## Adhesion between units and mortar

Adequate adhesion will normally be obtained with mortars manufactured in accordance with the relevant regulations. In other cases shear tests should be carried out to check that the shear strength fvko is not less than that for general purpose mortar. Tests have to be carried out with different preloads P and also with P 0. shear failure of the bond between mortar and units

## Allowance for imperfections

- shall be assumed for the full height of the wall to allow for construction imperfections, where hef is the effective height of the wall. Locally under the bearing of the concentrated load, the design compressive stress shall not exceed the following values Walls built with Group 1 masonry units (not shell bedded) k (1 + 0,15 x) (1,5 - 1,1 M k

## Bonding of masonry

(1)P Masonry units shall be bonded together, with mortar in accordance with proven practice. should be overlapped on alternate courses, so that the wall acts as a single structural element overlap > 0,4 Um or 40 mm, whichever is the greater Figure 5.7 Overlap of masonry units. At corners or junctions the overlap of the units, should not be less than the thickness of the units, cut units should be used, to achieve the specified overlap in the remainder of the wall.

## Characteristic compressive strength of unreinforced masonry made using lightweight mortar

(1) The characteristic compressive strength of unreinforced masonry, fk, made with Group 1, 2a and 2b masonry units and lightweight mortar, with all joints to be considered as filled, may be calculated using equation (3.3) provided that fb is not taken to be greater than 15 N mm2 and that there is no longitudinal mortar joint through all or part of the length of the wall. - the density of the used lightweight mortar, - the type of the masonry units. characteristic compressive strength of...

## Characteristic shear strength of unreinforced masonry

The characteristic shear strength fvk of unreinforced masonry can be determined - from the results of tests on masonry, - by calculation in the following way For general purpose mortar and when all joints may be considered as filled, fvk will not fall below the least of the values described below fvk fvko + 0,4 Sd or 0,065 fb, but not less than fvko or the limiting value given in table 3.5 fvko is the shear strength, under zero compressive stress sd is the design compressive stress...

## Characteristic values of actions

(1 )P Characteristic values Fk are specified - in ENV 1991 or other relevant loading codes, or - by the client, or the designer in consultation with the client, provided that the minimum provisions specified in relevant codes or by the competent authority are observed. (2)P For permanent actions where the coefficient of variation is large or where the actions are likely to vary during the life of the structure (for example, for some superimposed permanent loads), two characteristic values are...

## Compressive strength of mortar

- by designed mixes, which achieve the specified compression strength fm in accordance with EN 1015-11 - by prescribed mixes, manufactured from specified proportions of constituents, for example which may be assumed to achieve the relevant value of fm. Thin layer mortars and lightweight mortars - specification always by designed mixes,

## Creep shrinkage and thermal expansion

Table 3.8 Deformation properties of unreinforced masonry made with general purpose mortar Table 3.8 Deformation properties of unreinforced masonry made with general purpose mortar Final creep coefficient (see note 1) Final moisture expansion or shrinkage (see note 2) Dense aggregate concrete and manufactured stone 1. The final creep coefficient 4> c eel , where eca> is the final creep strain and Ee, a E. 2. Where the final value of moisture expansion or shrinkage is shown minus it indicates...

## Definitions and principal classification

- a force (load) applied to the structure (direct action), or - an imposed deformation (indirect action), for example, temperature effects or settlement. (i) by their variation in time - permanent actions (G), for example, self-weight of structures, fittings, ancillaries and fixed equipment, - variable actions (Q), for example, imposed loads, wind loads or snow loads, - accidental actions (A), for example, explosions or impact from vehicles, (ii) by their spatial variation - fixed actions, for...

## Design of structural members

(1)P The design of members shall be verified in the ultimate limit state. (2)P The structure shall be designed so, that cracks or deflections, which might damage facing materials, partitions, finishing's or which might impair water-tightness, (3) The serviceability of masonry members, should not be unacceptably impaired, by the behaviour of other structural elements, such as deformations of floors, etc.

## Distinction between principles and application rules depending on the character of the individual clauses

- general statements and definitions for which there is no alternative, - requirements and analytical models for which no alternative is permitted unless specifically stated. The principles are defined by the letter P, following the paragraph number, for example, (1)P. The application rules are generally recognised rules which follow the principles and satisfy their requirements. It is permissible to use alternative design rules differing from the application rules given in this Eurocode,...

## EC Part of the Eurocode programme

EN 1991 Eurocode 1 Basis of design and EN 1992 Eurocode 2 Design of concrete structures. EN 1993 Eurocode 3 Design of steel structures. EN 1994 Eurocode 4 Design of composite steel and EN 1995 Eurocode 5 Design of timber structures. EN 1996 Eurocode 6 Design of masonry structures. EN 1997 Eurocode 7 Geotechnical design. EN 1998 Eurocode 8 Design of structures for earthquake EN 1999 Eurocode 9 Design of aluminium alloy structures. These Structural Eurocodes comprise a group of standards for the...

## Effects of openings chases and recesses in walls

(1) If the stiffened wall is weakened by vertical chases and or recesses, other than those allowed by table 5.3, - the reduced thickness of the wall should be used for t - or a free edge should be assumed at the position of the vertical chase or recess. A free edge should always be assumed, when the thickness of the wall, remaining after the vertical chase or recess has been formed, is less than half the wall thickness. with a clear height of more than 1 4 of the storey height, or a clear width...

## Limit states and design situations Limit states

(1)P Limit states are states beyond which the structure no longer satisfies the design performance requirements. (3)P Ultimate limit states are those associated with collapse, or with other forms of structural failure, which may endanger the safety of people. (4)P States prior to structural collapse which, for simplicity, are considered in place of the collapse itself are also classified and treated as ultimate limit states. (5)P Ultimate limit states which may require consideration include -...

## Method for design of arching between supports

(1) When a masonry wall is built solidly between supports capable of resisting an arch thrust, the wall may be designed assuming that an horizontal or vertical arch develops within the thickness of the wall. Note In the present state of knowledge, walls subjected to mainly lateral loads should be designed only for arching horizontally. i _' _ i _'' I I _ _ I (2) calculation should be based on a three-pin arch and the bearing at the supports and at the central hinge should be assumed as 0,1...

## Method of design for a wall supported along edges

And there is an orthogonal strength ratio depending on the unit and the mortar used. The calculation of the design moment, Md, should take this into account and may be taken as either Md a Wk gF L2 per unit height of the wall Md m a Wk gF L2 per unit length of the wall when the plane of failure is perpendicular to the bed joints, ie. in the fxk2 direction, when the plane failure is parallel to the bed joints, ie. in the fxk1 direction fxk1 Plane of failure parallel to bed joints a is a bending...

## Particular materialindependent symbols used are as follows

S value of an internal action effect C nominal value, or function, of certain properties of materials yo coefficient defining the combination value of variable actions y1 coefficient defining the frequent value of variable actions y2 coefficient defining the quasi-permanent value of variable actions

## Representative values of variable actions

(1)P The main representative value is the characteristic value Qk. (2)P Other representative values are expressed in terms of the characteristic value Qk by means of a coefficient yi. These values are defined as (3) Supplementary representative values are used for fatigue verification and dynamic analysis. (4)P The coefficient y is specified - in ENV 1991 or other relevant loading codes, or - by the client or the designer in conjunction with the client, provided that the minimum provisions...

## Scope of Part of Eurocode

General basis for the design of buildings and civil engineering works in unreinforced, reinforced, prestressed and confined masonry, made with the following masonry units, laid in mortar made with natural sand, or crushed sand, - fired clay units, including lightweight clay units, - concrete units, made with dense or lightweight aggregates, - autoclaved aerated concrete units, - dimensioned natural stone units. Detailed rules which are mainly applicable to ordinary buildings common to all...

## Serviceability limit states

Or a function of certain design properties of materials related to the design effects of actions considered, determined on the basis of one of the combinations defined below. (2)P Three combinations of actions for serviceability limit states are defined X Gk,j ( + P) + Vl,1 Qk,1 + X V2,i Q (5) For building structures the rare combination may be simplified to the following expressions, which may also be used as a substitute for the frequent combination - considering only the most unfavourable...

## Stressstrain relationship

Figure 3.3 Stress-strain relationship for the design of masonry in bending and compression. Figure 3.3 Stress-strain relationship for the design of masonry in bending and compression. Figure 3.3 is an approximation and may not be suitable for all types of masonry units. For example, units with large holes (Group 2b and Group 3 units) may suffer brittle failure and be without the horizontal ductile range.

## Stiffened walls

1 Walls may be considered as stiffened at a vertical edge if and its stiffening wall is not expected, i.e. - both walls are made of materials with approximately similar deformation behaviour, - are approximately evenly loaded - are erected simultaneously and bonded together - and differential movement between the walls for example, due to shrinkage, loading etc., is not expected, the connection between a wall and its stiffening wall, is designed to resist developed tension and compression...

## Verification of unreinforced masonry walls

1 The design vertical load resistance of a single leaf wall per unit length, NRd, is given by Fim is the capacity reduction factor Fi or Fm, as appropriate, allowing for the effects of slenderness and eccentricity of loading fk is the characteristic compressive strength of masonry gM is the partial safety factor for the material taking into account the depth of recesses in joints greater than 5 mm. 2 The design strength of a wall may be at its lowest - in the middle one fifth of the heigth,...

## Modulus of elasticity

1 P The short term secant modulus of elasticity, E, shall be determined by tests in accordance with eN 1052-1 at service load conditions, i.e. at one third of the maximum load determined in accordance with EN 1052-1. 2 In the absence of a value determined by tests in accordance with EN 1052-1, the short term secant modulus of elasticity of masonry, E, under service conditions and for use in the structural analysis, may be taken to be 1 000 f 3 When the modulus of elasticity is used in...

## Analysis of shear walls

For the analysis of shear walls, the design horizontal actions and the design vertical loads shall be applied to the overall structure. This causes the following situation of the individual shear wall The most unfavourable combination of vertical load and shear should be considered, as follows - maximum axial load per unit length of the shear wall, due to vertical loads and considering the longitudinal eccentricity due to cantilever bending, or - maximum axial load per unit length in the...

## General

1 P The characteristic compressive strength of unreinforced masonry, fk, shall be determined from the results of tests on masonry. 2 The characteristic compressive strength of unreinforced masonry - may de determined by tests in accordance with EN 1052-1, - or it may be established from an evaluation of test data, based on the relationship between the characteristic compressive strength of unreinforced masonry, and the compressive strengths of the masonry units, and the mortar. In masonry...

## Characteristic flexural strength of unreinforced masonry

determinated from the results of tests on masonry - fxk1 failure parallel to the bed joints, - fxk2 failure perpendicular to the bed joints. - only for transient loads for example wind - fxk1 0, where failure of the wall would lead to a major collapse. fxk1 and fxk2 will be given in the NAD's fxk1 Plane of failure fxk2 Plane of failure parallel to bed joints perpendicular to bed joints Determination of the flexural strength by tests Examples of test set-ups and of typical test specimens for W...

## Outofplane eccentricity General

The out-of-plane eccentricity of loading on walls - from the material properties given in Section 3, - and from the principles of structural mechanics. A simplified method is given in Annex C - the joint between the wall and the floor may be simplified, by using uncracked cross sections - elastic behaviour of the materials A frame analysis or a single joint analysis may be used. Joint analysis may be simplified as shown in figure C.1 Figure C.1 Simplified frame diagram For less than four...

## Determination of effective height

1 The effective height hef can be taken as pn is a reduction factor where n 2, 3 or 4 depending on the edge restraint or stiffening of the wall. 2 The reduction factor, pn , may be assumed to be I For walls restrained at the top and bottom by reinforced concrete floors or roofs spanning from both sides at the same level or by a reinforced concrete floor spanning from one side only and having a bearing of at least 2 3 the thickness of the wall but not less than 85 mm 0,75 unless the...

## Partial safety factors for actions on building structures

Table 2.2 Partial safety factors for actions in building structures for persistent and transient design situations Table 2.2 Partial safety factors for actions in building structures for persistent and transient design situations For accidental design situations the partial safety factor For accidental design situations the partial safety factor for variable actions is equal to 1,0 3 By adopting the g values given in table 2.2, the following simplified combinations may be used - considering...