Explaining Clause 7.6 in ACI Code

From ACI Code

7.6 – Spacing limits for reinforcement:
From 7.6.1 to 7.6.5

7.6.1 and 7.6.2 are talking about spacing in reinforcements in typical beam. That we the spacing between bars should not be less than the bar size or 25 mm. If we are using bar size 32 mm so we can’t use spacing less than 32 mm and if we are using bar size 20 mm so we can’t use spacing less than 25 mm. And if we are using two layers of bars, so we should put the upper bars exactly over the lower bars and the spacing between both layers is not less than 25 mm.

7.6.3 and 7.6.4 talking about spacing in compression members. No matter if its spiral or tied reinforced. The clear spacing should not be less than 1.5X Bar diameter or not less than 40 mm. if we are using 20 mm bars so : 1.5X20=30 mm. So we can’t use spacing less than 40mm. but if we are using 32mm bars. So 1.5X32= 48 mm so we can’t use spacing less than 48 mm.

7.6.5 is talking about walls and slabs. So the maximum spacing between bars should not be more than 3X Wall Thickness. Or 450 mm. So if we have wall with thickness 200 mm, so 3X200 = 600 mm, so we should use 450 mm. but if we have wall with thickness 100 mm (3X100 = 300 mm) we should use spacing 300mm.