1.
Control joints are considered joints that will _______shortening, shrinkage and/or reduction in the length of the wall.
Correct Answer
D. Accommodate
Explanation
Control joints are considered joints that will "accommodate" shortening, shrinkage, and/or reduction in the length of the wall. These joints are designed to allow for the movement and adjustment of building materials, particularly in response to temperature changes, moisture variations, and other external factors. By accommodating these changes, control joints help prevent cracking, structural damage, and other issues that may arise due to the expansion or contraction of construction materials.
2.
A “standard hook” can be a 180° turn plus an extension of at least __________ bar diameters, but not less than ________ inches at the free end of the bar.
Correct Answer
B. 4, 2 ½
Explanation
A "standard hook" in masonry reinforcement typically consists of a 180° turn plus an extension of at least 4 bar diameters, but not less than 2 ½ inches at the free end of the bar. This configuration is commonly used to provide proper anchorage and development of reinforcement within masonry elements such as walls, columns, or beams. The specified extension length ensures adequate embedment and bond between the reinforcement and the surrounding masonry, enhancing structural performance and integrity.
3.
The cleanout opening at the bottom of a masonry wall is a minimum of __________.
Correct Answer
A. 3 inches in any direction
Explanation
The minimum size for a cleanout opening at the bottom of a masonry wall is 3 inches in any direction. This size allows for sufficient removal of debris and proper inspection before grouting the wall. While larger openings might be used in some cases, 3 inches is the established minimum requirement as per building codes and standards set by organizations like the National Concrete Masonry Association (NCMA).
4.
The minimum length of saw-cut prisms shall be ________inches.
Correct Answer
C. 4
Explanation
ASTM C1314 is a standard test method for compressive strength of masonry prisms, which is widely referenced in the construction industry. This standard specifies various requirements for preparing and testing masonry prisms, including the minimum length of saw-cut prisms. While some standards or specifications may vary slightly, 4 inches is commonly accepted as the minimum length for saw-cut prisms in masonry construction testing.
5.
Movements can occur from a number of sources, such as _________.
Correct Answer
D. All of the above
Explanation
Movements in masonry can arise from various sources, including ground settlement, material expansion and contraction, and seismic activity. Ground settlement occurs due to factors like soil consolidation or excavation, causing uneven stress on masonry structures. Material expansion and contraction, influenced by temperature and moisture changes, can lead to shifts in masonry elements, potentially causing cracks or displacement. Seismic activity, such as earthquakes, imparts dynamic forces on masonry structures, resulting in shaking and movement that can cause damage ranging from cracks to partial or complete collapse.
6.
The compressive strength of grout in concrete masonry construction is recommended to be at least _________ to _________ times the design strength of the masonry assemblage.
Correct Answer
B. 1.25, 1.33
Explanation
Grout is commonly used in concrete masonry construction to fill the voids between masonry units and provide additional strength and stability to the structure. The compressive strength of grout is crucial to ensure the overall performance and safety of the masonry assemblage. It is recommended that the compressive strength of grout should be at least 1.25 to 1.33 times the design strength of the masonry assemblage. This ensures sufficient strength and support to withstand various loads and stresses.
7.
The minimum clearance required between reinforcing steel and the CMU in a grouted cell using coarse grout is ___________.
Correct Answer
C. ½ inch
Explanation
In concrete masonry construction where reinforcing steel (rebar) is placed within grouted cells, a minimum clearance is required between the rebar and the concrete masonry unit (CMU) to ensure proper grout flow and consolidation. For grouted cells using coarse grout, the minimum clearance required between the reinforcing steel and the CMU is typically ½ inch. This clearance allows for adequate space for the grout to flow around the rebar and fill the voids in the masonry unit, ensuring proper bonding and structural integrity.
8.
The maximum grout pour using the high lift grouting method for a clear cell area of 3 inches by 3 inches is _________.
Correct Answer
D. 24 feet using fine grout
Explanation
When using the high lift grouting method for a clear cell area of 3 inches by 3 inches, the maximum grout pour is 24 feet if you're using fine grout. This limit is based on building codes and standards like the ICC and ASTM C476. However, it's important to remember that this is a general guideline, and the specific allowable pour height for your project might differ depending on local regulations, project specifications, and the chosen grout type.
9.
When the air temperature is 25°F, requirements shall include ___________.
Correct Answer
B. Maintaining mortar on board above freezing
Explanation
When the air temperature is 25°F (which is below freezing), it is crucial to ensure that the mortar remains above freezing temperature to prevent it from freezing and compromising its quality. Freezing temperatures can affect the hydration process of cement, leading to weakened mortar. Therefore, the requirement is to maintain the mortar on board above freezing to ensure its proper functionality and strength.
10.
In a low lift grout pour, the grouting is stopped approximately __________below the top of the masonry unit.
Correct Answer
C. 1 ½ inch
Explanation
During low lift grout pours, the objective is to fill the vertical cores of the masonry units with grout to provide structural integrity and support. To prevent excessive overflow and ensure proper consolidation, the grouting is usually stopped at a point below the top of the masonry unit. The common practice is to stop the grouting approximately 1 and ½ inch below the top of the masonry unit. This allows for adequate space for consolidation and reduces the risk of excessive overflow while still providing sufficient coverage and bonding within the unit.
11.
For coarse grout, the maximum total aggregate measured in a damp loose condition shall be _________ times the sum of the volume of the cementitious material.
Correct Answer
A. 3
Explanation
According to standard masonry specifications, the maximum volume of coarse aggregate allowed in grout is limited to three times the volume of the cementitious materials to ensure the proper flow and strength of the grout. This ratio helps maintain the appropriate consistency and bonding characteristics needed for effective masonry construction.
12.
When the mean daily air temperature is between 25°F and 40°F, the masonry shall be protected by covering with a weather-resistive membrane for ______hours.
Correct Answer
B. 24
Explanation
In colder temperatures between 25°F and 40°F, masonry needs protection to prevent potential damage due to moisture intrusion and freezing. To achieve this, a weather-resistive membrane is applied to shield the masonry from the elements. The period of protection is crucial to ensure proper curing and to maintain the integrity of the masonry. As per industry standards, this protection is typically maintained for a duration of 24 hours to allow for adequate curing and to safeguard the masonry from adverse weather conditions.
13.
Windbreaks shall be used when the temperature is below 25°F and the wind is _________.
Correct Answer
D. Greater than 15 miles per hour
Explanation
Windbreaks are employed to reduce the chilling effect of the wind on masonry when temperatures are below 25°F. However, they are typically recommended when the wind speed exceeds a certain threshold to be effective. In this case, according to industry standards, windbreaks are generally used when the wind speed is greater than 15 miles per hour. This ensures that the masonry is adequately protected from the harsh effects of the wind, which can exacerbate the loss of heat and potentially affect the curing process of the masonry
14.
After the initial water has been introduced to the mix, mortar should be used within ____________.
Correct Answer
D. 2 ½ hours
Explanation
After the initial water has been introduced to the mix, mortar should be used within 2 ½ hours. This time frame is crucial for maintaining the proper consistency and workability of the mortar. As the mortar begins to set, its effectiveness decreases, so it should be used within this time frame to ensure optimal performance in bonding masonry units.
15.
A common CMU size is 6” x 8” x 16”. 6” refers to the ____________.
Correct Answer
A. Width
Explanation
In the dimensions of a concrete masonry unit (CMU), the first number (6”) typically refers to the width or thickness of the block. The second number (8”) refers to the height, and the third number (16”) refers to the length of the block. Thus, in this case, the 6” dimension represents the width of the CMU.
16.
During hot weather conditions, newly constructed masonry shall be fog sprayed until damp at least ________ a day for the first three days.
Correct Answer
C. 3 times
Explanation
Hot weather conditions can accelerate the drying of masonry, potentially affecting its strength and durability. Fog spraying helps maintain moisture levels in the masonry, promoting proper curing. Therefore, fog spraying should occur at least 3 times a day for the first three days to ensure adequate moisture retention.
17.
When associated with masonry reinforcing steel, the d distance is defined as the distance from ________ to the center of reinforcing steel.
Correct Answer
A. The inside of the face shell
Explanation
In masonry construction, the d distance is typically measured from the inside surface of the face shell of the concrete masonry unit (CMU) to the center of the reinforcing steel. This measurement is important for ensuring proper placement and coverage of the reinforcing steel within the masonry assembly, which is critical for structural integrity and compliance with building codes and standards.
18.
When performing the Cone Penetrometer Test, the depth of penetration is measured in _______________.
Correct Answer
B. Millimeters
Explanation
The Cone Penetrometer Test is used to measure the consistency of grout or mortar. The depth of penetration is measured in millimeters, indicating how easily the cone penetrates the grout or mortar mixture.
19.
The recommended slump is necessary so that grout can flow___________.
Correct Answer
B. Completely surround the steel
Explanation
Slump is a measure of the consistency of grout or concrete. The recommended slump ensures that the grout can flow easily and completely surround the steel reinforcement, providing proper bonding and structural support.
20.
Current recommendations from the National Concrete Masonry Association (NCMA) based on engineering and aesthetic design, it is reasonable to maximize horizontal spacing of control joints at ________feet.
Correct Answer
D. 20 to 30
Explanation
Control joints are used to control cracking in masonry walls. The spacing of control joints is determined based on various factors, including engineering requirements and aesthetic considerations. The NCMA recommends a horizontal spacing of control joints between 20 to 30 feet.
21.
When installing high lift grating, what is the maximum allowable interruption between lifts when completing the full height of any section of wall within one day?
Correct Answer
A. One hour
Explanation
When high-lift grouting, the full height of any section of the wall should be completed in one day, with no interruption between lifts greater than "one hour." This guideline is essential to ensure the proper bonding and strength of the grout, which is crucial for the structural integrity and stability of the wall. Interruptions longer than one hour may result in cold joints or reduced adhesion between lifts, compromising the overall quality and durability of the construction.
22.
Expansion joints are used to provide for movement of a wall as it expands and must contain any incompressible material.
Correct Answer
B. False
Explanation
Expansion joints are designed to accommodate movement in masonry walls caused by thermal expansion, settlement, or other factors. They must contain compressible or incompressible materials to allow for movement while maintaining waterproofing and structural integrity.
23.
Mortar projections in grout cells must not project more than ____ inch(es) into the cell.
Correct Answer
B. 1/4
Explanation
To ensure proper consolidation and bonding of grout in masonry walls, mortar projections into grout cells should be limited to a maximum of 1/4 inch. Excessive mortar projections can interfere with the placement and consolidation of grout.
24.
The minimum cover of reinforcement, including the masonry unit, shall be _______ inch(es) when not exposed to weather.
Correct Answer
B. ¾
Explanation
The minimum cover of reinforcement, including the masonry unit, shall be 3/4 inch(es) when not exposed to weather. The minimum cover of reinforcement refers to the distance between the surface of the reinforcement and the exterior face of the masonry unit. This cover helps protect the reinforcement from corrosion and ensures proper structural performance.
25.
Grout should be placed within _______ hours after initial water is introduced to the dry ingredients.
Correct Answer
D. 1 ½
Explanation
Proper timing is crucial when mixing and placing grout to ensure optimal performance. Grout should be placed within 1 ½ hours after initial water is introduced to maintain the desired consistency and workability for proper consolidation and bonding.
26.
For concrete masonry, spacing of expansion joints should be between ______feet and located with consideration to the shape and plan of the structure.
Correct Answer
C. 100 and 150
Explanation
In concrete masonry construction, expansion joints are typically spaced between 100 and 150 feet apart. The specific spacing can vary depending on factors such as the shape and size of the structure, as well as environmental conditions. Properly spacing these joints is crucial to accommodate movement caused by temperature changes and to prevent cracking in the masonry.
27.
When required, three prism samples shall be made ____________.
Correct Answer
B. For each 5,000 square feet of wall area
Explanation
Prism samples are used to test the compressive strength of masonry walls. As per industry standards, three prism samples should be made for each 5,000 square feet of wall area or fraction thereof to ensure proper testing and compliance with specifications.