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Historic Preservation - Technical Procedures

Spectitle:

Stabilizing 2-Wythe Tile Walls Using Adhesive Foam Filler

Procedure code:

0421201R

Source:

Jacob Weinberger Us Cthouse/San Diego, Ca - Hallenbeck...

Division:

Masonry

Section:

Clay Tile Unit Masonry

Last Modified:

11/30/2012

Details:

Stabilizing 2-Wythe Tile Walls Using Adhesive Foam Filler



STABILIZING TWO-WYTHE TILE WALLS FOR SEISMIC RETROFIT USING
ADHESIVE FOAM FILLER


PART 1---GENERAL

1.01 SUMMARY

    A.   This procedure includes guidance on stabilizing two-wythe
         clay tile walls with a light weight rigid adhesive filler
         in the cavity between the wythes for seismic retrofit.

         NOTE:  THIS PROCEDURE SHOULD BE EXECUTED BY A SPECIALIST
         TRAINED IN MASONRY STABILIZATION AND IS RECOMMENDED FOR
         USE IN VERY LIMITED APPLICATIONS.

    B.   The filler material shall adhere to clay tile and have
         strength and rigidity properties so that the tile-foam
         composite will respond to earthquake shaking as a wall of
         thickness equal to the existing out-to-out dimensions of
         the two-wythe wall.

    C.   See 01100-07-S for general project guidelines to be
         reviewed along with this procedure.  These guidelines
         cover the following sections:

         1.   Safety Precautions

         2.   Historic Structures Precautions

         3.   Submittals

         4.   Quality Assurance

         5.   Delivery, Storage and Handling

         6.   Project/Site Conditions

         7.   Sequencing and Scheduling

         8.   General Protection (Surface and Surrounding)

         These guidelines should be reviewed prior to performing
         this procedure and should be followed, when applicable,
         along with recommendations from the Regional Historic
         Preservation Officer (RHPO).

1.02 REFERENCES

    A.   American Society for Testing and Materials (ASTM)
         www.astm.org
         

1.03 SUBMITTALS

    A.   Product Data:  Submit the manufacturer's product
         information including identification, packing, component
         mixing quantities and injection procedures curing times,
         workman's safety precaution, and by-products released to
         the atmosphere.

    B.   Test Report:  Submit the report of a testing program in
         compliance with Part 3 of this specification.

    C.   Injection procedure:  Submit data on injection procedures
         and equipment.  Include proposed locations, spacings and
         sizes of injection ports.

    D.   Submittals shall be reviewed by the Architect and
         approved by the Contracting Officer before proceeding.

1.04 QUALITY ASSURANCE

    A.   Engage a testing laboratory acceptable to the RHPO.

    B.   Testing laboratory responsibilities:

         1.   Observe preparation of the walls for injection.

         2.   At the beginning of the injection work, observe
              mixing and injection procedures for compliance with
              these specifications and manufacturer's
              instructions.

         3.   Upon completion of the project, drill and observe
              12 observation holes, (2 in each wall at each
              level) at locations to be selected by the
              Architect; confirm filling of the void between
              wythes with foam.

    C.   Mock-Ups:

         NOTE:  THE TESTING PROGRAM IS TO ESTABLISH ACCEPTABLE
         MATERIAL AND DEMONSTRATE THE INJECTION PROCEDURE.
         ALTERNATIVE MATERIALS AND PROCEDURES COMPLYING WITH PART
         1 AND PART 2 MAY BE PROPOSED.  DO NOT PROCEED WITHOUT
         REVIEW BY THE RHPO AND APPROVAL BY GSA.

         1.   Obtain clay tile units from the Building.  Protect
              the units from damage and surface contamination.

         2.   Clean the surfaces that will receive mortar with a
              wire brush.  Do not clean the surfaces to which the
              adhesive foam will be applied.

         3.   Construct two 2-wythe test panels and allow to cure
              for 28 days.  Install the units with the internal
              cells horizontal.

         4.   Construct end forms to enclose a void between the
              tile wythes.  The end forms shall not connect to
              the tile units in a way that prevents the units
              from deflecting outward under pressure from within
              the void.  The forms shall be tight enough to
              confine the adhesive foam placed in lifts.
              Coordinate with the foam installer for form
              pressure and anticipated confinement requirements.

         5.   Place two component epoxy adhesive foam fill into
              the void in 12" lifts through holes core drilled
              into one wythe.  (The holes for foam placement may
              be drilled prior to constructing the test panels).
              The depths of lifts shall be limited to prevent
              foam pressure from causing the wythes to bow
              outward and shall be the same as will be used in
              the building.  Fill to within 2" of the top of the
              panel.

         6.   Allow the foam fill to cure as recommended by the
              manufacturer.  Remove the forms.

         7.   Test the panels by loading to ultimate horizontal
              load.

         8.   Evaluation:  The panels shall break by cracking
              horizontally through the panel at about mid-height,
              without crushing of the foam or delamination of the
              foam from a tile surface except in that offset zone
              between the crack path through the tile masonry.  A
              break other than described above is not acceptable.

         9.   Report for each test panel:

              a.   Test set-up

              b.   Horizontal load at cracking

              c.   Horizontal load after cracking

              d.   Location and orientation of crack

              e.   Any delamination between foam and tile

              f.   Any visible distortion of foam under load

              g.   Any visible distortion of foam after cracking


PART 2---PRODUCTS

2.01 MANUFACTURERS

    A.   Delta Plastics
         www.deltafoam.com
         

2.02 MATERIALS

    A.   Fill Material:

         1.   Two-component epoxy adhesive foam complying with
              the testing program of Part 3, such as "Bisfoam-3 A & B" (Delta Plastics), or approved
              equal.

         2.   The cured foam, when exposed to an open flame, will
              char on the contact areas with little damage or
              deformation of the foam structure.  

         3.   The foam is to have a density value of less than 75
              along with a flame spread rating of less than 19.  

              CAUTION:  THE SMOKE EMITTED MAY CONTAIN
              DECOMPOSITION PRODUCTS OF CARBON, HYDROGEN, WATER,
              AND TRACES OF FLUORINE, BUT MAY HAVE ONLY A VERY
              LOW OFFENSIVE ODOR QUALITY.

    B.   Form Materials:  Materials to confine the foam and
         prevent flow out of the wall shall be as follows:
             
         1.   If least dimension of hole is less than 1-1/2 inch, use
              Type N mortar complying with ASTM C270.  Fill the
              hole to a depth equal to 1-1/2 times the exposed
              least dimension.

         2.   If least dimension of hole is 1-1/2 inch or greater,
              use unit brick masonry (common brick) and type N
              mortar complying with ASTM C270; minimum thickness
              of unit masonry form shall be at least the
              thickness of the existing clay tile wythe in which
              it is placed.

         3.   If least dimension of hole is 1inch maximum, use
              plastic foam joint filler:  diameter/injection/preformed,
              compressible, resilient, non-waxing, non-extruding
              strips of plastic foam of material as recommended by
              sealant manufacturer and of size, shape and density to
              control sealant depth and produce optimum sealant
              performance.

    C.   Brick:  Brick used for filling holes may be salvaged from
         the building.  New brick shall conform with ASTM C62,
         grade MW.

2.03 EQUIPMENT

    A.   Masonry drill

    B.   Injection equipment


PART 3---EXECUTION

3.01 PREPARATION

    A.   Surface Preparation:  

         1.   Expose wall surface to permit observation of voids
              that would prevent confinement of the foam.

         2.   Close and repair breaks and holes to confine the
              foam to the cavity between wythes of the wall,
              except at holes of less than 1-1/2 inch in least
              dimension, foam may be permitted to flow to within
              1-1/2 times the holes least dimension from the face
              at the wall.

         3.   Drill injection/verification holes through one
              wythe at 12 inch maximum on center horizontal and
              vertical spacing.  Injection/verification holes may
              be made in head or bed joints.

3.02 ERECTION, INSTALLATION, APPLICATION

    A.   Begin injection through injection/verification ports at
         the lowest course of tile.

    B.   Inject in approximately 12 inch lifts.  Inject into injection
         holes until flow of foam is verified at adjacent holes at
         the same level.  Plug verification holes with joint
         filler to confine the foam flow.

    C.   Complete each lift for the full length of all walls
         before proceeding to the next lift.  Allow each lift to
         cure before proceeding to the next lift.

    D.   Clean-up spills as they occur.  Protect finish materials
         from damage.

                         END OF SECTION
 


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