reduction factor of Components of connection of precast member controlled by yielding of steel elements in tension
0.90
reduction factor of plain concrete elements
0.60
reduction factor of anchors in concrete elements
0.45-0.75
Require strength U shall include internal load effects due to reactions induce by prestressing with a load factor of
1
For post tensioned anchorage zone design, design A load factor of 1.2 shall be applied to the maximum prestressing reinforcement jacking force
U, T, C
Prestress slab shall be classified as
For slabs with bonded prestressed reinforcement total quantity of As and Aps shall be adequate to develop a factored load at least 1.2 times the cracking load calculated on the basis of fr as give.
Eccentricity
Between tendons and the concrete centroid
Ln/3
Length of deformed reinforcement in positive moment shall be at least
ln/6
Length of deformed reinforcement in each side of support shall be at least
1.8m
distance between face of beam or wall to the nearest slab tendon shall not exceed to (blank)
1.4m
If spacing of slab tendons exceeds (blank) additional deformed shrinkage and temperature reinforcement
twice
for slabs with both flexural and shear design strength at least (blank) the required strength
C T
for class -----and --- members, stresses at service load shall be calculated using the uncracked section
C
for class ----- members, stresses at service load shall be calculated using the cracked transformed section
Act
is the are of that part of the cross-section between the flexural tension face and the centroid of the gross section.
0.7 Mpa
prestressed reinforcement to resist shrinkage and temperature stresses shall conform to the table and the effective prestress after losses shall provide and average compressive stress of at least ( blank) on gross concrete area
1860MPa
the maximum value of fpu permitted for design calculations A416M (strand)
1725MPa
the maximum value of fpu permitted for design calculations A421M (wire)
1035MPa
the maximum value of fpu permitted for design calculations A722M (high strength bar)
flexural cracking
bonded reinforcement shall be distributed to control _____ in tension zones of non-prestress and class C prestressed slabs and beams
250Mpa
the values of delta Fps shall not exceed to ___
local and general
anchorage regions of post-tensioned tendons shall consist of two zones
Localzone
shall be assumed to be a rectangular prism (equivalent rectangular prism for circular or oval anchorages) of concrete
generalzone
includes the local zone and shall be assumed to be the portion of the member through which the concentrated prestressing force is transferred
Specialanchoragedevices
Are used, supplementary skin reinforcement shall be provided in addition to the confining reinforcement specified for the anchorage device
Supplementary skin reinforcement
Shall be similar in configuration and at least equivalent in volumetric ratio to any supplementary skin reinforcement used in the qualifying acceptance tests of the anchorage device.
Methods shall be permitted for design of general zones
Strut and tie models
linear stress analysis
simplified equations
1.5
minimum edge distance is less than __ times the anchorage device lateral dimensions in that direction