Brick Masonry: Manufacturing Process

Question 1

How are raw materials converted during the manufacturing process of brick masonry? (2)

Answer 1

• natural clays are excavated from the earth, ground up, and screened to control particle size
• water is added to achieve a plastic consistency ready for molding into bricks

Question 2

What are the three major methods of brick forming?

Answer 2

• soft mud process
• dry-press process
• stiff mud process

Question 3

Describe the soft-mud process. (4)

Answer 3

• relatively moist clay is pressed into individual molds
• water-struck: molds are pre-wetted
• sand-struck: molds are pre-dusted with sand
• may be hand or machine pressed

Question 4

Describe the dry-press process.

Answer 4

clays are kept relatively dry and stiff, and machine-pressed into steel molds at high pressure

Question 5

Describe the stiff mud process. (4)

Answer 5

• moderately moist clay is extruded through dies and then sliced into individual units
• accounts for approximately 90% of U.S. made bricks
• the extrusion process naturally produces brick units with a smooth face and high dimensional uniformity
• various post-extrusion distressing steps can be used to create bricks with greater variation in shape and surface texture

Question 6

Describe the brick firing process. (3)

Answer 6

• brick placement and firing conditions affect finished brick color, uniformity of shape, hardness, and other physical properties
• tunnel kiln: bricks pass continuously from one end to the other
• periodic kiln: batches of bricks are loaded, fired, cooled, and removed

Question 7

How are bricks sized? (2)

Answer 7

• bricks are available in many sizes
• modular-sized bricks are sized so that the dimension of one brick plus one mortar joint equals a convenient nominal dimension

Question 8

What are the properties of solid brick? (2)

Answer 8

• solid bricks are frequently not 100% solid, to reduce weight and the cost of firing
• not less than 75% solid

Question 9

What are the properties of hollow brick? (3)

Answer 9

• lighter in weight
• require less energy to fire
• larger voids can readily accommodate steel reinforcing

Question 10

Define the following: course, bed joint, head joint, wythe, and collar joint.

Answer 10

• course: one horizontal row of bricks
• bed joint: horizontal mortar joint between courses
• head joint: vertical joint mortar between bricks in the same course
• wythe: one vertical stack of bricks
• collar joint: vertical joint between wythes