CGN4503 EXAM 2 QUESTIONS AND
ANSWERS 2026 VERIFIED.
Alligator cracking (definition) - ANS series of interconnected cracks that result in small,
sharped-angled pieces (size <30 cm)
alligator cracking (characteristics) - ANS Occurs: only in areas subjected to traffic (wheel
path); initiates at bottom of AC layer or stabilized base (bottom-up propagation)
Causes: the fatigue failure of asphalt layer or stabilized base under repeated traffic loading
How to fix: remove and re-build pavement structure
How to prevent: correct design of pavement structure (tensile stress/strain)
block cracking (definition) - ANS cracks that divide the asphalt surface into approx.
rectangular pieces (blocks range from 0.1 to 10 m^2 in area)
block cracking (characteristics) - ANS Occurs: All over pavement structure
Causes: mainly by thermal fatigue; brittle mixture subjected to daily temperature cycles; NOT
load induced, but load can increase severity
1
, How to fix:
How to prevent: proper selection of asphalt grade
longitudinal cracking in the wheel path (characteristics) - ANS Occurs: along wheel path;
top-down cracking (TDC); load induced
Causes: combo of a brittle asphalt surface layer (aging + low temperature) and near-surface
stresses induced by radial tires
How to fix:
How to prevent:
longitudinal cracking outside the wheel path (characteristics) - ANS Occurs: along center-
line, between wheel paths or shoulders; NOT load induced
Causes: construction issues during paving operation; highway widening; reflection of old cracks
How to fix: crack sealing
transverse cracking (definition) - ANS cracking perpendicular to the pavement structure
transverse cracking (characteristics) - ANS Occurs: NOT load induced; reflective cracking
can also result in transverse cracks
Causes: extremely low temperatures (typ. below -20 C)
How to fix:
2
ANSWERS 2026 VERIFIED.
Alligator cracking (definition) - ANS series of interconnected cracks that result in small,
sharped-angled pieces (size <30 cm)
alligator cracking (characteristics) - ANS Occurs: only in areas subjected to traffic (wheel
path); initiates at bottom of AC layer or stabilized base (bottom-up propagation)
Causes: the fatigue failure of asphalt layer or stabilized base under repeated traffic loading
How to fix: remove and re-build pavement structure
How to prevent: correct design of pavement structure (tensile stress/strain)
block cracking (definition) - ANS cracks that divide the asphalt surface into approx.
rectangular pieces (blocks range from 0.1 to 10 m^2 in area)
block cracking (characteristics) - ANS Occurs: All over pavement structure
Causes: mainly by thermal fatigue; brittle mixture subjected to daily temperature cycles; NOT
load induced, but load can increase severity
1
, How to fix:
How to prevent: proper selection of asphalt grade
longitudinal cracking in the wheel path (characteristics) - ANS Occurs: along wheel path;
top-down cracking (TDC); load induced
Causes: combo of a brittle asphalt surface layer (aging + low temperature) and near-surface
stresses induced by radial tires
How to fix:
How to prevent:
longitudinal cracking outside the wheel path (characteristics) - ANS Occurs: along center-
line, between wheel paths or shoulders; NOT load induced
Causes: construction issues during paving operation; highway widening; reflection of old cracks
How to fix: crack sealing
transverse cracking (definition) - ANS cracking perpendicular to the pavement structure
transverse cracking (characteristics) - ANS Occurs: NOT load induced; reflective cracking
can also result in transverse cracks
Causes: extremely low temperatures (typ. below -20 C)
How to fix:
2
