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Causes of Distress and Deterioration in Concrete


Quiz Questions

1. A visual inspection of the exposed concrete is the first step in an on-site examination of a structure. The purpose of such an examination is to locate and define areas of distress or deterioration.

It is important that the conditions observed be described in unambiguous terms that can later be understood by others who have not inspected the concrete. Terms typically used during a visual inspection are listed by category in Table 2-1.
True
False
2. Typical construction faults that may be found during a visual inspection include bug holes, evidence of cold joints, exposed reinforcing steel, honeycombing, irregular surfaces caused by improperly aligned forms, and a wide variety of surface blemishes and irregularities. These faults are typically the result of poor workmanship or the failure to follow accepted good practice.
True
False
3. Cracks that occur in concrete may be described in a variety of ways. Some of the more common ways are in terms of surface appearance, depth of cracking, width of cracking, current state of activity, physical state of concrete when cracking occurred, and structural nature of the crack.
True
False
4. Figure 2-3 shows and example of:
Cold joint
Pattern cracking
5. Figure 2-5 shows cracking caused by restrained volume changes.
True
False
6. the cracking figure 2-6 has been caused by:
Alkali-slice reaction
Transportation overload
7. The disintegration of concrete in figure 2-12 has been caused by:
Exposure to aggressive water
Alkali reaction
8. Figures 2-16, and 2-17 shows:
Light and medium Scaling
Sulfate attack
9. Figures 2-22 and 2-23 show deterioration and loss of joint sealant.
True
False
10. Corrosion of reinforcing steel may open cracks that allow moisture greater access to the interior of the concrete.
True
False
11. The following list could be the causes of Distress and Deterioration of Concrete

Accidental Loadings
Chemical Reactions
Acid attack
Aggressive-water attack
Alkali-carbonate rock reaction
Alkali-silica reaction
Miscellaneous chemical attack
Sulfate attack
Construction Errors
Corrosion of Embedded Metals
Design Errors
Inadequate structural design
Poor design details
Erosion
Abrasion
Cavitations
Freezing and Thawing
Settlement and Movement
Shrinkage
Plastic
Drying
Temperature Changes
Internally generated
Externally generated
Fire
Weathering
True
False
12. Accidental loading such as the impact of a barge against a lock wall or an earthquake can generate stresses higher than the strength of the concrete, resulting in localized or general failure.
True
False
13. Accidental loadings by their very nature cannot be prevented. Minimizing the effects of some occurrences by following proper design procedures (an example is the design for earthquakes) or by proper attention to detailing (wall armor in areas of likely impact) will reduce the impacts of accidental loadings.
True
False