Chapter 1 Flashcards
is a mixture of concrete and steel
Reinforced Concrete
is a mixture of calcareous and argillaceous mixture
Portland Cement
A process where the cement hardens when added with water.
Hydration
Type of portland cement that is common and all-purpose cement used for general construction.
Type I
Type of portland cement that has a lower heat of hydration and can withstand the exposure to sulfate attack.
Type II
Type of Portland cement that is a high-early-strength cement that will produce in the first 24 hours a concrete with a strength about twice that of Type I cement.
Type III
Type of Portland cement that is a low-heat cement that produces a concrete which generates heat very slowly. Used for very large concrete structures.
Type IV
Type of Portland cement that is used for concretes that are to be exposed to high concentrations of sulfate.
Type V
used primarily to increase concreteβs resistance to freezing and thawing, and provide better resistance to the deteriorating action of deicing salts.
Air-entraining admixtures
it causes the mixing water to foam
Air-entraining admixtures
used to accelerate the early strength development of concrete.
Accelerating Admixtures
used to slow down the setting of the concrete and to retard temperature increases. It can prolong the plasticity of the concrete.
Retarding Admixture
used to reduce the water content in concretes while at the same time, increasing their slumps.
Superplasticizers
Type of admixture that is usually applied to hardened concrete surfaces, but they may be added to concrete mixtures.
Waterproofing materials
are referred to as plain or deformed.
Reinforcing bars
used for wrapping around longitudinal bars, primarily in columns.
Plain bars
These bars are marked with the letter S and are the most widely used reinforcing bars.
ASTM A615: Deformed and plain billet steel bars
These bars are marked with the letter W and are used where controlled tensile properties and specially controlled chemical composition is required.
ASTM A706: Low-alloy deformed and plain bars.
These bars are marked with the letter R.
ASTM A996: Deformed rail steel or axle rail steel
Used primarily for the design of the buildings.
AMERICAN CONCRETE INSTITUTE (ACI code)
it provides explanations, suggestions, and additional information concerning the design requirements.
Commentary
loads of constant magnitude and remain in one position. They include the weight of the structure and any fixtures permanently attached to it.
Dead Loads
loads that can change in magnitude and position. They are induced by gravity.
Live Loads
Loads that are caused by group of trucks or train wheels
Traffic loads for bridges
Loads that are caused by the Vibration of movable loads.
Impact Loads
An example of this load is stopping a train on a railroad bridge or a truck on a highway bridge.
Longitudinal Load
Includes soil pressure, hydrostatic pressure, blast loads, and centrifugal forces.
Miscellaneous Load
Loads that are caused by explosions, sonic booms, and military weapons
Blast Loads
Loads that are caused by the environment in which the structure is located.
Environmental Loads
Given the cross section, concrete
strength, reinforcement size and
location, and yield strength, compute the
resistance or strength and the compare
to the strength required.
there should be one unique
answer.
Analysis
Given a factored design moment,
normally designated as ππ’, select a
suitable cross section, including
dimensions, concrete strength, and solve
for required reinforcement.
there are many possible
solutions.
Design
This is reached when a structure or structural element is no
longer acceptable or unfit for its intended
use
Limit State
These involves structural collapse of a part or all of the structure and loss of life can occur.
Ultimate Limit State
Minor local failure overloads causing adjacent members to failure until entire structure collapsed.
Progressive collapse
yielding of reinforcement to form plastic hinges at enough sections to make structure unstable.
Formation of Plastic Mechanism
members can fracture under
repeated stress cycles of service loads (may
cause collapse).
Fatigue
Functional use of structure is disrupted, but
collapse is not expected.
Serviceability Limit States
Damage or failures caused by abnormal
conditions or abnormal loadings
Special Limit States
this is based on working loads, also referred to as service loads or unfactored loads.
Working Stress Design
this requires that the design strength of a
member at any section should equal or
exceed the required strength
Strength Design
overload factor due to probable
variation of service loads.
Load Factor
load specified by general building
code (unfactored).
Service Loads
Also called the Allowable Stress Design, it is a method of design based on elastic stage of a structural member.
Working Stress Method
Also called the Ultimate Strength Design, it
is a method based on ultimate limit state
design.
Strength Design Method
ππ‘πππππ‘β π πππ’ππ‘πππ πΉπππ‘ππ π₯ πππππππ ππ‘πππππ‘β
Design Strength
are the initial shrinkage cracks due to carbonation shrinkage, hydration shrinkage, and drying shrinkage
Shrinkage Microcracks
are extensions of shrinkage microcracks. Occur at 15-20% ultimate strength of concrete.
Bond Microcracks
are microcracks that occur in the matrix. Occur at 30-45% ultimate strength of concrete.
Matrix Microcracks
Cracks that occur just before failure (90%)
Aggregate Microcracks
