Calculation of column formwork

SMC Project - Phase Appendix FORMWORK CALCULATION FOR COLUMNS I/ Input Data: 1/ Loads Maximum lateral pressure of concrete when using inner vibrator: F= 0.227 γ t0 ß1β2v½ = 0.227 x 2400 x x 1.2 x 1.15 x sqrt(13) = where γ: density of concrete = 2400 (kg/m3) t : Initial setting time of concrete (h)= 200/(T+15) = 10,842.96 kg/m2 T: temperature of concrete (35 o C) ß : Adjusting coefficient due to adding admixture If there is admixture ß =1.2 ß : Adjusting coefficient due to concrete slump If slump = 110-150mm, ß = 1.15 v: speed of casting concrete (m/h) The column 6.5m high will be cast within 30 minute -> v = 13 4.52 m The effective pressure height of liquid concrete h = F/γ 2/ Material characteristics No Elastic Modulus of steel E= Components Steel box 2x(50x50x2)mm Steel box (40x80x2)mm Plywood 18 mm b(cm) 100 2,100,000 (kG/cm2) h(cm) Jx(cm4) 29.542 13.118 48.6 d(cm) 0.2 0.2 1.8 Wx(cm3) 11.817 6.559 54 II/ Calculation and check for formwork system: 1/ Check of plywood: According to Manufacturer (TEKCOM), the plywood characteristics as below: Elastic modulus of plywood E= 45887.4 (kG/cm2) Bending strength Ru= 407.888 (kG/cm2) Plywood will be supported with intermediate ribs 80x40x2.0 (mm) with distance L Calculation for columns 50x50 cm Select L1= 0.25 Moment diagram Distributed load applied on formwork, 1m wide q=G.1= 10,842.96 kG/m Maximum moment at midle of span 84.71 kGm Mmax=q.L12/8= Checking stress σ=Mmax/W= 156.9 (kG/cm2) 0.8 is coefficient of working condition of plywood SMC-ACSC < 0.8 Ru =326 (kG/cm2) MS Column formwork (H=4.5m) Accepted Page Checking bending deflection fmax=q1.L14/(128EJ)= (Accepted) 0.15 (cm) Conclusion: Plywood secure with the arrangement of rib at distance 0.25m 2/ Longitudinal Rib 40x80x2 (mm) The ribs to be supported by crossing braces at spacing L2 L1= Select L2= Calculation diagram 0.25 0.4 m m q2 Moment diagram L2 L2 L2 M=q2 x L²/10 Maximum distributed load q applied on the midle longitudinal rib q2=L1xG= 2,710.74 kG/m Maximum moment at midle of span 43.37183971 kGm Mmax=q.L22/10= Allowable deflection [f] = L1/400 = 0.100 cm Checking stress σ=Mmax/W= 661.26 (kG/cm2) Checking bending deflection 0.02 (cm)