Technical University „Gheorghe Asachi”, Iasi Student: Lazăr Gheorghe

Facutly of Civil Engineering and Building Services M.Sc. Structural Engineering

Assignment No. 3 INTERNAL REINFORCEMENT

Personal Number: No.S=17

Calculate the resisting moment of a concrete beam section with the dimensions b=250mm+5N and h=500mm reinforced with 3* ϕ16mm glass fibre bars placed at the bottom side. The concrete class is C25/30 and the concrete cover cnom=20mm.

SOLUTION

Beam cross section : bw = 335 mm, h=500 mm Bottom reinforcement: 3ϕ16→As1=6.16 cm cnom=20mm

Strength characteristics of the glass fibres:

FFRPU=1350 N/mm2 -the tensile strength EFRP=60000 N/mm - the elasticity modulus of the fibres

Afrp=602.88 mm - the area of the glass bars εFRPu= FFRPU/ EFRP=0.0225-the ultimate strain of the glass fibres

fcd=16.67 N/mm2- the design strength of the concrete

Effective depth of the cross-section:

d=h- cnom-0.5*ϕ==500-20-0.5*16=479.2mm

cb=231,86 mm εcu=0.0211

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Technical University „Gheorghe Asachi”, Iasi Student: Lazăr Gheorghe

Facutly of Civil Engineering and Building Services M.Sc. Structural Engineering

=0.825>0.67

=0.92833>0.67

=0.0225*60000*602.88= 813888 N=813.9 kN

=0.825*16.667*0.928*231,86*335=991463.9 N=991.5 kN

=214,8313 kN*m