polymeric grids rm~presentation

REINFORCED MASONRY

WITH POLYMER GRIDSMasonry Buildings without RC Members

Prof. Daniel STOICA

Great Natural Catastrophes

Number of Great Natural Catastrophes


Economic losses in billion dollars


Dynamics of the number and economic losses

along five decades of the last century


Number and economic losses in 2000


Long term effects of catastrophes

European Macroseismic Scale EMS-98

Grade 5: Destruction

Grade 1: Slight damage

Grade 2: Moderate damage

Grade 3: Heavy damage

Grade 4:

Very heavy damage

HISTORY OF SCIENCE9,000 years ago - PALESTINE: Brick Masonry

MASONRY: Brittle Brick + Ductile Mortar

Question:

How and Why masonry as a construction material

was lasting so long?

Theory of Dislocation

The two models: one for force as vector (Newton) and another for stress as tensor (Pascal)


Concentration of stresses around a fault


Variation of stress with area for a constant force:

Bernoulli’s Hyperbola

EUROCODE 2: Ductility

Typical stress-strain curve for steel reinforcement

Answer:

Due to its ductility masonry is endowed with the capacity of self-protection by adaptation in time

CEMENT – the first discover of

Industrial Revolution

against masonryCORED BRICKS – the second

discovery of Industrial Revolution against masonry

HISTORY OF SCIENCE

Question:

Shall the factories producing cement

and cored bricks

be closed?

Eurocode 8 Provisions :

1. Reinforcing with steel reinforcement embeded in cement mortars

2.Confining with RC structural members

MATHEMATICAL THEORY OF PLASTICITY

a. Vertical force P b. Horizontal force Q

Prandtl’s Model - 1923

Limit state of tangential stresses

Shear compression diagram

P

Relation between compression and shear ,

where k is the maximum value of tangential stress

Final solution of the state of stresses in the mortar layer


Normal stress σx in x direction for y = 0

Normal stress σx in x direction for y = ±b

Normal stress σy in x direction


Variation of stresses on the thickness of mortar layer

Force of expulsion and prevention measure

Bed joint reinforced with polymer grid Reinforcement layout

Answer: No

By reinforcing masonry with polymer grids its

original capacity of self-protection is entirely restored

BASIC CONCEPT OF REINFORCING MASONRY

Isometric view of masonry structural member reinforced in horizontal layers

TENSAR®

Polymer Grids of high Strength and Density

with

Integrated Joints

Tensar® process

Performances of TENSAR grids - Bucharest 2001

dANA

fA

N

Bernoulli’s equilateral hyperbola

A f= constant

p = bf = constant


Congruence of Bernoulli’s hyperbola

Geometry of mono-axial grids Geometry of biaxial grids



Mechanism of stress transfer around integrated joints

Shear forces developed around integrated joints


Geometric Characteristics of Tensar SS Grids

Stress – Strain Diagrams


STATIC TESTS

on 1D models of

Short Columns

and 2D models of

Wall PanelsEC Peco Project 1994/96

EQ Engineering Laboratory of INCERC Iasi

Short columns of plain and reinforced masonry


Wall panels of plain and reinforced masonry/plaster submitted to axial compression


Wall panels of plain and reinforced masonry/plaster submitted to diagonal tension


Short columns of reinforced and confined masonry submitted to axial compression


Wall panels of confined masonry submitted to axial compression and diagonal tension

EC Peco Project 1994/96

SEISMIC TESTS

on 3D models of

Masonry Buildings

without RC members

Shaking Table of ISMES Bergamo, Italy

3D model of a masonry building without RC members before and after testing


3D model of a masonry building without RC members confined by two belts of reinforced plaster


Test on the shaking table at 14 dB


Seismic response of the model before and after repair

E U R O Q U A K EEC Inco Copernicus Project 1997/99

PSEUDO-DYNAMIC TESTS on 2D models

of Masonry Infills

without RC members

Reaction Wall of ELSA – JRC Ispra (Varese), Italy

Set up infill models of wall panels without openings


Layout of reinforced masonry infill without openings


The wall panel without openings prepared for testing


Damage pattern in the plain masonry infill without openings after occurring the failure mechanism


Pseudo-dynamic test with a frequency of 5 Hz


Damage pattern in the reinforced masonry infill without openings after the failure mechanism


Comparative hysteretic diagrams for wall panels without openings of plain and reinforced masonry


Envelope curves for the wall panels without openings


Set up infill models of wall panels with two openings


Layout of reinforced masonry infill with two openings


Vertically perforated bricks and the polymer grid used as reinforcement in the testing program


Reinforced masonry wall panel with openings confined with polymer grids Tensar SS30 before plastering


Pseudo-dynamic test with a frequency of 5 Hz


Damage pattern in the plain masonry infill with openings after occurring the failure mechanism


Damage pattern in the reinforced masonry infill with openings after occurring the failure mechanism


Comparative hysteretic diagrams for wall panels with openings of plain and reinforced masonry


Envelope curves for the wall panels with two openings

E U R O Q U A K EEC Inco Copernicus Project 1997/99

SEISMIC TESTS on 3D Models of Buildings

with RC frames and

Masonry infills


Masonry infill reinforced in bed layers with polymer grids Tensar SS20


3D model of a RC frame with masonry infills reinforced in bed layers before testing


Ground floor infill without openings


Cracks in the lower joint of RC frame

No X cracks in the reinforced masonry

infill


Cracks in the middle joint of RC frame


infill


Cracks in the upper joint of RC frame


infill


Deepening the bed joints


Plastic tubes for the fixing devices


Masonry wall prepared for installing the grids


Installing the grids over masonry infill and RC frame


Details of installed grids


The wall after installing the grids


Wrapping around the grids


Manual Plastering


3D model of a RC frame with masonry infills after confining and before the second series of tests


Cracks in the middle joint of RC frame; no X cracks


Cracks in the upper joint of RC frame; no X cracks

Comparative Analysis – SAP 2000

NUMERICAL VALIDATION

of the Tests on Physical Models

Comparative analysis –SAP 2000

Reference model

Comparative analysis – SAP 2000

The three models considered in comparative analysis


Corresponding drifts and overturning moments

Maximum response displacements

Maximum response velocities and accelerations


Time history of displacements at the first level of reference model

Time history of velocities at the first level of reference model

Time history of accelerations at the first level of reference model


Time history of kinetic energy at the first level of reference model

Time history of dissipated energy at the first level of reference model

Time history of potential energy at the first level of reference model


Influence of synthetic reinforcement on lateral deformation (a) and drift (b)

Inelastic response spectra of displacements for PGA=0.20 and r = QYB/QEB

Inelastic response spectra of accelerations for PGA=0.20 and r = QYB/QEB


Inelastic response spectra of velocities for PGA=0.20 and r = QYB/QEB

Inelastic response spectra of input energy for PGA=0.20 and r = QYB/QEB

Inelastic response spectra of kinetic energy for PGA=0.20 and r = QYB/QEB

ECOLEADER - Seriate 2001

SEISMIC TESTS

on 3D models of

Masonry Buildings

without RC members

The model of cored brick masonry with a curved

wall without openings and covered with a RC slab

without belt

Plan of the shaking table and basic steel frame

Masonry Buildings without RC Members

Plan of the model at levels 0.00 and 2480 mm


Plan of the model at level 510 mm


Plan of the model at the level 1500 mm


Coordinates of the three centers of reference


Center of Table:

CT (x=-140; y=0.00; z= -300)

Center of Gravity:CG (x=0.00; y=61.0; z=1665)

Center of Rotation:CR (x=0.00; y=1305; z=2000)

Shaking Table of

ISMES Bergamo,

Italy

Installing the model of cored brick

masonry reinforced in bed layers on the

shaking table

The model of cored brick masonry prepared for testing program


Testing program of the model of cored brick masonryreinforced only in bed layers


Shaking Table of

ISMES Bergamo,

Italy

The curved wall of the model after test


The model after the first series of tests

Map of cracks on Western Front: outside-left; inside-right


Map of cracks on Southern Front: outside-left; inside-right


Map of cracks on Northern Front: outside-left; inside-right


Map of cracks on Eastern Front: outside-left; inside-right


The model of cored brick masonry after confining


Testing program of the model of cored brick masonryafter confining


The model of cored brick masonry after confining prepared for testing program


Cracks on the outer walls of model


Cracks around the inner corner of curved wall


Crush of the cored bricks during tests while the polymer grids remained integer


The model of solid brick masonry with vaulted openings and covered with a wooden slab without any RC belt

Plan of the shaking table and basic steel frame


Plan of the model at levels 0.00 and 2480 mm


Coordinates of the three centers of reference


Center of Table:

CT (x=-160; y= 140; z= -300)

Center of Gravity:CG (x= 417; y=0.00; z= 1450)

Center of Rotation:CR (x=1485; y=0.00; z= 870)


The model of solid brick masonry prepared for testing program

Testing program of the model of solid brick masonryreinforced only in bed layers


The model after the first series of tests


Map of the outside cracks on Western Front


Map of the outside cracks on Southern-left and Northern-right Fronts


Map of the outside cracks on Eastern Front


Installing the model of solid brick masonry

after confiningon the shaking table

Shaking Table of ISMES

Bergamo, Italy

Testing program of the model of solid brick masonryafter confining


The model of solid brick masonry after confining prepared for testing program


The model after the second series of tests


Failure pattern in Tensar SS20 after 18 dB = 1.96 g


Comparative Analysis – SAP 2000

NUMERICAL VALIDATION

of the Tests on Physical Models

July 2001

Model of cored brick masonry reinforced only in bed layers

Model of cored brick masonry reinforced only in bed layers:First mode of vibration


S11 (11) –Front wall, Sidewall and Back wall


[kPa]


Model of cored brick masonry reinforced only in bed layers: Second mode of vibration


[kPa]



Model of cored brick masonry reinforced only in bed layers: Third mode of vibration


[kPa]


November 2001

Model of cored brick masonry reinforced in

bed layers and confined


Model of cored brick masonry reinforced in bed layers and confined: First mode of vibration


[kPa]



Model of cored brick masonry reinforced in bed layers and confined: Second mode of vibration


[kPa]



Model of cored brick masonry reinforced in bed layers and confined: Third mode of vibration


[kPa]


July 2001

Model of solid brick masonry reinforced only in bed layers


Model of solid brick masonry reinforced only in bed layers: First mode of vibration


[kPa]



Model of solid brick masonry reinforced only in bed layers: Second mode of vibration


[kPa]S22 (22) –Front wall, Sidewall; Back wall


Model of solid brick masonry reinforced only in bed layers: Third mode of vibration


[kPa]


November 2001

Model of solid brick masonry reinforced in

bed layers and confined


Model of solid brick masonry reinforced in bed layers and confined: First mode of vibration


[kPa]

S11 (11) –Front wall, Sidewall; Back wall


Model of cored brick masonry reinforced in bed layers and confined: Second mode of vibration


[kPa]



Model of cored brick masonry reinforced in bed layers and confined: Third mode of vibration


[kPa]


Dissipated Energy

during

Seismic Excitation

Model of cored brick masonry reinforced only in bed layers: Mass Damping Energy



Model of cored brick masonry reinforced in bed layers and confined: Mass Damping Energy


Model of solid brick masonry reinforced only in bed layers: Mass Damping Energy


Model of solid brick masonry reinforced in bed layers and confined: Mass Damping Energy

Model of cored brick masonry: increase of dissipation capacity after confining


Model of solid brick masonry: increase of dissipation capacity after confining


Study Cases

Romanian Ministry of Public Works

TECHNICAL AGREEMENT008 – 01/017 - 1999

Based on decision Nr. 908016 / 8.12.1999

September 1999

First Application:

Nuci, Ilfov County

Retrofitting a two story building with RC frames

built in 1929

Preparing the surfaces on

the front side

First Application1999

Preparing the surfaces

Preparing the surfaces on the lateral side

Installing the grids on the walls of ground floor

with special care for inner corner

First Application1999

Reinforcing the wall under the opening for window

July 2001

Second Application:

BucharestStr. Av. Gh. Stalpeanu 21

Retrofitting a two story building without RC built in 1934

Preparing the surfaces for installing the grids

Preparing the surfaces for

installing the grids

Second Application

2001

Preparing the surfaces for installing the grids

Preparing the surfaces for

installing the grids

Second Application

2001

Installing the grids over the round corner

Installing the grids over the round

corner

Second Application

2001

polymeric grids rm~presentation

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