuous in construction terms. The aim was to modify the behaviour mechanisms within the connection zone by introducing a beam hogging moment resistance capacity under dead loads and limiting the damage within the connection. This is to offer permanent dead load hogging moments that could counterbalance any temporary sagging moment generated under sway loads, enhance the rotational stiffness, balance the design requirements for the beam-end and beam mid-span moments, provide efficient continuity across the column, and reduce the deflection at the beam mid-span. Connection provides a hogging moment capacity under dead loads as well as under live loads. Connection could be dealt with as an equivalent monolithic connection under gravity loading by using the strong connection concept. The simplified semi-rigid analysis using short stubs with appropriate stiffnesses, reflecting the connection flexibility, was found to give the exact solution when the stub length approaches zero. 10. R. Vidjeapriya and K.P. Jaya, Behaviour of Precast Beam-Column Mechanical Connections under cyclic loading, ASIAN JOURNAL OF CIVIL ENGINEERING (BUILDING AND HOUSING) VOL. 13, NO. 2 (2012), 2011: Experiments were conducted on 1/3 scale models of two types of precast beam-column connections and a monolithic connection. The precast connections considered are the beam-column connections in which beam is connected to column with corbel using (i) J-bolt and (ii) cleat angle. The specimens were subjected to reverse cyclic loading. The experimental results of the precast specimens were compared with those of the monolithic connection. Axial load was applied to the column using 400kN capacity actuator. The cyclic loading is applied in the beam using another two actuators, one for positive load cycle and the other for the negative load cycle. The hysteresis behavior, load carrying capacity, energy dissipation capacity and ductility factor were measured and the performance for the precast and monolithic beam-column connections were compared. Precast specimens showed increased stiffness in the negative direction due to the presence of Corbel. In precast connection, the column reinforcements were free from strains compared to that of monolithic connection.

3. CASE STUDY State Highway 36 over Lake Belton Belton, Texas The Texas Department of Transportation undertook a project to replace an aging bridge that carries State Route 36 over Lake Belton in Belton, Texas. The existing bridge is multispan steel stinger bridge that is approximately 3700 feet long and is located approximately 35 feet above normal water levels The new bridge is a 32 span prestressed concrete U-Beam bridge that is supported on twin column reinforced concrete pier bents with a hammerhead bent cap. The proposed bridge is a twin span with two side by side bridges that were nearly identical.

There are 62 pier bents on the project. The superstructure is a standard precast prestressed U beam that is used in Texas. The beams support a standard 8" thick reinforced concrete deck.

Existing Bridge

Welded on main reinforcement Beam-Beam Connections

Proposed bridge

The existing bridge had a low strength rating; therefore the delivery of materials via the existing bridge not possible. In order to facilitate construction, prefabricated pier bent caps were proposed. The bent caps offer the following advantages when compared to conventional cast-in-place construction. In this bridge Precast elements were joined in cast-in-suite process were the joints are well designed members were used. The joints are foundation-column joints, column-beam joints and beam-slab joints. 1. Since a non-conventional grouted post tensioning tube connection was used, research was critical in order to determine the behavior of the connection. The research proved that the connection was viable and low cost. This connection is not recommended for high seismic zones; however there is on-going research in California to enhance this connection type for use in high seismic areas. 2. The tolerances on the vertical reinforcing projecting from the cast-in-place columns was set at ½” This was found to be more than adequate to make the connection.

Column – Beam Joint (Using Cast-in-situ concrete joint) 4. AIM: To Improve the Shear Capacity of Beam-Beam Connection with cast-in-situ concrete. 5. ADVANTAGES OF PC CONNECTIONS: 1. Commences on a modular architectural layout 2. Adopt high degree of the PC components repetition with optimal standardisation in 3. 4. 5. 6.

connection design, Achieve economy in mass production and Ease site assembly work Work processes to be streamlined to enable the fully automated assembly of prefabricated components Avoid complex ...