1. Role of Fibre in Reinforcement of Structure During Earthquake
Fibre Reinforcement, Earthquake and Structure failure
Ms. Chhavi Gupta*
Technical Skill Refinement Program (TSRP)
Feb. 04, 2017
Department Of Civil Engineering

2. Efforts to reduce failures Experimental studies Challenges
Contents
Motivation
Introduction
Efforts to reduce failures
Experimental studies
Challenges
Feb. 04, 2017,
Gupta, C. G.
Fibre Reinforcement, Earthquake and Structure failure 1

3. Motivation
The fifth revision of IS 1893 has brought more than fifty percent of the country under moderate and severe seismic zones.
Reasons of structure failure from
earthquake studies:
Breakdown of corners joint
Base Isolation
Rigidity of structure
The times of India
Subodh Varma | TNN | May 1, 2015
Focus on Breakdown of Corners Joint
Feb. 04, 2017,
Gupta, C. G.
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4. Introduction What is the behavior of structure During earthquake?
In a moment resistant frame, three types of joints can be identified as:
Seismic loading on interior joint
forces on exterior joint
Corner joint
Feb. 04, 2017,
Gupta, C. G.
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5. Introduction Corner joint-
Bending moment which tend to close the corner.
Bending moment which tend to open the corner.
Closing joint (top view)
Opening joint (top view)
Feb. 04, 2017,
Gupta, C. G.
Fibre Reinforcement, Earthquake and Structure failure 4

6. Introduction We focus on Case 2
CASE 1: Bending moment which tend to close the corner
Concern:
Anchorage of reinforcement is a serious problem in case of closing corner.
CASE 2: Bending moment which tend to open the corner. Concern: The diagonal resultant is tensile, that is a serious problem .
We focus on Case 2
Feb. 04, 2017,
Gupta, C. G.
Fibre Reinforcement, Earthquake and Structure failure 5

7. Efforts to reduce the failures
Nilsson, I.H.E. (1973)1
Indian Standards (1987), (1997)3
Efficiencies close to 100% were obtained
Noor, F.A. (1977)2
Past Efforts
Feb. 04, 2017,
Gupta, C. G.
Fibre Reinforcement, Earthquake and Structure failure 6

8. Efforts to reduce the failure
Issues-
Available space in joint is limited. Major role- Fibre can play major role as fibred reinforced concrete with simple detailing system so efficiency can be increased.
RCC beam with fibre during load
Feb. 04, 2017,
Gupta, C. G.
Fibre Reinforcement, Earthquake and Structure failure 7

9. Experimental and Analytical study
The efficiency of detailing systemSP1 was found to be %
2. The efficiency of this detailing system SP2 was obtained as 95.33%
Feb. 04, 2017,
Gupta, C. G.
Fibre Reinforcement, Earthquake and Structure failure 8

10. Experimental and Analytical study
Loading Arrangement:
Jack and a pump unit.
A pair of stiff mild steel bearing plate
50 mm diameter mild steel roller
Cover plate
The bearing plate as a point
Two 6 mm diameter mild steel runners
Proving ring of 50 KN capacity 
Loading Arrangement
Feb. 04, 2017,
Gupta, C. G.
Fibre Reinforcement, Earthquake and Structure failure 10

11. Experimental and Analytical study
Fibre Reinforced Portion
Portion of frame(corners), where steel fibres are provided
Loading Arrangement of Specimen
Feb. 04, 2017,
Gupta, C. G.
Fibre Reinforcement, Earthquake and Structure failure 9

12. Experimental and Analytical study
With the addition of0.5% , 1%, 1.5%, 2% volume fraction of fibres in SP2, The ultimate load carrying capacity of joint improved by 9.91%, 31.65%, 42.86% and % respectively as compared to specimen without fibres (SP2).
Specimen
Ultimate Load (KN)
Experimental
Analytical
Percentage error
SP2A
12.64
13.9
9.96
SP2B
15.14
13.95
7.85
SP2C
16.43
14.75
10.22
SP2D
13.68
15.51
13.37
Comparison of Ultimate Load for fibrous specimens
Efficiency of Specimens
Load verses first crack value
Feb. 04, 2017,
Gupta, C. G.
Fibre Reinforcement, Earthquake and Structure failure 11

13. Experimental and Analytical study
SP1=DETAILING SYSTEM1
SP2= DETAILING SYSTEM 2
SP2A = D.S 2 WITH 0.5% FIBRE
SP 2B = D.S 2 WITH 1% FIBRE
SP2C = D.S 2 WITH 1.5% FIBRE
SP2D = D.S 2 WITH 2% FIBRE
D.S =DETAILING SYSTEM
Load-Deflection behaviour of SP1, SP2, SP2A,SP2B, SP2C and SP2D
Feb. 04, 2017,
Gupta, C. G.
Fibre Reinforcement, Earthquake and Structure failure 12

14. Experimental and Analytical study
SP1=DETAILING SYSTEM1
SP2= DETAILING SYSTEM 2
SP2A = D.S 2 WITH 0.5% FIBRE
SP 2B = D.S 2 WITH 1% FIBRE
SP2C = D.S 2 WITH 1.5% FIBRE
SP2D = D.S 2 WITH 2% FIBRE
D.S =DETAILING SYSTEM
Moment-Rotation behaviour of SP1, SP2, SP2A, SP2B, SP2C and SP2D
Feb. 04, 2017,
Gupta, C. G.
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15. Challenges
After 1.5 and 2 percentage of steel fibre, balling effect decreases the strength and efficiency of fibre reinforcement concrete member.
Balling effect
A collection of long thin steel fibres, usually with aspect ratio higher than 100, will interlock to form a mat, or a ball, during mixing. Once these balls have formed, separating the fibres is extremely difficult. Bond is one of the reasons why straight smooth fibres cannot be successfully used in the field.
Feb. 04, 2017,
Gupta, C. G.
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16. References
Nilsson, I.H.E. (1973), “Reinforced Concrete Corners and Joints Subjected to Bending Moment-Design of Corners and joints in frame Structures”, National Swedish Institute for Building Research, Stockholm, Document No.D7-1973
Noor, F.A. (1977), “Ultimate Strength and Cracking of Wall Corners”, Concrete, V.11, No.7, July, pp
SP 34:1987 (1997),“Handbook on Concrete Reinforcement and Detailing”, Bureau of Indian Standards, New Delhi.
Feb. 04, 2017,
Gupta, C. G.
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17. THANK YOU
Special Thanks: Prof. Roshan Lal, PEC University of Technology India.
Thanks to Colleagues: Dr. Satyaprakash, Dr. Prabhas Yadav and Civil Engineering Department.