IAB_presentation-U.Miami-Oct.12.2007

Document Sample
IAB_presentation-U.Miami-Oct.12.2007 Powered By Docstoc
					    Industry / University
    Cooperative Research Center
Repair of Buildings and Bridges
with Composites (RB2C)




        Fall 2007 Plenary Meeting
        Miami Wind Research Center
        Miramar, FL, October 12, 2007
             NSF Industry/University Cooperative Research Center
             Repair of Buildings and Bridges with Composites – RB2C




                                          OUTLINE
1.   AASHTO LRFD Specifications for GFRP RC bridge decks and deck systems
2.   Development of measurement capabilities for lab and field structural testing
3.
3                        I section
     Precast prestressed I-section beams with external CFRP shear reinforcement
4.   Basalt Fibre Reinforced Cementitious (BFRC) matrix composites for
     infrastructure repair
5
5.   Experimental evaluation of GFRP reinforced concrete large-size columns
     E    i   t l    l ti     f        i f    d       t l       i     l
6.   Experimental evaluation of GFRP-confined large-size RC columns
7.                          y post-tensioned CFRP bar system for rehabilitation
     Validation of externally p                        y
8.   Understanding of width effect in FRP-concrete debonding
9.   Proposal for NSF ERC for Sustainable Construction in Coastal Regions


                                                                    Fall 2007 Plenary Meeting
                                                                Miami, FL, October 12-13, 2007
      NSF Industry/University Cooperative Research Center
      Repair of Buildings and Bridges with Composites – RB2C



                                    Project 01-08

AASHTO LRFD Design Guide Specifications
 for glass FRP reinforced concrete bridge
         decks and deck systems




                                                             Fall 2007 Plenary Meeting
                                                         Miami, FL, October 12-13, 2007
                                                Project 01-08




BACKGROUND

 Use of GFRP bars is viable alternative for
 construction of concrete bridge decks,
 especially in areas where corrosion of steel
 reinforcement is of concern

 Design principles for FRP reinforced
 concrete are well established, and guideline
 documents have been published in North
 America, Europe, and Japan

    Canada
 In Canada, use of FRP bars is codified in
 Section 16 of the Highway Bridge Design
 Code, and is making transition from
 government-subsidized research projects
 to actual commercialization

                                                    1/6
                                                                        Project 01-08




                           OBJECTIVE

To develop design specifications in LRFD format, to be considered
for adoption by AASHTO Subcommittee on Bridges and Structures



  Development of draft document finalized by Task Force under leadership
   f     I d t /U i      it C       ti R        h C t "R        i f B ildi
  of NSF Industry/University Cooperative Research Center "Repair of Buildings
  and Bridges with Composites" (RB2C) at the University of Miami

                                                                (
  The intended recipient is AASHTO Technical Committee T-6 (Fiber
                     p
  Reinforced Polymer Composites), which will interface with AASHTO
  Technical Committee T-10 (Concrete Bridges), and will then have the
  opportunity to take the guide through the AASHTO approval process



                                                                            2/6
                                           Project 01-08




SIGNIFICANCE

 In US, by October 2007, all new
 bridges financed with Federal
 funds will have to be designed
 following the AASHTO LRFD
 Bridge Design Specifications



 The lack of LRFD specifications
 that          the design f
 th t cover th d i of FRP RC
 decks represents the last barrier to
 the full utilization of this innovative
 and already competitive technology

                                               3/6
                                                         Project 01-08




                TASK FORCE

Antonio Nanni, Fabio Matta, Renato Parretti (NSF RB2C)
             Tim Bradberry (Texas DOT)
            Jim Gutierrez (California DOT)
              Paul Liles (Georgia DOT)
              Nick Marianos (C
              Ni k M i            lt t)
                            (Consultant)
         Gustavo Ranalli (Autostrade Group)
              Gamil Tadros (Consultant)
    Maher Tadros (University of Nebraska-Lincoln)
Louis Triandafilou (US Federal Highway Administration)
             Art Yannotti (New York DOT)
                                                             4/6
                                            Project 01-08




                           RESULTS
                      p
Self-contained draft specifications with
commentary prepared by RB2C Task
Force leaders, currently under review
by all members of Task Force

LRFD provisions maintained for
definition of loads, load factors, and
li it states
limit t t

Document covers specific properties of
      reinforcement
FRP reinforcement, defines design
algorithms/methodologies and
resistance factors, covers detailing, and
provides material and construction
specifications
                                                5/6
                                                   Project 01-08




Document includes 5 sections

   Section 1 – Introduction (scope, limitations,
   and design philosophy)
   Section 2 – Decks and deck systems
   Section 3 – Railings
   Section 4 – Material specifications
   Section 5 – Construction specifications
                             p


Submission of the final draft to Technical
Committee T-6 scheduled for January 2008

Task Force will then continue to provide
          support ntil      document
technical s pport until the doc ment is
adopted by AASHTO
                                                       6/6
             NSF Industry/University Cooperative Research Center
             Repair of Buildings and Bridges with Composites – RB2C




                                           Project 01-08

                                         Contacts

 Antonio Nanni, PhD, PE                       Fabio Matta, PhD                           Renato Parretti
    Professor and Chair                Research Assistant Professor                        Consultant
Civil, Arch. & Environ. Engr.           Civil, Arch. & Environ. Engr.                    U. Miami RB2C
      nanni@miami.edu
      nanni@miami edu                        fmatta@miami edu
                                             fmatta@miami.edu                           reparret@unina it
                                                                                        reparret@unina.it




                                                                    Fall 2007 Plenary Meeting
                                                                Miami, FL, October 12-13, 2007
     NSF Industry/University Cooperative Research Center
     Repair of Buildings and Bridges with Composites – RB2C



                                   Project 02-08

Development of measurement capabilities
   for lab and field structural testing




                                                            Fall 2007 Plenary Meeting
                                                        Miami, FL, October 12-13, 2007
                                                                     Project 02-08




                         BACKGROUND

Dramatic increase in number of externally funded research projects
(structural assessment, load testing, strengthening/repair) supported by:

   Recent increase in number of full-time Structural Engineering faculty

   Rapid and important increase in body of Graduate Students

   Partnership with newly established UM-RWDI “Miami Wind” Center,
   featuring one of the prime boundary-layer wind tunnel facilities in the
   Countryy

   Establishment of the NSF Industry/University Cooperative Research
   Center “Repair of Buildings and Bridges with Composites”


                                                                         1/6
                                               Project 02-08




OBJECTIVE
To acquire high-quality measurement
and data acquisition/processing know-
how and capabilities to:

   support growing research and service
   potential and provide faculty and
   students with crucial tools to deliver
       lt
   results

   attract or retain research partners, with
   emphasis on industry

   provide a backbone to credibly pursue
   external funding opportunities for
   experimental research components
                                                   2/6
                                                 Project 02-08




   ACQUISITIONS
    g q      y portable data acquisition
► high-quality p               q
  system, integrated signal conditioning
  moduli for 24 strain gauge input channels
  and 32 channels for VDC signals. Unit is
  controlled and operated via laptop PC

► several sensors, including:
  8 DC-LVDTs (max ±2")±2 )
  3 draw-wire transducers (max 12" range)
  4 electronic inclinometers (±10°)
  25 linear pote t o ete s ( 5 range)
   5 ea potentiometers (1.5" a ge)
  10 PI-gauge displacement transducers
  (±6000 με)
  6 donut load cells (pairs of 25-100-200 kip)
  6 tension/compression load cells (±10 kip)

                                                     3/6
                                                    Project 02-08




            DELIVERING RESULTS

Preliminary fi ld t t h
P li i                       been performed on t
            field tests have b       f    d         l b
                                               two slab
strip specimens supported by open-web steel joists in a
UM building slated for demolition (Lopez 2007)




                                                          4/6
                                                                  Project 02-08



                                                      30     8
Uniform pressure load test successfully performed on 30' by 8'
precast prestressed architectural panel at Miami's Construction
Research Lab on September 28, 2007

The test also allowed to cover the cost of
the data acquisition system




                                                                      5/6
                          Project 02-08




Improvement of available
equipment will be continuously
pursued by seeking internal and
external funding opportunities


Technical know-how will b
T h i lk         h     ill be
enhanced also through
interaction with our RB2C
partners at NCSU Constructed
Facilities Lab (CFL)


                              6/6
NSF Industry/University Cooperative Research Center
Repair of Buildings and Bridges with Composites – RB2C



                                      02-08
                              Project 02 08

                            Contacts
                           Fabio Matta, PhD
                    Research Assistant Professor
                     Civil, Arch. & Environ. Engr.
                          fmatta@miami.edu

          Hays, PhD,
   Carol Hays PhD PE                                 Metrovich,
                                             Brian Metrovich PhD
           Lecturer                             Assistant Professor
Civil, Arch. & Environ. Engr.              Civil, Arch. & Environ. Engr.
     c.hays@miami.edu                        bmetrovich@miami.edu




                                                       Fall 2007 Plenary Meeting
                                                   Miami, FL, October 12-13, 2007
    NSF Industry/University Cooperative Research Center
    Repair of Buildings and Bridges with Composites – RB2C



                                  Project 03 08
                                  P j t 03-08

          p
 Precast prestressed I-section beams
with external CFRP shear reinforcement




                                                           Fall 2007 Plenary Meeting
                                                       Miami, FL, October 12-13, 2007
                                                        Project 03-08




                    BACKGROUND


► Precast prestressed I-section
                      y
  beams are commonly used in
  buildings and bridges. Shear
  deficiencies may require
  rehabilitation


► Understanding the effect of the characteristic bulb geometry
  of the cross section on the shear strength contributed by
  externally bonded CFRP sheets is critical to develop
  rational design algorithms
                                                            1/4
                           Project 03-08




              OBJECTIVES

Investigate the
interaction between
CFRP sheets and the
bulb shape of I-section
beams

Translate the findings
T      l t th fi di
in rational design
language

                               2/4
                                                              Project 03-08




           EXPERIMENTAL PROGRAM
     p           g
Four-point bending tests on four different sets of full-scale beam
specimens designed to fail in shear:
GROUP 1: control beams
GROUP 2: +10% shear strength
GROUP 3: +25% shear strength
GROUP 4: +40% shear strength.


Selected specimens will include enhanced anchorage systems
(e.g., glass FRP anchorage bars in pre-cut grooves). In order to
                                         strength,
ensure that failure is governed by shear strength an appropriate
amount of external flexural reinforcement will be added.
                                                                  3/4
                                      Project 03-08




DELIVERABLES

► Study the effect of bulb shape on
  shear strength contributed by
  external CFRP reinforcement

► Evaluate the effect of
              (near-surface
  anchorages (near surface
  mounted glass FRP bars)

  Translate findings i proposed
► T    l t fi di     in       d
  design language for ACI 440.2R
  guidelines


                                          4/4
NSF Industry/University Cooperative Research Center
Repair of Buildings and Bridges with Composites – RB2C



                              Project 03 08
                              P j t 03-08

                            Contacts

                        Christian Aquino
                           M.S.
                           M S Student
                   Civil, Arch. & Environ. Eng.
                     c.aquino@umiami.edu

                        Antonio Nanni, PhD, PE
                           Professor and Chair
                        Civil, Arch. & Environ. Eng.
                             nanni@miami.edu




                                                       Fall 2007 Plenary Meeting
                                                   Miami, FL, October 12-13, 2007
     NSF Industry/University Cooperative Research Center
     Repair of Buildings and Bridges with Composites – RB2C



                                   Project 04-08

Basalt fiber reinforced cementitious (BFRC)
    i            i   f i f               i
matrix composites for infrastructure repair




                                                            Fall 2007 Plenary Meeting
                                                        Miami, FL, October 12-13, 2007
                                                                           Project 04-08




                          BACKGROUND
The project focuses on the strengthening and
upgrade of reinforced concrete structures using a
novel class of advanced composites made of
                               cement based
basalt fibers embedded in a cement-based matrix
(BFRC), primarily for concrete confinement




Basalt fibers are manufactured in a single-stage process by melting basalt rock

                                                                               1/5
                                                Project Proposal 04-08




                   OBJECTIVES

► Define the composition and properties of a suitable
  inorganic matrix

  Determine th compatibility between the fibers and
► D t    i the          tibilit b t     th fib    d
  the matrix by using optimized fiber sizings

► Assess the durability of the basalt fibers in an
  alkaline environment

► Develop a numerical model to predict the
  enhancement in the axial compressive capacity of
  full-size BFRC-confined
  full size BFRC confined RC columns

                                                             2/5
                                                           Project Proposal 04-08



                       SIGNIFICANCE
                         WHY BASALT?

► Mechanical properties, high strain to failure
► Basalt rock abundant all around the world
► Lower cost of fibers
► Environmentally safe, 100% natural
► Non-carcinogenic, non-toxic, non-corrosive, non-magnetic
► Possess high-heat stability and insulating characteristics, high range
  of application
► Good acid and solvent resistance and high bio-solubility




                                                                        3/5
                                                             Project Proposal 04-08

                                               Possible fiber systems in form of
RESEARCH TASKS                                 a) strands or     b) grids



   Investigation on
   mechanical and durability
   properties of constituents
   and composite material
   i. Basalt fiber
   ii. Cementitious Matrix
   iii Composite BFRC
   iii.
                                            Development and
                                            D     l       t d
                                            characterization
                                              of appropriate
                                               fiber sizing


              Basalt fibers sheet samples                                  4/5
                                                           Project Proposal 04-08




      Effect of BFRC confinement on plain concrete
                                    stress strain
         cylinders to determine the stress-strain
      constitutive laws for BFRC-confined concrete


    Implementation of
damaged-based plasticity
models for Finite Element
Method (FEM) analysis to           Above, load test set-up.
                                   Below constitutive models for concrete
                                   Below,
perform parametric study           in (a) tension and (b) compression

on full-size BFRC-jacketed                   (a)                       (b)
        RC columns
       i) Steel Plasticity Model
   ii) Concrete Plasticity Model
NSF Industry/University Cooperative Research Center
Repair of Buildings and Bridges with Composites – RB2C



                              Project 04 08
                              P j t 04-08

                            Contacts

              Francisco J. De Caso y Basalo
                         PhD.
                         PhD Student
                 Civil, Arch. & Environ. Eng.
               f.decasoybasalo@umiami.edu

                         Antonio Nanni, PhD, PE
                            Professor and Chair
                        Civil, Arch. & Environ. Engr.
                            a.nanni@miami.edu




                                                       Fall 2007 Plenary Meeting
                                                   Miami, FL, October 12-13, 2007
      NSF Industry/University Cooperative Research Center
      Repair of Buildings and Bridges with Composites – RB2C



                                    Project 05 08
                                    P j t 05-08

Experimental evaluation of GFRP reinforced
       concrete large-size columns

                                                                                                    1
                                                                                                   12" clear cover


                                                               cross tie #4                    8 #8 GFRP bars

                                                                                          2'
                                                               tie #4


                                                                        A                      A

                                                                                2
                                                                                2'




                                                             Fall 2007 Plenary Meeting
                                                         Miami, FL, October 12-13, 2007
                                                    Project 05-08




                BACKGROUND

The current ACI "Guide for the design and construction of
                                        bars
structural concrete reinforced with FRP bars" (ACI
440.1R-06) does not recommend the use FRP bars as
longitudinal reinforcement in compression members



This research project moves from the intent to provide a
full implementation of FRPs as concrete reinforcement



                                                        1/4
                                            Project 05-08




             OBJECTIVES

To verify whether or not FRP bar compressive
behavior does negatively impact column
performance



To characterize the contribution of FRP ties on
column confinement and prevention of bar
instability

                                                2/4
                                                                              Project 05-08




                    RESEARCH PROGRAM
Five column specimens will be tested: one is a steel RC column, the others are
           columns
GFRP RC columns. The GFRP RC columns are subdivided into two sets of two       two,
each set identical to the other, but using bars from a different manufacturer. The
purpose of duplication is to show that quality GFRP bars provide similar response.

                   Square column                     Longitudinal     Transverse
                    [24in x 24in]                   reinforcement    reinforcement
             Steel RC column benchmark                8 #8 bars      #4 ties @ 16’’
     HB GFRP column with
                                                      8 #8 bars      #4 ties @ 12’’
  proposed maximum spacing

   Pultrall GFRP column with    same volume of
                                                      8 #8 bars                12
                                                                     #4 ties @ 12’’
  proposed maximum spacing        longitudinal
                                 reinforcement
     HB GFRP column with          as for steel
                                                      8 #8 bars       #4 ties @ 3’’
   practical minimum spacing       [rmin = 1%]

   Pultrall GFRP column with
                                                      8 #8 bars       #4 ties @ 3’’
   practical minimum spacing
                                                                                  3/4
                                                     Project 05-08




                 DELIVERABLES

► Verifying whether longitudinal FRP reinforcement is not
  detrimental and lends itself to use in compression
  members

► Assess whether FRP ties increase the ductility of
  columns, in addition to serving as shear reinforcement

  Propose new language f ACI 440 1R guidelines th t
► P            l          for     440.1R id li   that
  improves design criteria for compression members



                                                         4/4
NSF Industry/University Cooperative Research Center
Repair of Buildings and Bridges with Composites – RB2C



                      Project P    l 05-08
                      P j t Proposal 05 08

                            Contacts

                         Antonio De Luca
                           Ph.D.
                           Ph D Student
                   Civil, Arch. & Environ. Engr.
                      adeluca@miami.edu


                       Antonio Nanni, PhD, PE
                          Professor and Chair
                      Civil, Arch. Environ. Engr.
                      Civil Arch & Environ Engr
                            nanni@miami.edu




                                                       Fall 2007 Plenary Meeting
                                                   Miami, FL, October 12-13, 2007
   NSF Industry/University Cooperative Research Center
   Repair of Buildings and Bridges with Composites – RB2C



                                 Project 06 08
                                 P j t 06-08

       p
    Experimental evaluation of
GFRP-confined large-size RC columns




                                                          Fall 2007 Plenary Meeting
                                                      Miami, FL, October 12-13, 2007
                                             Project 06-08




BACKGROUND
 The behavior of confined
 columns with circular cross-       Figure
 section subjected to pure axial
 loads has been extensively




                                                  (Roc 2007)
 studied.




                                                     cca
 However, existing models have
 note been sufficiently validated
 by testing full-scale specimens
 nor elements with prismatic
 cross sections.
 cross-sections.

                                                 1/4
                                            Project 06-08




             OBJECTIVES

To understand the effectiveness of the
                               cross sectional
confinement in relation to the cross-sectional
geometry and size.

    analyze     contribution
To anal e the contrib tion to the confinement
of the longitudinal and transverse steel
reinforcement.
reinforcement

To evaluate the efficiency of bent FRP sheets.

                                                 2/4
                              Project 06-08




SIGNIFICANCE

  Current models and
  design guidelines are
  based on small-scale
  specimens

  Limited studies are found
      large-size
  for large size prismatic
  members



                                  3/4
                                                  Project 06-08




       RESEARCH PROGRAM

Tests on 18 full-scale reinforced concrete
columns with prismatic cross section are planned
to investigate the behavior of axially loaded large-
                             y
size RC columns confined by means of external
Glass Fiber Reinforced Polymer (GFRP) and Basalt
Fiber Reinforced Concrete (BFRC) systems

Specimens represent real scale building columns



                                                      4/4
NSF Industry/University Cooperative Research Center
Repair of Buildings and Bridges with Composites – RB2C



                              Project 06 08
                              P j t 06-08

                            Contacts
                         Antonio De Luca
                           Ph.D.
                           Ph D Student
                   Civil, Arch. & Environ. Engr.
                      adeluca@miami.edu

                         Antonio Nanni, PhD, PE
                            Professor and Chair
                        Civil, Arch. & Environ. Engr.
                              nanni@miami.edu
                              nanni@miami edu




                                                       Fall 2007 Plenary Meeting
                                                   Miami, FL, October 12-13, 2007
       NSF Industry/University Cooperative Research Center
       Repair of Buildings and Bridges with Composites – RB2C



                                     Project 07 08
                                     P j t 07-08

Validation of externally post-tensioned CFRP
         bar system for rehabilitation




                                                              Fall 2007 Plenary Meeting
                                                          Miami, FL, October 12-13, 2007
                                       Project 07-08




                  BACKGROUND
The use of externally post-
tensioned steel t d
t    i    d t l tendons (EPT)
represents a viable option to
                    g
increase the design loads or to
correct strength and serviceability
deficiencies in bridge and buildings
structural members

Recently, EPT systems with
carbon fiber reinforced polymers
(CFRP) tendons have been
developed as a valid alternative to
th more common hi h t
the                              th
                     high-strength
steel strands
                                           1/5
                                                               Project 07-08




                BACKGROUND
An innovative EPT CFRP                         EPT configuration

system has been developed.
This technique consists of
unbonded CFRP bars whose
connection to the steel      Schematic of live-end of CFRP bar assembly
anchors at the dead - live
ends was engineered to
allow the bars to develop
the full tensile strength.

No hydraulic jacks are
                    post
needed to apply the post-
tensioning forces..             dead-end of CFRP          EPT installation
                                bar assembly
                                                   Project 07-08




                   OBJECTIVES
        p                   p          p
Few experimental tests were performed up to now in order
to validate the proposed anchor system.

    Experimental tests
    in order to:


 Investigate the behavior of the CFRP and end anchor
 assemblies

 Verify the effectiveness of using the proposed EPT CFRP
 system in increasing the flexural strength or controlling
                     f    i ti     i f    d       t
 the deflection of existing reinforced concrete (RC)
 th d fl ti
 members
                                                       3/5
                                                                                                          Project 07-08


                       RESEARCH TASKS
   TASK 1 (in progress):
Experimental tests on CFRP and end anchor
assemblies in order to investigate the influence of relevant
parameters, such as length and diameter of the bar, on
the load carrying capacity of the proposed anchor system.

                                        TEST MATRIX
      Influence of the bar diameter (D) Influence of the bar length (L)
               ⎧D= D1        ⎧D= D1         ⎧D= D1          ⎧L = L1           ⎧L = L1           ⎧L = L1
               ⎪             ⎪              ⎪               ⎪                 ⎪                 ⎪
        L= L , ⎨D= D , L= L ,⎨D= D , L= L , ⎨D= D
            1       2      2      2      3       2  D = D , ⎨L = L2 , D = D2, ⎨L = L2 , D = D3, ⎨L = L2
                                                         1
               ⎪             ⎪              ⎪               ⎪                 ⎪                 ⎪
               ⎩D= D3        ⎩D= D3         ⎩D= D3          ⎩L = L3           ⎩L = L3           ⎩L = L3
                                          L1<L2<L3; D1<D2<D3


An analytcal model able to simulate the load transfer
        y
mechanism between steel anchors and CFRP will be also
developed                                            4/5
                                                     Project 07-08


                          (      )
           RESEARCH TASKS (cont'd)
   TASK 2 :
   p
Experimental tests on full scale reinforced concrete
(RC) slabs upgraded with the proposed EPT CFRP
system in order to investigate the increase of the design
                     short-
loads or control the short and long term deflections

The effectiveness of the anchor system in developing the
full         f
f strength of the bars will be also investigated

  Task 1                                        Task 2
 RESULTS                                      RESULTS


              VALIDATION OF THE PROPOSED
                   EPT CFRP SYSTEM
                                                         5/5
            NSF Industry/University Cooperative Research Center
            Repair of Buildings and Bridges with Composites – RB2C



                                          Project 07-08

                                        Contacts
                                      Annalisa Napoli
                                       M Sc student
                                       M.Sc.
                               Civil, Arch. & Environ. Engr.
                                  a.napoli@umiami.edu

       Fabio Matta, PhD               Christian Carloni, PhD                Antonio Nanni, PhD, PE
Research Assistant Professor                    Lecturer                       Professor and Chair
 Civil, Arch. & Environ. Engr.       Civil, Arch. & Environ. Engr.         Civil, Arch. & Environ. Engr.
      fmatta@miami.edu
      fmatta@miami edu                   ccarloni@miami edu
                                         ccarloni@miami.edu                      nanni@miami.edu
                                                                                 nanni@miami edu




                                                                   Fall 2007 Plenary Meeting
                                                               Miami, FL, October 12-13, 2007
   NSF Industry/University Cooperative Research Center
   Repair of Buildings and Bridges with Composites – RB2C



                                 Project 08 08
                                 P j t 08-08

               g
An Understanding of the Width Effect
    in FRP-Concrete Debonding




                                                          Fall 2007 Plenary Meeting
                                                      Miami, FL, October 12-13, 2007
                                  Project 08-08




BACKGROUND

      The debonding mechanism has
      been shown to be one of the most
      important causes of inefficiency of
           repair. FRP-concrete
      the repair FRP concrete shear
      debonding has been idealized as
      a Mode-II interface fracture
      problem It was also shown that
      problem.
      the interface crack growth is
      associated with a fracture process
      zone of a fixed length, which
        o e o          ed e gt ,      c
      translates along the bonded
      length of the interface.



                                      1/5
                                                               Project 08-08



Factors which contribute to scaling of ultimate load at debonding
                           with FRP width

    1. The boundary layer effect at the edge of the FRP sheet;
  2. The restraint to the FRP sheet from the surrounding concrete;



                          OBJECTIVES

1.
1 To study the influence of the width of FRP on the
   stress/strain distribution.
2. To determine the factors related to the width of FRP which
                                           debonding.
   influence the ultimate stress/strain at debonding
3. To investigate the role of concrete in providing
   confinement/restraint to FRP.
4.
4 To study the influence of the width of the FRP on the
   cohesive interface fracture parameters.
                                                                     2/5
                                                                                                      Project 08-08



              EXPERIMENTAL PROGRAM
An experimental investigation into the influence of the width of the FRP
                                                        out.
sheet on the load carrying capacity has been carried out Direct shear
tests were used to evaluate the FRP-concrete debonding response using
the classical pull-push configuration. The bonded length of the sheet was
kept fixed. Different nominal widths of the FRP sheet were combined
with two different concrete block widths.
                                                                                         y
                                                                                             b1   Steel I-Beam
                                     FRP                                       FRP



                                      Adhesive      Restraint



                                       n
                                       l                                                          LVDT

                                                    Concrete
                                                    Block




                                                                                                       L
                                 L




                                                                Steel I-Beam                      x




                                            Restraint                                b
                                                        h




                                                                                                                 3/5
                                                                                                                                  Project 08-08



                                                               RESULTS
1. Typical load versus global slip response
2. Ultimate nominal stress σu in the FRP at debonding
                               10
3. The surface strains in the FRP and concrete were determined using a
               9
   full-field optical technique (DIC)
              2400
               8
                                                    P crit
                                                 B
                               2100
                                7
        σu Applied Load (kN)




                               1800                          b1=12 mm                                        P crit
                                6 A              B'          no central region
           (N/mm )




                               1500
        2




                                5




                                                                                              LVDT
                                             A
                 m




                                                      LVDT


                                4
                               1200
                                3                                           b1                 b1=25
                                                                                               Serie1 mm
                                900                                                                  b = 125 mm
                                                                                               b1=20 mm
                                                                                               Serie2
                                2
                                600                                                                  b = 52 mm
                                1
                                                                                                       regression
                                300
                                0
                                                                          free FRP




                                    00       Steel
                                               0.2            0.4          0.6          0.8          Steel
                                                                                                      1               1.2
                                                                              ss
                                                                          Stres




                                             Beam                   Global Slip (mm )                Beam
                                         0           0.1             0.2         0.3          0.4            0.5            0.6
                                                                             b b /b
                                                                                1                                                     4/5
                                                          Project 08-08



                                    RESULTS
CONCLUSIONS
                                                    b = 125mm
1.   Stress state in the FRP
     is inhomogeneous                               b1 = 25mm
     across its width.
2.   Central region where the                             y
     state of strain is uniaxial.             FRP
                                                              b1    Steel I-Beam

3.   Edges regions
     associated with both
     axial strain and shear
     strain
     strain.                                                       LVDT

4.   Ultimate nominal stress
     increase is related to the




                                                                         L
                                                                    x

     central region.
5.
5    Th f t                ti
     The fracture properties
     from the central portion                         b

     of FRP away from the
     edge regions are
     independent of the FRP
     width
                                                                   5/5
   NSF Industry/University Cooperative Research Center
   Repair of Buildings and Bridges with Composites – RB2C



                                 Project 08 08
                                 P j t 08-08

                               Contacts

                            Christian Carloni
                             Visiting Scholar
                      Civil, Arch. & Environ. Engr.
                          ccarloni@miami.edu



Acknowledgements: Dr. Kolluru V. Subramaniam (CUNY)
                  Mitsubishi Chemical




                                                          Fall 2007 Plenary Meeting
                                                      Miami, FL, October 12-13, 2007
ERC Vision: Presentation at NSF, Arlington, VA (April 13, 2007)



                                                  ERC for
                                        Sustainable Construction
                                          in Coastal Regions
USGS




                                                   NSF I/UCRC Plenary Meeting, October 12, 2007
                                                Overall Mission of ERC


Overall Mission of              ERC
Sustainable Construction in Coastal Regions

  Build safer and affordable human habitat challenged by
  natural hazards and population concentration: focus on
  coastal regions
  Residential construction as primary research target
  because of social and economical impact
  Develop curricula to educate new generation of
  professionals operating in the building industry and
  contribute to its implementation
  Create team of researchers and stakeholders to develop
         p y           g       p     quality of life and
  and deploy technologies to improve q     y
  safety at lower cost
                                                                1 / 18
Primary University Partners in the US




                               2 / 18
                                                  Thrust Areas from 3-Plane Framework


ERC 3-Plane Framework
                       Environment / Marketplace
               Requirements                     Products and Outcomes
    Systems
    S t
Requirements
                     Implementation of Innovation & Economics (TA-6)
                 New Urbanism (TA-7)
               Social Impacts (TA-8)
               S i lI      t (TA 8)

                    Structures for Reduction of Wind / Surge / Flood
                    Hazards (TA-4)
               Moisture Transport & Prevention / Remediation            Technology
               of Damage (TA-5)                                         Elements

                                          g
                Assessment of Wind / Surge / Flood Hazards (      )
                                                             (TA-1)
            Simulation of Dynamic Loads (TA-2)
                              Knowledge Base                        Fundamental
          Multi-scale / Functionally-Graded Materials (TA-3)
                                                                    Insights
            q
          Requirements and                                  p
                                                 Scholarship and
                 Mentoring                       Creativity
                                Education

                                                                                  3 / 18
                   Thrust Areas from 3-Plane Framework / Knowledge Base / TA-1




TA-1: Assessment of Wind /
Surge / Flood Hazards


  Provide design loads on
  structures impacted by                      Hurricane Rita rainfall simulation from UM
                                                                      MM5 model (Chen)

  natural hazards (storm,
         floods)
  surge, fl d )

  Implement risk analysis for
  built infrastructure in coastal
  regions
    g
                                                Real time Forecasting of Winds, Waves
                                                       and Surge, NOPP (Graber et al.)

                                                                                   4 / 18
                Thrust Areas from 3-Plane Framework / Knowledge Base / TA-2




TA-2: Simulation of
Dynamic Loads
                                                           Simulation of wind
                                                  load on residential building

 Numerical modeling of
 interaction between air /
 water and structure
                                             Generation of active turbulence
 Experimental validation in
 laboratory (wind / water
 tunnel) and field
 (         g              )
 (monitoring of structures)
                                       Aeroelastic study of suspended bridge

                                                                             5 / 18
                       Thrust Areas from 3-Plane Framework / Knowledge Base / TA-3



TA-3: Multiscale / Functionally
-Graded Materials

 Innovative materials and reinforcement
 technologies for better protecting coastal
 building infrastructure under extreme
 weather conditions

 Quantum improvement in durability to
 enhance weathering resistance and long-
 term survivability in coastal regions

 Education and training of future
 engineers and general public on need of
 new paradigms for building codes for
 improved sustainability in coastal
 communities

                                                                            6 / 18
                            Thrust Areas from 3-Plane Framework / Knowledge Base / TA-3


                                  micro
Fundamental Research: Nano / micro-
fiber reinforced cementitious materials

Quantum improvement in strength and durability,
understanding of physical properties and modeling

    u sca e ode g e odo ogy
   Multiscale modeling methodology
   Fast and cost-effective nano/micro
   materials development
   Macro properties during/upon exposure to
   Macro-properties
   extreme loads
   Multi-functionality characteristics: impact
   tolerant, self cleaning durable,
   tolerant self-cleaning, durable
   environmental friendly, low cost
   Elimination of conventional reinforcing steel
   in concrete structures exposed to harsh
   environments

                                                                                 7 / 18
                          Thrust Areas from 3-Plane Framework / Knowledge Base / TA-3



Fundamental Research: N
F d         t lR         h Nanocompositeit
platelet technology for improved glazing

Quantum improvement in impact
resistance for new and existing
glazing applications

   Synthesis of layered inorganic
   materials tailored for compatibility
   with specific polymers
   Transparency to visible light with
   blockage of UV wavelengths
   Ultra-tough polymer
             p               y
   nanocomposites in multi-layered




                                                                                          ano
                                                                                  R. Giorda
   window applications

                                                                               8 / 18
                 Thrust Areas from 3-Plane Framework / Technology Base / TA-4




TA-4: Structures for Reduction
of Wind / Surge / Flood Hazards


  Development of durable and




                                                                                  ette
                                                                           M. Avere
  affordable structural systems to
  resist natural hazards

  Sustainability (e.g., economy,
  constructability social
  constructability,
  acceptance) of structural systems
  and construction methods




                                                                           F. Matta
                                                                       9 / 18
                   Thrust Areas from 3-Plane Framework / Technology Base / TA-4



Development of smart integrated structural systems

  Continuous-membrane
  system for global
  resilience to extreme
  loads

  Prognostic systems
                      for
  using smart sensors f
  performance prediction

  Evolution of structural
  systems for sustainable
  construction                                        Continuous membrane
                                                      C ti           b
                                        reinforcement and anchorage system

                                                                        10 / 18
                  Thrust Areas from 3-Plane Framework / Technology Base / TA-5



TA-5: Moisture Transport & Prevention /
TA 5 M i t     T       t P       ti
Remediation of Damaged Areas

 Water intrusion and transport
      g         g       p
 through building envelopes under
 high winds

 Indoor microbiological colonization
 and bio-aerosol exposures

 Prevention / remediation of
 P       i          di i      f
 damages (innovative water-proof
           ,                    g ,
 roof vents, ventilation strategies,
 anti-mold materials)
                                                                       11 / 18
                   Thrust Areas from 3-Plane Framework / Technology Base / TA-5


TA 5:
TA-5: Moisture Transport & Prevention /
Remediation of Damaged Areas

                              Structural
     Water                     damage
   intrusion
                              Insulation
                                failure

                                 Mold
                                growth




                                                  Mold in bathroom, HVAC ductwork,
                                                      and crawl space (IRINFO.org)

                                                                          12 / 18
               Thrust Areas from 3-Plane Framework / Technology Integration / TA-6



TA-6:
TA 6: Implementation & Innovation
of Economics

 Economics and decision theory of resilient
 construction, with emphasis on how attitudes
 might evolve over time (e.g., forecast fatigue)

 Cost-benefit analyses for more resilient
 Cost benefit
 structures: sturdier buildings that go unoccupied
 do not make us safer

 How best to draw and maintain data panel, and
 leverage internet protocol for quality control and
 real-time response

                                                                           13 / 18
                                         Thrust Areas from 3-Plane Framework / Technology Integration / TA-6


        p
TA-6: Implementation & Innovation of Economics

              Of the ten most expensive hurricanes in US history, seven
                                       g
              occurred in 14 months Aug. 2004 – Oct. 2005: Katrina, Rita,
              Wilma, Charley, Ivan, Frances and Jeanne

                                                                Hurricane Katrina aid will dwarf aid for
              120
                       $104.4
                                                                major natural and man-made
              100                                               disasters. Congress may authorize
                                                                $150-$200b ultimately (~$400k for
              80                                                     h f 500 000 displaced f ili )
                                                                each of 500,000 di l       d families).
 $ billions




              60                                                Is the incentive to buy insurance and
                                            $43.9               insure to value diminished?
              40
                                                                 $17.7              $15.5              $15.0
              20

               0
                    Hurricane Katrina   Sept. 11 Terrorist   Hurricane Andrew      Northridge     Hurricanes Charley,
                          (2005)          Attack (2001)            (1992)       Earthquake (1994)  Frances, Ivan &
                                                                                                    Jeanne (2004)


                                                                                                                        14 / 18
                Thrust Areas from 3-Plane Framework / Technology Integration / TA-7




TA-7: New Urbanism

Quality of response of coastal built areas to natural
hazards involves arrangement and connection
between structural and i f t t l components:
b t        t t l d infrastructural                t

   Design of the urban infrastructure to minimize
   infrastructural damage and hazards to human life

   Integration of infrastructures for transportation,
   water and power supply, waste water


                                                                            15 / 18
               Thrust Areas from 3-Plane Framework / Technology Integration / TA-8




TA-8: Social Impacts

 Communities experience damage from natural hazards
 also due to their “condition” prior to the event: social
   i ti t       increasingly able t id tif
 scientists are i       i l bl to identify
 social/economic/political/cultural vulnerabilities in
 addition to those attributable to the built environment

 There is a societal assumption that the built environment
 is constructed to benefit social activities and processes
 of the society. To date, building construction in coastal
 regions has failed to accomplish this generic goal


                                                                           16 / 18
                  Thrust Areas from 3-Plane Framework / Technology Integration / TA-8



                TA 8
Focus Areas for TA-8

  Risk perception with regard to impact of natural hazards on the built
     i
  environmentt
  Perceptions of responsibility and efficacy in achieving sustainable
  construction
  Assignment of responsibility for achieving sustainable construction
  and implications on sustainability
  Exploration of degree and reasons for resistance to hazard
  mitigation within coastal communities
  Analysis of social impacts of non-sustainable construction on
     id t      d          iti in
  residents and communities i coastal regions of coast: concept of
                                        t l i    f     t        t f
  social vulnerability and its implications
  Analysis of contribution of sustainable housing to resiliency of
  families and coastal communities: concept of community resiliency

                                                                              17 / 18
                                                     Industry and Other Partners



Industry d Oth P t
I d t and Other Partners

GOVERNMENT / CODE AGENCIES
DCA - Florida Department of Community Affairs /
Florida Building Commission
               g
FEMA - Region 4
ICC - International Code Council
NIST - Building and Fire Research Laboratory, Materials
and Construction Research Division

TRADE ASSOCIATIONS
       SSOC    O S
ACMA - American Composite Manufacturers Association
FHBA - Florida Home Builders Association
IBHS - Institute for Business and Home Safety


                                                                         18 / 18

				
DOCUMENT INFO
Shared By:
Categories:
Tags:
Stats:
views:19
posted:12/10/2011
language:English
pages:76