Mayank's House — Beam Reinforcement Details

PLINTH BEAM — PB 300×450mm

Sheet 1 of 5 · +450mm NGL

3-span continuous elevation · 3500+3500+4000mm · 2T16 bottom + 2T12 hanger + extra 2T12@supports · T8 stirrups @100(conf)/@150(mid)

300

Width mm

450

Depth mm

2T16

Bottom

2T12

Hanger

+2T12

@ Supports

Stirrups

396

d eff. mm

PB LONGITUDINAL ELEVATION — GRID B : B1 → B4 (11000mm) — REPRESENTATIVE OF ALL 7 BEAM LINES

CONTINUOUS OVER B2 & B3 · CONFINEMENT ZONES L/6 FROM COLUMN FACE · NOT TO SCALE

2T16 Bottom (continuous + hooks)

2T12 Top Hanger

+2T12 Extra @ supports (L/4 each side)

T8 Stirrups @100(conf)/@150(mid)

Confinement Zone L/6 from col. face

BENDING MOMENT DIAGRAM (SCHEMATIC)

3-SPAN CONTINUOUS · SAGGING = BOT STEEL · HOGGING = TOP STEEL

PB DESIGN PARAMS

IS 456

Parameter	Value
Section	300×450mm
Clear cover	30mm (stirrup face)
d effective	396mm
Bottom steel	2T16 → Ast 402mm²
Top hanger	2T12 → 226mm²
Extra top	2T12 @ each support
Extent of extra top	L/4 each side of col
Stirrups normal	T8 @ 150mm c/c
Stirrups conf.	T8 @ 100mm (L/6)
Confinement L/6	583mm from col. face
Lap length T16	800mm (50d min)
Anchorage Ld	600mm into column
Grade concrete	M20 (fck=20)
Grade steel	Fe500 (fy=500)

GF BEAM — GB 230×450mm

Sheet 2 of 5 · +3450mm GF SLAB SOFFIT

Narrowed to 230mm · Same depth 450mm · Carries GF slab + FF column loads · 2T16 bottom · 2T12 hanger · T8@100/150

230

Width mm

450

Depth mm

2T16

Bottom

2T12

Hanger

+2T12

@ Supports

Stirrups

404

d eff. mm

GB LONGITUDINAL ELEVATION — 3 SPANS (3500+3500+4000mm)

SAME SPANS AS PLINTH · 230mm WEB (vs 300 PB) · SAME STEEL ARRANGEMENT · GF SLAB 125mm ABOVE

2T16 Bottom (same as PB)

2T12 Top Hanger

+2T12 Extra @ supports

T8@100/150

GF Slab 125mm above

FF / ROOF BEAM — FB 230×375mm

Sheet 3 of 5 · +6450mm ROOF LEVEL

Reduced depth 375mm (lighter roof only) · 2T12 bottom (vs 2T16 GF) · 2T10 hanger · T8@100/150 · same 3 spans

230

Width mm

375

Depth mm

2T12

Bottom

2T10

Hanger

+2T10

@ Supports

Stirrups

331

d eff. mm

FB LONGITUDINAL ELEVATION — ROOF BEAM (3500+3500+4000mm)

DEPTH REDUCED TO 375mm · 2T12 BOT (vs 2T16 GF) · 2T10 HANGER · ROOF SLAB + WATERPROOFING ABOVE

2T12 Bottom (reduced from 2T16)

2T10 Hanger (reduced from 2T12)

+2T10 Extra @ supports

T8@100/150

Roof Slab + Waterproofing

BEAM CROSS-SECTIONS — ALL 3 TYPES

Sheet 4 of 5 · AT MID-SPAN

Sections at mid-span showing bar arrangement · cover · effective depth · stirrup detail · neutral axis

PB — 300×450mm CROSS-SECTION

2T16 BOT · 2T12 TOP · T8@150 · c=30mm

GB — 230×450mm CROSS-SECTION

2T16 BOT · 2T12 TOP · T8@150 · c=30mm

FB — 230×375mm CROSS-SECTION

2T12 BOT · 2T10 TOP · T8@150 · c=30mm

SECTION OVER SUPPORT — HOGGING ZONE

ALL BEAM TYPES · TOP BARS ACTIVE · EXTRA STEEL IN TENSION

BEAM–COLUMN JOINT ANCHORAGE

HOOK DETAIL · BEAM BARS INTO COLUMN

BAR BENDING SCHEDULE — ALL BEAMS

Sheet 5 of 5 · COMPLETE BBS

Indicative quantities for PB + GB + FB · all beam lines · total steel tonnage · IS 456 compliance notes

COMPLETE BBS — PB + GB + FB

ALL 7 LONGITUDINAL + 4 TRANSVERSE BEAM LINES × 3 FLOORS

Mark	Beam	Bar Dia	Position	Cut Len/bar	No. Bars	Total m	Wt (kg)
PLINTH BEAM PB (300×450mm) — 7 beam lines
PB-B1	PB Longitudinal (×3)	T16	2 nos. Bottom cont.	11600	3×2=6	69.6m	109
PB-B2	PB Transverse (×4)	T16	2 nos. Bottom cont.	8100	4×2=8	64.8m	102
PB-H1	PB Longitudinal (×3)	T12	2 nos. Top hanger	11600	6	69.6m	62
PB-H2	PB Transverse (×4)	T12	2 nos. Top hanger	8100	8	64.8m	58
PB-E1	All PB	T12	Extra top @ int.sup.	2000	~48	96m	86
PB-S1	All PB	T8	Rect. stirrups	1500	~560	840m	332
GF BEAM GB (230×450mm) — 7 beam lines
GB-B1	GB Longitudinal (×3)	T16	2 nos. Bottom cont.	11600	6	69.6m	109
GB-B2	GB Transverse (×4)	T16	2 nos. Bottom cont.	8100	8	64.8m	102
GB-H1	All GB	T12	Top hanger + extra	—	14+48	227m	202
GB-S1	All GB	T8	Rect. stirrups 150×390	1180	~560	661m	261
FF BEAM FB (230×375mm) — 7 beam lines
FB-B1	FB Longitudinal (×3)	T12	2 nos. Bottom cont.	11600	6	69.6m	62
FB-B2	FB Transverse (×4)	T12	2 nos. Bottom cont.	8100	8	64.8m	58
FB-H1	All FB	T10	Hanger + extra top	—	14+48	227m	140
FB-S1	All FB	T8	Rect. stirrups 150×315	1010	~560	566m	223

PLINTH BEAM TOTAL

T16: ~211 kg
T12: ~206 kg
T8: ~332 kg
≈ 749 kg

GF BEAM TOTAL

T16: ~211 kg
T12: ~202 kg
T8: ~261 kg
≈ 674 kg

FF BEAM TOTAL

T12: ~120 kg
T10: ~140 kg
T8: ~223 kg
≈ 483 kg

T16 All Beams
422 kg
T12 / T10 All
548 kg
T8 Stirrups All
816 kg
GRAND TOTAL BEAMS
1906 kg

BEAM SIZE COMPARISON

ALL 3 FLOORS

Property	PB Plinth	GB Ground	FB First
Width b	300mm	230mm	230mm
Depth D	450mm	450mm	375mm
d effective	396mm	404mm	331mm
Bottom bars	2T16	2T16	2T12
Ast bottom	402mm²	402mm²	226mm²
Top hanger	2T12	2T12	2T10
Extra top	+2T12	+2T12	+2T10
Stirrups	T8@150	T8@150	T8@150
Conf. stirrups	T8@100	T8@100	T8@100
Cover	30mm	30mm	30mm
Level	+450mm	+3450mm	+6450mm
Design LL	3.0 kN/m²	2.0 kN/m²	1.5 kN/m²
Steel total	~749 kg	~674 kg	~483 kg

ENGINEERING NOTES

IS 456:2000 · IS 13920 · SP 16

Design Code: IS 456:2000 · Limit State Method
· All beams: M20 concrete + Fe500 steel
· Cover to stirrup face: 30mm all beams
· Beams are continuous over all intermediate supports
· Extra top bars extend L/4 beyond each column face
· Confinement zone L/6 from column face → T8@100
· Normal mid-span zone: T8@150mm stirrups
· 4m span (Bay 3→4): stirrups at @120mm mid
· Lap splice at mid-span only (away from high-moment zones)
· Lap length T16: 800mm · T12: 600mm · T10: 500mm
· Anchorage (Ld) into column: min 600mm with 90° hook
· Stirrup 135° hook at one corner, alternating each stirrup
· Beams cast monolithic with slabs — pour in one operation
· Minimum 2 bars top & bottom per IS 456 Cl. 26.5.1.1