quizzes and surveys total Flashcards
Tensile stresses are induced upon heating a restrained material. T OR F
false
Plastic mechanical properties of materials include:
stiffness, yield strength, ductility, possion’s ratio, tensile strength
yield strength, ductility, tensile strength
Brittle materials (as compared to ductile materials) are characterized by:
high stiffness, small strain at failure, low fracture energy
in a creep test, strain is measured with time under constant load t or f
true
Viscoelastic materials must be modeled by combinations of springs and dashpots to represent instantaneous and time-dependent behavior, respectively. t or f
true
A Kelvin model (spring and dashpot in parallel) sustains permanent deformation on unloading.
t or f
false
A Burgers model [Maxwell (spring & dashpot in series) and Kelvin (spring & dashpot in parallel) in series] exhibits stress relaxation in a relaxation test.
Correct!
t or f
true
Asphalt Concrete (as compared to Portland Cement Concrete):
includes interlocked particles, has a lower matrix volumetric concentration 20%
Sources of variability for properties measured in this course include:
testing, material,sampling
Tensile stresses are induced upon cooling a restrained material. t or f
true
Elastic mechanical properties of materials include
poissons ratio, stiffness
In a creep test, stress is measured with time under constant deformation. t or f
false
A Maxwell rheological model (spring & dashpot in series as shown) exhibits increasing deformation with time in a creep test.
true
The type of material failure induced by repeated loading is:
fatigue
The strain at failure for brittle materials is lower than for ductile materials.
true
A Kelvin rheological model (spring and dashpot in parallel as shown) sustains permanent deformation on unloading in a creep
false
The response of a Burgers rheological model (Maxwell and Kelvin models in series as shown) in a creep test to loading is:
instantaneous and time dependent
Aggregate types commonly used in civil engineering large-particle composites include:
You Answered
igneous, sedimentary, recycled pavements
aggregate gradation is defined as
particle size distribution
The smallest size aggregates used in civil engineering large-particle composites is:
filler (passing the #200 or 0.075mm sieve)
A coarse aggregate test for interparticle friction is:
CAA
a fine aggregate test for durability is
sand equivalent
a maximum sand equivalent is specified
false
a coarse aggregate test for durability is
soundness, quick chemical test for reactive silica
