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Eurocode 2 SLS design of rectangular reinforced concrete cross-section for crack control

Description:
SLS design of rectangular reinforced concrete cross-section for crack control (calculation of required reinforcement for given bending moment / axial force, direct calculation of crack width)
According to:
EN 1992-1-1:2004+AC2:2010 Section 7.3.4
Applicable for:
Uniaxial bending. High bond reinforcement bars (ribbed)
Supported National Annexes:
Nationally Defined Parameters (NDPs) automatically filled for supported countries
All Calculations
Input
MPa
e.g. 30 MPa for concrete class C30/37. For a list of concrete classes see Table of Concrete Design Properties
A value of 1.0 will yield the most economic reinforcement. Lower values may be provided if concrete stress limitation is desired. According to EN 1992-1-1 §7.2(2) to avoid longitudinal cracks the compressive stress in the concrete should be limited to 0.6fck for the characteristic SLS combination for adverse environment (exposure classes XD, XF, XS) and in the absence of other measures. According to EN 1992-1-1 §7.2(3) the effects of non-linear creep should be considered when the compressive stress in the concrete exceeds 0.45fck for the quasi-permanent SLS combination
The parabolic stress-strain law may be used for SLS (no partial safety factors) according to EN1992-1-1 §3.1.7(1) Figure 3.3. The linear stress-strain law (without tension) is a good approximation and it can also take into account an effective modulus of elasticity e.g. due to the effects of creep or aggregate type.
A value of 1.0 corresponds to the value of the secant modulus of elasticity Ecm as defined in EN1992-1-1 Table 3.1. To take into account the long-term effects of creep a value of 1 / [1 + φ(∞, t0)] can be provided, as specified in EN 1992-1-1 §7.4.3(5). To take into account more refined values of the modulus of elasticity based on the aggregate type an appropriate value can be provided, e.g. as specified in EN 1992-1-1 §3.1.3(2) and the National Annex.
MPa

m
m

Initial reinforcement: When the required reinforcement is requested the initial reinforcement will be modified accordingly.

Enter 0 to disable the bottom reinforcement layer. Non-integer values are handled by suitable modification of bar cross-sectional area.
mm
m

Enter 0 to disable the top reinforcement layer. Non-integer values are handled by suitable modification of bar cross-sectional area.
mm
m
Distance from bar centroid of top reinforcement layer to concrete edge

Enter 0 to disable the side reinforcement layer. Non-integer values are handled by suitable modification of bar cross-sectional area.
mm
m
Distance from centroid of side reinforcement layer to concrete edge

kNm
The design value of the bending moment at the appropriate SLS combination for which the required reinforcement will be determined
kN
The design value of the axial force at the appropriate SLS combination for which the maximum bending moment resistance of the cross-section will be calculated (typically the quasi-permanent combination for reinforced concrete, see EN1992-1-1 §7.3.1).
The specified layers will be modified proportionally by multiplication by the same factor. The rest of the layers will remain unchanged.
According to EN1992-1-1 §7.3.4(2). Typically the crack control verification of reinforced concrete is carried out for the quasi-permanent combination therefore a value of kt = 0.4 for long-term loading is applicable. For short-term loading a value of kt = 0.6 is applicable. Intermediate values are possible.
mm
According to the National Annex to EN1992-1-1 §7.3.1(5). Typically for crack control verification of reinforced concrete a value of wmax = 0.3 mm is applicable.
mm
Crack control verification is strongly affected by the concrete cover c (distance between the surface of longitudinal reinforcement closest to the nearest concrete surface). Larger values of c produce more unfavorable results.
Rectangular concrete cross-section and effective area in tension for crack control
Rectangular concrete cross-section and effective area in tension for crack control
Nationally Defined Parameters
According to EN1992-1-1 §6.2.2(1) and the National Annex.
Note: Always verify the validity of the Nationally Defined Parameters (NDPs). Please inform us of any discrepancy using our Contact Form. The NDP value is left blank for all NDPs that we do not have this information available. Interested users who have access to the corresponding NDPs can notify us using our Contact Form to fill-in the missing information.