EXPERIMENTAL RESEARCH ON STEEL COLUMN TO INCREASE STRENGTH BY RESTRAIN BARS

Transcription

1 EXPERIMENTAL RESEARCH ON STEEL COLUMN TO INCREASE STRENGTH BY RESTRAIN BARS M.MhanaRam 1, R.AmuthaSelvaKumar 2, S.ShanmugaPriya 3 S.RajendraPrasad 1, R.Swathika 1 1 PG Schlar, Civil Department, Sri Vidya Cllege f Engineering & Technlgy, TN, India 2 Assistant Prfessr, Civil Department, Sri Vidya Cllege f Engineering & Technlgy, TN, India 3 Assistant Prfessr, Civil Department, Annaprana Engineering Cllege, TN, India ABSTRACT The main aim f the research wrk is t increase the strength f the steel clumn (Tube-Sectin) fr new and existing structure by adding restrain bars. By increasing the strength f the clumn by restrain bars fr the new structure, the utcme f the sectin will be mre efficient and the perfrmance f the clumn in buckling will als increase. And fr the existing structure, strengthening the clumn can be dne by adding restrain bars in it, thus the clumn tend t buckle can be restrained s that the lad carrying capacity f the clumn can be increased. The increased strength f clumn can be identified by testing the cnventinal and cntemprary clumn fr buckling. Technically, In ther wrds, by increasing the mment f inertia f the clumn, the clumn can resist mre crippling lad. Keywrd: - Steel Clumn, Restrain Bar, Mment f Inertia, Rehabilitatin f Steel Clumn, Strengthening f Steel Clumn. 1. INTRODUCTION Day by day lts f structures are spruting everywhere in and arund bth rural and urban areas. This tremendus develpment shws strng grwth in infrastructure. Always while there is strng grwth in infrastructure, mre structure will be cnstructed in cnventinal types. Mst f the cnventinal type structure will nt be efficient as much. When the structure is nt much effective it usually leads t failure f structure at certain disaster level r may be inefficient t take design lad r sme time will cause much bigger sectin t resist the design lad. As a Structural Engineer it is need t design a structure as an efficient ne. And when prviding higher sectin it will have much weight, thus the dead lad f the structure will be increased. S as a Structural Engineer it is necessary t design cntemprary structures that are much efficient. 1.1 Need f the Prject Wrk The need f the prject wrk is t vercme the prblems like T bring an easy methd f rehabilitatin T ensure sectin design is much efficient Reducing the material weight Glbal warming

2 1.2 Objective The main aim f the research prject is t find a new methd f strengthening the steel clumn by using restrain bars. The bjective f the prject is t bring ut the efficient clumn sectin design. When efficient sectin is designed we can ensure the maximum lad carrying capacity. In cntemprary clumn design it will take mre lad than the cnventinal clumn, at the same time material will be used less fr the cntemprary design clumn f same lad carrying capacity. Here is the tw main bjective f the research wrk. A new rehabilitatin methd, fr existing building An effective sectin design, fr new building 2. METHODOLOGY Prject wrk will be carried ut thrugh the Experimental Research wrk. Mdels will be designed with available general criteria. All mdels will be tested with the Lading Frame. With the testing results varius graphs will be pltted fr cmparisns. 3. WORK PLAN Tube Sectin was selected fr this prject wrk. The entire clumn mdels will be in the height f 1.0m. And the restrain bars will be place in the center f the clumn and it be welded rigidly t arrest the mvement f the restrain bars. The height f the restrain bars will be varied frm 1/3 Height f the clumn t 2/3 height f the clumn (0.4m t 0.8m). Height will in the increment measure f 0.1m. In every size 3 numbers f mdels are tested and mean value f the result is taken as final value. Tube Sectin Height f Mdel 1.0m 3.1 Cnventinal Mdel Details 3 Number f mdel will be tested (withut restrain bar) 3.2 Cntemprary Mdel Details Mdel with restrain bar height 0.4m, 3 numbers f mdels will be tested Mdel with restrain bar height 0.5m, 3 numbers f mdels will be tested Mdel with restrain bar height 0.6m, 3 numbers f mdels will be tested Mdel with restrain bar height 0.7m, 3 numbers f mdels will be tested Mdel with restrain bar height 0.8m, 3 numbers f mdels will be tested Fig-10: Crss Sectinal View

3 In fig 5, the cnventinal clumn is shwn with the base plate welded n tp and bttm. Fig 5: Cnventinal Clumn with Base Plate Fig 6: Cntemprary Clumn In the fig 6, the cntemprary clumn in shwn, this is welded with the restrain bars and base plates. Base plate is welded n bth ends. 4. TESTING SETUP Fr testing f the clumn 500 kn lading frame with prving ring is used. All clumns are test in lading frame and readings are taken fr ultimate lad. The weight f the prving ring is10.5 Kg, this weight will be added t the lad, in calculatin. Fig-7: Testing Setup

4 5. RESULT AND DISCUSSIONS Testing is carried by using f the lading frame. Ttal numbers f 18 specimens are tested in lading frame. All the results are tabulated as fllws. Table-1: Result fr the Cnventinal Clumn Result fr the cnventinal clumn S.N Specimen N Lad, In kn 1 Specimen Specimen Specimen Mean Value 8.79 Table-2: Result fr the Clumn with Restrain Bar (0.4m) Result fr the Clumn with Restrain Bar (0.4m) S.N Specimen N Lad, In kn 1 Specimen Specimen Specimen Mean Value Table-3: Result fr the Clumn with Restrain Bar (0.5m) Result fr the Clumn with Restrain Bar (0.5m) S.N Specimen N Lad, In kn 1 Specimen Specimen Specimen Mean Value

5 Table-4: Result fr the Clumn with Restrain Bar (0.6m) Result fr the Clumn with Restrain Bar (0.6m) S.N Specimen N Lad, In kn 1 Specimen Specimen Specimen Mean Value Table-5: Result fr the Clumn with Restrain Bar (0.7m) Result fr the Clumn with Restrain Bar (0.7m) S.N Specimen N Lad, In kn 1 Specimen Specimen Specimen Mean Value Table-6: Result fr the Clumn with Restrain Bar (0.8m) Result fr the Clumn with Restrain Bar (0.8m) S.N Specimen N Lad, In kn 1 Specimen Specimen Specimen Mean Value The weight f the prving ring is 10.5kg, which is cnverted t kil newtn and the values are added t the lad. Exact lad are calculated and tabulated in table

6 Table-7: Exact Ultimate Lad, In kn S.N Specimen Type Mean Value Ultimate Lad, In kn 1 Cnventinal With Restrain Bar 0.4m With Restrain Bar 0.5m With Restrain Bar 0.6m With Restrain Bar 0.7m With Restrain Bar 0.8m Frm the result, it s clear that the lad carrying capacity f the clumn will be increased when the restrain bar is attached with clumn. The increments f lad carrying capacity with the length f the restrain bar are pltted in graph-1. Ultimate Lad Cmparisn, kn Lad, kn Cnventinal 0.4m 0.5m 0.6m 0.7m 0.8m Graph-1: Ultimate Lad Cmparisn In graph 2, the ultimate lad is cmpared with the cnventinal clumn t 0.8m restrain bar attached clumn. When restrain bar is attached with the clumn t height f 0.8m in the clumn the lad carrying capacity is increased t 2.1 ( kn) times when cmpared with the cnventinal clumn (8.893)

7 Cmparisn f Ultimate Lad Cnventinal VS 0.8m restrain bar kn kn Cnventinal 0.8m Graph-2: Cmparisn f Ultimate Lad Cnventinal VS 0.8m restrain bar 6. CONCLUSION As expected the lad carrying capacity f the clumn is increased when restrain bar is attached with the clumn. This methd can be extensively used fr the rehabilitatin purpse. The strength can be increased t the clumn as required by the altering the height f the restrain bar. The lad carrying capacity f the clumn increases as the restrain bars attached. When cmparing the cnventinal clumn with mdified clumn (0.8m), the lad carrying capacity f the clumn is increased t 9.76kN. Mdified clumn carried lad f kN, but cnventinal clumn carried nly 8.993kN. 7. REFERENCE 1. Take Hirashima and Hideki Uesugi, Lad-Bearing Capacity f H-Shaped Steel Clumns under Lcal Buckling at Elevated Temperature, Fire Safety Science-Prceedings f The Eighth Internatinal Sympsium, Pg.N Sreedhar Kalavagunta, Sivakumar Naganathan and Kamal Nasharuddin Bin Mustapha, Axially Laded Steel Clumn Strengthened with CFRP, Jrdan Jurnal f Civil Engineering, Vlumn 8, N.1, 2014, Pg.N Hanan H. Eltbgy, Structural Design f Steel Fiber Reinfrced Cncrete In-Filled Steel Circular Clumns, Steel and Cmpsite Structure, Vl.14, N.3 (2013) , Pg.N Uttam Kumar, Ygendra Tandel, Dr.C.H.Slanki, Behaviur f Gesynthetic Encased Sand Clumn In Sft Sil, Internatinal Jurnal f Engineering Research & Technlgy (IJERT), ISSN: , Vl.2, Issue 6, June 2013, Pg.N R.K.Rajput, Strength f Materials: Mechanics f Slids, 2006 Editin