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Historic Preservation - Technical Procedures

Spectitle:

Standard Testing Sequence For Removing Unknown Stains From Concrete

Procedure code:

0371003S

Source:

Hstrc Concrete: Investigation & Rpr/Pre-Conf Training - 1989

Division:

Concrete

Section:

Concrete Cleaning

Last Modified:

02/24/2012

Details:

Standard Testing Sequence For Removing Unknown Stains From Concrete



STANDARD TESTING SEQUENCE FOR REMOVING UNKNOWN STAINS FROM
CONCRETE


PART 1---GENERAL

1.01 SUMMARY

    A.   This standard outlines a testing sequence of trial and
         error techniques that may be used to determine the most
         effective method of removing unknown stains from
         concrete.

    B.   It is important to identify the cause of staining and the
         nature of the stain as part of selecting the proper
         removal techniques.  

    C.   For removal of a specific stain type, see the appropriate
         procedure(s) as listed below:

         1.   Aluminum Stains:  See 03710-04-R.

         2.   Asphalt Stains:  See 03710-05-R.

         3.   Beverage Stains:  See 03710-06-R.

         4.   Blood Stains:  See 03710-07-R.

         5.   Bronze and Copper Stains:  See 03710-44-R.

         6.   Candy and Confectionery Stains:  See 03710-08-R.

         7.   Caulking Compound Stains:  See 03710-09-R.

         8.   Chewing Gum:  See 03710-10-R.

         9.   Coal Tar Stains:  See 03710-12-R.

         10.  Creosote Stains:  See 03710-13-R.

         11.  Curing Compound Stains:  See 03710-14-R.

         12.  Surface Dirt:  See 03710-15-R.

         13.  Efflorescence:  See 03710-16-R.

         14.  Epoxy Coatings and Epoxy Adhesives:  See 03710-17-R.

         15.  Finishing and Curing Discolorations:  See 03710-18-R.

         16.  Fire, Smoke, Soot, Pitch and Wood Tar Stains:  See
              03710-19-R.

         17.  Graffiti (paint-based):  See 03710-21-R.

         18.  Grease Stains:  See 03710-01-R.

         19.  Gypsum Plaster Stains:  See 03710-22-R.

         20.  Ink Stains:  See 03710-24-R.

         21.  Iodine Stains:  See 03710-25-R.

         22.  Iron Rust Stains:  See 03710-26-R.

         23.  Mildew Stains:  See 03710-28-R.

         24.  Moss Stains:  See 03710-29-R.

         25.  Linseed, Soybean and Tung Oil Stains:  See 03710-30-R.

         26.  Lubricating and Petroleum Oil Stains:  See 03710-31-R.

         27.  Old Resilient Flooring Adhesives:  See 03710-03-R.

         28.  Paint, Shellac and Varnishes:  See 03710-32-R.

         29.  Perspiration Stains:  See 03710-33-R.

         30.  Plywood or Joint Sealant Stains:  See 03710-34-R.

         31.  Tobacco Stains:  See 03710-37-R.

         32.  Urine Stains:  See 03710-38-R.

         33.  Wood Stains:  See 03710-42-R.


PART 2---PRODUCTS

2.01 MATERIALS

    A.   See individual procedures for specific solvents, bleaches
         and acids that may be used in stain removal.

    B.   Clean, potable water

    C.   Accessible source of water, soap and towels for washing
         and rinsing in case of emergencies associated with the
         use of chemicals

2.02 EQUIPMENT

    A.   Nylon bristle brushes (metallic brushes should not be
         used)


PART 3---EXECUTION

3.01 ERECTION, INSTALLATION, APPLICATION

    A.   If the type of stain can not be identified, conduct tests
         in an inconspicuous area.  

    B.   If a particular stain type is suspected, begin by using
         simple cleaning techniques as outlined in item C. below.
         If this fails, then proceed to item D. and use solvents
         or bleaches judiciously selected for removal of those
         materials believed to be causing the discoloration.

    C.   ALWAYS start with the most mild method of cleaning and
         proceed to stronger methods.  Use small test patches
         until a satisfactory surface is restored.  Use materials
         in the following sequence:

         1.   Water with soft brushes

         2.   Water with mild soap

         3.   Water with stronger soap

         4.   Water with stronger soap plus ammonia

         5.   Water with stronger soap plus vinegar

         NOTE:  ONLY AFTER TRYING THESE METHODS IN THIS SEQUENCE
         SHOULD ONE PROCEED TO STRONGER CHEMICAL CLEANERS AS
         OUTLINED BELOW.

    D.   If the nature of the stain is completely unknown, begin
         testing various agents on inconspicuous areas of stained
         concrete in the following sequence until an effective
         method is determined.

         1.   Organic Solvents

         2.   Oxidizing bleaches, like those based on peroxides
              or hypochlorites.  Avoid using any colored
              oxidizing agent like potassium permanganate which
              might impart additional color to the stain.

         3.   Reducing bleaches, some of which are used in an
              acidic medium

         4.   Acids and other acidic materials

                        END OF SECTION