Sheet1Ellen MarshDesign and Construction A1 CourseworkReferencesCalculationsOutput

Task: Design a reinforced concrete beam B1-B2 to EC2. Determine the loading on beam B1-B2 and then design a reinforced concrete member ofsuitable size and shape, with appropriate configuration of longitundinal reinforcement andlinks.

Building InformationTwo storey building

Fire-resistance of 1 hour.

Variable loads = qk3.5kN/m2

Additional permanent load0.5kN/m2

Take gravitational constant g as10m/s2

Exposure class of XC2 and XD1

Concrete class C32/4032N/mm2Materialswith nominal cover of 30 + cwherec = 10mm40mmCover=40mm

25mm Thick Screed=2300Kg/m3

Self weight concrete 25KN/m3

Layouta=6.5mb=5mc=4m

ActionsPermanent Loads (G)

BSEN1991-1-1Self-weight concrete slab6.3.1.2Slab thickness = 0.12mSelf weight= 3kN/m2

Screed Self-Weight

Thickness = 0.025mSelf-weight=0.575kN/m2

Additional Permanent Load0.5kN/m2G = 4.075Variable Loads (Q1)3.5kN/m2Q1 = 3.5BS EN1990For ULS Load Combination 1 the slab design load isTable NA A1.2 (A)1.35xG + 1.5Q1=10.8kN/m2For a 6.5m span 69.9kN/mper 1m width

Flanged Beam120mm

380mm

250mm

fyk =500N/mm2fck=32N/mm2

Loading

Slab design load = 53.8kN/m

Using shear force coefficient of 0.6 for a penultimatesupport and 0.5 for an internal support the designload is:

Slab: 1.1 x 69.9=76.87kN/mBeam: 1.35x0.25x0.38x25=3.21kN/mTotal:80.08kN/mUDL =80.08

Analysis

p.52 IstructE Design moments and shears can be derived using Manual for beamselastic analysis and also taking in account that the moment at the support will not be zero. This is because the support is not pinned and is not entirely fixed. Therefore an assumption is made that the moment at the support is taken at a 1/4 of the maximum bending moment.

Max. bending moment=423kNmBM at support=106kNmNew max. BM = 0.75*max317kNm

Shear Design load x L/2 = 260kN

Durability

Using cover of 40mm from exposure classes andapproximating 20mm Main Bars and 10mm Shear Links

Main bars20mmShear 10mm

Effective depth d = 500-20-10-40/2d (mm)=450=450mm

Flexural DesignBSEN1991-1-1The effective flange width beff for a T beam may be 5.3.2.1 (3)derived as:beff = bw + 2(0.2b1 + 0.1l) < 0.2lwhere (0.2b1 + 0.1l) < 0.2l, therefore use 0.2ll taken as 5mbw = 0.25mtake 0.2lbeff =1m

k= Med/bd2fckIstructE Manualk =310 x106 / 250 x 4502 x 325.4.4.1k= 0.19k2TRUE

Asmax (0.08SQRT(fck)/fyk)bw(0.08SQRT(fck)/fyk)bw0.23

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