Please use this identifier to cite or link to this item: https://hdl.handle.net/11681/11058
Title: The structural and durability properties of various concrete repairs
Authors: United States. Assistant Secretary of the Army (R & D)
Pace, Carl E.
Keywords: Abrasion
Concrete repair
Concrete to concrete bonding
Concrete structures
Bonding
Freeze-thaw durability
Concrete deterioration
Freeze-thaw tests
Concrete durability
Shear strength
Frost resistance
Publisher: Structures Laboratory (U.S.)
Engineer Research and Development Center (U.S.)
Series/Report no.: Miscellaneous paper (U.S. Army Engineer Waterways Experiment Station) ; SL-79-20.
Description: Miscellaneous Paper
Abstract: Many old concrete structures exist and are in need of repair. The structural deterioration will accelerate with advancing age and progressively diminish their service lives. Methods of evaluation and repair are necessary. Durable concrete can be produced and placed; therefore, the main problem is to have a durable interface between the old and the new concrete. The bonding of epoxy resin, cement mortar, latex polymer mortar, and latex polymer mortar plus fiberglass fabric was tested in a freezing and thawing environment subjected to conditions of complete submergence, one-half submergence, and stress conditions. Many surfaces are subjected to abrasion. The latex polymer was tested to determine if it helped to increase abrasion resistance. These tests showed that for early ages of repair water will collect at the interface of the old and new concrete and when the water concentration is sufficient and freezing occurs, the overlay will be debonded. The epoxy bond exhibited a constant number of specimen failures with cycles of freezing and thawing. The concrete-to-concrete bonding had more specimens fail at early intervals of freezing and thawing than in later intervals, indicating that as similar characteristics develop between the repair and the aged concrete, less water collected at the interface. All four bonding types had about tne same final percent failures in the freezing and thawing environment, which in all probability suggests that the failures due to water collecting at the interface for early ages of repair are essentially comparable. Specimens which were subjected to freezing and thawing plus stress showed more failures than the unstressed specimens. The specimens which were one-half submerged showed no failure in the freezing and thawing environment. Epoxy bonding should not be used in a freezing and thawing environment where there is a possibility of water collecting at the interface. The latex polymer showed a considerable decrease in shear strength with cycles of freezing and thawing. The concrete-to-concrete bonding to a dry interface is an acceptable bonding. The fiberglass fabric is a promising material to be added in thin overlays to prevent cracking. The stressing of the specimens at various intervals of freezing and thawing had an adverse effect on the durability of the shear strength of the repaired interface. Any eccentricity of the load causing shear at the repair interface produces tension on the interface. Tension was a predominant factor in shear stress failures. A concrete overlay should be placed on a surface which is surface dry.
Rights: Approved for public release; distribution is unlimited.
URI: http://hdl.handle.net/11681/11058
Appears in Collections:Miscellaneous Paper

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