NHI 2-Week Bridge Inspection Training
Exam #1 Questions Fully Solved.
Creep - Answer Gradual, continuing deformation due to constant stress below yield strength.
Fatigue - Answer Tendency to fail at stress below yield stress when subject to cyclical
loading.
Rolled 'I' beam - Answer flanges and web 1 piece, <36" deep, compact section (no stiffener
needed).
Build-up I beam - Answer larger shape, welded=new bridges, rivets=older bridges.
Physical Properties: Steel - Answer Resists impact & vibration, 0.1%-2.1% carbon and various
yield strength.
Mechanical Properties: Steel - Answer Isotropic=high comp. & tens. strength, elastic, ductile;
temperature, welding and fatigue prone failures, prone of corrosion if unprotected, resist
fatigue cracking (fracture toughness).
High performance steel - Answer Improved weldability, high toughness, ductile and
corrosion resistance.
High Strength Bolt - Answer A325 (92ksi yield & 120ksi tensile) and A490 (130ksi yield &
150ksi tensile).
Types of Steel deficiencies - Answer Corrosion, fatigue cracking, overloads (deformation),
collision, heat damage and weathering steel failure.
Steel - location for inspection - Answer Areas of high stress, water/debris trap, problem
details, traffic exposure and overall structure.
Physical Properties: Concrete - Answer Thermal expansion, porous=flow of water, volume
changes due to moisture, fire resistance and formability.
Mechanical Properties: Concrete - Answer Good compressive and poor tensile, minimal
elasticity, exhibit long-term creep and isotropy.
Exam #1 Questions Fully Solved.
Creep - Answer Gradual, continuing deformation due to constant stress below yield strength.
Fatigue - Answer Tendency to fail at stress below yield stress when subject to cyclical
loading.
Rolled 'I' beam - Answer flanges and web 1 piece, <36" deep, compact section (no stiffener
needed).
Build-up I beam - Answer larger shape, welded=new bridges, rivets=older bridges.
Physical Properties: Steel - Answer Resists impact & vibration, 0.1%-2.1% carbon and various
yield strength.
Mechanical Properties: Steel - Answer Isotropic=high comp. & tens. strength, elastic, ductile;
temperature, welding and fatigue prone failures, prone of corrosion if unprotected, resist
fatigue cracking (fracture toughness).
High performance steel - Answer Improved weldability, high toughness, ductile and
corrosion resistance.
High Strength Bolt - Answer A325 (92ksi yield & 120ksi tensile) and A490 (130ksi yield &
150ksi tensile).
Types of Steel deficiencies - Answer Corrosion, fatigue cracking, overloads (deformation),
collision, heat damage and weathering steel failure.
Steel - location for inspection - Answer Areas of high stress, water/debris trap, problem
details, traffic exposure and overall structure.
Physical Properties: Concrete - Answer Thermal expansion, porous=flow of water, volume
changes due to moisture, fire resistance and formability.
Mechanical Properties: Concrete - Answer Good compressive and poor tensile, minimal
elasticity, exhibit long-term creep and isotropy.
