2020. 2. 12. 06:35ㆍ카테고리 없음
If crack control is required, a minimum amount of bonded reinforcement is required to control cracking in areas where tension is expected. The required minimum areas of reinforcement may be calculated as follows: A s,min σ s = k c k f ct,eff A ct(7.1)where: A s,min is the minimum area of the reinforcing steel within the tensile zone A ct is the area of concrete within tensile zone.
Σ s is the absolute value of the maximum stress permitted in the reinforcement immediately after formation of the crack. This may be taken as the yield strength of the reinforcement, f yk. A lower value may, however, be needed to satisfy the crack width limits according to the maximum bar size or spacing (cf.
For pure tension k c = 1,0;. For bending or bending combined with axial forces:- For rectangular sections and webs of box sections and T-sections:(7.2)where: σ c is the mean stress of the concrete acting on the part of the section under consideration: σ c = N Ed/( b⋅ h)(7.4)with N Ed the axial force at the serviceability limit state acting on the part of the cross-section under consideration (compressive force positive).
Crack Width Calculation Eurocode 2 Slab With Opening Door
N Ed should be determined considering the characteristic values of prestress and axial forces under the relevant combination of actions b the width of the section h the height of the section h. h. = h for h.