Masonries Structures - Part I

8/13/2019 Masonries Structures - Part I

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MASONRIES STRUCTURES

PART 1

2013

-

2014


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MASONRY TYPES

ZNA

(URM)

UNREINFORCED/SIMPLE

MASONRY

Masonry with insufficient reinforcement to

reinforced masonry (such as confined masonry,

with reinforce in horizontal joints, masonry with r

The confinement elements and the construcunder the present CODE shall not be consider

and seismic loads safety checking.

ZC

(CM)CONFINED MASONRY

Masonry provided with reinforced concre

confinement in the vertical direction (column t

(beam ties) cast after the masonry laying.

ZC+AR

(CM+RH)

CONFINED MASONRY AND

REINFORCED IN HORIZONTAL

JOINTS

Confined masonry to that in the horizontal jo

reinforcement is provided, in order to increase

and the ductility of the wall.

ZIA

(RCM)REINFORCED CORE MASONRY

Masonry composed of two layers of masonry

between reinforced grout space, with or withou

between layers and with the three components w

retrieve all types of requests.

ZIC

(IM)INFILL MASONRY

Masonry consists of one or more layers of bricks

bond between layers, framed in a reinforced conc

made after the frame erection.


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STRUCTURAL MASONRY WALLS TYPES

MASONRY

STRUCTURAL WALL

Wall intended to resist against the horizontal and vertical forces acting essentially in

CR6-2014: Masonry walls that meet the minimum geometric data from paragraph

foundation and erected from materials referred to Chap. 3 and 4 are "structural wa

and composed according to the provisions of this CODE.

MASONRY BRACING

STRUCTURAL WALL

Perpendicular wall to another structural wall, which is working on taking vertical a

contribute to its stability, in buildings with floors that download in a single direction

elements of the slab, which have no charge from direct vertical forces, but which ta

the horizontal plane, are defined as bracing walls

MASONRY

NONSTRUCTURAL WALL

(PARTITIONING WALL)

Wall that is not part of the main structure of the building, the wall of this type ca

prejudice to the integrity of the rest of the structure, but only after a specialized tech

CR6-2014: nonstructural wall will be designed to answer the following charges:

self-weight;

weight of objects hanging on the wall;

loads perpendicular to the plane (out of plane) from human action or eartab. 6.12 NA SR EN 1991-1-1)

INFILL PANEL WALL

Infill partition wall embedded in a RC/steel frame, which is not part of the main scertain conditions, contribute to the lateral stiffness of the building and sei

suppression during building exploitation or creating new openings for doors/window

made only on the basis of justification by calculation (technical expertise or

constructive measures.

This wall will be designed to take orders from:

when interacting with the frame for the seismic design;

self-weight;

weight of suspended/hanging objects;

loads perpendicular to the plane (out of plane) for human action, earthq

panel).


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Types of identified degradation led to the following classification for structural elemen

1. coupling beams (spandrels), represented by the horizontal elements of mason

door openings;

2. piers consists of masonry vertical elements between the window openings;

3. structural wall or pillar of a structural wall.


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1. Masonry elements

Provisions of this Code shall apply to the design of all parts / masonry construction elem

nonstructural, executed with the following types of masonry elements corresponding to

burnt clay masonry units - SR EN 771-1;

masonry elements of autoclaved aerated concrete (AAC) - SR EN 771-4;

1.2. Masonry elements grouping

1.2.1. Grouping according to the confidence level ofmechanical properties

a. The average compressive strength of the element: the arithmetic average of the com

the elements.

b. The characteristic compressive strength of the element: value of the strength o

prescribed probability of 5% of not being attained in a hypothetically unlimited te

generally corresponds to a specified fractile of the assumed statistical distributproperty of the material or product in a test series. A nominal value is used as the c

some circumstances.

c. The standardized compressive strength of the element: the compressive strength o

to the equivalent strength of an "air dried" element of 100 mm width and 100 mm heig

d. Masonry element Category I: masonry element for which the probability of failing

average/characteristic strength is 5%.

e. Masonry element Category II: masonry that does not meet the level of confidence of m


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1.2.2. Grouping on the basis of the geometrical characteristics

(1) Masonry elements are grouped according to the values of following geometrical par

a. volume of voids (% of GDP gross volume);

b. volume of each void (% of GDP);

c. minimum thickness of internal and external wall (mm);

d. cumulative thickness of interior and exterior walls in each direction (% of the siz

direction).

Figure 3.1. Internal geometry of a cored brick

A - void-handling area; a - the current void-area; te - the thickness of the outer wall; ti - t

inner wall.

The implementation of structural masonry walls shall be used only burnt clay bricks or

of autoclaved aerated concrete (AAC) assigned to groups 1 and 2, which have the propeP100-1-2013


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Inner vertical wall elements shall be continuous throughout the length of the element (in the pstructural masonry walls, and other items can be used in group 2: burnt clay bricks and vertic

special geometry (with thin walls - Group 2B) which satisfy the following conditions on the geome

a. voids volume 50% of the block;

b. outer wall thick 11mm te 25

Each void volume (%from the gross

volume)

12.5%- Each of multiple voids 2

- Each of handling voids

declared value of the

inner and outer wall

thickness (mm)

Without requests

Inner wall Ou

ag0.15g ag0.20g ag0.15g

5 10 8

GEOMETRICAL PROPERTIES FOR MASONRY ELEMENTS


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1.2.3. Grouping from the masonry exteriorprofile point ofview

In terms of masonry exterior profile faces the masonry elements are classified as follo

elements with all sides flat (no prints or profiles, with/without internal cavity for

elements with mortar pocket; elements with mortar pocket or with mortar additional prints;

elements with profile "tongue and groove".

1.2.4. Grouping element according to the apparent density in the dry state

(1) The wall elements are grouped according to the apparent density in the dry state as

Elements LD (low density) - masonry elements with low density in dry conditio

used only in protected masonry

Elements HD (high density) masonry elements of burnt clay masonry units

conditions > 1000 kg/m3 and masonry facade elements (masonry unprotected a


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(2) The burnt clay masonry for which, depending on the volume of voids, dry conditio

kg/m3 and all the AAC elements fall within LD (low density).

(3) To compute the self-weight of the masonry (load on the structure and foundations

seismic action, etc.) masonry elements density is calculated approximately as follows:

For burnt brick elements the design density - with relation (kg/m3) = 1800 (1-vgol

volume of voids which develop along the entire height of the item (not including the finFor AAC elements the design density (which takes into account the average humidity

relation (kg/m3) = 8 5 ( f b +2) where fb is the average standardized strength in N/mm2.

(4) To calculate the design weight for unplastered masonry LD elements and general

normal thickness joints will take into account the weight of the mortar as follows:

average thickness of a vertical and horizontal joints will take trost = 12 mm

the average density of the grout will take m = 2000 kg/m3.

(5) To calculate the design weight for unplastered masonry LD elements and thin joints

equal to the design weight as defined above.

(6) To calculate the design weight for unplastered masonry HD elements, regardless

(G or T) will be equal to the design weight as defined above masonry .


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SPECIAL REQUIREMENTS FOR MASONRY

The provisions of this chapter refers to masonry wall structures made with these t

burnt clay, filled and hollow vertical (EN 771-1);

autoclaved aerated concrete - AAC (EN 771-4).

Vertical cored masonry used in areas with seismic acceleration ag0.20g must

conditions: One void area 1200 mm2

Interior vertical wall continues throughout the length of the (the plane of the wa

In terms of specific design and execution established by this Code, for structu

and other items can be used in group 2: burnt clay bricks and vertical cored b

geometry (thin walls - Group 2B) satisfying the following conditions on block geom

voids volume 50 % of the block;

outer walls thickness 11mm te

< 15mm;

inner walls thickness 6mm ti < 10mm;

vertical interior walls are made continuously throughout the length of the ele

the wall).

To implement structural masonry walls, regardless of design land accelera

Category I masonry units, except buildings mentioned below.

Category II masonry can be used only for:

structural walls in buildings of importance classes III and IV in areas with ag 0

structural walls and household annexes temporary buildings in all seismic zon


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MECHANICAL PROPERTIES OF MASONRY

For masonry charged only with gravitational loads type, the relevant design compressi

the direction perpendicular to the horizontal joints. In the case of seismic loads charge

particular for masonry with vertical cored elements, the compression strength must be

both perpendicular and parallel to void directions, since the simultaneous action of the

horizontal loads develop in the plane of the wall a bidirectional compression stress staimportant component parallel to horizontal joints (layer).

Determination of compressive strength of masonry

RD 1 - perpendicular to the layer (D1) RD 2 - the plane of the wall (D2


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COMPRESSIVE STRENGTH OF MASONRY

fb - uniform standardized compressive strength of masonry normal on the horizontal jo

The compressive standardized strength is the strength to compression of masonry tra

masonry in equivalent air having 100 mm width x 100 mm height. On request, the

declare standardized compressive strength. It is determined and declared by the m

basis of average strength obtained by testing according to EN 772-1.

Compressive strength fb standard is defined by two values, depending on the position

force against the face of the alignment:

normal to horizontal joint (layer) fb;

parallel to the horizontal joint in the wall plane fbh (compression at the edges).


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PHYSICAL PROPERTIES OF MASONRY

Depending on the intended use at the design, for items made of burnt clay used for out

protection or with limited protection, will consider the following physical properties as

1:

apparent density and absolute dry;

water absorption the masonry capacity to absorb mortar water and / or from th

greatly influence the mechanical resistance and durability of masonry; a part of

absorbed by the element until an apparent condition surface saturation ; bricks

but which are moist on the inside gives the best grip.

Active soluble salt content.

For AAC masonry elements shall consider the following physical properties as defined

The absolute and apparent density in the dry state, at the end of the autoclaving proces

contains water in a proportion of about 30 % by weight. While, after a period of 912 mowater is eliminated to leave a water content of only 5 to 8% by weight (the equilibrium m

water vapor permeability;

water absorption;

thermal properties.

MORTARE


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MASONRY MORTARS

Ensure the masonry

body

Linking masonry after rupture by adherence and friction;

Transmit and standardize the internal efforts and some strains betw

Assure the compressive , tensile and shear strength; Protects against water infiltration and air from outside the building

Participate at the plastic image of the building by color or spec

apparent masonry / unplastered);

In mortar the beds the reinforcements are included and fitted

(connectors, anchors);

G

Masonry mortars for

general use: mortar notset special conditions of

design and / or use

Method of defining the composition:

Performing masonry mortar (designed mortar for) compositiochosen by the manufacturer to obtain the specified characte

Recipe for masonry mortar (prescribed composition for maso

Composition of mortar for general use - Table 3.1

How to make: industrial mortar for masonry (dry or fresh) and mix constituents are semi-industrial masonry mortar (pre-dosed or premixed) constit

delivered to site where they are mixed according to the recipe givMasonry mortar preparation at construction site, will be used to: Buildings of importance classes III and IV, in all seismic zones; Buildings of importance classes II in seismic areasag0,15g; Household annexes and temporary constructionMasonry mortars are classified according to EN 998-2, accordi

expressed by the letter M followed by uniform compressive strengthaverage unit compressive strength fm= 5N/mm

2).

Mortar class Cement Sand

M2.5 c 1 4

M2.5 c-v 1 7

M5 c 1 3

M5 c-v 1 5

M7.5 c 1 2.75 M10 1 2.5


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T

Thin layer mortar for masonry. Performance mortar for masonry with t

less than or equal to the value indica

polymer additives and other special c

shrinkage and improve workability witho

0.5-3mm, but their use requires proc

production unlevelings, mortar is applied

for brick masonry elements.

GROUT

It is a G type mortar. Cement, sand, gravel mono granular a

water; It can be powerful recipe or

GLUE MORTAR

Performance mortar for masonry with cem

(polymer); is used for thin beds and only m

by these specifications.


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PERFORMANCE REQUIREMENTS

FOR DRY MORTAR

Adhesion to masonry

In a simplified manner, the phenomeno

explained by entering the pores of the m

water and fine particles originating from th

after hydration, it hardens to form a crys

properties different from those of mortar

intimate connection with the complex char

chemical mortar with masonry.

Adhesion depends on the properties of t

for water retention capacity of mixing), thelements to be used together with the mor

water absorption rate) and quality of execu

quantify the adhesion bond strength

element;

ensure the bonding mortar :

resistance to tensile and / or

exterior;

resistance to dimensional change

(of shrinkage or temperature); penetration of water and air tightn

In operation, the deterioration of bond

masonry, is a fragile and can produce:

exceptional character, after the act

seismic forces, cracks can propaga

severe damage or even collapse;

foundation failure, deformations ca

changes, cracks can be sources of w

occurring in exterior walls.


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UNITARY MORTAR STRENGTH

fm

Average unit compressive streng

masonry with elements of b

elements used to design and spe

the project will be chosen so

relations (4.1), (4.2a) or (4.2b), to o

minimum characteristic resistarequired by P 100-1, tables 8.2 an

on design seismic acceleration a

building height.

Class mortar for masonry determ

(2) must satisfy the sustainability

Cap.4.3.

fvko

Adhesion shear strength declare

strength fvk0

fxk1

Adhesion flexural strength - t

strength for bending for bre

parallel to the joints involved (fxk

fxk2

Adhesion flexural strength - t

strength for bending for bre

perpendicular to the joints involve


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CONCRETE

Concrete is used for:

alveoli or voids fill for reinforced masonry special shaped elem

confinement elements for masonry elements (column and beam

reinforced core for reinforced core masonry (ZIA/RCM);

coupling beams (spandrels) for masonry structural walls for do

openings.

fck (N/mm2) - characteristic compressive strength associated wcube / cylinder at 28 days;

fcvk (N/mm2) - characteristic shear resistance;

for items confinement minimum class C12/15 concrete will be.

the middle layer of the walls of ZIA will use concrete

characteristic compressive strength 12 N/mm2 fmbk or concret

Concrete mortar (grout) is defined as a "very fluid mixture of ceme

for filling the alveoli or small spaces."

The material is used to fill openings in special forms used for reincentral reinforced core masonry (ZIA/RCM). The ability to complet

other confined spaces should be considered the main requiremen

Unit strength for concrete:

fcd - design compressive strength of concrete 6.6.3.3. (5)

fcd * - baseline design compression resistance of concrete 6.6.3

Rc * (baseline)

fck - unitary characteristic compressive strength of concrete 3.3


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Mechanical properties of concrete for containment elements and ZIA - Ta

Design values (N/mm2) Casting height (cm)Class of concrete /

C12/15

Tensile strength

(yM=1.50)

150 0.55


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confinement of the masonry elements beams and columns ties - ( ZC ) ;

confinement of the masonry elements and reinforcement in horizontal joints ( ZC

middle layer of the reinforce cored masonry ( ZIA ) ;

other structural elements: floors, coupling beams (spandrels) and cored brick wa

basement walls , foundations

The reinforce steels in Table 8.7.will be from ductility class B to ST 009 , except for steel

areas with ag 0.25g , the reinforcement for confinement elements (beam and column ti

coupling beams (spandrels) and to reinforce masonry in joints or beds, on the ground fl

with height P +2 E which will use steel ductility class C.

The longitudinal modulus of elasticity for reinforcement will be Es = 200000 N/mm2.

Coefficient of thermal expansion of steel will take ts = 12x10 - 6/1 C.

Masonry reinforcement can have two objectives:

enhancing the strength and ductility of the requests or perpendicular to the plane of the

reduce cracking caused by local concentration of effort or movement from thermal effechumidity.

OTHER MATERIALS FOR THE REINFORCEMENT OF MASONRY

Masonry can be armed with:

High- density polymer grids

FRP

insertion of products in bed joints;

insertion of products in the plaster.


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Minimum mechanical properties of steels used for confinem

and reinforcement masonry and ZIA elements

Steel typeYield limit Design dtreng

Re (Rp,02) (N/mm2) fyd (N/mm2)

Strength category 2 340 300

Strength category 1 240 210

DESIGN VALUES FOR MECHANICAL PROPERTIES OF MASONRY


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DESIGN VALUES FOR MECHANICAL PROPERTIES OF MASONRY

All masonry unitary strength design values (f zd), for all requests are obtained by dividing the cha

values (f zk) the partial safety factor for material

.

=

(2.1)

Partial safety coefficient

(taking into account the uncertainties and dimensional variations for

differently depending on:

load case for checking: fundamental and seismic; limit state check: ULS or SLS;

quality of masonry elements and mortar;

execution control type defined in applicable technical regulations.

Partial safety coefficient values

- To calculate the ultimate limit state (ULS), the fundamental lo

clay masonry bricks - see Table 2.1.

Element

category

Mortar Control type

Reduced Normal Spec

1st Category From recipe, prepared onto site (G) 2.7 2.5 2.2

From recipe, industrially prepared (G) 2.5 2.2 2.0

Performance (T) and (G) - 2.0 1.8

2nd Category From recipe, prepared onto site (G) 3.0 2.8 2.5

From recipe, industrially prepared (G) 2.7 2.5 2.2

Partial coefficient values are taken as follows:


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Element

category

Mortar Co

Reduced

1st Category From recipe, prepared onto site (G) 2.4

From recipe, industrially prepared (G) 2.2

Performance (T) and (G) -

2nd Category From recipe, prepared onto site (G) 2.7

From recipe, industrially prepared (G) 2.4

Partial coefficient values are taken as follows:

for persistent design situation (the fundamental load case):

o for the ultimate limit state (ULS) in Table 2.1

o for serviceability limit state (SLS) with values:

= 1,50 for all parts / components of masonry buildings of importance assigned

according to P 100-1

= 1,0 for all parts / components of masonry buildings of importance placed in c

for seismic design situation (seismic load case):

values of P 100-1, tab.8.13 for structural walls;

Table 8.13


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To check the masonry strength for transient design situation (during construct

strength values set for the fundamental load case is increased by 25%.

The conditions are considered as a normal control type for execution if:

works are monitored on an ongoing basis by a RTA engineer ; designer look for / control, rhythmic the progress of work ;

the RTA permanently verifies the materials quality and the work ;

all preliminary checks are performed even for intermediate stages taking

regulations.

Conditions are considered as a reduce control type for execution if:

works are not monitored on an ongoing basis by a RTA engineer ;

designer does not look for / control, rhythmic the progress of work ; the RTA does not permanently verifies the materials quality and the work ;

all preliminary checks are not performed even for intermediate stages takin

regulations.


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The definition of characteristic strength (Rk) of masonry: is "the masonry stre

probability of being reached is 5% in a series of alleged attempts (hypothetical) unlimit

According to this definition, if one accepts the assumption of normal distribution of t

the characteristic strength is calculated from the average resistance values and coe

by relationship:

Rk = Rmed (1-1.645vR)

=

- Average strength =

standard deviation

=

Coefficient of variation

fk CHARACTERISTIC

COMPRESSIVE

STRENGTH

OF

MASONRY

UNIT


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fk CHARACTERISTIC COMPRESSIVE STRENGTH OF MASONRY UNIT

With burnt brick masonry elements or AAC elements, erected with gen

for normal loads to the joints horizontal plane shall be calculate

compression unit strength for masonry and plaster, with the relationsh

= .

. (4.1)

Values of the constant K for ceramic brick masonry and mortar for gen

Table 4.1.

Characteristic values for fk for burnt clay masonry elements in Grou

the standardized strength fb = 5.0 15.0 N/mm2 with M2.5 M15

calculated with formula (4.1) in view of the conditions from (3) are g

and 4.2b.

Masonry element type Consta

Solid ceramic elements (group 1) 0.5

Vertical cored elements (group 2 and 2S) 0.4

AAC elements (group 1) 0.5

fk Characteristic compressive strength (fkn N/mm2) of burnt clay mason

f 1 d l t (G) i fi 4 1b T bl 4 2


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from group 1 and general mortar (G) - weaving as fig.4.1b - Table 4.2a

Characteristic compressive strength (fk n N/mm2) of vertical cored

made of burnt clay in Group 2 and 2S and for general mortar (G) - wea

4.1b - Table 4.2b

Standardize strength fb (N/sq.mm)Mortar strength (N/sq. mm)

M15 M12.5 M10 M7.5

15.0 6.60 6.25 5.85 5.35

12.5 5.80 5.50 5.15 4.70

10.0 4.95 4.70 4.40 4.05

7.5 4.05 3.85 3.60 3.30

5.0 NA 2.70 2.50

Standardize strength fb

(N/sq.mm)

Weaving type

Fig. 4.1.

Mortar strength (N/sq. mm)

M15 M12.5 M10 M7.5

15.0a 6.75 6.40 6.00 5.50

b 5.40 5.10 4.80 4.40

12.5a 5.95 5.60 5.25 4.80

b 4.75 4.50 4.20 3.85

10.0a 5.10 4.80 4.50 4.15

b 4.10 3.85 3.60 3.30

7.5a 4.15 3.95 3.70 3.35

b 3.30 3.15 2.95 2.70

5.0a

NA2.75 2.55

b 2.20 2.05

fk Characteristic compressive strength fk in N/mm2 for masonry solid br

Group 1 and for general mortar (G) weaving as Fig 4 1 Table 4 2c


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Group 1 and for general mortar (G) - weaving as Fig.4.1 - Table 4.2c

Figure 4.1 Composition of masonry

(a) without mortar joint parallel to the wall (b) with mortar bed joints pa

Standardize strength fb (N/sq.mm)Mortar strength (N/sq. mm)

M15 M12.5 M10 M7.5

8.0 5.31 5.03 4.70 4.31

7.0 - 4.58 4.28 3.93

6.0 - - 3.84 3.53

5.0 - - 3.38 3.10

4.0 - - - 2.66

3.0 - - - -

fk For structural walls with elements of burnt clay bricks and AAC:


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y

Table 8.2.Minimal required values for characteristic compressive stren

structural walls of buildings of importance classes III IV

Number of levels nnivHorizontal land design accelera

0.10g and 0.15g 0.20g and 0.25g

1 1.70 2.15

2 1.85 2.30

3 2.00 2.50

4 2.50 3.00

5 2.70 -

Documents

Masonries Structures - Part I