CLA CLA Hardscape & Materials

Question 1

What is the recommended minimum thickness for a concrete pedestrian walkway slab in a residential landscape setting?

Accepted Answer

4 inches

Answer

2 inches

Answer

8 inches

Answer

12 inches

Question 2

Which paving pattern for rectangular brick or concrete pavers provides the greatest interlocking structural strength for vehicular areas?

Accepted Answer

Herringbone (45° or 90°)

Answer

Running bond

Answer

Stack bond

Answer

Basketweave

Question 3

What material is a 'geo-grid' used for in landscape and hardscape construction?

Accepted Answer

Soil reinforcement in retaining walls and base courses

Answer

Drainage filtration under gravel

Answer

Weed suppression under mulch

Answer

Pipe protection in utility trenches

Question 4

Which type of retaining wall system uses interlocking concrete blocks with no mortar and relies on mass and batter for stability?

Accepted Answer

Segmental retaining wall (SRW)

Answer

Poured concrete cantilever wall

Answer

Gravity stone wall with mortar

Answer

Sheet pile wall

Question 5

What is 'batter' in the context of retaining wall design?

Accepted Answer

The inward lean of a wall face from vertical to improve stability

Answer

The mix ratio of concrete in the footing

Answer

The drainage aggregate placed behind a wall

Answer

The texture of a wall's exposed face

Question 6

What is the function of a 'weep hole' or drainage aggregate in a retaining wall?

Accepted Answer

Relieve hydrostatic pressure by allowing water to drain through or around the wall

Answer

Anchor the wall to bedrock below

Answer

Support the wall cap during construction

Answer

Provide aeration to plant roots behind the wall