Experimental analysis of the efficiency of carbon fiber anchors applied over CFRP to firebrick ...

209 Pages·2013·16.65 MB·English

Università degli Ministero dell’Istruzione

Studi di Catania dell’Università e della Ricerca

Experimental analysis
of the efficiency of carbon fiber anchors
applied over CFRP to firebrick bonded joints

CARMELO CAGGEGI

PHD SCHOOL ON “INGEGNERIA STRUTTURALE E GEOTECNICA” - XXV CICLO
UNIVERSITY OF CATANIA (ITALY)

PHD SCHOOL ON “SCIENCE, INGENIERIE ET ENVIRONNEMENT”
UNIVERSITY PARIS-EST (FRANCE)
Experimental analysis
of the efficiency of carbon fiber anchors
applied over CFRP to firebrick bonded joints

Phd Thesis

CARMELO CAGGEGI*

Italian Supervisor - University of Catania

Professor Massimo Cuomo

French Supervisor - University of Paris-Est Marne-La-Vallée

Professor Luc Chevalier

Others members of thesis group

Ass. Prof. Vincent Pensée (UPE MLV), Ass. Prof. Loredana Contrafatto (UNI CT)

PHD SCHOOL ON “INGEGNERIA STRUTTURALE E GEOTENICA” - XXV CICLO
UNIVERSITY OF CATANIA (ITALY)

PHD SCHOOL ON “SCIENCE, INGENIERIE ET ENVIRONNEMENT”
UNIVERSITY PARIS-EST (FRANCE)

* EMAIL ADDRESS: [email protected] TEL. MOBILE : [phone]
Phd Thesis

Discussed and defended in public by

CARMELO CAGGEGI*

on 21 MARCH 2013 in the University of Catania

Commission:

Reporter: SACCO Elio (Professor),
University of Cassino and of the meridional Lazio.

Reporter: MEFTAH Fekri (Professor),
INSA Rennes.

Examiner: ASCIONE Luigi (Professor),
University of Salerno.

Examiner: FAGONE Mario (Ass. Professor),
University of Florence.

Examiner: PENSEE Vincent (Ass. Professor),
University of Marne-La-Vallée Paris-Est.

French Supervisor : CHEVALIER Luc (Professor),
University of Marne-La-Vallée Paris-Est.

* EMAIL ADDRESS: [email protected] TEL. MOBILE: [phone]
To Mariella
This research has been financed by
the Italian Ministry of Education, University and Research (Phd scholarship).

A scholarship “Vinci_2010” has been conferred by
the University “Italo-francese” (UFI) to this research work.

Two annual scholarships (2011_2012) of “soutiene à la co-tutele” have been conferred by
the Phd School SIE (University Paris Est) to this research work.

The experimental session in France has been financed by
the ESIPE (Ecole Supérieure d'ingénieurs Paris-Est Marne-la-Vallée) and
the laboratory MSME (Modélisation et Simulation Multi échelle).
I would like to thank:

Prof. Massimo Cuomo
For his guidance during my Phd studies, the encouragement and for the aid to generate the scientific
collaborations

Prof. Luc Chevalier
For his supervision, for the sound advices, for the confidence and for the warm welcoming

Ass. Prof. Vincent Pensée
For his encouragement, continual support and for his great availability

Ass. Prof. Mario Fagone
For the collaboration in the experimental session and for the great availability.

Ass. Prof. Giovanna Ranocchiai
For the work implemented in the experimental session in Florence

Prof. Silvia Briccoli Bati
For her contribution in the experimental phases in Florence

Ass. Prof. Anas Batou
For the assistance in the use of the“Code Aster – Salome Meca” software

Ass. Prof. Loredana Contrafatto
For the assistance and guidance in some difficult situations

Benoit Proust
For the passion that he showed during the construction of the steel experimental apparatus

Giuliana Di Iacovo
For the meticulously construction of the test specimens

I want also to thank Prof. Giuseppe Oliveto, for the passion that he showed in the coordination of the
doctoral school of Catania, the Ass. Prof. Rosa Caponetto, for her continual encouragement, and Madame
Cecile Blanchemonche for her availability.

I’m very grateful to my girlfriend Mariella, that encourage me also from 2000 km of distance with love and
patience (TJ). A big “grazie” to my sister Anna Maria that gave me aid and a lot of energy. I would like to
thank also my mother and my father for their support and to my grandparents their cheer.
During the three years of phd studies I had the luck to meet very special people that helped me and
encouraged me during the most difficult phases of my research; each one of them can find his/her “Thank
you” below:
grazie merci cám an gracias 谢谢 ευχαριστώ
English abstract

Author - Caggegi Carmelo

IN THESE RECENT YEARS, THE STRENGTHENING OF MASONRY BUILDING HAS KNOWN A MASSIVE USE OF CFRP
SHEETS. THOSE COMPOSITE MATERIALS GLUED ON THE ELEMENTS TO REINFORCE ARE EXPOSED TO PREMATURELY
DEBONDING CRISIS DUE TO A TENSION LOAD WHICH IS MUCH SMALLER THAN THE TENSILE STRENGTH OF THE CFRP.
ONE WAY TO UPGRADE FAILURE LOAD OF CFRP-TO-SUPPORT BONDED JOINT IS TO REINFORCE THE COHESION
BETWEEN THE FIBERS AND THE SUPPORT BY THE USE OF MECHANICALS ANCHORS BUILT WITH THE SAME FIBERS OF
THE COMPOSITE AND FASTENED IN THE SUPPORT LIKE “NAILS”. RESEARCH ON THE USE OF ANCHORS FOR MASONRY
SUPPORTS HAS BEEN LIMITED AND, IN THIS FRAMEWORK, THERE ARE NO EXPERIMENTAL ANALYSES RELATED TO
THE DESIGN AND THE PLACEMENT OF FIBER ANCHORS.
THE AIM OF THIS THESIS IS TO PROVIDE EXPERIMENTAL DATA TO QUANTIFY THE EFFICIENCY OF THE CARBON FIBER
ANCHORS APPLIED ON A REINFORCED FIRE BRICK. THIS IS A GROUND WORK TO STUDY CFRP TO MASONRY BONDED
JOINT FASTENED BY FIBER “NAILS”. SPECIFICALLY, THE ANALYSIS OF THE DISPLACEMENT AND THE STRAIN FIELDS OF
THE REINFORCED SURFACE HAVE BEEN REALIZED BY MEANS OF DIGITAL IMAGE CORRELATION (DIC), AN OPTICAL
APPEALING METHOD NEVER USED TO STUDY A FRP TO SUPPORT BONDED JOINT FASTENED BY FRP ANCHOR.
THE RESEARCH DEMONSTRATES THAT THE USE OF THE CFRP ANCHORS INCREASES THE RESISTANCE AND THE
DUCTILITY OF THE REINFORCEMENT.
Italian abstract

Autore: Caggegi Carmelo

NEGLI ULTIMI ANNI IL RINFORZO DELLE STRUTTURE IN MURATURA HA CONOSCIUTO UN USO MASSIVO DELLE
BANDE IN CFRP. QUESTI MATERIALI FIBROCOMPOSITI, INCOLLATI SUGLI ELEMENTI DA RINFORZARE, SONO ESPOSTI
A UNA CRISI CAUSATA DA DEBONDING A TENSIONI MOLTO PIÙ PICCOLE DELLA RESISTENZA A TRAZIONE DEL
COMPOSITO. UNA POSSIBILE SOLUZIONE PER INCREMENTARE IL CARICO ULTIMO DI QUESTI SISTEMI RINFORZATI È
MIGLIORARE L’ADERENZA TRA LE FIBRE E IL SUPPORTO USANDO PARTICOLARI ANCORAGGI MECCANICI. QUESTI
ULTIMI, REALIZZATI CON LE STESSA TIPOLOGIA DI FIBRE DEL MATERIALE DI RINFORZO, VENGONO INFISSI
ALL’INTERNO DEL SUPPORTO COME DEI VERI E PROPRI “CHIODI”. LA RICERCA INERENTE L’USO DI QUESTA
TIPOLOGIA DI ANCORAGGI SU SUPPORTI IN MURATURA È MOLTO LIMITATA E, IN QUESTO CONTESTO, NON
ESISTONO ANALISI SPERIMENTALI CONNESSE AL PROGETTO E ALLA COLLOCAZIONE SPAZIALE DI QUESTI DISPOSITIVI
MECCANICI.
L’OBIETTIVO DI QUESTA TESI È DI PROVVEDERE DEI DATI SPERIMENTALI ATTI A QUANTIFICARE L’EFFICIENZA DEGLI
ANCORAGGI IN FIBRE DI CARBONIO APPLICATI SU MATTONI PIENI RINFORZATI TRAMITE BANDE IN CFRP. QUESTA È
UNA RICERCA PRELIMINARE A UN PIÙ AMPIO STUDIO SU SUPPORTI IN MURATURA. NELLO SPECIFICO, L’ANALISI DEI
CAMPI DI SPOSTAMENTO E DI DEFORMAZIONE SULLA SUPERFICE RINFORZATA È STATA EFFETTUATA UTILIZZANDO
LA CORRELAZIONE DI IMMAGINI, UN METODO OTTICO MAI USATO PRIMA PER LO STUDIO DI SUPPORTI RINFORZATI
DA FRP E CHIODATI CON FRP ANCHOR.
IL LAVORO DI TESI DIMOSTRA CHE L’USO DEGLI CFRP ANCHOR AUMENTA LA DUTTILITÀ E LA RESISTENZA ULTIMA DEI
RINFORZI.
French abstract

Auteur - Caggegi Carmelo

DANS LES DERNIERS ANNEES, LE RENFORCEMENT DES BATIMENTS EN MAÇONNERIE A CONNU UN USE MASSIVE DES
CFRP BANDS. CES MATERIAUX COMPOSITE, ATTACHES SUR LES ELEMENTS A RENFORCER, ONT EXPOSES A UNE
FRACTURE PREMATURE POUR DELAMINAGE DU A TENSION PLUS PETIT DE LA RESISTANCE A TRACTION MAXIMAL
DU CFRP. UNE FAÇON POUR ACCROITRE LA RESISTANCE MAXIMALE DU SYSTEM RENFORCE PAR CFRP EST
AMELIORER LA COHESION ENTRE SUPPORT ET COMPOSITE EN UTILISANT ANCRAGES MECANIQUES. CES DERNIERS
SONT REALISES EN UTILISANT LE MEMES TYPOLOGIE DE FIBRES DU RENFORCE ET EN LES INSERANT DANS LE
SUPPORT COMME DES « CLOUS ». LES RECHERCHES SCIENTIFIQUES SUR L'USE DE CETTE FAÇON D'ANCRAGE SUR
SUPPORT EN MAÇONNERIE A ETE TRES LIMITE ET, DANS CETTE CONTEXTE, IL N'Y A PAS DES ETUDES
EXPERIMENTALES SUR LE PROJET ET LE PLACEMENT DES ANCRAGES.
L'OBJECTIF PRINCIPAL DU PRESENT TRAVAIL DE THESE EST QUANTIFIER L'EFFICACITE DES ANCRAGES EN FIBRE DE
CARBONE APPLIQUES SUR BRIQUE CUIT PLEIN RENFORCE PAR CFRP BANDS. CETTE RECHERCHE EST LA PREMIERE
PHASE D'UNE ETUDE PLUS VASTE SUR LES SYSTEMES MAÇONNERIE-CFRP RENFORCE PAR « CARBON FIBER ANCHOR
». DANS L'ETUDE, L'ANALYSE DES DEPLACEMENT ET DES DEFORMATION DE LA SURFACE RENFORCE A ETE FAIT EN
UTILISANT LA CORRELATION DES IMAGES (DIC), UNE AVANTAGEUSE METHODE OPTIQUE JAMAIS UTILISE POUR
L'ETUDE DES SYSTEMES « SUPPORT-CFRP BAND- ANCRAGES ».
LE PRESENT TRAVAIL DE THESE DEMONTRE QUE LES ANCRAGES EN CFRP AUGMENTENT LE RESISTANCE MAXIMAL ET
LA DUCTILITE DES RENFORCEMENTS PAR BANDE DE COMPOSITES.
Contents

Introduction ......................................................................................................................................... 5
1. FRP reinforced systems: from debonding fracture to mechanical anchors ................................. 8
1.1 Materials ................................................................................................................................... 8
1.1.1 Mechanical property of FRP ............................................................................................. 8
1.1.2 Mechanical property of masonry ..................................................................................... 11
1.2 Strengthening design criteria, application and failure modes .............................................. 12
1.3 The debonding crisis ................................................................................................................ 14
1.3.1 Definitions ........................................................................................................................ 14
1.3.2 Analytical considerations .................................................................................................. 19
1.3.3 Experimental and numerical study ................................................................................... 22
1.3.4 Debonding strength and masonry; a case study ............................................................... 30
1.4 Mechanicals anchors ................................................................................................................ 31
1.5 The reinforcement of the masonry structures using FRP strips and anchors; a new scientific
field to analyze ................................................................................................................................ 38
2 Experimental Program .................................................................................................................. 42
2.1 Motivation, goals and methodology ........................................................................................ 43
2.2 Experimental Setup .................................................................................................................. 44
2.2.1 Boundary conditions ......................................................................................................... 44
2.2.2 Specimens .......................................................................................................................... 45
2.2.2.1 Materials .................................................................................................................... 45
2.2.2.1.1 Fire brick ............................................................................................................. 45
2.2.2.1.2 Epoxy resin primer .............................................................................................. 48
2.2.2.1.3 Epoxy resin adhesive ........................................................................................... 48
2.2.2.1.4 Carbon fabric ..................................................................................................... 49
2.2.2.2 Design of specimen’s geometry .................................................................................. 49
2.2.2.3 Anchor details ............................................................................................................ 54
2.2.2.4 Specimen construction details .................................................................................... 56
2.2.3 Universal machine ............................................................................................................ 59
2.2.4 Mechanical systems to contrast the brick and to grip the fibers ...................................... 59
2.2.4.1 Steel lock .................................................................................................................... 60
2.2.4.1.1 Design; hypothesis and FEM studies .................................................................. 60
2.2.4.1.2 - Realization process ............................................................................................ 68
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