Materials

Question 1

Uses for UNreinforced concrete

Answer 1

Walls, Pedestals, Members supported by other structural members
NOT for column design

Question 2

Concrete Slump Tests: What does it measure? What is typical water to concrete ratio?

Answer 2

Measure of concrete consistency (plasticity)
W/C typically 0.4 to 0.6 but must be at least 0.25
Higher ratio means more water which means less strength

Question 3

What does “Grade 60” mean for reinforcement bars?

Answer 3

Strain equals to 60/ 29,0000 (E of steel) –> yield strength of steel

Question 4

Is modulus of elasticity the secant modulus or the tangent modulus?

Answer 4

Secant modulus

Question 5

On ductility vs strength graph, what are ranges from left to right?

Answer 5

Elastic rrange –> plastic range (strain hardening) –> necking range

Question 6

Modulus of Rupture

Answer 6

Tests determine tensile strength associated with cracking

Question 7

Carbon Steel carbon content percentages

Answer 7

Higher carbon, higher strength but reduced ductility
Low < 0.15%
Mild 0.15% - 0.3%
Medium 0.3% - 0.59%
High: 0.6% - 1.7%

Question 8

what does alloy do to steel?

Answer 8

Additional strength and mechanical properties like wear resistance and corrosion protection (ex. stainless steel)

Question 9

Ductility related to strain

Answer 9

Ductility = final strain / yield strain

Question 10

Material toughness

Answer 10

ability to absorb energy without fracturing

Question 11

material resilience

Answer 11

ability to absorb energy elastically and release w/o permanent deformation