HomeMy Public PortalAboutPacket_City Council Special Meeting_03202019City of Iona
Special CityCouncil Meeting
NOTICE IS HEREBY GIVEN, that the Iona City
Council will convene a Special Council Meeting. The
meeting will be held on March 20, 2019 at the hour of
6:00 p.m. at the Iona Community Center located at 3548
N. Main.
Agenda:
1. Welcome
2. Pledge of Allegiance
3. Items of Business
a. DN Tanks proposal for a type III tank
b. Dome Technology's Water Tank discussion
c. Forsgren Engineering to present Specs and Plans for Water Tank Project
d. Approve Specs and Plans to go out for bid ACTION ITEM
4. ADJOURNMENT
Posted this 19t day of March, 2019
SPECIAL CITY COUNCIL MEETING
VISITOR'S SIGN IN
MARCH 20, 2019
6:00 P.M.
PRINT
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SIGN
ADVERTISEMENT FOR BIDS
City of Iona Water System Improvements
North Tank
RECEIPT OF BIDS: Sealed Bids for construction of the Iona Water System Improvements — North Tank will
be received by the City of Iona, at the City Office located at 3548 N Main Street, Iona, Idaho 83427, until 3
pm local time on April 11, 2019, at which time the Bids received will be publicly opened and read.
DESCRIPTION OF WORK: The Project consists of construction of a 1.0 MG tank prestressed concrete water
tank and appurtenances.
OBTAINING CONTRACT DOCUMENTS: Copies of the CONTRACT DOCUMENTS may be obtained on or
after March 27, 2019 at the office of the ENGINEER (Rexburg) upon payment of $125.00 for each set, none of
which will be refunded. Upon purchase of the Contract Documents Bidders will be placed on the plan holders
list. Acknowledgment on the plan holders list is mandatory for all bidders.
The CONTRACT DOCUMENTS may be examined at the following locations:
Forsgren Associates, Inc.
350 North 2nd East
Rexburg, Idaho 83440
(208) 356-9201
City of Iona, City Office
3548 N Main Street
Iona, Idaho 83427
(208) 523-5600
PRE -BID CONFERENCE: A pre -bid conference will be held at 10 am local time on April 5, 2019 at the Iona
City Office, 3548 N Main Street, Iona, Idaho 83427. Attendance at the pre -bid conference is highly
encouraged but is not mandatory.
BID SECURITY: Each proposal must be submitted on the prescribed form and accompanied by Bid Security in
the form of a certified cashier's check or a corporate bid bond executed on the prescribed form, payable to the
City of Iona in the amount of five percent (5%) of the amount bid. The Successful BIDDER will be required to
furnish Performance and Payment Bonds, each in the amount not less than 100% of the contract price.
ADDRESS AND MARKING OF BID: The envelope enclosing the bid shall be sealed and addressed to the
City of Iona and delivered or mailed to City of Iona, 3548 N Main Street, Iona, Idaho 83427. The envelope
shall be plainly marked in the upper left-hand corner with the name and address of the bidder and shall bear
the words "Bid for," followed by the Project title per the Contract Documents and the date and hour of opening
of bids. The certified or cashier's check, money order, or bidder's bond shall be enclosed in the same envelope
with the bid. Refer to "Instructions to Bidders" for additional submittal requirements.
LABOR REQUIREMENTS: The attention of Bidders is directed to the applicable federal and state
requirements regarding conditions of employment to be observed.
PROJECT ADMINISTRATION: All questions relative to this project prior to the opening of bids shall be
directed, in writing, to the ENGINEER for the project. It shall be understood, however, that no interpretations of
the specifications will be made by telephone.
OWNER
City of Iona
3548 N Main Street
Iona, ID 83427
Telephone: (208) 523-5600
ENGINEER
Forsgren Associates, Inc.
Contact: Dave Noel P.E.
Telephone: (208) 356-9201
dnoel@forsgren.com
OWNER'S RIGHTS RESERVED: The OWNER reserves the right to waive any informalities or to reject any or
all bids, if in the best interest of the OWNER.
Publish: DATE March 27019
DATE April 3, 2019
Dan Gubler, Mayor
ADVERTISEMENT-1
01-18-0124 (IONA NORTH TANK)
D115-06:
3.7.3 Wall thickness. The wall thickness shall be such that (1) compressive
stresses for the empty tank under external loads and horizontal prestress are within
allowable limits, (2) flexural stresses and reinforcing bars are not excessive and (3)
concrete cover is as required by Sec. 3.11 and the concrete placement can take place
without segregation.
For proper placement of concrete, the following values shall be used as
minimum thicknesses for the walls:
Cast -in -place .... 9 in. (230 mm)
Precast wall with external prestressing 5 in. (130 mm)
Precast with internal prestressing 7 in. (175 mm)
Gmr�il
Amy Sullivan <treasurer@cityofiona.org>
Tank companies
1 message
Brad Andersen <oneh20boy@hotmail.com> Wed, Mar 20, 2019 at 9:25 AM
To: "cityclerk@cityofiona.org" <cityclerk@cityofiona.org>, Amy Sullivan <treasurer@cityofiona.org>
I won't be able to make the meeting tonight concerning the awarding of the tank contract but I would like this email read
and/or given to the council and attorney.
I feel in the best interest of the city that the mayor and the two council members (Kathy and new guy appointed, I think his
name is wadsworth) recuse themselves in voting for awarding the tank contract. Their church leader is the CEO for Dome
Technology and I feel that they cannot be objective and unbiased and at the very least it is unethical and could be
perceived as being biased in their thinking and voting. I would have the two remaining council members (Rob and Mike)
make that decision with input from Zech.
Thanks brad Andersen
Sent from my iPhone
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d o n ' t w a n t t o s e e a n y o n e p r o t e s t i n g t h e i r d e c i s i o n i f d o m e t e c h n o l o g y g e t s t h e c o n t r a c t . I a m j u s t t r y i n g t o l o o k o u t t h e
c i t y . I f I w a s n ' t i n t h e s a m e s i t u a t i o n I w o u l d r e c u s e m y s e l f . T h a n k s b r a d
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[ Q u o t e d t e x t h i d d e n ]
Amy Sullivan <treasurer@cityofiona.org>
Public Comments re Tonight's Special Meeting
1 message
Andrew Rawlings <ARawlings@holdenlegal.com> Wed, Mar 20, 2019 at 1:46 PM
To: Dan Gubler <dangubler@cityofiona.org>, Rob Geray <robgeray@cityofiona.org>, Kathy McNamara
<kathymcnamara@cityofiona.org>, Michael Thompson <michaelthompson@cityofiona.org>,
"peterwadsworth@cityofiona.org" <peterwadsworth@cityofiona.org>
Cc: Amy Sullivan <treasurer@cityofiona.org>, Keri West <cityclerk@cityofiona.org>, Zech Prouse
<publicworks@cityofiona.org>
All;
Amy brought the issues raised in Brad Anderson's emails (see attached) to my attention for a
response.
My response is that, from the City's perspective, neither of the councilmembers mentioned (Kathy
McNamara or Pete Wadsworth) need to recuse themselves. Specifically:
1. I understand that tonight's special meeting of the City Council is not intended to award any
contract, but merely to approve the specifications that will be sent out to elicit bids for the
City's Tank project. Thus, the only decision to be made is whether the specifications
generated by the City's engineer for this project reflect what the City wants. As a result, any
interaction with the CEO of one of the potential bidders is irrelevant at this stage.
2. The decisions regarding the Tank are made as "proprietary" function of City government. In
essence, the City stands in the same place as any other person buying a water tank. There
are, admittedly, certain restrictions on how that contract is bid and selected, but the City (and
its water service) are propriety functions, operated like any business that is subject to certain
legal restrictions. Due Process requires that a decision -maker be fair and impartial, which is
a bar to a biased decision -maker. While that applies to a quasi-judicial function (like a
zoning application), it does not apply to proprietary functions.
3. While the Due Process protections are not in play, other laws do still apply. For example, the
Ethics in Government Act of 2015 (Idaho Code § 74-401, et seq.) bars the participation of any
councilmember (or a member of the councilmember's close family) with a financial interest.
There is no indication of any relevant personal, financial, or familial interest in relation to the
decision to be made at tonight's special meeting.
4. Finally, by way of definition, a biased decision -maker is one who is "not capable of judging
a particular controversy fairly on the basis of its own circumstances." Davisco Foods Intl,
Inc. v. Gooding Cty.,141 Idaho 784, 791,118 P.3d 116,123 (2005) (quoting Eacret v. Bonner Cty.,
139 Idaho 780, 785, 86 P.3d 494, 499 (2004) (which is, in turn, quoting Hortonville Joint School
Dist. No. 1 v. Hortonville Education Assn, 426 U.S. 482, 493, 96 S.Ct. 2308, 2314, 49 L.Ed.2d 1, 9
(1976))). Thus, to whatever extent Due Process requires a fair and impartial decision -maker,
that is the standard for actual bias. Whether a councilmember can make an unbiased
decision (based on the above -described standard) in relation to a "church leader" is beyond
the scope of this response; but the relationship with a "church leader" is not (by itself) a per se
indication of bias.
It is up to the councilmembers to decide how they act. From the City's perspective, however, I am
not aware of a basis to be concerned about the bias alleged in relation to tonight's special meeting
of the City Council.
I was not planning on attending tonight's meeting, nor will I unless the City requests that I be
there. If you have any questions about what I have presented, please feel free to contact me.
Cordially,
D. Andrew Rawlings
HOLDEN, KIDWELL, HAHN & CRAPO, P.L.L.C.
http://www.holdenlegal.com
P.O. Box 50130
Idaho Falls, Idaho 83405
Phone: (208) 523-0620
Fax: (208)523-9518
Email: aawlings@holdenlegal.com
Physical Address:
1000 Riverwalk Drive, Suite 200
Idaho Falls, Idaho 83402
Confidentiality Notice: The information contained in this e-mail message and any accompanying attachments, all of
which may be confidential and/or privileged, is intended only for use by the person or entity to whom it is
addressed. If you are not the intended recipient, any unauthorized use, disclosure, or copying of this e-mail and/or its
contents is strictly prohibited and may be unlawful. If you are not the intended recipient, please immediately notify
the sender by return e-mail and delete the original message and all copies from your system. Thank you.
1
2
SECTION 13000
PRESTRESSED CONCRETE WATER TANK
PRESTRESSED CONCRETE WATER TANK
PART 1 - GENERAL
3 1.1 DESCRIPTION
4 A. Work Included
5 1. This section is for a proprietary prestressed concrete culinary water holding tank
6 designed and constructed to meet the general design dimensions and elevations
7 provided in the contract documents in conjunction with the requirements of either:
8 a. AWWA D110 or
9 b. AWWA D115
10 2. Proprietary tanks shall be designed and constructed by a single source acting as
11 General Contractor for this project.
12 3. This section specifies the design qualifications for the Tank Contractor and
13 requirements for the construction of a prestressed, concrete water tank; including all
14 reinforcing, concrete work, prestressing, and appurtenances directly related to the tank
15 unless otherwise specified.
16 4. This section also provides clarification for site work, excavation, disinfection, testing,
17 and backfill pertaining to the tank.
18 5. In the event of discrepancy between this section of the Specifications and any other
19 section of the Specifications or the appropriate AWWA standard, this section shall
20 govern.
21 6. The Contractor shall furnish all labor, materials, tools, and equipment necessary to
22 construct the prestressed concrete water tank and appurtenances as indicated on the
23 drawings, and as specified in the Contract Documents.
24 B. Related Work Described Elsewhere
25 1. Site work, excavation, and grading
26 2. Process Piping and connections
27 3. Concrete foundation and structural backfilling
28 C. Description of System
29 1. The tank shall consist of a cast -in -place reinforced concrete foundation, cast -in -place
30 reinforced concrete floor, horizontally prestressed cast -in -place or pre -cast concrete
31 wall, and cast -in -place free span or column supported concrete roof.
32 2. Ancillary tank components are shown on the contract drawings and include a minimum
33 of the following:
34 a. two access hatches, access to each hatch from the ground surface,
35 b. tank venting,
36 c. interior tank coating,
37 d. exterior tank coating,
38 e. and pipe penetrations.
39 f. Additionally, bid form includes alternate for a ground level man -way.
40 3. Process piping connections include an overflow, inflow, and discharge pipe mounted
41 inside the tank extending through the tank floor and foundation.
42 4. Civil work components include clearing and grubbing the site, rock removal, blasting,
43 excavation, and structural fill for the foundation base, and backfill and final grading.
44
45 1.2 QUALITY ASSURANCE
46 A. Qualifications and Experience
47 1. The Prestressed Concrete Tank shall be constructed by a single Tank Contractor
48 experienced in the construction of circumferentially prestressed concrete tanks.
13000 - 1
01-18-0124 (IONA NORTH TANK)
SECTION 13000
PRESTRESSED CONCRETE WATER TANK
1 2. The Tank Contractor may subcontract the tank to a Tank Designer who meets the
2 experience requirements of this section for performing tank design. The tank design
3 must be stamped by a structural engineer holding a current professional engineering
4 license in the State of Idaho. The design engineer shall have been the engineer of
5 record for a minimum of 3 similar tanks in the past 10 years.
6 3. The Tank Contractor and designer as a single team shall have constructed a minimum
7 1 similar prestressed concrete tanks of similar size in the past 5 years.
8 4. The Tank Contractor may subcontract tank prestressing operations to a Tank
9 Prestressor who meets the experience requirements of this section for performing tank
10 prestressing operations.
11 5. The Tank Contractor or Tank Contractor's listed Tank Prestressor shall be a specialist
12 in the prestressing of prestressed concrete and having at least 10 continuous years'
13 experience in the construction of concrete structures which have been circumferentially
14 prestressed.
15 6. The superintendent for the Tank Contractor shall have successfully completed
16 construction of a minimum of 3 tanks similar in design. Construction superintendent
17 shall have been in the direct employment of the qualified Tank Contractor for a
18 minimum of 5 years and will be required to be on the project site in responsible charge
19 full time, during all tank construction activities. Experience gained not performed while
20 in the employment of the Tank Contractor will not be considered for meeting the
21 necessary experience requirements.
22 B. Submittals
23 1. CONTRACTOR shall submit Shop Drawings, operation and maintenance instructions,
24 and other information as specified herein. Shop Drawings shall include the following at
25 a minimum:
26 a. Dimensioned Drawings with plan and section views.
27 b. Assembly and installation instructions with drawings and an overview of equipment
28 safety precautions.
29 c. Protective coating information and materials of construction for all components.
30 d. A comprehensive list of any exceptions or substitutions, which includes
31 corresponding section name and subtitle and proposed substitution.
32 e. Construction schedule of values
33 f. Construction schedule and detailed work plan describing construction
34 implementation in accordance with Part 3 of these Specifications.
35 g. Manufacturer's warranty information.
36 h. A written guarantee stating that the unit shall perform within the design criteria as
37 contained herein.
38 i. Structural support and design calculations bearing the stamp of a licensed
39 professional engineer registered in Idaho.
40 2. Manufacturer's Certifications: CONTRACTOR shall provide written certifications of
41 correct installation to ENGINEER for approval prior to final acceptance.
42 3. O&M Manuals: Prior to final acceptance by ENGINEER, CONTRACTOR shall furnish
43 six (6) complete sets of O&M manuals for approval. All O&M manuals shall be provided
44 in white 3-ring binders. Upon approval of the O&M manual, a complete digital copy of
45 the O&M manual shall be provided on a CD-ROM in `.pdf format.
46 C. Handling and Storage
47 1. Special care shall be exercised during delivery, handling, and storage of equipment and
48 material to prevent damage, degradation of materials, and fouling. Delivery, handling,
49 and storage of the equipment and materials shall be in accordance with the
50 manufacturer's recommendations and as specified in Division 1.
51 2. All parts of the equipment shall be shipped to the jobsite adequately protected from
52 breakage and dirt. All equipment shall remain boxed until the time of installation.
53 D. Manufacturer's Warranty
�s
13000 - 2
01-18-0124 (IONA NORTH TANK)
SECTION 13000
PRESTRESSED CONCRETE WATER TANK
1 1. CONTRACTOR shall provide a manufacturer's warranty on the tank and appurtenances
2 provided under this specification for (6) six years from substantial completion for both
3 materials and workmanship. Any repairs or replacement of components made during
4 the warranty period shall be made at no cost to ENGINEER or to OWNER.
5 2. The date of substantial completion shall be defined as the date upon which the tank has
6 passed all testing requirements and can be continuously operated as agreed upon by
7 both ENGINEER and CONTRACTOR.
8 E. Codes & Standards
9 1. All Codes shall be considered the most current version of that code unless noted
10 otherwise.
11 a. ACI 301 Specifications for Structural Concrete
12 b. ACI 305 Hot Weather Concreting
13 c. ACI 306 Cold Weather Concreting
14 d. ACI 309R Guide for Consolidation of Concrete
15 e. ACI 318 Building Code Requirements for Reinforced Concrete and Commentary
16 f. ACI 350 Code Requirements for Environmental Engineering Concrete Structures
17 and Commentary
18 g. ACI 350.3 Seismic Design of Liquid Containing Concrete Structures and
19 Commentary
20 h. ACI 372R Design and Construction of Circular Wire- and Strand Wrapped
21 Prestressed Concrete Structures
22 i. ACI 506R Guide to Shotcrete
23 j. ASTM A123/A123M Standard Specification for Zinc (Hot -Dip Galvanized) Coatings
24 on Iron and Steel Products
25 k. ASTM A185 Standard Specification for Steel Welded Wire Reinforcement, Plain, for
26 Concrete
27 I. ASTM A416 Standard Specification for Steel Strand, Uncoated Seven -Wire for
28 Prestressed Concrete
29 m. ASTM A475 Standard Specification for Zinc -Coated Steel Wire Strand
30 n. ASTM A615/A615M Standard Specification for Deformed and Plain Carbon -Steel
31 Bars for Concrete Reinforcement
32 o. ASTM A706/A706M Standard Specification for Low -Alloy Steel Deformed and Plain
33 Bars for Concrete Reinforcement
34 p. ASTM A722/A722M Standard Specification for Uncoated High -Strength Steel Bar
35 for Prestressing Concrete
36 q. ASTM C31 Standard Practice for Making and Curing Concrete Test Specimens in
37 the Field
38 r. ASTM C33 Standard Specification for Concrete Aggregates
39 s. ASTM C39 Standard Test Method for Compressive Strength of Cylindrical Concrete
40 Specimens
41 t. ASTM C231 Test Method for Air Content of Freshly Mixed Concrete by the
42 Pressure Method
43 u. ASTM C618, Type F Standard Specification for Coal Fly Ash and Raw or Calcined
44 Natural Pozzolan for Use in Concrete
45 v. ASTM D698 Standard Test Methods for Laboratory Compaction Characteristics of
46 Soil Using Standard Effort (12,400 Ft. — Ibf/ft3) 600 KN-M/M3)
47 w. ASTM C920 Specification for Elastomeric Joint Sealants
48 x. ASTM D1056 Standard Specification for Flexible Cellular Materials — Sponge or
49 Expanded Rubber
50 y. ASTM C1116/C1116M Standard Specification for Fiber -Reinforced Concrete and
51 Shotcrete
52 z. ASTM D1556 Standard Test Method for Density and Unit Weight of Soil in Place by
53 the Sand -Cone Method
54 aa. ASTM D1557 Standard Test Methods for Laboratory Compaction Characteristics of
55 Soil Using Modified Effort (56,000 Ft. — Ibf/ft3) 2700 KN-M/M3)
13000 - 3
01-18-0124 (IONA NORTH TANK)
SECTION 13000
PRESTRESSED CONCRETE WATER TANK
1 bb. ASTM D2000 Classification System for Rubber Products in Automotive Applications
2 cc. ASCE Standard 7 Minimum Design Loads for Buildings and Other Structures
3 dd. AWWA C652 Standard for Disinfection of Water -Storage Facilities
4 ee. AWWA D110 Wire and Strand Wound, Circular, Prestressed Concrete Water Tanks
5 ff. AWWA D115 Tendon -Prestressed Concrete Water Tanks
6 gg. TID-7024, Dynamic Pressure on Fluid Containers of Nuclear Reactors and
7 Earthquakes
8 hh. US Army Corps of Engineers Specification CRD-C-572, Specification for PVC
9 Waterstop
10 F. Design Criteria
11 1. The prestressed concrete tank shall be designed and constructed in accordance with
12 the most recent versions of:
13 a. the provisions of AWWA D110 Standard for Wire or Strand Wound Circular
14 Prestressed -Concrete Water Tanks, ACI 350, ACI 350.3, ASCE 7 and IBC.
15 b. Or the provisions of the provisions of AWWA D115 Tendon -Prestressed Concrete
16 Water Tanks, Cast -in -Place, ACI 350, ACI 350.3, ASCE 7 and IBC.
17 2. Prestressed concrete shall be defined as concrete having stressed horizontal
18 reinforcing steel prior to filling the water tank structure.
19 3. Prestressed concrete tank design shall incorporate the following minimum dimensions
20 for all tank types, caste -in -place, or pre -cast:
21 a. Diameter — 100 feet
22 b. Height to overflow — elevations as shown on drawings
23 c. Height of wall, defined as a continuous prestressed structural members rising from
24 the floor to the first horizontal joint — overflow elevation as shown on drawings plus 1
25 foot
26 d. Height of cast -in -place free span roof — not to exceed rise of 1 foot for each 8 feet of
27 diameter
28 e. Floor thickness — 6"
29 f. Wall thickness (defined as core wall or structural portion of the wall that will be
30 prestressed) — 9"
31 g. Roof thickness — as required by structural calculation
32 4. The Tank Contractor shall use the following loadings and requirements in the design
33 calculation:
34 a. Capacity: 1.0 million gallons.
35 b. Dimensions: see section 1.2 F.
36 c. Dead Load: shall be the estimated weight of all permanent imposed loads. Unit
37 weight of concrete 150 pounds per cubic foot; steel 490 pounds per cubic foot.
38 d. Live Load: shall be the weight of all the liquid when the reservoir is filled to
39 overflowing. Unit weight of liquid 62.4 pounds per cubic foot.
40 e. Total Roof Live Load: 20 psf.
41 f. Superimposed Roof Dead Load: 20 psf.
42 g. Wind Loads: shall be as required by ASCE 7
43 h. Minimum Backfill Height: 4.3 feet.
44 i. Maximum Backfill Height: 8.9 feet.
45 j. Backfill Downward Drag Coefficient: n/a
46 k. Equivalent Liquid At -Rest Pressure: 35 pcf.
47 I. Backfill Pressure Increase on Wall Under Seismic Excitation: n/a psf.
48 m. Equivalent Liquid Passive Earth Pressure: 350 pcf.
49 n. Backfill Soil Density: 130 pcf.
50 o. Lateral Vehicle Surcharge on Tank Wall: n/a psf.
51 p. Foundation Loads: the tank foundation shall be proportioned so that soil pressure
52 shall be less than the soil bearing capacity. The allowable net soil bearing capacity
53 is 4500 psf. Net soil bearing capacity is defined as the gross bearing capacity
54 excluding liquid and/or soil overburden pressure.
13000 - 4
01-18-0124 (IONA NORTH TANK)
SECTION 13000
PRESTRESSED CONCRETE WATER TANK
1 q. Settlements: Tank shall be designed for maximum total settlement of 1.5 inches
2 and a maximum differential settlement of .75 inches.
3 r. Groundwater elevation is in excess of 50 feet below the tank foundation.
4 s. Coefficient of friction will be .4.
5 t. Seismic Criteria:
6 u. Seismic Criteria:
7 1) Seismic Design Criteria: Seismic design shall be based on the applicable
8 sections of AWWA D110 or AWWA D115, ACI 350.3, ASCE 7-10, TID 7024
9 and the local jurisdictional building code. Impulsive and convective forces, as
10 well as, fluid spectral velocity shall be calculated utilizing each code and the
11 maximum value of each component shall be used to calculate the total base
12 shear. The wall bearing pads cannot be considered as contributing to the shear
13 resistance during a seismic event.
14 2) Design Criteria:
15 a) Design loads per current version of IBC and ACI 350 governing codes.
16 b) Designer shall list all design loads on the construction submittal documents.
17 3) Sloshing Height: The sloshing height shall be calculated using AWWA D110 or
18 AWWA D115, but need not exceed the fluid displacement calculation when
19 determined using ACI 350.3, TID 7024 or ASCE 7. The effects of the "sloshing
20 wave" shall be accounted for by increasing the freeboard between the normal
21 operating surface and the underside of the roof, or a roof capable of resisting
22 the uplift of such a wave designed. A minimum freeboard height of 12 inches
23 above the design liquid level shall be utilized. Any confined portion of the
24 convective (sloshing) mass shall be calculated and applied as an additional
25 impulsive mass.
26 5. Base Restraint Cable Design:
27 a. The base restraint cables shall be designed for the total base shear obtained from
28 the maximum values of impulsive and convective components and the dynamic
29 effects of backfill. The allowable cable stress is 0.75 fpu.
30 b. For the total base shear obtained from the loading conditions of ASCE 7 that
31 incorporate an over strength factor (Omega Factor), the allowable cable stress shall
32 be increased by 20%. The Omega factor shall be 2.0 for all loading cases.
33 6. Vent Capacity Requirements:
34 a. Maximum Fill Rate: 2000 gpm.
35 b. Maximum Draw Down Rate: 800 gpm.
36 c. Overflow Design Capacity: 2000 gpm.
37 7. Floor Slab:
38 a. The floor slab shall be designed as a membrane floor not less than 6 inches thick.
39 Construction joints will only be allowed as shown on the shop drawings and as
40 approved by the Engineer. Construction joints shall incorporate a 9 inch horizontal
41 PVC waterstop oe equivalent hydrophilic water stop as approved by engineer.
42 b. Wall footings may be constructed above or below floor grade. If required, the floor
43 shall have thickened regions to facilitate transitions from under slab concrete pipe
44 encasements into the floor, appurtenance loadings and column bases shall
45 incorporate a 2 inch recess centered below each column. The recess shall have a
46 diameter equal to the length of the column footing minus 6 inches.
47 c. Minimum concrete cover to the tank interior and sub -base material shall be no less
48 than 2" and 3", respectively.
49 d. Minimum cross sectional area ratio of floor reinforcement to concrete shall be 0.5%.
50 e. The floor concrete shall incorporate a shrinkage reducing admixture.
51 f. Polypropylene or cellulose fibers may be used at the Tank Designer's discretion.
52 8. Cast -in -Place Concrete Roof: The roof shall be either a two way roof slab with concrete
53 support columns and bases or a free span concrete dome as follows:
54 a. Two Way Roof Slab with Concrete Columns and Bases
55 1) The roof shall be cast -in -place, flat -slab reinforced concrete with a minimum
56 thickness of 9 inches.
P
13000 - 5
01-18-0124 (IONA NORTH TANK)
SECTION 13000
PRESTRESSED CONCRETE WATER TANK
1 2) The roof shall be of flat -slab two-way action design, constructed of cast -in -place
2 concrete, shall incorporate drop panels and shall be supported by interior
3 columns.
4 3) The interior columns shall have a minimum diameter of 18 inches.
5 4) Columns shall be reinforced with vertical and spiral reinforcement.
6 5) The roof shall be supported by solid neoprene or natural rubber bearing pads,
7 according to the specifications herein, allowing free radial movement of the wall
8 and roof. A seismic connection between the roof and wall shall be incorporated.
9 The connection shall permit free radial movement of the wall and roof, and shall
10 be capable of directing and resisting the shear load tangential to the wall.
11 a) All neoprene or natural rubber pad sections shall be based on continuous
12 loading values not to exceed those allowed in the neoprene design manual.
13 b) The minimum bearing pad thickness under roof slab shall be'/z inch.
14 c) The minimum total pad width under roof slab shall be 2 inches.
15 d) The remaining voids between wall and roof, not taken up by the solid
16 neoprene or natural rubber pads, shall be filled with closed cell rubber pads
17 and soft mastic to ensure a substantially unrestrained free movement of
18 wall and roof.
19 6) Non -prestressed steel -reinforced concrete flat slabs shall conform to the
20 applicable requirements of ACI 350, including sanitary environmental durability
21 coefficients factor with special attention to crack control.
22 7) The design shall provide a weather -tight roof to minimize cracking and to
23 prevent leakage and contamination of the contents. Consideration shall be
24 given for the exposure conditions. Reinforcement of concrete slabs shall also
25 be provided to resist temperature stresses.
26 8) The roof slab, columns, and bases shall be integral to the tank design and
27 included in the tank design package.
28 b. Cast -in -Place Reinforced Concrete Dome Roof Free Span
29 1) A reinforced concrete dome may be used for the roof of the tank. The design of
30 the dome shall be in accordance with the current version of ACI 350.
31 2) The exterior of the dome shall be waterproofed with a membrane roofing with
32 minimum warranty of 15 years.
33 3) The dome ring beam shall be prestressed and designed in accordance with
34 recommendations from ACI 350 and ACI 334.
35 4) The dome roof shall be integral to the tank design and included in the tank
36 design package.
37 9. Water Tightness Criteria:
38 a. Maximum measurable loss is .125" per 24 hours
39 b. and, zero visible leakage at the following locations:
40 1) Pipe penetrations,
41 2) Man -ways,
42 3) Wall to floor connections.
43
44 1.3 SUBMITTALS
45 A. Submittals Required Upon Request Prior to Award:
46 1. Tank Contractors shall submit preliminary design drawings and calculations showing
47 the dimensions of the tank, details of the type of construction, prestressing methods,
48 and sizes of principal members. The drawings and calculations shall be of sufficient
49 detail to show compliance with the specification and all required standards and shall be
50 signed and sealed by an Engineer registered in the state of Idaho.
13000 - 6
01-18-0124 (IONA NORTH TANK)
�a
SECTION 13000
PRESTRESSED CONCRETE WATER TANK
1 2. Tank Contractors shall submit an experience record for the tanks they have designed
2 and built in their own name or one of their divisions meeting the Qualifications and
3 Experience criteria identified in Section 1.02 A.1 and 1.02 A.2. The record shall include
4 the Tank Contractor's experience in the design and construction of prestressed cast-in-
5 place or shotcrete concrete tanks. The record shall also indicate the size of the tank,
6 mapped seismic acceleration for short periods (Ss), the name and address of the
7 Owner, the year of construction, and the name of the Engineer for each project.
8 3. Tank Contractors shall submit the name of the tank designer currently in their employ,
9 and his/her experience as the designer of meeting the requirements of Section 1.02
10 A.3.The record shall also indicate the size of the tank, mapped seismic acceleration for
11 short periods (Ss), the name and address of the Owner, the year of construction, and
12 the name of the Engineer for each project.
13 4. Tank Contractors shall submit the resumes for each member of the project team
14 including the tank superintendent, project manager, shotcrete foreman, and reinforcing
15 member foreman that will be used for this project, meeting the requirements of Section
16 1.02 A.4.
17 5. Failure to submit any of the above, upon request, may cause the bid to be considered
18 non -responsive.
19 B. Design Submittal after Execution of Contract:
20 1. Design calculations and drawings in quadruplicate, showing details and procedures of
21 construction, shall be submitted to the Engineer for approval after execution of the
22 Contract. After approval by the Engineer, one set of the drawings and calculations will
23 be returned to the Tank Contractor, and any changes found necessary by the Engineer
24 shall be made by the Tank Contractor.
25 2. Approval by the Engineer of the drawings and calculations submitted by the Tank
26 Contractor will not in any way relieve the Tank Contractor of full responsibility for the
27 accuracy and completeness of the drawings and calculations.
28 3. Design calculations and drawings shall be stamped by a professional engineer meeting
29 the requirements of Section 1.02.A.3, and registered in the state of Idaho.
30 C. Design Submittal after Execution of Contract prior to Notice to Proceed:
31 1. NSF 61 certifications for all material components that will be indirect contact with
32 potable water and all materials that will be exposed to the interior of the tank.
33 D. Construction Submittals for Review Prior to Use:
34 1. Design proportions for all concrete and shotcrete. Concrete strengths of trial mixes.
35 2. Admixtures to be used in the concrete or shotcrete and their purpose.
36 3. Reinforcing steel shop drawings showing fabrication and placement.
37 4. Catalog cuts or shop drawings of all appurtenances, i.e. hatch, vent, ladders,
38 waterstops.
39 1.4 GUARANTEE
40 A. The Tank Contractor shall guarantee the structure against defective materials or
41 workmanship for a period of six (6) years from the date of substantial completion. If any
42 materials or workmanship are found to be defective within five years, they shall be replaced
43 or repaired by the Tank Contractor at the Tank Contractor's expense within 6 months of
44 discovery and notification.
45 PART 2 - PRODUCTS
46 2.1 NSF 61 CERTIFICATION
47 A. All materials that will be exposed to the interior of the tank shall have a current NSF 61
48 certification and shall be valid for this project.
13000 - 7
01-18-0124 (IONA NORTH TANK)
SECTION 13000
PRESTRESSED CONCRETE WATER TANK
1 B. All materials that will be in direct contact with potable water shall have a current NSF 61
2 certification and shall be valid for this project.
3 C. If NSF 61 certification is not available at time of bid, Contractor shall obtain certification prior
4 to any concrete placement and shall include in the bid price the cost to obtain NSF 61
5 certifications as needed to comply with DEQ requirements.
6 2.2 CONCRETE
7 A. Cement shall be Portland cement Type I or Type IIN.
8 1. Fly ash will not be accepted as a cement substitute.
9 B. Admixtures, other than air -entraining, superplasticizers, shrinkage reducing and water
10 reducing admixtures will not be permitted unless approved by the Engineer.
11 C. All Concrete shall have a minimum compressive strength of 4,500 psi at twenty-eight days
12 and a maximum water to cementitious ratio of 0.42.
13 D. The coarse and fine aggregate shall meet the requirements of ASTM C33. Coarse
14 aggregate shall be No. 57 with 100% passing the %" sieve or No. 67 with 100% passing the
15 1 inch sieve. Superplasticizers, water -reducing, and shrinkage reducing (if applicable)
16 admixtures shall be incorporated into the floor concrete. If fibers are used, they shall be
17 virgin polypropylene or cellulose fibers, manufacture of fibers and fiber type shall be
18 submitted for approval prior to use with the concrete mix design;
19 1. Microfiber by Grace;
20 2. Fibermesh 150 by Propex;
21 3. UltraFiber 500 by Buckeye;
22 4. or equal.
23 5. Fiber lengths shall be a maximum of 3/4 inches. The amount of fibers added to the
24 concrete mix shall conform to the tank designer's recommendations.
25 E. Proportioning for concrete shall be in accordance with ACI 301.
26 F. All concrete shall have a maximum water soluble chloride ion concentration of 0.06% by
27 weight of cementitious material.
28 2.3 SHOTCRETE
29 A. Shotcrete shall conform to ACI Standard 506, except as modified herein.
30 B. The wet mix process shall be employed for shotcreting.
31 C. Shotcrete used for covering prestressed reinforcing shall consist of not more than three
32 parts sand to one part Portland cement by weight. Additional coats of shotcrete shall consist
33 of not more than four parts sand to one part Portland cement by weight. Shotcreet mix
34 design shall be submitted to Engineer for approval prior to use.
35 D. In exterior shotcrete applications polypropylene fibers shall be included in the shotcrete
36 used for the finish cover coat for exterior shotcrete only. Fibers shall be;
37 1. Fibercast 500 by Propex;
38 2. Fibermesh;
39 3. or equal.
40 4. Fibers shall be virgin polypropylene and comply with ASTM C-1116 performance level I.
41 Fiber length shall be % inch.
42 5. The amount of the fibers added to the shotcrete used for the finish cover coat shall
43 conform to the tank designer's recommendations.
44 6. Structural fibers may be added to the shotcrete of the dome or the wall. Structural
45 Fibers shall be supplied from either of the following manufactures:
46 a. Euclid
47 b. Grace
48 2.4 ASR ABATEMENT:
13000 - 8
01-18-0124 (IONA NORTH TANK)
SECTION 13000
PRESTRESSED CONCRETE WATER TANK
1 1. Fly ash may be incorporated into the concrete mix for ASR abatement. Fly ash shall
2 conform to ASTM C618, Type F. Compressive strength requirements for concrete
3 cannot be achieved with the use of fly ash and shall be solely based on cement content.
4 a. Mix designs shall be tested in accordance with ASTM C1567 standard.
5 b. Mortar Bars shall expand less than 0.10% in 28 days. (Note this is a modification
6 from the 14 days specified in the test.).
7 c. Test results must be submitted for approval 10 days prior to the use of any concrete
8 mix.
9 2. Lithium nitrate may be incorporated into the concrete mix for ASR abatement.
10 a. Mix designs shall be tested in accordance with Army Core of Engineers CRD 662-
11 10 standard.
12 b. Mortar Bars shall expand less than 0.10% in 28 days. (Note this is a modification
13 from the 14 days specified in the test.).
14 c. Test results must be submitted for approval 10 days prior to the use of any concrete
15 mix.
16 B. Shotcrete shall have a minimum strength of 4,500 psi at twenty-eight days and have a
17 maximum water to cementitious ratio of 0.42.
18 C. Rebound material shall not be reused in any form for shotcrete.
19 D. If used by the Tank Contractor, the total volumetric air content of the shotcrete before
20 placement shall not exceed 7% (±1 %) as determined by ASTM C-173 or ASTM C-231.
21 E. Fine Aggregates:
22 1. The fineness modulus shall be between 2.7 and 3.0. A well -graded coarse sand shall
23 be used for all shotcrete applications.
24 2. The gradation for the fine aggregates shall adhere to the "Grading No. 1" requirements
25 listed in "Table 1.1 — Grading Limits for Combined Aggregates" of ACI 506.
26 F. All shotcrete shall have a maximum water soluble chloride ion concentration of 0.06% by
27 weight of cementitious material.
28 2.5 REINFORCING STEEL
29 A. Reinforcing steel shall be new billet steel Grade 60, meeting the requirements of ASTM
30 A615. Welded wire fabric and weldable reinforcing steel shall conform to ASTM A185 and
31 ASTM A706, respectively
32 B. Reinforcing steel shall be accurately fabricated and shall be free from loose rust, scale, and
33 contaminants, which reduce bond.
34 C. Reinforcing steel shall be accurately positioned on supports, spacers, hangers, or other
35 reinforcements and shall be secured in place with wire ties or suitable clips. Rebar chair
36 supports may be either steel with plastic tips, turned up legs or plastic.
37 D. Circumferential reinforcing shall be continuous through vertical joints of prestressed walls.
38 2.6 BASE RESTRAINT CABLES
39 A. The tank designer may elect to use base restraint cables to resist earthquake and/or wind
40 loads. If base restraint cables are used, base restraint cables shall be hot -dip galvanized
41 seven -wire strand and shall be manufactured in accordance with ASTM A416 prior to
42 galvanizing, and ASTM A475 after galvanizing. Only seven -wire strand will be allowed.
43 B. Hot -dip galvanized seven -wire strand shall have a nominal strand diameter of 0.375 in, 0.50
44 in or 0.60 in. 0.375 inch diameter strand shall have an MUS after galvanization of 21.36 kips
45 and a min. yield at 1 % extension of 15.60 ksi. 0.50 inch diameter strand shall have an MUS
46 after galvanization of 38.25 kips and a min. yield at 1 % extension of 28.00 ksi. 0.60 inch
47 diameter strand shall have an MUS after galvanization of 54.20 kips and a min. yield at 1 %
48 extension of 40.70 ksi. All strands shall have a minimum of weight of zinc coating of 0.85
49 ounces per square foot.
13000 - 9
01-18-0124 (IONA NORTH TANK)
SECTION 13000
PRESTRESSED CONCRETE WATER TANK
1 C. Neoprene sleeves for base restraint cables shall be closed -cell conforming to ASTM D1056,
2 Type 2, Class A, and Grade 3. The sleeves shall have a compression deflection limited to
3 25% at 9 to 13 psi, hardness of 60 to 80 durometer, a minimum tensile strength of 175 psi,
4 a minimum elongation of 180%, and a maximum compressive set of 35%.
5 2.7 MORTAR FILL AND NON -SHRINK GROUT
6 A. Mortar fill and non -shrink grout shall have a minimum compressive strength of 4,500 psi at
7 twenty-eight days, have a maximum water to cementitious ratio of 0.42 and meet all
8 requirements for concrete contained in this specification.
9 B. Portland cement grout will not be accepted.
10 2.8 ELASTOMERIC MATERIALS
11 A. A 9-inch minimum waterstop with centerbulb shall be polyvinyl chloride meeting the
12 requirements of the Corps of Engineers Specification CRD-C 572. Splices shall be made in
13 accordance with the Manufacturer's recommendations subject to the approval of the
14 Engineer. Waterstop shall be manufactured by;
15 1. Greenstreak Plastic Products Company, Inc.
16 2. Or equal.
17 B. Bearing pads shall be neoprene and have a minimum thickness of 0.75 inch. Neoprene
18 bearing pads shall have a hardness of 40 durometer, a minimum tensile strength of 1,500
19 psi, a minimum elongation of 500%, and a maximum compressive set of 50%. Pads shall
20 meet the requirements of ASTM D2000 Line Call -Out M 2 BC 410 Al 4 B14 or M 2 BC 414
21 A14 C12 F17 for 40 durometer material.
22 C. Sponge filler shall be closed -cell neoprene or rubber conforming to ASTM D1056, Type 2,
23 Class A, and Grade 1 or 3. Compression deflection limited to 25% at 2 to 5 psi.
24 D. Polysulfide or polyurethane sealant will be a two or three component elastomeric compound
25 meeting the requirements of ASTM C920. Sealants shall have permanent characteristics of
26 bond to metal surfaces, flexibility, and resistance to extrusion due to hydrostatic pressure.
27 Air cured sealants shall not be used.
28 E. The remaining voids below the wall, not taken up by the solid neoprene or natural rubber
29 pads, shall be filled with closed cell rubber pads and soft mastic to ensure a substantially
30 unrestrained free movement of wall and roof.
31 2.9 EXTERIOR COATINGS
32 A. An exterior coating shall be applied to the above grade exterior concrete wall surfaces and
33 the roof using Gaco Western's coatings as follows:
34 1. All coatings shall be applied by a certified GaCo installer and installed according to
35 Gaco recommendations,
36 2. 1st coat primer E5320 shall be applied at a rate of 200 sq ft per gallon,
37 3. 2nd and 3rd coats of polyurea U8782 shall be applied in 2 coats minimum totaling a 30
38 mil thickness,
39 4. 4th and 5th coats of silicon S20 shall be applied in 2 coats minimum totaling a 15 mil
40 thickness.
41 5. An or equal system may be considered upon documentation from Contractor showing
42 performance criteria and testing data of a proposed substitute system are equal to or
43 better than the Gaco products specified."
44 B. An Alternate exterior coating may be applied as follows:
45 1. An exterior PVC membrane may be used on the exterior of the tank. Manufacture
46 specifications for the membrane shall be submitted to Forsgren for approval prior to
47 use. A PVC membrane supplied from one of the following manufacture shall be used:
48 a. Ferrai
49 b. Versidag
13000 - 10
01-18-0124 (IONA NORTH TANK)
SECTION 13000
PRESTRESSED CONCRETE WATER TANK
1 c. Mehler
2 2.10 INTERIOR COATINGS
3 A. A water proof membrane shall be applied to the interior wall surface.
4 B. Membrane shall overlap on to the floor 12" and extend above the high water elevation 12".
5 C. Membrane shall be an interior water tight polyurea coating from Versa Flex Aqua Vers 405
6 with Aqua Vers 20 primer.
7 D. Other manufactures may be submitted to Forsgren for approval. Approval will be provided
8 if performance criteria and testing data are equal to or better than Versa Flex Aqua Vers
9 405 with Aqua Vers 20 primer.
10 2.11 APPURTENANCES
11 A. The Contractor shall provide and install all appurtenances as shown on the drawings.
12 Appurtenances shall include the following:
13 1. Inlet Pipe: 16"
14 2. Outlet Pipe: 16"
15 3. Overflow Piping and Weir: 16"
16 4. Roof Sleeve: 24"
17 5. Roof Hatch: A 4 feet x 4 feet minimum rectangular aluminum hatch with lockable,
18 hinged cover and curb frame. The hatch shall have a lift handle, padlock tab, padlock
19 and a cover hold open mechanism. All hardware shall be aluminum or stainless steel.
20 Locate hatch as shown on drawings.
21 6. Roof Ventilator: Fiberglass or aluminum, with stainless steel insect 20 x 20 screen,
22 minimum diameter 2 feet.
23 7. Interior Ladder: The ladder shall extend from the floor to the hatch. The ladder shall be
24 made out of 6061-T6 aluminum and have an OSHA -approved stainless steel fall
25 prevention device consisting of a sliding, locking mechanism and safety belt. Location
26 as shown on the drawings.
27 8. Exterior Ladder: The ladder shall extend from the final grade to the tank roof. The
28 ladder shall be made out of 6061-T6 aluminum.
29 9. Handrail: Provide handrail all sides of roof access. Handrail material shall be made out
30 of 6061-T6 aluminum.
31 PART 3 - EXECUTION
32 3.1 SAFETY
33 A. Every precaution shall be taken to keep personnel and visitors outside the prestressing
34 area.
35 B. At no time shall anyone stand in the line of stressed members.
36 C. No personnel are allowed outside of the tank, other than the prestressing crew, within 100
37 feet from the operation. Additional precautions shall be taken by Tank Contractor should
38 specified clearance not be available.
39 D. Where access to the site by unauthorized persons is outside the Tank Contractor's control,
40 while prestressing work is in progress, Tank Contractor shall erect protective fencing.
41 E. Tank Contractor to conform and enforce all Local and Federal OSHA safety rules and
42 regulations.
43 3.2 CLEARING, GRUBBING, AND STRIPPING
13000 - 11
01-18-0124 (IONA NORTH TANK)
SECTION 13000
PRESTRESSED CONCRETE WATER TANK
1 A. All trees, shrubs, brush, stumps, roots, and other unsuitable material shall be removed to a
2 minimum distance of 10 feet outside the edge of the tank foundation, plus additional areas
3 necessary for the tank construction. The limits of clearing shall be as shown on the
4 drawings and/or as approved by the Engineer.
5 B. No burning will be allowed unless approved by the Engineer and local authorities. All trees
6 and vegetation shall be disposed of off -site, unless approved otherwise by the Engineer.
7 C. All topsoil shall be stripped from the proposed construction work area and stockpiled on
8 site.
9 3.3 EXCAVATION AND BACKFILL
10 A. The Site Work Contractor shall excavate to such depths and widths to provide adequate
11 room for tank construction and onsite observation. A minimum working area of 6 feet
12 beyond the circumference of the tank foundation at an elevation ranging from 12 inches to
13 72 inches below the top of the tank foundation, as needed to expose rock, shall be
14 provided. Excavated material is not suitable for structural backfill material but may be
15 distributed on site with coordination of City staff.
16 B. The Contractor shall excavate to competent basalt using conventional excavation
17 equipment. The basalt surface shall be clean to a condition that can be obtained using
18 conventional excavation equipment. Excavation shall extend to 10 feet beyond the
19 circumference of the tank foundation.
20 C. After excavation is complete, the Engineer shall inspect the subgrade for conformance with
21 the original geotechnical report and its suitability for the tank foundation. Before any fill is to
22 be placed against rock surfaces, the rock shall be relatively free of all vegetation, dirt, clay,
23 boulders, scale, excessively cracked rock, loose fragments, ice, snow, and other
24 objectionable substances. All free water left on the surface of the rock shall be removed.
25 D. A concrete leveling course may be placed directly on the rock of the excavated foundation.
26 This concrete shall be mechanically anchored to the rock and these anchors shall be
27 continuous with the tank foundation.
28 E. The tank exterior shall be backfilled and rough graded to the contours shown on the
29 drawings. Material used for backfilling shall be locally available pit run material with a
30 maximum grain size not to exceed 6" and not more than 10" passing the #200 sieve. All fill
31 materials for backfill shall be approved by the Engineer and/or Owner and Geotechnical
32 Engineer.
33 1. Frozen material shall not be used for backfill nor shall fill material be placed on snow,
34 ice, or frozen material. Rock or concrete spoils (greater than 6 inches) shall not be
35 used in backfill within 10 feet of the tank foundation.
36 2. Backfill shall be placed in successive uniform layers not exceeding 8 inches, and shall
37 be compacted to 95% of the maximum laboratory density in accordance with ASTM
38 D698.
39 3. Only hand -operated, light- weight earth moving equipment may be operated on the
40 backfill material within a distance of 5 feet from the tank.
41 4. Earth moving equipment limited to a maximum size and weight of a CAT D4 dozer and
42 CAT 928G wheel loader can be operated on the backfill material beyond a 5 foot
43 distance from the tank wall.
44 F. The tank interior under the slab and within the foundation wall shall be backfilled with a'%
45 washed round rock placed directly on the exposed excavated rock layer below.
46 1. Fill shall be placed in 12 inch lifts and vibrated with a vibratory plate compactor to
47 achieve maximum consolidation of the rock.
48 2. At the top course of rock a filter fabric material shall be placed over the washed rock
49 and the final course of fill shall be a'% minus well graded road base.
50 3. Fill placement shall occur after achieving 70% design strength of the concrete
51 foundation wall.
13000 - 12
01-18-0124 (IONA NORTH TANK)
SECTION 13000
PRESTRESSED CONCRETE WATER TANK
1 G. Or, the tank interior under the slab and within the foundation wall shall be backfilled with a
2 minus well graded road base placed directly on the exposed excavated rock layer below.
3 1. Fill shall be placed in 8 inch lifts and compacted to 95% maximum dry density of ASTM
4 1557.
5 2. Fill placement shall occur after achieving 100% design strength of the concrete
6 foundation wall.
7 3.4 FLOOR
8 A. The floor and wall footings shall be constructed to the dimensions shown on the Approved
9 Shop Drawings.
10 B. Prior to placement of the floor reinforcing, a 6 mil polyethylene moisture barrier shall be
11 placed over the backfill base material. Joints in the polyethylene shall be overlapped a
12 minimum of 6 inches.
13 C. Prior to placement of the floor concrete, all piping that penetrates the floor shall be set and
14 encased in concrete.
15 D. Where PVC water stop is used, the vertical waterstop shall be placed and supported so that
16 the bottom of the center bulb is at the elevation of the top of the footing. The waterstop shall
17 be supported without puncturing any portion of the waterstop other than pre -manufactured
18 holes, grommets or hog rings for tying at 12 inches o.c. The waterstop shall be spliced
19 using a thermostatically controlled sealing iron and each splice shall be inspected using a
20 penknife prior to encasement in concrete. Spark testing of the welded joint shall not be
21 permitted.
22 E. Where hydrophilic water stop is used, placement shall be in accordance with manufactures
23 recommendations.
24 F. The floor shall be cured by applying one coat of curing compound, curing blankets and/or
25 flooding with water, and shall remain saturated for a minimum of seven days.
26 3.5 CONCRETE
27 A. All concrete shall be conveyed, placed, finished, and cured as required by pertinent ACI
28 standards.
29 B. Weather Limitations
30 1. Unless specifically authorized in writing by the Engineer, concrete shall not be placed
31 without special protection during cold weather when the ambient temperature is below
32 35 degrees Fahrenheit and when the concrete is likely to be subjected to freezing
33 temperatures before initial set has occurred and the concrete strength has reached 500
34 psi. Concrete shall be protected in accordance with ACI 306. The temperature of the
35 concrete shall be maintained in accordance with the requirements of ACI 301 and ACI
36 306. All methods and equipment for heating and for protecting concrete in place shall
37 be subject to the approval of the Engineer.
38 2. During hot weather, concreting shall be in accordance with the requirements of ACI
39 305.
40 3. Placement of concrete during periods of low humidity (below 50%) shall be avoided
41 when feasible and economically possible, particularly when large surface areas are to
42 be finished. In any event, surfaces exposed to drying wind shall be covered with
43 polyethylene sheets immediately after finishing, or flooded with water, or shall be water
44 cured continuously from the time the concrete has taken initial set. Curing compounds
45 may be used in conjunction with water curing, provided they are compatible with
46 coatings that may later be applied, or they are degradable.
47 C. Finishes
48 1. The tank shall be given the following finishes:
13000 - 13
01-18-0124 (IONA NORTH TANK)
SECTION 13000
PRESTRESSED CONCRETE WATER TANK
1 a. The floor slab shall receive a mechanical hard -trowel finish. The top of the wall
2 footing, exterior to the waterstop, shall receive a steel trowel or magnesium trowel
3 finish.
4 b. Column footings shall receive a steel trowel finish on the top surface and a form
5 finish on the sides.
6 c. Columns shall have a form finish.
7 d. The interior surface of the tank wall and roof shall have the following finish:
8 e. Formed — form finish,
9 f. Shotcrete — natural gun / muzzle finish suitable for interior coating.
10 g. The exterior surface of the roof shall receive a smooth finish and a form finish on
11 the bottom and edge surfaces suitable for exterior coatings.
12 h. Exterior shotcrete shall receive a natural gun /nozzle finish suitable for exterior
13 coatings.
14 D. Curing
15 1. Concrete shall be cured using water methods, sealing materials, or curing compounds.
16 Curing compounds shall not be used on surfaces to which decorative coatings, mortar,
17 or shotcrete is to be applied. Curing compounds used within the tank shall be suitable
18 for use with potable water.
19 E. Testing
20 1. For all concrete, two sets of five cylinders for the first 10 cubic yards, and one set of five
21 cylinders for every 50 cubic yards thereafter placed in the same day. Two cylinders
22 shall be tested at seven days, two at 14 days, and two at twenty-eight days, and one
23 held as a spare.
24 2. Slump, air content and temperature testing shall be performed on each truck.
25 3. All concrete testing shall be in accordance with ASTM C31 and C39. Contractor shall
26 make available all concrete trucks for testing by Owner representative. Contractor shall
27 also provide location for testing, disposal of excess testing materials and wash down
28 water. Owner will provide all testing reports to Contractor upon request. Contractor
29 may elected to provide concurrent concrete testing at the contractor's expense.
30 3.6 SHOTCRETING
31 A. Weather Limitations
32 1. Shotcrete shall not be placed in freezing weather without provisions for protection
33 against freezing. Shotcrete placement can start without special protection when the
34 temperature is 35 degrees Fahrenheit and rising, and shall be suspended when the
35 temperature is 40 degrees Fahrenheit and falling. The surface to which the shotcrete is
36 applied shall be free from frost. Cold weather shotcreting shall be in accordance with
37 ACI 506, ACI 301 and ACI 306.
38 2. Hot weather shotcreting shall be in accordance with the requirements of ACI 506, ACI
39 301 and ACI 305.
40 B. Coating Over Prestressed member
41 1. Each prestress member shall be individually encased in shotcrete. Shotcrete thickness
42 shall be sufficient to provide a clear cover over the strand of at least 3/8 inch.
43 2. Finish cover coat shotcrete shall be applied as soon as practical after the last
44 application of strand coat.
45 3. The minimum final shotcrete cover over the outermost prestressed member shall be 1.5
46 inches.
47 C. Placement of Shotcrete
13000 - 14
01-18-0124 (IONA NORTH TANK)
SECTION 13000
PRESTRESSED CONCRETE WATER TANK
1 1. Shotcrete shall be applied by automated shotcrete equipment using the wet mix
2 process only. Nozzles shall be kept mounted on power driven machinery enabling the
3 nozzle to travel parallel to the surface to be sprayed at a uniform linear or bi-directional
4 speed. The nozzle shall be kept at a uniform constant distance from the surface, always
5 insuring a right angle spray of the material to the surface. The high velocity impact shall
6 be developed pneumatically by injecting compressed air at the nozzle.
7 2. Shotcrete shall be applied by an ACI 506 certified nozzleman.
8 3. For localized touchup, manually applied shotcrete is allowed. The shotcrete nozzle shall
9 be held at a small upward angle not exceeding 5 degrees and constantly moving during
10 application in a smooth motion with the nozzle pointing in a radial direction toward the
11 center of the tank. The nozzle distance from the prestressing shall be such that
12 shotcrete does not build up or cover the front face of the strand until the spaces behind
13 and between the prestressing elements are filled.
14 D. Curing
15 1. Shotcrete shall be cured using water curing methods, sealing materials or curing
16 compounds at the option of the Tank Contractor. Curing compounds shall not be used
17 on surfaces to which decorative coatings, mortar or shotcrete is to be applied.
18 2. Water curing is not required should additional shotcrete be applied on the entire wall
19 surface within the following twelve hours.
20 3. Indiscriminate use of continuous water cure for intermediate layers shall be avoided.
21 4. Complete shotcrete surfaces, which do not receive any additional coatings, may be
22 water cured for a period of at least seven days by encapsulating the shotcrete inside of
23 plastic sheeting.
24 E. Testing
25 1. Shotcrete applied with an automated process shall be in accordance with ACI 301 and
26 conform to Division 13, Section 3.08.E "Concrete Testing" of these specifications.
27 3.7 EXTERIOR COATINGS
28 A. The bid shall be based on provision of a white exterior coating, in the event Owner selects
29 an alternate color for the exterior wall coating resulting in an increase in cost, a Change
30 Order shall be negotiated at the time of selection.
31 B. All Work shall be performed by workmen skilled in the application of these types of
32 products. The Manufacturer's application instructions shall be submitted to the Engineer for
33 approval. The Contractor shall confer with the Manufacturer's representatives regarding
34 application techniques and shall follow the Manufacturer's instructions implicitly.
35 C. The concrete surface to be coated shall be clean, free of all laitance, dirt, grease, or other
36 foreign materials. All defective surfaces shall be filled and/or repaired. Application shall be
37 in full accordance with the manufacturer's instructions or as amended by the Engineer.
38 3.8 INTERIOR COATINGS
39 A. All Work shall be performed by workmen skilled in the application of these types of
40 products. The Manufacturer's application instructions shall be submitted to the Engineer for
41 approval. The Contractor shall confer with the Manufacturer's representatives regarding
42 application techniques and shall follow the Manufacturer's instructions implicitly.
43 B. The concrete surface to be coated shall be clean, free of all laitance, dirt, grease, or other
44 foreign materials. All defective surfaces shall be filled and/or repaired. Application shall be
45 in full accordance with the manufacturer's instructions or as amended by the Engineer.
46 3.9 DISINFECTION
47 A. The Contractor shall, at the completion of tank construction, thoroughly clean the interior of
48 the tank.
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PRESTRESSED CONCRETE WATER TANK
1 B. The Contractor shall notify the Engineer prior to disinfecting the tank. Disinfection shall
2 meet with the approval of the Engineer, AWWA C652, and the appropriate state agency.
3 C. The tank floor and interior of the wall shall be disinfected by using a solution of chlorine and
4 water per Method 3 of AWWA C652.
5 D. Prior to placing the tank in service, a bacteriological test shall be taken, and successful
6 results received. Testing shall be by an independent testing laboratory at the expense of the
7 owner.
8 E. Water for the disinfection testing will be provided by the City.
9 3.10 WATERTIGHTNESS TEST
10 A. Upon completion, the tank shall be tested to determine watertightness. The tank shall be
11 filled with potable water to the maximum level. Water will be furnished to the tank by the
12 owner. The test shall consist of measuring the liquid level over the next twenty-four hours to
13 determine if any change has occurred. If a change is observed and exceeds the maximum
14 allowance, the test shall be extended to a total of five days. If at the end of five days the
15 average daily change has not exceeded the maximum allowance, the test shall be
16 considered satisfactory.
17 B. Watertightness testing will be determined by deferential water surface elevation
18 measurements for a period of twenty-four hours. Surface water elevation shall not drop in
19 excess of 0.125". If the liquid elevation drop exceeds this amount, it shall be considered
20 excessive, and the tank shall be repaired and retested.
21 C. Damp spots will not be permitted at any location on the tank wall. Damp spots are defined
22 as spots where moisture can be picked up on a dry hand. All such areas shall be repaired
23 as necessary.
24 D. Measurable flow, damp spots or standing water on the wall footing are not permissible and
25 shall be corrected.
26 3.11 CLEAN-UP
27 A. The premises shall be kept clean and orderly at all times during the work. Upon completion
28 of construction, the Tank Contractor shall remove or otherwise dispose of all rubbish and
29 other materials caused by the tank construction operation. The Tank Contractor shall leave
30 the premises in as good a condition as it was found.
31
32 END OF SECTION
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