CTE Pavement Design & Materials 2

Question 1

What is the primary structural advantage of jointed plain concrete pavement (JPCP) over flexible asphalt pavement?

Accepted Answer

High beam strength that distributes loads over a larger area, reducing subgrade stress

Answer

Concrete pavement's high flexural strength distributes wheel loads over a larger area than flexible pavement, resulting in lower stress on the subgrade and potentially extending pavement life.

Question 2

What is 'load transfer efficiency' (LTE) at concrete pavement joints, and how is it typically achieved?

Accepted Answer

Percentage of deflection transferred across a joint; achieved with dowel bars or aggregate interlock

Answer

LTE measures how effectively a loaded slab transfers deflection load to the adjacent unloaded slab; smooth round dowel bars are the most reliable mechanism for achieving high LTE at transverse joints.

Question 3

What is Reclaimed Asphalt Pavement (RAP) and what is its primary benefit?

Accepted Answer

Removed and reprocessed old asphalt pavement reused as aggregate and binder in new HMA mixes, reducing material costs and virgin material use

Answer

RAP consists of salvaged asphalt pavement materials that are crushed and screened for reuse, providing recycled aggregate and residual asphalt binder that reduce cost and conserve virgin materials.

Question 4

What is the difference between a 'perpetual pavement' and a conventional flexible pavement design?

Accepted Answer

Perpetual pavements are designed to be structurally durable indefinitely with only surface renewal needed, avoiding full-depth failure

Answer

Perpetual pavement design uses a rich, fatigue-resistant bottom layer to prevent bottom-up cracking, allowing only the surface to wear while the structural section remains intact for 50+ years.

Question 5

In rigid pavement, what is 'pumping' and what causes it?

Accepted Answer

Ejection of subbase material through joints/cracks under repeated loading; caused by water accumulation under slabs

Answer

Pumping occurs when repeated traffic loads cause fine-grained, saturated subbase or subgrade material to be ejected through joints or cracks, eroding support and causing faulting.

CTE - Certified Transportation Engineer Practice Test

CTE - Certified Transportation Engineer Practice Test

CTE Pavement Design & Materials 2