K A

yk s,prov

Basic span/effective depth ratios for flat slabs are lightly stressed (p = 0.5%) = 30 nominally reinforced (p = 0.15%) = 41

Span reinforcement is typically T12 @ 250 mm crs. (452 mm2/m) 100 x 452

100/4

bd min

1000 x 175

By interpolation (p = 0.26%), basic span/effective depth ratio = 37.5

max. span 5200

4.2.1.1.8 Crack control

Use method without direct calculation. 4.4.2.3

Estimate service stress, a&, under quasi-permanent loads as follows: 4.4.2.3(3)

G. + Q„ = G„ + 0.3Q. = 6.4 + 0.3 x 5 = 7.9 kN/m2 2.3.4

Ratio of quasi-permanent to ultimate design loads = 7.9/16.2 = 0.49 NAD

s.prov s,prov

Limit bar size using EC2 Table 4.11 or bar spacing using EC2 Table 4.12. The relevant limits are shown in Table 4.3.

Table 1

Table 4.3 Crack control limits

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