## Info

(2) These values are assumed to take account of differences between the strength of test specimens of the structural materials and their strength in situ. (3) The values given above are valid when the quality control procedures given in chapter 7 are followed. They apply to characteristic values defined in chapter 3 and for design data as described in chapter 4.2. (4) Higher or lower values of Yc may be used if these are justified by adequate control procedures. (5) These values do not apply...

## Yg And Yq Safety Factors

B See Eurocode 1 in normal cases for building structures yQ,inf 0. c See relevant clauses b See Eurocode 1 in normal cases for building structures yQ,inf 0. c See relevant clauses (3) Where, according to 2.3.2.3 P(3), favourable and unfavourable parts of a permanent action need to be considered as individual actions, the favourable part should be associated with YG,inf 1091 and the unfavourable part with YG,sup 1111 P(4) Prestressing. For the evaluation of local effects (anchorage zones,...

## Strut And Tie Method Example

Figure 2.2 Definition of dimensions Figure 2.2 Definition of dimensions (4) The distance lo between points of zero moment may be obtained from Figure 2.3 for typical cases. Figure 2.3 Approximate effective spans for calculation of effective breadth ratios Figure 2.3 Approximate effective spans for calculation of effective breadth ratios The following conditions should be satisfied i) The length of the cantilever should be less than half the adjacent span. ii) The ratio of adjacent spans should...

## Fwn

4 To find the least amount of shear reinforcement, for low and intermediate shear stresses, the upper limits given in 1 above for cot 0 will normally govern the design. For higher shear stresses, the largest value of cot 0 corresponding to the lowest amount of shear reinforcement may be found by equating the design shear force Vsd to V d2. The amount of shear reinforcement is then found by equating the design shear force Vsd to V d3. The value of cot 0 may alternately be selected to optimise...

## Appendix Supplementary information on the ultimate limit states induced by structural deformations

A3.0 Notation See also 1.6 and 1.7 Fv Sum of all vertical loads under service conditions fctk, 0.05 Lower characteristic value of tensile strength of concrete htot Total height of structure from top surface of foundation or non-deformable sub-stratum in metres Nsd m Mean axial design force in columns in one storey 2m Mean slenderness ratio of columns within storey considered vu Longitudinal force coefficient for a member P 1 The combinations of actions and the safety factors given in 2.3 shall...

## Prestressing units

5.3.1 Arrangement of the prestressing units P 1 In the case of pre-tensioning, the tendons shall be spaced apart. P 2 In the case of post-tensioned members, bundled ducts are not normally permitted. 3 A pair of ducts, placed vertically one above the other, may be used if adequate precautions are taken for tensioning and grouting. Particular care is necessary if the tendons are doubly curved. P 1 The concrete cover between the inner surface of the formwork and either a pre-tensioned tendon or a...

## Durability requirements

4.1.0 Notation See also 1.6 and 1.7 dg Largest nominal maximum aggregate size Ah Tolerance on cover to reinforcement difference between minimum and nominal cover lt Diameter of a reinforcing bar, diameter of a tendon or of a prestressing duct lt n Equivalent diameter of a bundle of reinforcing bars P 1 The requirement of an adequately durable structure is met if, throughout its required life, a structure fulfils its function with respect to serviceability, strength and stability without...

## Appendix Nonlinear analysis A Notation See also and

1 r m Average curvature at the section considered 1 r cr Curvature calculated on the basis of a cracked section Myd Moment which produces the stress fyd in the reinforcement Myk Moment which produces the stress fyk in the reinforcement Coefficient which takes account of the bond properties of the reinforcement 2 Coefficient which takes account of the nature and duration of loading c Strain at the extreme compression fibre, calculated ignoring tension stiffening esm Average steel strain,...

## Good Bond Conditions Concrete

P 1 The quality of the bond depends on the surface pattern of the bar, on the dimension of the member and on the position and inclination of the reinforcement during concreting. 2 For normal weight concrete, the bond conditions are considered to be good for a all bars, with an inclination of 45 to 90 to the horizontal, during concreting Figure 5.1 a b all bars which have an inclination of 10 to 45 to the horizontal during concreting and are either placed in members whose depth in the direction...

## Shear Concrete Strut

4.3.2.4 Elements requiring design shear reinforcement Vsd gt VRd1 P 1 In beams, bent-up bars shall not be used as shear reinforcement except in combination with stirrups. At least 50 of Vsd shall be resisted by vertical stirrups. P 2 Where inclined shear reinforcement is used, the angle between the reinforcement and the longitudinal axis of the beam should not be less than 45 . P 3 Where the load is not acting at the top of the beam, or when the support is not at the bottom of the beam...

## Longitudinal reinforcement

Figure 5.16 Edge reinforcement for a slab 5.4.3.3 Shear reinforcement 1 A slab in which shear reinforcement is provided should have a depth of at least 200 mm . 2 In detailing the shear reinforcement, 5.4.2.2 applies except where modified by the following rules. Where shear reinforcement is required, this should not be less 60 of the values in Table 5.5 for beams. 3 In slabs if r 1 3 VRd2, see 4.3.2 , the shear reinforcement may consist entirely of bent-up bars or of shear assemblies. 4 The...

## Construction rules

P 1 The concrete used in construction shall be such that its specified properties will be maintained over the life of the structure. 2 For the construction rules related to concrete and concrete technology, the relevant Sections in ENV 206 apply. 6.3.2 Formwork and falsework 6.3.2.1 Basic requirements P 1 Formwork and falsework shall be designed and constructed so that they are capable of resisting all actions which may occur during the construction process. They shall remain undisturbed until...

## List of references see clause

BRITISH STANDARDS INSTITUTION, London BS 648 1964, Schedule of weights of building materials. BS 6399, Loading for buildings. BS 6399-1 1984, Code of practice for dead and imposed loads. BS 6399-3 1988, Code of practice for imposed roof loads. BS 8110, Structural use of concrete. BS 8110-1 1985, Code of practice for design and construction. BS 8110-2 1985, Code of practice for special circumstances. CP3, Code of basic data for the design of buildings. CP3 Chapter V, Loading. CP3 Chapter V-2,...

## Minimum Concrete Cover

5.2.5 Anchorage of links and shear reinforcement P 1 The anchorage of links and shear reinforcement shall normally be effected by means of hooks, or by welded transverse reinforcement. High bond bars or wires can also be anchored by bends. A bar should be provided inside a hook or bend. 2 For the permissible curvature of hooks and bends, see 5.2.1.2 2 . 3 The anchorage as a whole is considered to be satisfactory where the curve of a hook or bend is extended by a straight length which is not...

## Tangent Modulus Of Elasticity Concrete

Total cross-sectional area of a concrete section Area of a prestressing tendon or tendons Area of reinforcement within the tension zone Area of reinforcement in the compression zone at the ultimate limit state Cross-sectional area of shear reinforcement Design value of the secant modulus of elasticity Tangent modulus of elasticity of normal weight concrete at a stress of oc 0 and at time t Tangent modulus of elasticity of normal weight concrete at a stress of Bc 0 and at 28 days Secant modulus...

## Links Reinforcement

It is also permitted to use a diagram in which the resisting tensile force is progressively decreasing on the length lb,net. Figure 5.11 Envelop line for the design of flexural members. Anchorage lengths 3 The anchorage lengths of bent-up bars which contribute to the resistance to shear should be not less than 1.3 lb,net in the tension zone and 0.7 lb,net in the compression zone. 5.4.2.1.4 Anchorage of bottom reinforcement at an end support 1 Over supports with little or no end fixity it is...

## Anchorage Length

These values are derived from the following formulae with Yc 1.5 plain bars, f 0.36 fck Yc high bond bars, fbd 2.25fctk 0.05 c where fck and fctk 0.05 are as defined in Chapter 3.1. 3 In the case of transverse pressure p in N mm2 transverse to the possible plane of splitting the values of Table 5.3 should be multiplied by 1 1 - 0.04 p d 1.4 , where p is the mean transverse pressure. P 1 The basic anchorage length is the straight length required for anchoring the force As.fyd in a bar, assuming...

## Column Eccentricity

Modulus of elasticity of the concrete see 3.1.2.5.2 moment of inertia gross section of the column or beam respectively height of the column measured between centres of restraint effective span of the beam factor taking into account the conditions of restraint of the beam at the opposite end 1.0 opposite end elastically or rigidly restrained 0.5 opposite end free to rotate 0 for a cantilever beam. 2 Isolated columns are considered slender if the slenderness ratio of the column considered exceeds...

## Torsion Reinforcement In Euro Code

When the reinforcement is known, 0 and T d2 may be determined from Equations 4.44 and 4.45 below. If the resulting value of 0 lies outside the limits given by 4.42 the nearest limit should be taken. 8 The resultant of the tensile forces Fs1 As1 fyld is assumed to act at the centre of gravity of the equivalent hollow section a portion of the longitudinal steel or the prestressing tendons may therefore be placed along the centre line of the member however, in order to ensure that the outward...

## Column Head Reinforcement

Is the distance from the column face to the edge of the column head is the diameter of a circular column. For a rectangular column with a rectangular head with overall dimensions l1, and l2 li lci 2lm l2 lc2 21h2, li r l2 , dcrit may be taken as the lesser of 2 For slabs with column heads where 1h gt 1.5 d hH see Figure 4.23 , the critical sections both within the head and in the slab should be checked. 3 The provisions of 4.3.4.3 apply for checks within the column head with d taken as d see...

## What Is Mean By Bent Up Bars

6 The diameter of the shear reinforcement should not exceed 12 mm where it consists of plain round bars. 7 The maximum longitudinal spacing smax of successive series of stirrups or shear assemblies is defined by the following conditions with Vsd, VRd1 and VRd2 as defined in 4.3.2 if Vsd r 1 5 VRd2 smax 0.8 d 8 300 mm 5.17 if 1 5 VRd2 lt Vsd r 2 3 VRd2 smax 0.6 d 8 300 mm 5.18 if Vsd gt 2 3 VRd2 smax 0.3 d 8 200 mm 5.19 8 The maximum longitudinal spacing of bent-up bars is defined by smax 0.61...

## Elasticity Concrete

1 The values of the material properties required for the calculation of instantaneous and time dependent deformations of concrete depend not only upon the concrete strength class but also upon the properties of the aggregates and other parameters related to the mix design and the environment. For this reason, where an accurate calculation is considered necessary, the values should be established from known data appropriate to the particular materials and conditions of use. For many...

## Nomogram For K Steel Unbraced

Curvature at the critical section at the base of a model column Moment of inertia gross section of a beam Moment of inertia gross-section of a column Reduction factor for the calculation of the second order eccentricity e2 Equation 4.68 Coefficient, taking account of decrease in curvature 1 r due to increasing axial force Equation 4.71 Resisting design axial compression force Design ultimate capacity of the section subjected to axial load only Second order eccentricity Additional eccentricity...

## Reinforcing steel

3.2.0 Notation see also 1.6 and 1.7 Characteristic 0.2 proof-stress of reinforcement Characteristic tensile strength of reinforcement Elongation of reinforcement at maximum load Characteristic elongation of reinforcement at maximum load P 1 This section applies to bars, coiled rods and welded fabric, used as reinforcement in concrete structures. P 2 The requirements apply to the product in the condition in which it is delivered. In the case of coiled rods, the requirements apply to the material...

## Ultimate limit states

4.3.1 Ultimate limit states for bending and longitudinal force 4.3.1.0 Notation See also 1.6 and 1.7 Ag1 Area of tension reinforcement effective at a section Ag2 Area of reinforcement in the compression zone at the ultimate limit state s1 Strain in tension reinforcement, for section analysis s2 Strain in compression reinforcement, for section analysis pm Steel strain corresponding to Pm,t see 2.5.4.0 p Variation of steel strain corresponding to Pc see 2.5.4.0 P 1 This section applies to...

## Extreme Compression Fibre

In the derivation of Table 4.3, it has been assumed that 7 For simplification, a constant value Bc fc may be adopted in the range cl gt c gt cu see Figure 4.1 8 Other idealized stress-strain diagrams may be used e.g. bi-linear , provided they are effectively equivalent to the one described in 3 and 4 . b Stress distribution for cross-section design 9 The preferred idealization for cross-section design is the parabolic rectangular one, given in Figure 4.2. In this diagram cu max is taken as 3.5...

## Eurocode Structure Class

1 In order to satisfy the provisions of 4.1.3.3 P 3 , these minimum values for cover should be associated with particular concrete qualities, to be determined from Table 3 in ENV 206. 2 For slab elements, a reduction of 5 mm may be made for exposure classes 2 5. 3 A reduction of 5 mm may be made where concrete of strength class C40 50 and above is used for reinforced concrete in exposure classes 2a 5b, and for prestressed concrete in exposure classes 1 5b. However, the minimum cover should...

## Prestressing steel

See note preceeding 3.2 . 3.3.0 Notation see also 1.6, 1.7 Tensile strength of prestressing steel Characteristic tensile strength of prestressing steel 0.1 proof-stress of prestressing steel Characteristic 0.1 proof-stress of prestressing steel Elongation of prestressing steel at maximum load Characteristic elongation of prestressing steel at maximum load P 1 This section applies to wires, bars and strands used as prestressing tendons in concrete structures. P 2 The requirements apply to the...