Question

USING USA IBC CH.9

1.            Name the standard which governs all aspects of concrete; materials used to produce concrete, concrete itself
                and testing thereof.

                What other standards are also permitted to be used in compliance tests for concrete?

2.            There are many documents for structural concrete construction using steel as reinforcement. List five such documents.

3.           For Group R-3 buildings not more than three stories above grade plane, the specified compressive strength of concrete in vertical walls exposed to weather shall not be less than _______.

                A. 2000 psi                          B. 2500 psi                          C. 3000 psi                          D. 3500 psi

4.            For nonstructural concrete subjected to freeze-thaw exposure class F3, the specified minimum compressive strength of concrete is ______.

                A. 2000 psi                          B. 2500 psi                          C. 3000 psi                          D. 3500 psi

5.            Under certain condition, the thickness of plain concrete footings for buildings of light-frame construction which are less than two stories above the grade plane may be reduced by _____.

                A. 3 inches                          B. 3.5 inches                       C. 4 inches                         D. 6 inches

6.           The thickness of concrete floor slabs supported directly on the ground shall not be less than ______.

                A. 3.5 inches                      B. 4.5 inches                       C. 5.5 inches                      D. 7.5 inches

7.            A vapor retarder placed between the base course or the subgrade and a concrete floor is not required for:

                A. Group R-3, detached unheated garages
B. Group R-3, detached and unheated storage rooms of any size
C. Group R-3, detached and unheated utility room
D. Driveways that will not be enclosed at a later date

8.            With respect to shotcrete concrete, which one of the following is not true?

                A. Coarse aggregate size is ¾ inch or less
B. Maximum size of steel rebar is #5 in the absence of any preconstruction test
C. When using #5 or smaller bars, minimum clearance between parallel bars is 2 ½ inches
D. When larger than #5 bars are permitted based on preconstruction tests, minimum clearance between the
     parallel bars equals 4 x bar diameter used

9.           During the curing period of shotcrete concrete, a minimum temperature of ______ is maintained.

                A. 32⁰ F                                 B. 36⁰ F                                 C. 40⁰ F                                D. 44⁰ F

10.          When normal cement is used, final curing for shotcrete concrete shall continue for _____ after pouring.

A. 12 hours                         B. 24 hours                         C. 7 days                             D. 28 days

Answer 1

1. ACI cement and concrete standards governs all aspects of concrete. other standards that can be used are ASTM, IBC etc.

2. various standards for structural concrete using steel are

a. ACI 318 (Design of Reinforced Concrete Members, Columns, and Surfaces )

b. ANSI RCC design

c. IBC 2018

d. Euro code for RCC design

(note :- provisions given below for answers 3-10 are from IBC 2018)

3. as per 1904.1 for group R-3 buildings not more than three stories above grade plane, the specified compressive strength for in vertical walls exposed to the weather shall be not less than 3,000 psi (option C)

4. as per 1904.2 For non structural concrete subjected to freeze thaw exposure class F3, the specified minimum compressive strength is 3500 psi (option D)

5. as per 1809.7 thickness of plane concrete footing can be reduced to 6 inches (option D)

6. as per 1907.1 the thickness of concrete structure supported directly on ground shall not be less than 3.5 inch (option A)

7. as per 1907.1 vapor retarder is not required for detached structures accessory to occupancies in Group R-3, such as garages, utility buildings or other unheated facilities,unheated storage rooms having an area of less than 70 square feet (6.5 m2 ) and carports attached to occupancies in Group R-3,For driveways, walks, patios and other flatwork that will not be enclosed at a later date thus option A,C,D are correct as option B has size restriction as per code.

8. as per 1908.4.2 option C is incorrect because when larger than #5 bars are permitted based on preconstruction tests minimum clearance between parallel bars equals 6 times bar diameter used.

9. as per 1908.9 during curing period of shortcrete concrete a minimum temperature of 40oF is maintained (option C)

10. as per 1908.9.2 when normal cement is used final curing for shortcrete shall continue for 7days after pouring. (option C)