lesson 11

What is the purpose of concrete formwork?

• To increase the weight of the concrete

• To hold freshly poured concrete in the desired shape

• To provide color to the concrete

• To speed up the drying process of concrete

What are bars or wires laid into concrete along lines of tension called?

• Capillary breaks

• Isolation joints

• Expansion joints

• Reinforcement

What is a Slab on Grade or Ground-Bearing Slab?

• A concrete surface supported by the ground beneath

• A concrete slab with no reinforcement

• A concrete slab with no formwork

• A suspended concrete slab

What is the purpose of a capillary break layer in concrete slab construction?

• To increase the weight of the slab

• To drain water easily and discourage moisture from rising through capillary action

• To speed up the curing process

• To provide color to the slab

What is the purpose of isolation joints in concrete slabs?

• To allow unrestrained expansion and contraction of the slab

• To increase the strength of the slab

• To provide a smooth finish to the slab

• To prevent cracking in the slab

What is the purpose of a vapor retarder or moisture barrier in concrete slab construction?

• To provide additional protection against subgrade moisture

• To increase the weight of the slab

• To speed up the curing process

• To provide color to the slab

What is the purpose of reinforcing bars in a concrete slab?

• To improve resistance to cracking from various stresses

• To provide color to the slab

• To increase the weight of the slab

• To speed up the curing process

What is the process of drawing a wood plank or metal straightedge across the surface of freshly poured concrete called?

• Striking off or Screeding

• Broom finish

• Edging and Grooving

• Trowelling

What is the purpose of control joints or contraction joints in concrete slabs?

• To provide a smooth finish to the slab

• To prevent cracking in the slab

• To increase the strength of the slab

• To create a natural plane of weakness in the slab

What are the guidelines for hot weather concreting?

• Reduce the cement content, cool mixing water, and use shades or covers

• Increase the cement content, heat mixing water, and use shades or covers

• Reduce the cement content, heat mixing water, and use shades or covers

• Increase the cement content, cool mixing water, and use shades or covers