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Historic Preservation - Technical Procedures

Spectitle:

Repairing Spalled Granite Using Epoxy Adhesive

Procedure code:

0446521R

Source:

National Capitol Region Specifications

Division:

Masonry

Section:

Granite

Last Modified:

06/14/2012

Details:

Repairing Spalled Granite Using Epoxy Adhesive



REPAIRING SPALLED GRANITE USING EPOXY RESIN


PART 1---GENERAL

1.01 SUMMARY

    A.   This procedure includes guidance on repairing minor
         cracks and spalls in granite.  This includes those
         smaller than 6"x6".  For larger fragments, see 04465-28-
         R.

    B.   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 SUBMITTALS

    A.   Product Data:  Submit manufacturer's product literature
         for epoxy adhesives or resins.

    B.   Samples:

         1.   Submit samples of dowels for patch anchorage.

         2.   Sample Stone Repair:  Reattach stone fragments and
              patch stone at locations selected by the RHPO using
              methods specified.  Provide one sample each
              material.


PART 2---PRODUCTS

2.01 MANUFACTURERS

    A.  Akemi Plastics, Inc.
         www.akemi.de; info@akemi.de

    B.  Sika Corporaton
         www.usa.sika.com
         
         
2.02 MATERIALS

    A.   Epoxy Based Stone Repair Adhesive, such as "Akepox"
         (various "Akepox" products from Akemi), "Sikadur Hi-Mod" (Sika
         Corporation), or approved equal.

    B.   Clean, soft cloths

    C.   Acetone (C3H6O):

         1.   A volatile fragrant flammable liquid ketone used
              chiefly as a solvent and in organic synthesis.

         2.   Other chemical or common names include Dimethyl
              ketone; Propanone

         3.   Potential Hazards:  VOLATILE AND FLAMMABLE SOLVENT

         4.   Available from chemical supply house or hardware
              store.

    D.   Clean, potable water

2.03 EQUIPMENT

    A.   Stiff natural bristle brush

    B.   Trowel

    C.   Chisel

    D.   Putty knife


PART 3---EXECUTION

3.01 PREPARATION

    A.   Surface Preparation:  Temporarily remove and store light
         fixtures, mounting brackets, conduit, signs and other
         building accessories to facilitate the restoration work.
         Reinstall all removed items.

3.02 ERECTION, INSTALLATION, APPLICATION

    A.   Carefully remove loose stone fragments from building.
         Re-use all pieces of broken stone that are in sound
         condition, without serious cracks or flaws.

    B.   Clean any exposed metal anchors of all corrosion by
         scraping and brushing with stiff wire brushes.

    C.   Clean surfaces to be laminated of grease and dust.
         Surfaces should also be dry.

    D.   Mix hardener with mastic as per manufacturer's
         instructions.

    E.   Apply adhesive evenly and completely to surfaces to be
         laminated.  Set stone while adhesive is still tacky.
         Secure stone fragments in place against movement until
         adhesive is cured.

    F.   Clean any residual adhesive from the stone with acetone.

    G.   Pieces larger than 6"x6" should be further anchored with
         rods drilled through the fragment and into the back-up
         stone.  See 04465-28-R.

                         END OF SECTION
 


spalled granite, minor cracks, granite spalls, granite cracks