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Concrete > CT Concrete Standard Specifications Chapter 51 & 90 > Flashcards

CT Concrete Standard Specifications Chapter 51 & 90 Flashcards

1
Q

Concrete Washouts must have a sign saying what? With What Dimensions?

A

CONCRETE WASHOUT ON A 4’x2’ SIGN

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2
Q

Thickness of Polyethylene for temporary concrete washout

A

10 mils, and free of holes and defects

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3
Q

Portable Temporary Concrete washout bin size

A

55 gallons

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4
Q

Temporary Concrete Washout Bins size

A

5 CY

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5
Q

What is required if colored concrete is to be incorporated into the work?

A

technical data, manufacturer specs working plan for mixing, delivery, placement, finishing and curing

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6
Q

When do we need test panels?

A

When texture or color is used/notify the architect

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7
Q

Default compressive strength for concrete in structures

A

3600 PSI @ 28 days

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8
Q

Approximate sack range for structural concrete

A

7-8.8 sacks

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9
Q

Weight limits for bridges after pour

A

1000 lbs at 2,400 PSI
4000 lbs at 3250 PSI or 28 days
Nothing over 10,000 until pre-tensioned

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10
Q

Are the bottom of footing elevations final? Who do you coordinate with if not? Its a good time to verify what?

A

No, they are approximate. Coordinate with SR at the very least. Geotech and Bridge design if you want further consultation or confirmation. Good time to ensure the soil is what was expected.

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11
Q

When the roughened surface is shown, what should the amplitude be?

A

1/4”

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12
Q

Forms Details (Total of 5)

A
  1. Mortar Tight
  2. True to dimensions, lines, and grades of the structure
  3. Strong enough to prevent deflection during concrete placement up to 3/32” and/or 1/270 center to center length between joists
  4. Form exposed surfaces so that similar texture color and appearance is obtained
  5. use form panels that are 3X6 as least except for smaller members or at the ends
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13
Q

Fillet Dimensions at all sharp corners

A

3/4” X 3/4”

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14
Q

May remove forms not supporting dead load after how long?

A

24 hours

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15
Q

When to water form before placing concrete?

A

Immediately before placing concrete

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16
Q

When can you add water to mix?

A

Before 1/4 CY is discharged

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17
Q

Except for piles, what is the maximum fall height of concrete?

A

8 ft

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18
Q

How long before deck for stem and soffit pour?

A

A minimum of 5 days

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19
Q

Can you vibrate forms or reinforcement for consolidation?

A

NO

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20
Q

MUST PROVIDE SAFE ACCESS FOR INSPECTORS

A
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21
Q

The amplitude of roughness between girder tops and deck?

A

1/4”

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22
Q

Details for Hydrostatic pressure relief holes

A

3” diameter, 15’ O.C. directly above the footings

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23
Q

Ordinary surface finish (General Definition)

A

Applies to all surfaces, but might not be the final finish. Basic finishes

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24
Q

Class 1 Surface Finish

A

Smooth even surface of uniform texture and appearance without bulges, depressions, or imperfections

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25
Q

Class 2 Finish

A

Special Case where mortar is added to exterior

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26
Q

CoC For Cement must be signed by?

A

-If sent directly to the job site it must be signed by the cement material supplier
-If mixed and sent to the job site, the CoC must be signed by the concrete manufacturer

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27
Q

If Blended cement is used, show what on ticket?

A

Show true percentages of supplementary concrete material

28
Q

Admixtures used?

A

Must be on authorized material list

29
Q

What weights should be on weighmaster ticket in concrete delivery?

A

Actual weights, not theoretical or intended

30
Q

At what PSI for compressive strength does prequalification start being required?

A

3600 PSI–> All Structural concrete needs to be prequalified in this case

31
Q

Where will Contractor QC test results be submitted too?

A

DIME

32
Q

QC Summary

A

Submited Monthly by contractor showing test results, inspection reports, various documentation, and CoC fo structural concrete signed by QC manager

33
Q

What volume does the compressive strength test represent?

A

300 CY

34
Q

Contractor’s responsibilities for QC

A

-CIP Structures
-Maintain QC Plan
-Provide Inspector
-Provide testing services
-QC inspector AUTHORIZES or REJECTS material
-QC inspectors have no ties to subcontractors/ May be contractors employees

35
Q

QC manager availability

A

Must be on site or within 3 hours away

36
Q

Aggregate QC Test Frequency

A

Once per day of pouring

37
Q

Slump Test Frequency

A

Once Per 100 CY

38
Q

Uniformity Tests

A

When Ordered by Engineer

39
Q

Air Content Tests

A

Once per 30 CY only applicable in freeze-thaw where concrete is air entrained if not in freeze thaw areas then 100 CY

40
Q

Temperature check frequency

A

Once per 100 CY or once a day (whichever is more frequent)

41
Q

Density Testing Frequency

A

Once per 100 CY or once a day (whichever is more frequent)

42
Q

Compressive Strength-How often to check

A

Once per 100 CY or once a day (whichever is more frequent)

43
Q

Inspection reports from Contractor’s QC

A

Must be sent to the Engineer (As inspector I want these)

44
Q

If 3 subsequent batches fail

A

STOP (if applicable or reasonable) Revise operations and increase inspection frequency. Must be authorized before resuming.

45
Q

The Department’s QC does what in relation to collecting concrete cylinders, regardless if contractor is testing as well. Which should be used for making decisions?

A

-Will still collect cylinders for the compressive strength test. These results will be the ones utilized for making decisions.

46
Q

If the concrete batch fails any test

A

REJECT MATERIAL–> Within reason

47
Q

How OFF can the specific material proportions be in a concrete mix?

A

-Cumulitive Aggregate ±1 %
-Aggregates Weighed Seperatly ±1.5%
-Cement and SCM weighed in any combo +2% to -1%
-Water ±1.5% of weight or volume

48
Q

Concrete Temperature upon placing

A

50-90 degrees Fahrenheit

49
Q

Hand mixing is allowed up to

A

1/3 CY

50
Q

How many revolutions after adding water

A

30 times

51
Q

How long before need to discharge all concrete, How many revolutions? (No additive to retard)

A

1.5 hours and 250 revolutions

52
Q

Under what circumstances should 90-minute discharge time be reduced?

A

If concrete temperature goes over 85 degrees

53
Q

If admixture to retard concrete set time is utilized then what can set time be? Revolution Count? Max Temp?

A

Concrete temp must not reach 85 degrees
Time limit becomes 2 hours
Revolution limit 300

54
Q

Slump Range for (Nominal and Maximum) Also, what is nominal and maximum procedures:
-Concrete Structures Over 12 inches in thickness
-Sections 12 inches or less
-CIP Concrete Piles

A

Nominal and maximum values allow for a buffer zone. If venturing into a nominal zone then correct operations. Do not place if exceeding the maximum.

-Concrete Structure Over 12 inches–> Nominal (1-3”) Max ( 5”)
-Concrete Structures Under 12 inches–> Nominal (1-4”) Max ( 6”)
-CIP Concrete Piles–> Nominal 5-7” Max (8”)

If Type F or G (High Range Water Reducers) admixtures are used , 9” may be used

55
Q

When can maximum water requirements be exceeded?

A
  1. Recieve authorization to increase cementitious material content
  2. Increase the water and cement material at a ratio that does not exceed 30 lbs of water to 100 lbs of cement per CY.
56
Q

How long to cure mortar?

A

3 Days

57
Q

Water Method for Curing

A

-7 Day Cure time
-Mist do not allow for running water over surface
-Mats, rugs, carpets, earth, or sand blankets, sheeting material
-Keep surface temp below 140 degrees

58
Q

The application rate of curing compound

A

150 sq ft/gal

59
Q

Curing Compound application method

A

Machine application only. Hand application for small irregular areas

60
Q

When to apply curing compound

A

Before sheen or shrinkage cracks form

61
Q

Can Curing compound be applied to freestanding water?

A

NO

62
Q

If film is damaged on curing compound within 7 days of cure

A

Come back and reapply

63
Q

Water Membrane method

A

using burlene, primarily on bridge decks 72 hours

64
Q

Form in Place method & What should be done after pour?

A

7-day curing time. 5 days for over 20” in the least dimension. Reseal forms after pouring to ensure water-tight connections.

65
Q

Where to find testing frequency for concrete?

A

Chapter 90 SS and Chapter 6 Construction Manual

66
Q
A

Concrete (6 decks)

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