Westgate Village Post Tensioned Concrete precon agenda 5-8-18Project Name/Location:
Meeting Date:
First Pour Date:
Post -Tensioned Concrete
reconstruction Meeting Agenda
Westqate Village Mixed Use
5/8/2018 Permit number BLD20161538
5/14/2018
Project Team Information
Building Inspector*
Name/Company: Milton Thompson/City Of Edmonds Building Development
Phone: 425-754-6345 Email:_milton.thompson@edmondswa.gov
Owner's Representative
Name/Company: not _present - Anthony Jansen / Henbart LLC.
---- —
Phone: 206-290-0958— Email: anthonyj@henbart.com
Structural Engineer`
Name/Cornpany:
Phone: 206/957/3907 Email: SKodama@quantumce.com
General Contractor*
Name/Company: Murph Cruses W.G. Clark -_Construction CO.
Phone: 206-909-0071 Einail:.rcruse@w-qclark.com
Special Inspectors ---
Name/Company: Trip_ Edgerton / Mayes Testing Engineers
Phone: 425--742-9360 _ Ernai.l: tedgerton@mayestestin� com
PT Supplier
Name/Company: -Kurt Barpass / pTC INC.
Phone: 425-745-1304 __ Em.aiI: cloudspirt3@gmail . com ______
Debar Supplier
Nam.e/Cornpany: not present - Addison steel
Phone: _253.-474-0711_ Email:
Sandro Kodama / Quantum Consulting Engineers
Concrete Supplier
Nu.rn.e/Company: not present - Miles Sand and Gravel
Ph.oite:
253-833-3705
E;rtail:
PT Placer
Name/Company:
Jaun Carmona
/ Carmona Construction LLC
Phone:
425-309-2243
jjcarmona@carmona-construction.com
Rebar Placer
- -
Name/Company:
Jaun Carmona
/ Carmona Construction LLC
Phone:
425-309-2243
Emcj.armona@carmona-construction.com
Concrete .Placer
.Name/Company:
Jaun Carmona
/ Carmona Construction LLC
Phone:
425-309-2243
Ejn.adcarmona@carmona-construction.com
Concrete Finisher
niisher
Nance/Company:
_Jaun Carmona
/ Carmona Construction LLC
Phone:
425-309-2243
rrnj.parmona@carmona-construction.com
*Attendance is required
Submittals
The following submittals shall be reviewed, approved, and on -site prior to placing
concrete for post -tension beams and/or slabs:
X Concrete Mix Design
X Rebar Shop Drawings
X PT Shop Drawings
X Formwork Shop Drawings
or System Information
General PT Items
X Stab Penetration & In -Slab Conduit Layout
'X Stressing Pocket Bonding Agent & Grout Data
X Embedded Items
Deferred Submittals (Hold Down Anchors,
X In -Slab Duct Systems, etc.)
1) Pour Statistics
Expected Number- of Pours: 3
Number of Levels: 2
Typical Slab Thicknesses: 9" & 12
Largest Pour: 433 C.Y. 11, 689 S.F.
Typical Pour: 393 C.Y. 11,705 S.F.
2) Concrete Mix
The concrete mix shall be approved by the Structural Engineer (EOR), and
shall be as follows:
Mix design # will be used. #156000
Mix is continuously approved: ON
The maximum aggregate size is 3/4" inches.
The minimum clearance or spacing is inches.
The maximum allowed slump is 6" inches.
The minimum slump for use with PT is 4 inches.
Design concrete strength is 5000 psi at 28 days.
Strength for stressing is 3500 psi at 3 days.
NOTE: The maximum slump for the mix may not be exceeded, even if the
di-awings or specifications allow a higher slump. Under no circumstances shall
the maximum slump allowed be the average slump expected.
3) Concrete Sampling
Tests shall be taken at the point of placement whenever possible.
4) Rejection Procedures
Concrete not in conformance with the mix designs or other stated
requirements shall be rejected. Rejection procedure shall be:
Mayes Testing special inspector to notify WGC superintendent
That he has rejected the load. The supplier will be notified
and the load(s) sent back.
5) PT Samples
Sample pieces of PT cable approximately 6 feet long are to be delivered with
every shipment of cable to the job site. Samples shall be from the same batch
as the strands with which they were sent. These samples are to be tagged
and held in the testing laboratory along with the mill certifications.
6) Stressing Equipment
Well calibrated, properly maintained equipment is critical to reliably stressing
PT cables.
Will 2 sets of stressing equipment be kept on site? ON
Will matching ram and gauge calibrations be supplied? YON
A 3rd back up ram will also be on site
NOTE: Extra equipment may be useful in cases of equipment malfunction or
tolerance problems.
7) Structural Observation
Structural observation by a representative of the FOR is strongly encouraged.
The planned structural observation schedule includes:
- Observation of PT with the inspector prior to the first pour: ON
- Pre -pour observation of any subsequent placements with
significant differences from the first: Y)o
- Observation of PT for 3 total pours. city, EOR, GC
- Observation report will be written and submitted to _ owner
8) Mechanical/Electrical/Plumbing Coordination
The contractor shall ensure that placement of nonstructural systems is
coordinated with the placement of reinforcement.
9) Unusual Conditions
Please note any conditions that make the PT for this project unusual or
different from typical project completed in this area:
PT Beams or Walls: Drop beams at L2 mid section and SW wall
Corrosion -Resistant Systems: N/A
Large or Numerous Deck Openings: 1 stairwell / 2 elevators
Stressing Accessibility: From deck shoring
In -Slab Ducting System: N/A
Other Conditions: N/A
Items Reviewed Prior to Each PT Deck Pour
1) Overpour
Check vertical element for overpours. Overpours are locations where vertical
sections have been poured higher- than per plans such that they extend
vertically in the slabs or beams. Concrete walls and columns shall not extend
more than 1/2 inch into the bottom of beams, slabs, or drop caps. If slop joints
are used at the top of a wall, no overpour is acceptable.
2) Formwork
Formwork shall be stable, cambered if required, clean, and properly
supported to carry the weight of all materials and construction loading.
3) Construction Joints
All construction joints shall be inspected for any required keyways and added
rebar per the structural drawings.
4) Stud Rails
The size, length, spacing, and number of studs and the thickness, length, and
width of the bottom plate shall be reviewed to verify compliance with the
structural drawings. The number, placing, and positioning of the stud rail
shall also be reviewed to verify compliance with the structural drawings.
5) PT Support
All PT cables shall be supported by rebar, on chairs, or on continuous slab
bolsters at a maximum spacing of 4 feet on center. All cables shall be
securely tied to these supports to ensure final position after concrete
placement. Back-up bars are required at all anchor locations per the
structural drawings and the PT shop drawings. Hairpins are required at
locations where horizontal curvature of the cable is severe as defined in the
structural drawings.
6) PT Placement
PT Cables shall be installed and placed to the allowable tolerances as
indicated on the structural drawings. Slab tendon tolerance shall be
+/_ 1/8" inches for the vertical profile as shown on the PT shop drawings.
The special inspector shall review all cable count, spacings, profiles, and
anchorages prior to placing concrete. All stressing end anchors and pocket
formers shall be firmly connected to the edge form. Grommets shall be well
greased.
7) PT Clearance
A minimum clearance of 3" inches (3" is typical) shall be verified from PT
cables to the edges of openings or sleeves. Sleeves may not be used near
anchors.
8) PT Encapsulation
For encapsulated systems as shown on the structural drawings, all PT system
components shall be enclosed in a watertight assembly. Because PT cables
under stress corrode much faster than typical steel, this assembly is critical
to providing a high level of durability. All components of the systems shall be
firmly attached to the anchors. Transulucent sleeves shall be completely
filled with grease. Cuts or tears in the cable sheathing shall be taped with a
spiral wrap. No bare cable may be exposed. The inspector shall issue a
report verifying that these conditions have been satisfied for each pour.
9) Rebar
All rebar shall be installed and placed within allowable tolerances as
indicated in the structural drawings and per ACI 318. The special inspector
shall review all rebar sized, spacings, clearances, and laps prior to pouring.
No wet setting of rebar- is permitted.
10) Unexpected Pour Interruptions
The contractor shall have a contingency plan for the creation of construction
joints to allow for the unexpected interruption of a pour due to pump failure,
concrete supply interruption, heavy rains, etc. This plan should be discussed
with the FOR in advance, and materials for additional keyways and
reinforcing should be available on site.
11) 4 Hour Waiting Period
A 4 hour minimum time between the special inspector's approval of
reinforcement and placing of the concrete shall be observed. The purpose of
the waiting period is to assure that work is complete, inspected, and approved
prior to the start of the pour. Exception: The city inspector may make an
exception to the 4 hour minimum rule for a minor item provided the concrete
is never placed at any point on the deck until the inspector has completed the
final inspection and has approved all mild steel and PT cable placement in
writing. No other workers may be on the deck during this final inspection.
Violations may result in a stop -work order.
Items Reviewed During Each PT beck Pour
1) Special Inspection During the Pour
Special inspection shall be provided continuously through out the pour. At
a minimum, one special inspector shall observe the placement of concrete
on the deck and one inspector shall meet the concrete trucks to verify batch
tickets and take test cylinders at the point of delivery.
2) Pour Watch
The contractor shall designate an individual to be on pour watch and
accompany the special inspector to correct any PT or other reinforcement
that is displaced during the pour. This individual may not have other duties
that will conflict with the pour watch.
3) 'Pest Cylinders
The city requires a minimum of 3 laboratory cured cylinders for every 150
cubic yards of concrete placed. Of those, one is to be tested at 7 days and
two at 28 days. In total, the special inspector shall take total test
cylinders for verifying the concrete strength. These shall be as follows:
3 at 3 days (for stressing — must be field cured)
1 at 7 days
3 at 28 days
at 56 days
at 90 days
It may be helpful to take one additional cylinder to hold in case of problems
with other cylinders. Other testing issues to consider:
Will maturity testing be used? Y/01
Are 4x8 cylinders acceptable? ( ' N
May all the cylinders be field -cured? YG
Field cured cylinders must be placed on the deck or in a thermocouple box
connected to the deck and protected in such a way as to assure that they
benefit from the deck's heat of hydration. Under no circumstances may lab
cured cylinders be used in place of field cured cylinders for determining the
strength of the deck for stressing purposes.
4) Air Entrainment and Slump
Air content as specified in the drawings is air content at the point of
placement. Target slump as specified in the mix design shall be the slump
allowed at the point of placement. If the concrete is pumped, the concrete
supplies- shall coordinate with the contractor to provide the proper allowance
for air loss and slump changes due to pumping to ensure that air content
and slump will be as specified. Concrete with excessive slumps will not be
placed.
5) Adding Water
No water shall be added to the concrete at the site unless the supplier has
withheld an equal or greater amount from the total water shown on the
approved mix design. Each batch ticket shall clearly show how much water,
if any, may be added. The person responsible for ordering the concrete and
requesting that permissible amounts of added water be listed on the batch
ticket is Jorge - Carmona The ticket shall be provided to the inspector
who will observe the addition of any water and log it in the inspection
report.
6) Superplaticizer
A superplasticizer may be added at the site after the concrete has been
successfully tested for slump. A quality -control representative of the
concrete supplier should be on site to establish the dosage for the initial
loads. Superplasticizer shall not be used in conjunction with air
entrainment unless the potential air loss has been accounted for by the
supplier.
7) Concrete Placement
Place concrete per the requirements of ACI 301, taking any necessary
precautions for hot or cold weather conditions if required. Do not dislocate
rebar, post -tensioning cables, or other reinforcement while placing concrete.
Special precautions may be necessary if concrete is being placed with a
bucket due to the surge at the discharge point, or if hoses are being dragged
across the deck.
8) No Wet Setting
All rebar and post -tension placement should be completed within the area of
the pour before the pour begins. No placing of rebar, post -tensioning,
inserts, sleeves, conduit, dowels, anchor bolts, etc., shall be allowed after
the inspector has given the final approval to pour.
9) Consolidation
Consolidation, particularly around the PT anchors, is critical. It is difficult
to segregate PT concrete mixes with a vibrator, so additional vibration
should be done if there are any doubts about adequate consolidation.
Anchors have failed due to inadequate consolidation. Besides requiring
repair, these failures involve high forces and flying concrete and can be
extremely dangerous. Disturbing the concrete around the PT anchors after it
has been placed and consolidated is prohibited.
10) Evaporative Retarder
Follow curing procedures as specified in the structural drawings or
specifications. Good curing is one of the most important strategies in
creating quality concrete. If curing with a spray -applied curing compound,
apply the product immediately after slab finishing. On slabs with a broom
finish or other roughened finish, apply two coats in opposite directions. See
drawings or specifications for additional curing information.
Items Reviewed. After Each PT Deck Pour
1) Stressing Preparation
Clean out any slurry or concrete from the anchors to allow proper seating of
the wedges. Clean the tendon tails of grease with a cloth or other- means in
order to accept the paint that the inspector will use for measuring the
elongation.
2) Concrete Stressing Strength
Concrete strength shall be a minimum of 3500 psi for stressing.
3) Stressing
The contractor- shall follow the stressing procedures given on the structural
drawings and the PT shop drawings. Stressing involves extremely high forces
and failure to follow proper procedures may cause serious injury. Stressing
shall consist of stressing one cable, then stopping while the stressing foreman
and the special inspector both independently measure the elongation. If the
elongation as determined by the special inspector is within tolerance, they
may repeat this procedure for a second cable. If the second cable is also
within tolerance, they may repeat the procedure for a third cable. If the third
cable is also within tolerance, it is acceptable for the stressing crew to
proceed slightly ahead of the special inspector. This procedure shall be
repeated as often as is deemed necessary by the special inspector. The
special inspector shall observe all stressing crew work simultaneously,
multiple special inspectors are required. Measured elongation tolerances
shall be:
7% of the calculated value unless noted: 7-% .
For short pulls, are tolerances of '/4" acceptable? ON
In cases where the actual elongation falls outside of this range, do not
proceed. Contact the FOR and the PT supplier to determine the problem
before continuing. Stressing shall not continue until the FOR approves the
resumption of stressing. Note that special inspector measures elongations
and gauge readings, but does not operate the stressing equipment.
4) Elongation Reports
Once stressing is completed, the inspector shall fax (or email) the final
stressing report to the FOR for review and approval as soon as possible. The
tendon tails may not be cut off until approval is received.
5) Cutting and Capping Tendon Tails
Cutting and finishing of the tendon tails shall be witnessed by the special
inspector. The watertight cap shall be applied immediately to the anchor to
ensure that the cable, which was dried during the cutting process, remains
dry. Finishing of the stressing end shall be verified by the inspector.
6) Stressing Blockouts
Stressing Blockouts shall be patched within one week of receiving approval to
cut the tendon tails. Before patching, the concrete in the blockouts shall be
kept clean and free of rust inhibitors or other materials which may interfere
with the bond of the grout patch.
7) Stripping Forms
Unless noted otherwise on the structural drawings, slab and beam formwork
may be stripped after the stressing report has been approved. Verify the
reshoring schedule with the form work supplier before loading the newly
poured deck with formwork.
8) Soffit Curing
When required by the structural drawings or specifications, apply a spray -
applied curing compound to the bottom of the slab and beams after removal
of the forms. This limits drying on the underside of the structure after the
concrete is exposed and improves the quality of curing.
9) Closure Strips
Closure strips may require that forms remain in place on each side of the
closure until the strip has been poured and the concrete in it has reached
75% of its design strength. Closure strips for this project shall be poured no
sooner than 28 days after the slab on both sides has been poured and
stressed.
10) Cutting, Coring, and Drilling
The contractor- shall take precautions when cutting, coring, drilling, or
shooting into PT slabs and beams to avoid damage to the reinforcing. Cables
and rebar shall be located and the information submitted to the FOR for
review. Work may not begin until the FOR has approved the specific location
where work is to be done.