DESIGN PRECAST PRESTRESSED HOLLOW CORE SLABS
Design Code, EC2 Fire rating, N.A 60 90 120 240 min Select HC, SB_HC265 SB_HC320 SB_HC345 SB_HC400 SB_HC425 SB_HC500 GF_HC360 SEF_HC200 SEF_HC265 SEF_HC320 SEF_HC400
Diameter of Strands; Strand 1, 0 9.53 12.9 15.2 mm nos, 0 3 4 , Strand 2, 0 9.53 12.9 15.2 mm nos, 0 3 4 5 , Strand 3, 9.53 12.9 15.2 mm nos, 11 5 6 7 8 9 10 11 12 13 14 Strand 4, 0 mm nos, 0
Concrete strength ; fck,cube,transfer 30 25 27 28 30 33 35 36 38 40 45 50 N/mm2 fck,cube,topping 40 30 33 35 36 38 40 42 45 47 48 50 55 58 60 N/mm2 fck,cube,service 50 33 35 40 43 45 48 50 53 55 58 60 N/mm2
fpst = 1860 N/mm2
Max initial prestress = fpst_initial = 70 60 75 % of fpst % loss = 25 20 22 25 27 28 29 30 %
Lifting for Demoulding Stage lifting location , 0.0 0.25 0.50 0.75 0.80 1.00 1.25 1.50 1.60 1.65 m from each ends of the HC slab
Reinforcement for topping concrete fst, 500 460 500 N/mm2 BRC, 500 460 485 500 N/mm2 φrebars , 0 10 12 13 16 20 25 mm rebarspacing , 200 100 125 150 175 200 225 250 275 300 350 400 450 500 550 600 mm c/c φmesh , 0 8 10 12 13 mm meshspacing , 200 100 150 200 250 300 mm c/c Note: Cover to rebars for topping taken as 30mm from top. Hollow Core Span, Ls = m Nos of equal span props during topping stage, Nprops = 0 nos (unavailable) note refers to Props AT EQUAL SPACINGS other that those at the supporting beams location
topping, htopping = 75 0 25 30 40 50 60 65 75 80 85 90 95 100 105 110 115 120 125 130 135 140 145 150 155 160 165 170 175 180 185 190 200 210 215 225 230 250 260 265 270 275 280 290 300 mm
Live Loads, LL = 3 0 0.25 0.5 0.75 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 6.5 7 7.5 8 8.5 9 10 12 12.5 15 16 20 25 30 35 kN/m2 Constructio Live Loads, LLtopping = 3 0 1 1.5 2 2.5 3 3.5 4 4.5 5 7.5 10 kN/m2 sdL= 1.2 0.0 0.25 0.5 0.75 1.0 1.2 1.25 1.5 1.75 2.0 2.25 2.5 2.75 3.0 3.25 3.5 3.75 4.5 5.0 5.5 6.0 6.5 7.0 kN/m2
Bearing length, Lb 150 75 80 85 90 95 100 105 110 115 120 125 130 135 140 145 150 155 160 165 170 175 mm
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