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Welcome to HRC Bagh. Workshop on Safer Building Through Improving Steel Detailing. Objective. To understand the recommended practices with reference to earthquake resistant techniques to make their houses safe; To improve steel detailing in in building construction;
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Welcome to HRC Bagh Workshop on Safer Building Through Improving Steel Detailing
Objective • To understand the recommended practices with reference to earthquake resistant techniques to make their houses safe; • To improve steel detailing in in building construction; • To sensitize the stakeholders to adopt earthquake safer techniques; • To ensure the effective technology transfer to the target groups.
WELCOME Bagh Seismic zone
RC Frame Buildings DHQH Bagh 7
RC Frame Buildings Margalla Tower 9
Earthquake 2005 Ring Spacing
Spacing of Stirrups Effects
Common Practice New
Recommended Spacing Ring Spacing= 4″
Recommended Shape of Seismic Stirrup Such stirrups do not open even during strong shaking 3″ 135°
Proper Column Base “L” Should be= 12 inch 19
Our Practice Result Mistake
Interior Beam-Column Joint 0‘-6" Beam long bar should passed from the center of column
Wrong Practice Is it ok?
Right way at middle/ Junction Minimum= 2 Feet
Practice still continued Length of vertical bar not sufficient for 2nd Storey
Proper way of Lapping Not more than 50 % bars lapped at a section Sufficient lapping length Location at mid height Min 4‘-0" Within lapping length, stirrups at closer spacing
Our Practice (New) Lap length is 15”
Overlapping in Beam Recommended Overlap should be equal to= 60 x D
Framing around opening New After Remedy
Infill Walls Connection With? Before OCT 2005
Beam bar not bent up near support to overcome negative movement Why crack develop?
What is Our Practice Construct beam and slab together
Steel Reinforcement • Commonly used steel reinforcement • Mild Steel • High Strength Deformed Bar • Should be free from loose mill scale, loose rust, coat of paints and oils, cracks, surface flaws, laminations etc • Should comply with requirement of dimension and weight • Should not break while bending
Simple Steel Quality Test Making close hook 4d and bent the bar at 180 degree then straight it. Good quality bar doesn't break, while bad quality steel breaks.
Spacers Concrete Cover Column= 1.5″ Beam= 1.5″ Slab=3/4″ Foundation=3″