LEC 1.3 Flashcards
In reinforced concrete the process is the following MWHAHAHAA ; )
- Design for Ultimate Limit States (Moment and Shear)
- Check for Serviceability Limit States
- Check for deflections
In prestressed concrete, the process is MWEHEHE ; D
- Design for serviceablity limit states (Cracking and Stress)
- Check for deflections
- Check Ultimate Limit State ( moment)
- Design for shear for ultimate limit states
The main objective of structural design process of reinforced concrete is to ensure that the structure is able to withstand the load effects with an appropriate margin of _________ against failure.
safety
__________ is a condition where the structure ceases to fulfill its intended function
failure
failure occur because the structure has achieved its maximum resistance and can no longer carry ______________, or although it can still carry the loads, because it has undergone _______________ that have rendered the structure unusable.
imposed loads, excessive deformation
in reinforced concrete, structures must be designed to be both __________ and _____________ ( or serviceable)
safe, functional
When a structure or structural element becomes unfit for its INTENDED USE, it is said to have reached a _________________.
limit state
The limit states for reinforced concrete structures can be divided into three basic groups such as
strength, serviceability, special
These limit state involve structural collapse of part or all of the structure
strength limit state
These limit state involve disruption of the FUNCTIONAL USE of the structure, but not collapse per se.
Serviceability limit states
This class of limit states involves damage or failure due to ________________ or _______________.
abnormal conditions, abnormal loadings
FORMS OF PRESTRESSING
is a single unit made of steel
Wires
FORMS OF PRESTRESSING
two, three or seven wires are wound to form a prestressing ________.
strands
FORMS OF PRESTRESSING
A group of strands or wires are wound to form a prestressing ___________
tendon
FORMS OF PRESTRESSING
a group of tendons form a prestressing ___________
cable
FORMS OF PRESTRESSING
a tendon can be made up of a single steel ____________.
bar
When there is adequate bond between prestressing tendon and concrete, it is called a ______________. Pre-tensioned and grouted post tensioned tendons are ______________.
bonded tendons 2x
When there is no bond between the prestressing tendon and concrete, it is called ___________________. When grout is not applied after post - tensioning, the tendon is an _____________.
unbonded tendon
The analysis of prestressed members can be different for the different stages of loading. The stages of loading are as follows:
Initial, Intermediate, Final
The analysis of prestressed members can be different for the different stages of loading. The stages of loading are as follows:
During tensioning of steel
At transfer of prestress to concrete
Initial
The analysis of prestressed members can be different for the different stages of loading. The stages of loading are as follows:
this includes the loads during transportation of the prestressed members
intermediate
The analysis of prestressed members can be different for the different stages of loading. The stages of loading are as follows:
at service, during operation
at ultimate, during extreme events
final
What are the three overload behavior and strength in flexure of prestressed member
service load, cracked stage, overload
overload behavior and strength in flexure of prestressed member
Loading stages
Beam in linear elastic
the principle of superposition is valid
beam remain uncracked
steel stress within elastic ranges
service load
