aci - troubleshooting surface imperfections
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Surface imperfections (Concrete)TRANSCRIPT
Troubleshooting Surface Imperfections
An ACI HandbookH
B-1
1(05)
Troubleshooting Surface Imperfections
The following concrete surface imperfections are described, with definitions, photographs, and bibliographies.
Plastic Cracking
Honeycomb
Delamination
Crazing
Efflorescence
Curling
Bug Holes (Blow Holes)
Popout
Alkali‐Silica Reaction (ASR)
Dusting
Concrete Blisters
Scaling
Blowup
Plastic Cracking (Plastic Shrinkage Cracking) Plastic cracking (plastic shrinkage cracking) is cracking that occurs in the surface of the fresh concrete soon after it is placed and while it is still plastic.
RELATED ARTICLES: Comparison of Industrial Concrete Floor Slabs in the Auckland and Christchurch Markets, Cement and Concrete
Association of New Zealand, Mar. 2001, 40 pp. Halvorsen, G. T., “Troubleshooting Concrete Cracking During Construction,” Concrete Construction, Oct. 1993, 4 pp. Hover, K., “The Gentle Art of Fogging,” Concrete Construction, June 2005, 2 pp. "Plastic Shrinkage Cracking," Concrete‐in‐Practice: What, Why & How? CIP 5, National Ready Mixed Concrete
Association, Silver Spring, MD, 1998, 2 pp. Senbetta, E., and Bury, M. A., “Control of Plastic Shrinkage Cracking in Cold Weather,” Concrete International, V. 13,
No. 3, Mar. 1991, pp. 49‐53. Sprinkel, M. M., “Predicting Plastic Shrinkage Cracking in LMC Overlays,” Concrete Construction, July 1988, 2 pp. “What Causes Concrete to Crack?,” Portland Cement Association, Skokie, IL, 1 p. OTHER REFERENCES: ACI Committee 305, Hot Weather Concreting (ACI 305R‐10), American Concrete Institute, Farmington Hills, MI, 2010,
pp. 4‐6, 8, 11, 16, 18. ACI Committee 224, Control of Cracking in Concrete Structures (ACI 224R‐01), American Concrete Institute,
Farmington Hills, MI, 2001, pp. 26‐27, 36‐38. ACI Committee 223, Guide for the Use of Shrinkage‐Compensating Concrete (ACI 223R‐10), American Concrete
Institute, Farmington Hills, MI, 223, 2010, p. 16.
ACI Committee 544, State‐of‐the‐Art Report on Fiber Reinforced Concrete (ACI 544.1R‐96), American Concrete Institute, Farmington Hills, MI, 1996, pp. 42, 47, 51‐52. Balaguru, P., “Use of Fibers for Plastic Shrinkage Crack Reduction in Concrete,” Design and Production Practices to
Mitigate Cracking (SP‐204), American Concrete Institute, Farmington Hills, MI, 2001, pp. 171‐194. Kosmatka, S.; Kerkhoff, B.; and Panarese, W., Design and Control of Concrete Mixtures, Fourteenth Edition, Portland
Cement Association, Skokie, IL, 2003, 372 pp.
Lerch, W., “Plastic Shrinkage,”ACI Proceedings, V. 53, No. 2, 1957, pp. 797‐802. Morris, P., and Dux, P., “A Review of ACI Recommendations for Prevention of Plastic Cracking,” ACI Materials Journal,
V. 102, No. 5, Sept.‐Oct. 2005, pp. 307‐314. Naaman, A.; Wongtanakitcharoen, T.; and Hauser, G., “Influence of Different Fibers on Plastic Shrinkage Cracking of
Concrete,” ACI Materials Journal, V. 102, No. 1, Jan.‐Feb. 2005, pp. 49‐58.
HoneycombHoneycomb refers to voids left in concrete due to failure of the mortar to effectively fill the spaces among coarse‐aggregate particles.
RELATED ARTICLES: Engineering and Design ‐ Standard Practice for Concrete for Civil Works Structures, EM 1110‐2‐2000, U.S. Army Corps
of Engineers, Feb. 1994, pp. 8‐1 to 8‐9. Ford, J., “Troubleshooting Common Defects in Vertical Cast‐in‐Place Concrete,” Concrete Construction, Dec. 1992, pp.
879‐880. Honeycombing, Cement Concrete & Aggregates Australia, Sept. 2001, 2 pp. Hover, K., “Vibration Tune‐up,” Concrete International, Sept. 2001, pp. 31‐35. Troubleshooting: “Honeycomb and Voids,” Concrete Construction, Dec. 2000, 1 p.
OTHER REFERENCES: ACI Committee 309, Identification and Control of Visible Effects of Consolidation on Formed Concrete Surfaces (ACI
309.2R‐98)(Reapproved 2005), American Concrete Institute, Farmington Hills, MI, 1998, pp. 3‐6. ACI Committee 309, Guide for Consolidation of Concrete (ACI 309R‐05), American Concrete Institute, Farmington
Hills, MI, 1998, pp. 17‐18. ACI Committee 546, Guide to Concrete Repair (ACI 546R‐14), American Concrete Institute, Farmington Hills, MI, 2014,
70 pp. ACI Committee 228, Report on Nondestructive Test Methods for Evaluation of Concrete in Structures (ACI 228.2R‐13),
American Concrete Institute, Farmington Hills, MI, 2013, 82 pp. [Report deals with nondestructive methods for detecting the presence of voids and honeycomb.] Kosmatka, S.; Kerkhoff, B.; and Panarese, W., Design and Control of Concrete Mixtures, Fourteenth Edition, Portland
Cement Association, Skokie, IL, 2003, pp. 4, 8. Smoak, W. G., Guide to Concrete Repair, U.S. Department of the Interior, Bureau of Reclamation, 1998, 184 pp. Suprenant, B., and Basham, K., “Placing and Vibrating Poured Concrete Walls,” Concrete Construction, Feb. 1993, pp.
131‐134.
DelaminationDelamination is a separation along a plane parallel to a surface. Delamination separation, as in the separation of a coating from a substrate or the layers of a coating from each other, or in the case of a concrete slab, is a horizontal splitting, cracking, or separation within a slab in a plane roughly parallel to, and generally near, the upper surface. It is found most frequently in bridge decks and caused by the corrosion of reinforing steel or freezing and thawing. Delamination is similar to spalling, scaling, or peeling except that delamination affects large areas and can often only be detected by nondestructive tests, such as tapping or chain dragging.
RELATED ARTICLES: Bimel, C., “Is Delamination Really A Mystery?, ” Concrete International, V. 20, No. 1, Jan. 1998, pp. 29‐34. Comparison of Industrial Concrete Floor Slabs in the Auckland and Christchurch Markets, Cement and Concrete
Association of New Zealand, Mar. 2001, 40 pp. “Delamination of Troweled Concrete Surfaces,” Concrete‐in‐Practice: What, Why & How? CIP 20, National Ready
Mixed Concrete Association, Silver Spring, MD, 2004, 2 pp. “Do Pan Floats Cause Blisters or Delaminations?,” Concrete Construction, Dec. 2000, 3 pp. Jana, D., “Concrete, Construction, or Salt—Which Causes Scaling?, Part I: Importance of Air‐void System in Concrete,”
Concrete International, V. 26, No. 11, Nov. 2004, pp. 31‐38. Khan, M. S., “Detecting Corrosion‐Induced Delaminations,” Concrete International, V. 25, No. 7, July 2003, pp. 73‐78. Lankard, D. R., “Air Entrainment and Delaminations,” Concrete International, V. 26, No. 11, Nov. 2004, pp. 21‐30. Manning, D. G., and Holt, F. B., “Detecting Delamination in Concrete Bridge Decks,” Concrete International, V. 2, No.
11, Nov. 1980, pp. 34‐41. Samples, L. M., and Ramirez, J. A., “Field Investigations of Concrete Bridge Decks in Indiana: Part I: New Construction
& Initial Field Investigation of Existing Bridge Decks,” Concrete International, V. 22, No. 2, Feb. 2000, pp. 51‐63. Samples, L. M., and Ramirez, J. A., “Field Investigations of Concrete Bridge Decks in Indiana: Part II: Detailed
Investigation of Existing Decks,” Concrete International, V. 22, No. 3, Mar. 2000, pp. 59‐63. Suprenant, B. A., and Malisch, W. R., “Diagnosing Slab Delaminations: Part 1,” Concrete Construction, Jan. 1998, 4 pp. Suprenant, B. A., and Malisch, W. R., “Diagnosing Slab Delaminations: Part 2,” Concrete Construction, Feb. 1998, pp.
169‐174. Suprenant, B. A., and Malisch, W. R., “Diagnosing Slab Delaminations: Part 3,” Concrete Construction, Mar. 1998, pp.
277‐283. OTHER REFERENCES: ACI Committee 302, Guide for Concrete Floor and Slab Construction (ACI 302.1R‐04), American Concrete Institute, Farmington Hills, MI, 2004, pp. 7, 23, 30, 47, 48, 52, 58, 67.
Crazing
Crazing is the development of craze cracks, a system of fine random cracks in a concrete surface. The pattern of craze cracks existing in a surface is also referred to as crazing.
RELATED ARTICLES: “Crazing: Care and Maintenance,” Technical Bulletin #32, Cast Stone Institute, 1 p. “Crazing Concrete Surfaces,” Concrete‐in‐Practice: What, Why & How? CIP 3, National Ready Mixed Concrete
Association, Silver Spring, MD, 1998, 2 pp. “Is Craze Cracking a Terminal Illness?,” Concrete Construction (Problem Clinic), Feb. 1997, pp. 238. Malisch, W., “Avoiding Common Outdoor Flatwork Problems,” Concrete Construction, July 1990, pp. 632‐638. “What Causes Concrete to Crack?,” Portland Cement Association, Skokie, IL, 1 p. OTHER REFERENCES: Fentress, B., “Slab Construction Practices Compared by Wear Tests,” ACI Journal, July 1973, pp. 486‐491. “Non‐Structural Cracks in Concrete,” Concrete Society Technical Report No. 22, 3rd edition, The Concrete Society,
London, 1992. “What is Crazing, What Causes It and How To Avoid It,” Cement Concrete & Aggregates Australia, 1 p.
EfflorescenceEfflorescence is a deposit—usually white—formed on the surface of a concrete or masonry surface. Salts or bases emerge in solution to form the deposit, usually as a result of evaporation or carbonation.
RELATED ARTICLES: Beall, C., “How to Stop Efflorescence,” Masonry Construction, May 1988, pp. 79‐82. Troubleshooting: “Efflorescence,” Concrete Construction, Aug. 2000, p. 82. Kenney, A. R., “Avoiding Efflorescence in Architectural Precast Concrete,” Concrete Journal, July
1996, pp. 498‐500. Neville, A., “Efflorescence—Surface Blemish or Internal Problem?, Part 1: The Knowledge,” Concrete
International, V. 24, No. 8, Aug. 2002, pp. 86‐90. Neville, A., “Efflorescence—Surface Blemish or Internal Problem?, Part 2: Situation in Practice,”
Concrete International, V. 24, No. 9, Sept. 2002, pp. 85‐88. Schierhorn, Carolyn, “Efflorescence & Stains: A Quiz,” Masonry Construction, Aug. 1995, pp. 409‐
412. OTHER REFERENCES: Bensted, J., “Efflorescence—Prevention is Better Than Cure,” Concrete, Sept. 2000, pp. 40‐41. Higgins, D. D., “Efflorescence on Concrete,” Appearance Matters, Cement and Concrete Association
(U.K.), 1982, 8 pp. Kennerley, R. A., Efflorescent Deposits on Concrete, New Zealand Concrete Construction, Dec. 1981,
pp. 21‐24. Kresse, P., Efflorescence and Its Prevention, Betonwerk + Fertigteiltechnik (Germany), Oct. 1991, pp.
73‐87. Ritchie, T., “Efflorescence, CBD 2,” Canadian Building Digest, Division of Building Research, National
Research Council, Feb. 1960, 4 pp. Suprenant, B., “Efflorescence—Minimizing Unsightly Staining,” Concrete Construction, Mar. 1992,
pp. 240‐243.
CurlingCurling is the upward movement of a slab's corners and edges due to differences in moisture content or temperature between the top and bottom of a slab. The top dries or cools and contracts more than the wetter or warmer bottom. Because of the reduced subgrade support, cracks often develop parallel to joints or cracks, and at the corners where joints intersect.
RELATED ARTICLES: Comparison of Industrial Concrete Floor Slabs in the Auckland and Christchurch Markets, Cement and Concrete
Association of New Zealand, Mar. 2001, 40 pp. “Curling of Concrete Slabs,” Concrete‐In‐Practice: What, Why, & How? CIP 19, National Ready Mixed Concrete
Association, Silver Spring, MD, 2004, 2 pp. Holland, J. A., and Walker, W., “Controlling Curling and Cracking in Floors to Receive Coverings,” Concrete
Construction, July 1998, 2 pp. Mailvaganam, N.; Springfield, J.; Repette, W.; and Taylor, D., “Curling of Concrete Slabs on Grade,” Construction
Technology Update, No. 44, Dec. 2000, 2 pp. Ryan, J. T., "Controlling Slab Curling," Concrete Construction, June 1996, 3 pp. Suprenant, B. A., “Why Slabs Curl, Part I: A Look at the Curling Mechanism and the Effect of Moisture and Shrinkage
Gradients on the Amount of Curling,” Concrete International, V. 24, No. 3, Mar. 2002, pp. 56‐61. Suprenant, B. A., “Why Slabs Curl, Part II: Factors Affecting the Amount of Curling,” Concrete International, V. 24, No.
4, Apr. 2002, pp. 59‐64. Tarr, S.; Craig, P.; and Kanare, H., “Concrete Slab Repair: Getting Flat is One Thing, Staying Flat is Another! ,” Concrete
Repair Bulletin, Jan./Feb. 2006, pp. 12‐15. Walker, W., and Holland, J. A., “The First Commandment for Floor Slabs: Thou Shalt Not Curl Nor Crack...(Hopefully),”
Concrete International, V. 21, No. 1, Jan. 1999, pp. 47‐53.
Ytterberg, R. F., “Shrinkage and Curling of Slabs on Grade, Part I—Drying Shrinkage,” Concrete International, V. 9, No. 4, Apr. 1987, pp. 22‐31. Ytterberg, R. F., “Shrinkage and Curling of Slabs on Grade, Part II—Warping and Curling,” Concrete International, V. 9,
No. 5, May 1987, pp. 54‐61. Ytterberg, R. F., “Shrinkage and Curling of Slabs on Grade, Part III—Additional Suggestions,” Concrete International, V.
9, No. 6, June 1987, pp. 72‐81. OTHER REFERENCES: Abdul‐Wahab, H. M. S., and Jaffar, A. S., “Warping of Reinforced Concrete Slabs Due to Shrinkage,” ACI Journal,
Proceedings, V. 80, No. 2, Mar.‐Apr. 1983, pp. 109‐115. Al‐Nasra, M., and Wang, L. R. L., “Parametric Study of Slab‐on‐Grade Problems due to Initial Warping and Point
Loads,” ACI Structural Journal, V. 91, No. 2, Mar.‐Apr. 1994, pp. 198‐210. ACI Committee 302, Guide for Concrete Floor and Slab Construction (ACI 302.1R‐04), American Concrete Institute,
Farmington Hills, MI, 2004, pp. 9, 11, 50, 58, 62, 70‐71. ACI Committee 360, Design of Slabs‐on‐Ground (ACI 360R‐10), American Concrete Institute, Farmington Hills, MI,
2010, 72 pp. Concrete Floors on Ground, Portland Cement Association, Skokie, IL, 2001, p. 106. Garber, G., Design and Construction of Concrete Floors, John Wiley & Sons, New York, 1991, pp. 154‐159. Suprenant, B., and Malisch, W., “Repairing Curled Slabs,” Concrete Construction, May 1999, pp. 58‐65.
Bug HolesBug holes (or blow holes), usually not exceeding 15 mm (0.6 in.) in diameter, resulting from entrapment of air bubbles in the surface of formed concrete during placement and consolidation.
P3: Ordinary smooth‐form, as‐cast concrete with numerous evenly scattered bugholes. Most of them are in the 1/8 to 1/4‐in. range.
P5: Bugholes as large as 1 in. across, seen in combination with a wide range of other sizes of voids, some of significant depth. This would qualify as a smooth‐form finish only if bugholes larger than 3/4 in. are filled.
RELATED ARTICLES: “Bugholes,” Concrete Technology, Portland Cement Association, Skokie, IL, 1 p. “Bugholes in Formed Concrete,” ASCC Position Statement 8, American Society of Concrete Contractors, St. Louis, MO,
2003, 1 p. Ford, J., “Troubleshooting Common Defects in Vertical Cast‐in‐Place Concrete,” Concrete Construction, Dec. 1992, pp.
879‐880. Reading, T. J., “The Bughole Problem,” ACI Journal, Mar. 1972, pp. 165‐171. Samuelsson, P., “Voids in Concrete Surfaces,” ACI Journal, Nov. 1970, pp. 868‐874.
OTHER REFERENCES: ACI Committee 309, Identification and Control of Visible Effects of Consolidation on Formed Concrete Surfaces (ACI
309.2R‐98), American Concrete Institute, Farmington Hills, MI, 1998, pp. 6, 8‐10. Blake, L. S.; Kinnear, R. G.; and Murphy, W. E., “Symposium on Surface Treatment of In‐Situ Concrete,” Cement and
Concrete Association, London, 1964, 27 pp. Blowholes (Bugholes), Cement Concrete & Aggregates Australia, Sept. 2001, 2 pp. Bugholes in Concrete Surfaces: Annotated Bibliography, Portland Cement Association, Skokie, IL, 2004, 4 pp. Guide for Surface Finish of Formed Concrete, American Society of Concrete Contractors, St. Louis, MO, 1999, 50 pp. Houston, B. J., “Methods of Reducing the Size and Number of Voids on Formed Concrete Surfaces,” Technical Report
No. 6‐788, U.S. Army Engineer Waterways Experiment Station, Vicksburg, MS, July 1967.
McGovern, M., “Smooth Moves,” Concrete Construction, Sept. 1999, pp. 48‐50. Smoak, W. G., Guide to Concrete Repair, U.S. Department of the Interior, Bureau of Reclamation, 1998, 184 pp. Thompson, M. S., “Blowholes in Concrete Surfaces,” Concrete, (Published by The Concrete Society, London), Feb.
1969, pp. 64‐69.
PopoutA popout is the breaking away of small portions of a concrete surface due to localized internal pressure that leaves a shallow, typically conical, depression. Small popouts leave holes up to 0.4 in. (10 mm) in diameter; medium popouts leave holes 0.4 to 2 in. (10 to 50 mm) in diameter; and large popouts leave holes greater than 2 in. (50 mm) in diameter.
RELATED ARTICLES: Malisch, W., “Avoiding Common Outdoor Flatwork Problems,” Concrete Construction, July 1990, pp. 632‐638. “Troubleshooting: Popouts,” Concrete Construction, Oct. 2000, 1 p.
OTHER REFERENCES: ACI Committee 221, Guide for Use of Normal Weight and Heavyweight Aggregates in Concrete (ACI 221R‐
96)(Reapproved 2001), American Concrete Institute, Farmington Hills, MI, 1996, pp. 6‐9. ACI Committee 302, Guide for Concrete floor and Slab Construction (ACI 302.1R‐04), American Concrete Institute,
Farmington Hills, MI, 2004, pp. 66‐67. Landgren, R., and Hadley, D. W., Surface Popouts Caused by Alkali‐Aggregate Reaction, Research and Development
Bulletin RD121, Portland Cement Association, Skokie, IL, 2002, 20 pp. Popouts, Cement Concrete & Aggregates Australia, Sept. 2001, 2 pp. Verbeck, G., and Landgren, R., “Influence of Physical Characteristics of Aggregates on Frost Resistance of Concrete,”
Proceedings of the American Society for Testing and Materials, V. 60, ASTM, West Conshohocken, PA, 1960, pp. 1063‐1079.
Alkali‐Silica ReactionAlkali‐Silica Reaction (ASR) is the reaction between alkalies (sodium and potassium) in portland cement and certain siliceous rocks or minerals, such as opaline chert, strained quartz, and acidic volcanic glass, present in some aggregates. The products of the reaction may cause abnormal expansion and cracking of concrete in service.
RELATED ARTICLES: Doran, D. K., Alkali‐Silica Reaction in Concrete (ASR), The Institution of Structural Engineers, Nov. 2004, 1 p. Fournier, B., and Malhotra, V. M., “Reducing Expansion Due to Alkali‐Silica Reactivity,” Concrete International, V. 18,
No. 3, Mar. 1996, pp. 55‐59. Grattan‐Bellew, P. E., and Mitchell, L., “Preventing Concrete Deterioration Due to Alkali‐Aggregate Reaction,”
Construction Technology Update, No. 52, Mar. 2002, 2 pp. Helmuth, R., “Alkali‐Silica Reactivity: An Overview of Research,” SHRP‐C‐342, Strategic Highways Research Program;
also LT177, Portland Cement Association, Skokie, IL, 1993, 115 pp. Mather, B., “Landmark Series: Cracking of Concrete in the Tuscaloosa Lock,” Concrete International, V. 26, No. 9,
Sept. 2004, pp. 61‐86. Michigan Tech Transportation Institute, “Guidelines for Detection, Analysis, and Treatment of Materials‐Related
Distress in Concrete Pavements,” FHWA‐RD‐01‐163, Federal Highway Administration, McLean, VA, Mar. 2002. Portland Cement Association, Alkali‐Aggregate Reaction, 2006, 1p. Tuthill, L. H., “Alkali‐Silica Reaction — 40 Years Later,” Concrete International, V. 4, No. 4, Apr. 1982, pp. 32‐36.
OTHER REFERENCES: ACI Committee 201, Guide to Durable Concrete (ACI 201.2R‐08), American Concrete Institute, Farmington Hills, MI,
2001, 49 pp. ACI Committee 221, State‐of‐the‐Art Report on Alkali‐Aggregate Reactivity (ACI 221.1R‐98)(Reapproved 2008),
American Concrete Institute, Farmington Hills, MI, 1998, 31 pp. “Alkali‐Silica Reaction in Concrete: 2004 Edition,” Building Research Establishment Digest 330, Building Research
Establishment, London, 2004. Kosmatka, S.; Kerkhoff, B.; and Panarese, W., Design and Control of Concrete Mixtures, Fourteenth Edition, Portland
Cement Association, Skokie, IL, 2003, 372 pp. Stark, D., “Alkali‐Silica Reaction in Concrete,” Significance of Tests and Properties of Concrete and Concrete‐Making
Materials (ASTM STP 169D), ASTM, West Conshohocken, PA, 2006, pp. 401‐409.
DustingDusting is the development of a soft, powdery material that can be easily rubbed off the surface of hardened concrete.
RELATED ARTICLES: Dusting of finished surfaces Basham, Kim, “Cold‐Weather Concrete Construction,” Concrete International, V. 27, No. 11, Nov. 2005, pp. 31‐34. “Dusting Concrete Surfaces,” Concrete‐in‐Practice: What, Why & How? CIP 1, National Ready Mixed Concrete
Association, Silver Spring, MD, 1998, 2 pp. Fentress, Blake, “Slab Construction Practices Compared by Wear Tests,” ACI Journal, V. 70, No. 7, July 1973, pp. 486‐
491. Frey, George, “Construction Considerations for Serviceable Concrete Floors,” ACI Journal, V. 70, No. 6, June 1973, pp.
418‐419. Kauer, J. A., and Freeman, R. L., “Effect of Carbon Dioxide on Fresh Concrete,” ACI Journal, V. 52, No. 12, Dec. 1955,
pp. 447‐454. Dusting of formed surfaces Reading, T. J., “Deleterious Effects of Wood Forms on Concrete Surfaces,” Concrete International, V. 7, No. 11, Nov.
1985, pp. 57‐62. Reading, T. J., “Effects of Release Agents Used on Plywood Forms,” Concrete International, V. 7, No. 7, July 1985, pp.
15‐22. Wastlund, Georg, and Eriksson, Anders, “Wear Resistance Tests on Concrete Floors and Methods of Dust
Prevention,” ACI Journal, V. 43, No. 10, Oct. 1946, pp. 181‐199. OTHER REFERENCES: ACI Committee 201, Guide to Durable Concrete (ACI 201.2R‐08), American Concrete Institute, Farmington Hills, MI, 2001, pp. 27, 33. ACI Committee 302, Guide for Concrete Floor and Slab Construction (ACI 302.1R‐04), American Concrete Institute, Farmington Hills, MI, 2004, pp. 26, 41, 43, 44, 46, 62, 64, 65. Bakke, K., “Abrasion Resistance,” Significance of Tests and Properties of Concrete and Concrete‐Making Materials (ASTM STP 169D), ASTM, West Conshohocken, PA, 2006, pp. 184‐193. Feld, J., “Study of Dusty Concrete Ceilings,” ACI Journal, V. 45, No. 5, May 1949, pp. 673‐678. Garber, G., Design and Construction of Concrete Floors, John Wiley & Sons, New York, 1991, pp. 245‐261. Vassour, V.; Kettle, R.; and Sadegzadeh, M., “The Relative Performance of Abrasion Apparatus in Accordance with BS 8204 (Part 2: 1999),” Cement, Concrete, and Aggregates, V. 24, No. 2, ASTM, West Conshohocken, PA, 2002, pp. 73‐80.
Concrete BlistersBlisters are air‐ or water‐filled bulges that form under a dense skin of mortar during finishing of a concrete surface. They can vary from about 1/4 to 3 in. in diameter and may move during troweling or be apparent only after finishing is completed. They break under traffic after the concrete has hardened.
RELATED ARTICLES: “Concrete Blisters,” Concrete‐in‐Practice: What, Why & How? CIP 13, National Ready Mixed Concrete Association,
Silver Spring, MD, 2005, 2 pp. “Hard Trowel Finish on Air‐Entrained Concrete,” ASCC Position Statement #1, American Society of Concrete
Contractors, St. Louis, MO, 2003, 1 p. Lankard, David R., “Air Entrainment and Delaminations,” Concrete International, V. 26, No. 11, Nov. 2004, pp. 21‐30. Peterson, Carl O., “Concrete Surface Blistering—Causes and Cures,” Concrete Construction, Sept. 1970, p. 317.
OTHER REFERENCES: ACI Committee 302, Guide for Concrete Floor and Slab Construction (ACI 302.1R‐04), American Concrete Institute,
Farmington Hills, MI, 2004, pp. 67‐68. Concrete Slab Surface Defects: Causes, Prevention, Repair (IS 177), Portland Cement Association, Skokie, IL, 2001, pp.
1‐2. Rollings, R. S., and Wong, G. S., “Investigation of a Concrete Blistering Failure,” Materials: Performance and
Prevention of Deficiencies and Failures, American Society of Civil Engineers, Fairfax, VA, 1992, pp. 16‐30. Suprenant, B., and Malisch, W., “Sealing Effects of Finishing Tools,” Concrete Construction, Sept. 1999, pp. 39‐43.
Scaling
Scaling is local flaking or peeling away of the near‐surface portion of hardened concrete. ACI 116‐00, Cement and Concrete Terminology, defines degrees of scaling as follows:
Light scaling doesn’t expose coarse aggregate.
Medium scaling loss of surface mortar to 5 to 10 mm in depth and exposure of coarse aggregate.
Sever scaling loss of surface mortar to 5 to 10 mm in depth with some loss of mortar surrounding aggregate particles 10 to 20 mm in depth.
Very severe scaling loss of coarse aggregate particles as well as mortar generally to a depth greater than 20 mm.
RELATED ARTICLES: Browne, Frederick P., and Cady, Phillip D., “Deicer Scaling Mechanisms in Concrete,” Durability of Concrete (SP‐47),
American Concrete Institute, Farmington Hills, MI, 1975, pp. 101‐119. Jana, D., “Concrete, Construction, or Salt—Which Causes Scaling? Part 1,” Concrete International, V. 26, No. 11, Nov.
2004, pp. 31‐38. Jana, D., “Concrete, Construction, or Salt—Which Causes Scaling? Part 2,” Concrete International, V. 26, No. 12, Dec.
2004, pp. 51‐56. Johnston, C. D., “Deicer Salt Scaling Resistance and Chloride Permeability,” Concrete International, V. 16, No. 8, Aug.
1994, pp. 48‐55. Lankard, D., “Scaling Revisted,” Concrete International, V. 23, No. 5, May 2001, pp. 43‐49. Malisch, W., "Avoiding Common Outdoor Flatwork Problems," Concrete Construction, July 1990, pp. 632‐638. McDonald, D. B., and Perenchio, W. F., “Effects of Salt Type on Concrete Scaling,” Concrete International, V. 19, No. 7,
July 1997, pp. 23‐26. Michigan Tech Transportation Institute, Guidelines for Detection, Analysis, and Treatment of Materials‐Related
Distress in Concrete Pavements, FHWA‐RD‐01‐163, Federal Highway Administration, McLean, VA, Mar. 2002. Pinto, R., and Hover, K., Frost and Scaling Resistance of High‐Strength Concrete (RD 122), Portland Cement
Association, Skokie, IL, 2001, 75 pp. “Scaling Concrete Surfaces,” What, Why, & How? CIP 2, National Ready Mixed Concrete Association, 1998, 2 pp.
OTHER REFERENCES: ACI Committee 201, Guide to Durable Concrete (ACI 201.2R‐08), American Concrete Institute, Farmington Hills, MI,
2008, pp. 5‐6, 11. ACI Committee 345, Guide for Concrete Highway Bridge Deck Construction (ACI 345R‐11), American Concrete
Institute, Farmington Hills, MI, 1991, pp. 3, 13, 16, 23, 25, 31. ACI Committee 302, Guide for Concrete Floor and Slab Construction (ACI 302.1R‐04), American Concrete Institute,
Farmington Hills, MI, 2004, pp. 65‐66. Deicers: Bibliography of Resources (LB05), Portland Cement Association, Skokie, IL, 2001, 6 pp. Kosmatka, S.; Kerkhoff, B.; and Panarese, W., Design and Control of Concrete Mixtures, Fourteenth Edition, Portland
Cement Association, Skokie, IL, 2003, 372 pp. Litvan, G. G., “Phase Transitions of Adsorbates: VI, Effect of Deicing Agents on the Freezing of Cement Paste,” Journal
of the American Ceramic Society, Jan. 1975, pp. 26‐30. Litvan, G. G., “Frost Action in Cement in the Presence of De‐Icers,” Cement and Concrete Research, May 1976, pp.
351‐356. Verbeck, G. J., and Klieger, P., “Studies of ‘Salt’ Scaling of Concrete,” Bulletin No. 150, Highway (Transportation)
Research Board, Washington, DC, 1957, pp. 1‐13.
BlowupA blowup is a localized upward movement of a concrete curb or slab, usually at a joint or crack. Blowups often occur when joints have become filled with incompressible material and thermal expansion during hot weather creates compressive forces high enough to cause buckling of pavements, sidewalks, or curbs. Cracking may also occur, parallel to or perpendicular to joints.
RELATED ARTICLES: Albright, Richard O., “Beware of Unrestrained Expansion,” Concrete Construction, Apr. 1998, pp. 371‐374. Burke, Martin P., Jr., and Bugler, John W., “The Long‐Term Performance of Unsealed Jointed Concrete Pavements,”
Paper No. 02‐2394, Transportation Research Board’s 81st Annual Meeting, 2002, 14 pp. Burke, Martin P., Jr., “Reducing Bridge Damage Caused by Pavement Forces, Part 1: Some Examples” Concrete
International, V. 26, No. 1, Jan. 2004, pp. 53‐57. Burke, Martin P., Jr., “Reducing Bridge Damage Caused by Pavement Forces, Part 2: The Phenomenon” Concrete
International, V. 26, No. 2, Feb. 2004, pp. 83‐89. Concrete Q&A: “Expansion Joints in Exterior Pavements?” Concrete International, V. 28, No. 1, Jan. 2006, pp. 107‐
108. NCHRP W35, Rehabilitation Strategies for Highway Pavements (Part B), Appendix A, “Pavement Distress Types and
Causes,” pp. A‐11 to A‐12. Troubleshooting: “Blowup,” Concrete Construction, Jan. 2000, p. 106. OTHER REFERENCES: Burke, M.P., Jr., “Pavement Pressure Generation: Neglected Aspect of Jointed Pavement Behavior,” Transportation
Research Record 1627, TRB, National Research Council, Washington, DC, 1998, pp. 22‐28. Design and Construction of Joints for Concrete Highways, TB010P, American Concrete Pavement Association, Skokie,
IL, 1991, 24 pp. Kerr, Arnold D., “Assessment of Concrete Pavement Blowups,” Journal of Transportation Engineering, American
Society of Civil Engineers, Mar./Apr. 1997, pp. 123‐131.