Page 1
Introduction
The Crom Corporation has been building
PRESTRESSED CONCRETE TANKS since
1953. Our chief purpose is to provide a
turnkey design and construction service
stressing good workmanship, structural
integrity, pleasing appearance, greatest
economy and watertightness. CROM® tanks
are known for superb longevity and low
maintenance costs. This publication
describes our company and its operations.
The tanks featured to the right have been
in service for several decades.
1
1 City of Selma, Alabama
Three Digester Tanks
50’ x 33’
Consulting Engineers:
Rader & Associates
Built in 1967
2 City of Ocala, Florida
Three Digester Tanks
45’ x 24’3”
Two Trickling Filters
120’ x 7’11”
One Final Sedimentation Tank
40’ x 8’8”
Consulting Engineers:
Russell & Axon
Built in 1955
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COVER PHOTOS:
1 Department of Veteran Affairs
Gainesville, Florida; Malcolm Randall
VA Hospital
750,000-Gallon Water Storage Tank
42’ x 72’4” with dome and 650 GPM aerator
Consulting Engineers:
Polyengineering, Inc.
2 Metro Water & Sewer Department
Nashville,Tennessee
10,000,000-Gallon Equalization Tank
195’ x 44’10” with dome
Consulting Engineers:
Brown & Caldwell
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3 City of Fernandina Beach, Florida
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1,500,000-Gallon Elongated Aeration Tank
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221’ long x 84’ wide x 11’9” high
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Consulting Engineers:
Owner is Engineer
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4 City of Belleview, Florida
Belleview WWTP
Two 600,000-Gallon SBR Tanks
72’ x 21’
Consulting Engineers:
Barnes, Ferland & Associates, lnc.
3
4
5
5 Loudoun County Sanitation Authority
Ashburn,Virginia; Broad Run WRF
Two 620,000-Gallon Anaerobic Digesters
50’ x 63’11” with conical roofs
Consulting Engineers:
CH2M Hill
The Crom Corporation • 250 SW 36th Terrace • Gainesville, FL 32607 • Telephone (352) 372-3436 • FAX (352) 372-6209 • www.cromcorp.com
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Page 2
History of Prestressed
Concrete Tanks
Circular prestressed concrete tanks have been in various stages
of development and perfecting for decades. Early systems used in the
United States called for the use of cast-in-place concrete in the core
wall of the tank and steel rods with turnbuckles as the prestressing
elements. Although theoretically this approach to circumferentially
prestressed concrete tanks was sound, deficiencies in placement of
concrete together with insufficient residual compression in the core
wall brought about modifications and improvements.
In the early 1930’s, the matter was fully understood when
J.M. Crom, Sr. began the development of what was later to become
the COMPOSITE system of tank wall construction, using a steel
shell cylinder with shotcrete encasement for the core wall, and high
strength wire for the prestressing elements.
Successors to Mr. Crom have over the years improved and
perfected the COMPOSITE system for tank wall construction. These
improvements have included the selection of better construction
materials, together with ever-improving design and construction
procedures. Consideration was given to:
• Ready-mixed concrete and pneumatically applied
shotcrete in combination with a steel shell diaphragm.
• Rods, cables and high-strength wires for purposes
of prestressing.
• Emulsion type sealants, polysulphides, polyurethanes,
and epoxies for sealing the steel shell diaphragm.
• Wall base joints using conventional waterstops; special
bearing pad and waterstop combinations; and monolithic
floor-wall joint connections.
Emerging from all of these was the development of the prestressed
COMPOSITE wall system:
The steel shell diaphragm was found to be the most
foolproof means for making the core wall watertight.
•
• Shotcrete with its high cement factor and low water/cement
ratio had greater corrosion inhibition, impermeability and
strength than conventional concrete.
• High-strength wire could be used to more accurately
apply prestressing forces and could be better protected
from corrosion and mechanical damage.
In the early 1950’s, J.M. Crom, Sr. and three associates, Ted Crom,
Jack Crom, Jr., and Frank Bertie, established The Crom Corporation,
with headquarters in Gainesville, Florida, for the prime purpose of
perfecting the design and construction techniques for tanks with
composite walls. Since then, their successors have continued the
tradition of excellence initiated by the company’s founders.
The company has constructed in its own name and with its own
forces over 4,000 circular and elongated PRESTRESSED CONCRETE
TANKS.
History ...continued
Page 3
In the due course of time, the features in the composite wall design
using diaphragm, shotcrete, and high strength wire were incorporated
in American Water Works Association Standard D110 “Wire- and
Strand-Wound, Circular, Prestressed Concrete Water Tanks” and
designated as “Type II core wall: Shotcrete with a Steel Diaphragm.”
For all practical purposes, as we continue our description of
CROM® tanks in this publication, the terms “Prestressed Concrete
Tanks with Composite Wall” and “AWWA D110 Tanks with Type II
wall” are synonymous.
(Left)
Steel Shell Diaphragm
(Middle)
Shotcrete
(Right)
High Strength
Prestressing Wires
City of Gainesville, Florida
Three 5,000,000-Gallon
Reservoirs
160’ x 33’3” each.
Tanks Built in 1968 & 1972:
Consulting Engineers:
CH2M Hill
(formerly Black, Crow
& Eidsness, Inc.)
Tank Built in 1992:
Consulting Engineers:
CDM Smith (formerly Camp
Dresser & McKee, Inc.)
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Page 4
Prestressed Concrete
Tank Design - AWWA D110
Type II Composite Wall:
“Shotcrete with a Steel Diaphragm”
The Crom Corporation has developed tank technology with the
finest attributes:
Guaranteed Watertightness
Structural Integrity
Greatest Economy
Best Appearance
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•
•
•
• WATERTIGHTNESS
Watertightness of the AWWA D110 Prestressed Concrete
Tank with Type II Composite wall is made possible by combined
performance of a steel shell diaphragm, shotcrete encasement, and
wire prestressing.
The steel shell extends continuously the full height of the tank
wall, thus precluding by positive means any through-wall leakage.
The diaphragm has no horizontal joints. The vertical joints which
connect the steel shell panels are sealed by epoxy injection after
the diaphragm is encased inside and outside with shotcrete.
The corrugations in the steel cylinder, running in a vertical direction,
provide a mechanical bond between the diaphragm and the shotcrete
encasement. Mild steel reinforcement is included to resist bending
moments, shrinkage, and temperature stresses. Circumferential
prestressing assures permanent ring compression in the tank
core wall.
• STRUCTURAL INTEGRITY
The Crom Corporation designs its structures under the
supervision of professional engineers; trains and certifies its key
employees; selects and uses the best available construction materials;
and adheres rigidly to high standards of quality construction.
• ECONOMY
Economy is a natural by-product of the AWWA D110 Prestressed
Concrete design with Type II Wall – lesser quantities of materials and
labor are utilized than is possible under conventional reinforced
concrete design.
Of greater significance is the quality of permanence inherent in
the construction materials used. Shotcrete is a durable, impermeable,
high-strength building material whose long life under minimum
maintenance procedures is universally recognized.
Under most operating conditions, interior surfaces of the tank do
not require painting. This is a major cost benefit. Exposed exterior
surfaces are usually painted for beautification.
• APPEARANCE
In AWWA D110 Prestressed Concrete Tanks with Type II Walls,
the soft texture of the shotcrete finish assures lasting beauty with a
minimum of care. The low silhouette dome roof, pleasing in line and
shape, completes the structure’s architectural appeal.
Prestressed Concrete Tank
AWWA D110 Type II Composite Wall Design:
“Shotcrete with a Steel Diaphragm”
Page 5
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Page 6
Method of Company
Operations
The Crom Corporation is a highly specialized construction
company that devotes its efforts to engineering design and
complete construction of PRESTRESSED CONCRETE TANKS.
Its design/build operations include:
• Tank Design
• Reliable Preliminary Cost Estimates
• Strict Specifications
• Complete Tank Construction
• Expert Workmanship
• Five-Year Guarantee
TANK DESIGN
The Crom Corporation assists the client by submitting, upon
request, preliminary designs for the prestressed concrete tanks
required for the project.
Close coordination with the client permits early and accurate
engineering decisions regarding tank dimensions, piping, sumps,
launders and other appurtenances, including accommodations
for equipment.
This service is provided without cost or obligation. It ensures a
well coordinated project from early design to full construction stage.
RELIABLE PRELIMINARY
COST ESTIMATES
As part of its service, The Crom Corporation offers reliable
cost estimates at preliminary stages of design. This allows the
consulting engineer and the owner to evaluate the economy of the
PRESTRESSED CONCRETE design in comparison with competing
construction techniques.
Preliminary estimates provided by The Crom Corporation
are accurate and reliable. Within the limits of given time, project
conditions, general economic conditions and scope of work
envisioned, The Crom Corporation will not exceed its early
estimate when the project is brought to the point of bidding.
STRICT SPECIFICATIONS
Page 7
The Crom Corporation adheres to the highest standards of
professional engineering and construction. Tank structures are
designed and built in accordance with applicable sections of:
• ACI 372 Design and Construction of Circular Wire and
Strand Wrapped Prestressed Concrete Structures, published
by American Concrete Institute.
• AWWA D110 Wire- and Strand-Wound Circular,
Prestressed Concrete Water Tanks; Type II Wall: Shotcrete with
a Steel Diaphragm, published by the American Water Works
Association.
Design drawings and calculations prepared by The Crom
Corporation will carry the seal of one of the company’s full-time
registered professional engineers. The installations shown in this
publication are typical of tanks built under these strict specifications.
Florida Power & Light Company
5,000,000-Gallon Reclaimed Water
Tank
120’ x 59’2” with dome
Consulting Engineer:
Mathews Consulting, Inc.
New Hanover County Water &
Sewer District
Wilmington, North Carolina
Two 1,000,000-Gallon Finished
Water Storage Tanks
100’ x 17’6” with dome
Consulting Engineer:
Arcadis
Town of Braselton, Georgia
Two 1,200,000-Gallon Sequential
Batch Reactors
92’1” x 24’
600,000-Gallon Aerobic Digester
65’3” x 24’6”
Consulting Engineer:
Engineering Management, Inc.
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COMPLETE TANK CONSTRUCTION
The Crom Corporation provides a complete tank construction
service. The company prefers no division of responsibility with respect
to the tank structure itself. As a consequence, tanks are built totally
by The Crom Corporation, including wall footings, floor slab, circular
wall, dome roof, and other such appointments as are required for the
structure. By avoiding a division of responsibility, the consulting
engineer and the owner can proceed with confidence that the tank
will be built expertly and the responsibility for its performance will
be clearly shouldered by The Crom Corporation.
1
The floor of the prestressed tank is a heavily reinforced
membrane concrete slab. This view illustrates placement of floor
concrete, reinforced with mild steel bars: a strong foundation.
2 Steel shell diaphragm is erected on a system of formwork
especially designed for this purpose. Steel shell extends continuously
the full height of the tank to insure watertightness. To avoid joint
sealing problems, no horizontal splices are allowed in the diaphragm.
Vertical joints in the steel shell are sealed watertight by epoxy
injection.
Exterior encasement of the steel shell is accomplished with
3
shotcrete, which is pneumatically placed concrete. The core wall of
the tank is built up to its full thickness by applying successive layers of
shotcrete.
4
The wall formwork has been removed and the inside face of
the diaphragm is now encased with shotcrete. To insure good
workmanship, all shotcrete nozzlemen are certified by the American
Concrete Institute.
Vertical reinforcing bars are placed to design requirements and
5
will later be encased in shotcrete. Once this encasement is complete,
the tank wall is ready for epoxy injection of the vertical joints in the
encased diaphragm.
6
Dome roof construction is undertaken with the aid of a system of
forms made to the accurate curvature of the dome shell. Ordinarily,
the dome has a rise from springline to apex of 1/10th the diameter of
the tank.
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Page 10
EXPERT WORKMANSHIP
A hallmark of The Crom Corporation business style is the high
standard of quality workmanship required of its field crews. The
company over a period of many years has thoroughly trained field
construction personnel totaling more than 500 people who have
become experts in tank construction. Unlike work in other fields,
construction of tanks for water service is critical in that leakage
cannot be tolerated.
By constant control of its field operations, The Crom Corporation
is able to guarantee the highest quality of workmanship in terms of
watertightness, appearance, and dimensional accuracy of its structures.
Because the company specializes in one area of construction, the
high risk often associated with tank construction is overcome.
Inspection of tanks built as early as 1953 indicates that these
vessels have endured the test of time and arduous service.
7
Once the roof formwork is completed with an overlay of
sheathing, reinforcement is placed.
8
The free-span dome roof is constructed of cast-in-place
concrete. This view shows dome concrete being placed by the
pumpcrete method.
9 Both the core wall and the free-span dome roof are
circumferentially prestressed using high-strength steel wire
wrapped around the tank in a continuous helix. Wall prestressing
is designed to carry the tank’s hydraulic load, while dome ring
prestressing resists the horizontal forces of roof live and dead loads.
10 To avoid over-stressing or under-stressing of the tank, the
tension in the wire is accurately measured to within 2% accuracy
by the use of a direct-reading electronic digital stressometer.
11 In order to afford complete protection for the prestressing
elements, a shotcrete covercoat is placed over the wire, permanently
bonding the wire to the tank wall. Whenever two or more layers
of prestressing steel are required, a flash coat of shotcrete separates
the layers. Once the cover coat has been finished, the tank is
structurally complete.
12 Final stage of construction involves the erection of accessories
and painting of the exterior surfaces for decorative purposes.
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FIVE-YEAR GUARANTEE
The Crom Corporation guarantees workmanship and materials
on the structural portion of its tanks for a five year period. If leakage
or other defects appear within the five year period, The Crom
Corporation promptly makes repairs at its own expense upon
written notice by the owner that such defects have been found.
The tanks illustrated on these pages, like all structures built by
The Crom Corporation, carry this 5-year guarantee.
It is common knowledge among consulting engineers and owners
that representatives of The Crom Corporation frequently inspect
tank installations long after they have been built in an effort to verify
that both the owner and the consultant continue to be pleased
with the project.
The Crom Corporation is available on short notice anywhere
in its area of operations for consultations or inspections.
City of Whiteville, North Carolina
Whiteville WWTP
856,000-Gallon Sludge Storage
Tank
92’ x 20’
152,000-Gallon Aerobic Digester
38’ x 20’
Consulting Engineers:
Green Engineering, PLLC
Georgia Department of Water
Services
Yellow River Water Reclamation
Facility
Lilburn, Georgia
Two 20,000,000-Gallon Equalization
Tanks
260’ x 52’6” with domes
Consulting Engineers:
Jordan, Jones & Goulding
CH2M Hill
Precision Planning, Inc.
City of Harrisonburg,Virginia
Tower Street Reservoir
8,000,000-Gallon Water Storage
Tank
140’ x 70’ with dome
Consulting Engineers:
Wiley/Wilson
Page 13
City of Jacksonville Beach, Florida
Four 1,430,000-Gallon Sequential
Batch Reactors
97' x 28'
Consulting Engineers:
Waitz & Moye, Inc.
City of St. Cloud, Florida
Northeast Water Repump Station
750,000-Gallon Water Storage
Tank
85’ x 17’8” with dome
Consulting Engineers:
Reiss Engineering
Gwinnett County Board of
Commissioners
Lower Big Haynes Creek
Pump Station
Loganville, Georgia
4,000,000-Gallon Wastewater
Equalization Tank
125’ x 43’8” with dome
Consulting Engineers:
Gresham Smith and Partners
Hillsborough County Board of
County Commissioners
Tampa, Florida
Two 5,000,000-Gallon Water
Storage Tanks
160’ x 33’3” with domes
Consulting Engineers:
AECOM (Formerly Boyle Engineering
Corporation)
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Typical Installations
Water supply systems, wastewater treatment plants, and industrial
installations create corrosive environments with varying degrees of
severity. These facilities derive great benefits from the permanent and
maintenance-free nature of PRESTRESSED CONCRETE TANKS .
Over 4,000 tanks have been built by The Crom Corporation
ranging in capacity from 25,000 gallons to 21 million gallons. These
tanks are employed in applications virtually without limit.
Marion County Utilities
Department
Stonecrest Subregional WWTP
Summerfield, Florida
One of Two 1,117,000-Gallon
Wastewater Package
Treatment Tanks
110' x 16'6”
Consulting Engineers:
GAI Consultants, Inc.
Loudoun County
Sanitation Authority
Ashburn,Virginia
Two 1,800,000-Gallon
Permeate Tanks
65’6” x 70’3” with dome
Consulting Engineers:
CH2M Hill
Stafford County Department
of Public Utilities
Aquia WWTP – Stafford,Virginia
Two Aeration Reactors
154’ x 18’6”
Secondary Clarifier
175’8” x 15’4”
Consulting Engineers:
Parsons
Water Reservoirs
Page 15
PRESTRESSED CONCRETE RESERVOIRS are usually built with
free-span dome roofs of concrete construction. Accessories, including
ventilator, hatch cover, liquid level indicator, and interior ladder, are of
fiberglass construction. Exterior ladder is fabricated aluminum. These
features insure freedom from maintenance problems. All accessories
use stainless steel fasteners throughout.
The typical projects illustrated here exemplify the functional beauty
of reservoirs built by the CROM® system.
Notla Water Authority
Blairsville, Georgia
500,000-Gallon Clearwell
73’ x 21’2” with dome
Consulting Engineers:
G. Ben Turnipseed Engineers, Inc.
South Walton Utility Co., Inc.
Walton County, Florida
2,000,000-Gallon Water Storage
Tank
85’ x 47’4” with dome
Consulting Engineers:
Baskerville-Donovan, Inc.
City of Cape Coral, Florida
12,000,000-Gallon Water Storage
Tank
210’ x 46’3” with dome
Consulting Engineers:
MWH Americas
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Water Tanks with
Aerators
Reinforced plastic, widely known as fiberglass, is ideally suited
for applications in water, wastewater, and industrial plants, where
corrosion is a serious consideration. One such application is the
aeration of water for removal of hydrogen sulphide using a natural
draft tray aerator.
Since aeration and storage of water are often complementary
operations, installations which combine fiberglass aerators and
CROM® PRESTRESSED CONCRETE TANKS are both attractive
and efficient.
Because of the release of hydrogen sulphide gases during the
aeration process, the non-submerged interior concrete surfaces of
these tanks may be subject to corrosive attack, and should be
protected. This is often accomplished by poly-lining or coating the
concrete surfaces above the high water line, or by exhaust fans, or by
submerging the free-board surfaces (wall and roof) so as to achieve a
self-washing effect. Periodic inspections should be made to evaluate
the condition of these tanks.
City of Kissimmee
Southwest WTP
2,000,000-Gallon Water
Storage Tank
100’ x 34’1” with dome
and 12,000 GPM Aerator
Consulting Engineers:
Jacobs
Southlake Utilities, Inc.
Clermont, Florida
1,000,000-Gallon Self-Washing
Water Storage Tank
80’ x 26’7” with flat roof and
5,000 GPM Aerator
Consulting Engineers:
Sambamurthi Munipalli, P.E.
Page 17
Dauphin Island Water & Sewer
Authority
Dauphin Island, Alabama
1,000,000-Gallon Water Storage
Tank
80'4” x 29’ with dome and
1,900 GPM Aerator
Consulting Engineers:
ADL/Constantine Engineering
Jacksonville Electric Authority
Jacksonville, Florida
Cecil Commerce Center
2,000,000-Gallon Water Storage
Tank
138' x 19' with dome and 20,000 GPM
Aerator
Consulting Engineers:
MWH Americas, Inc.
City of Haines City, Florida
Two 500,000-Gallon Water Storage
Tanks
60' x 23'8" with domes and 5,000 GPM
Aerators
Consulting Engineers:
Envisors Consulting, LLC
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Page 18
Tanks with Architectural
Treatment
Utility, low maintenance costs, watertightness, and beauty
are all attributes of PRESTRESSED CONCRETE TANKS built by
The Crom Corporation.
Because of their proximity to sensitive residential or downtown
neighborhoods, some installations demand superlative appearance.
In these situations, CROM® PRESTRESSED CONCRETE TANKS with
architectural treatment are ideal.
James City Service Authority
Williamsburg,Virginia
Two 500,000-Gallon Water Storage
Tanks
55' x 28'2" with domes
Consulting Engineers:
AES Consulting Engineers/
NICE Engineering
City of Tuscaloosa, Alabama
Jerry Plott WTP
1,000,000-Gallon Clearwell Tank
90' x 24'5-1/2” with dome
Consulting Engineers:
CH2M Hill
Page 19
City of Boca Raton, Florida
5,000,000-Gallon Reclaimed Water
Tank
155’ x 35’6” with dome
Consulting Engineers:
Mathews Consulting, Inc.
Broward County Board of County
Commissioners
Miramar, Florida
1,500,000-Gallon Water Storage
Tank
90' x 32'2" with dome
Consulting Engineers:
Hazen and Sawyer
City of Miramar, Florida
Weston Pump Station
3,000,000-Gallon Water Storage
Tank
110' x 42'3” with dome
Consulting Engineers:
Tetra Tech
Knoxville Utilities Board
Knoxville,Tennessee
Mark B. Whitaker WTP
Two 4,000,000-Gallon Clearwells
135' x 38'3" with dome
Consulting Engineers:
Burns and McDonnell
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Page 20
(Left)
Town of Chatom, Alabama
Two 175,000-Gallon Sequential
Batch Reactors
36' x 23'
One 75,000-Gallon Equalization
Tank
33’ x 11’6”
Consulting Engineers:
ADL, Inc./Constantine
Engineering, Inc.
(Right)
Manchester,Tennessee
One 95,000-Gallon Sludge
Thickener Tank
34’ x 14’
Two 650,000-Gallon Anaerobic
Digesters
68’ x 24’
One 750,000-Gallon Clarifier Tank
89’ x 16’ (not shown)
Consulting Engineers:
Griggs & Maloney, Inc.
Emerald Coast Utilities Authority
(ECUA)
Cantonment, FL
One 3,000,000-Gallon Influent
Equalization Tank
140' x 28’
Four 1,500,000-Gallon Clarifiers
125’ x 16’6”
Two 1,500,000-Gallon Sludge
Storage Tanks
120’ x 20’
Two 2,150,000-Gallon Effluent
Equalization Tanks
110’ x 28’2” with domes
Two 10,000,000-Gallon Reject
Storage Tanks
260’ x 27’2”
One 4,700,000-Gallon Effluent
Equalization Tank
156’ x 32’10” with dome
Consulting Engineers:
Baskerville-Donovan, Inc.
Tanks for
Wastewater Treatment
Vessels required in wastewater treatment plants include
equalization tanks, sludge digesters, effluent storage tanks, clarifiers,
aeration tanks, SBR tanks, and package treatment tanks. Each of these
provides an ideal application for the PRESTRESSED CONCRETE
design, which permits economical construction and freedom from
the usual corrosion problems encountered in wastewater treatment
facilities. Installations depicted on these pages are representative of
the superior structures built by The Crom Corporation.
Page 21
Utilities Board of the City of
Muscle Schoals, Alabama
85,000-Gallon Pre-Aeration Tank
30’ x 18’
Consulting Engineers:
Garver, LLC
Metro Water Services
Nashville,Tennessee
Five 2,800,000-Gallon Anaerobic
Digesters
108’ x 40’6”
Four 440,000-Gallon DAFT Tanks
65’ x 17’7”
Consulting Engineers:
Earth Tech/Black & Veatch
Paulding County Board of
Commissioners
Hiram, Georgia
470,000-Gallon Sludge Storage
Tank
64' x 19'6"
Consulting Engineers:
Arcadis
City of Ottawa
Ontario, Canada
Two 3,300,000-Gallon Modified
Egg-Shaped Anaerobic Digesters
82'1/4” x 117’9-3/8” with conical floor
and conical roof
Consulting Engineers:
CH2M Hill
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Tanks for Reuse Water
More and more communities are utilizing municipally treated
wastewater in an effort to augment their water supply. The Crom
Corporation built its first reuse water tank in 1976 for Pinellas
County, Florida. Consultants have recognized the advantages of
CROM® PRESTRESSED CONCRETE TANKS ever since. CROM®
tanks can be partially or fully buried, or easily embellished with
architectural treatments. Along with in-plant installations, reuse
tanks can be built within residential areas, or on golf courses, or on
agricultural lands: wherever the demand for irrigation water is the
greatest. Typical of such installations are the tanks pictured here:
watertight, attractive, and permanent.
Primland Resort
Meadows of Dan,Virginia
500,000-Gallon Reuse Water
Tank
75’ x 15’8” with flat roof
(left-tank under construction;
right-finished installation )
Consulting Engineers:
Draper Aden Associates, Inc.
Pinellas County Utilities
Largo, Florida
5,000,000-Gallon Reuse Water
Storage Tank
155’ x 35’6” with dome
Consulting Engineers:
Parsons Engineering Science, Inc.
Florida Power & Light Company
West Palm Beach, Florida
3,000,000-Gallon Reclaimed
Water Tank
160' x 20’ with dome
Consulting Engineers:
Jordan, Jones & Goulding, Inc.
Page 23
City of Clearwater, Florida
5,000,000-Gallon Reclaimed Water
Tank
140’ x 43’5” with dome
Consulting Engineers:
McKim & Creed Engineers, P.A.
City of Apalachicola, Florida
750,000-Gallon Reuse Water Tank
70’ x 26’1” with dome
Consulting Engineers:
Baskerville-Donovan, Inc.
City of Tavares, Florida
5,000,000-Gallon Reclaimed
Water Tank
160’ x 33’3” with dome
Consulting Engineers:
Malcolm Pirnie, Inc.
On Top of the World
Clearwater, Florida
2,400,000-Gallon Reuse Water
Storage Tank
120’ x 28’6” with dome
Consulting Engineers:
Jones Edmunds & Associates, Inc.
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Page 24
Circular and Elongated
Prestressed Concrete
Oxidation Tanks
In 1978, The Crom Corporation was given the opportunity to
design and build a pair of CIRCULAR tanks for the City of Deland,
Florida, constructing a clarifier tank in the center of the vessel, and
a dual oxidation channel along the outer ring. The tanks have been
watertight and free from maintenance problems. All walls are of the
Composite Design, equivalent to AWWA Standard D 110 Type II Wall
System: “Shotcrete with a Steel Diaphragm.”
By the mid 1980’s, Design Engineers became interested in
ELONGATED aeration tanks with separate multiple clarifiers.
CROM® engineers developed unique design and construction methods
to accommodate the different aeration processes being specified.
These ELONGATED tanks feature COMPOSITE walls per AWWA
Standard D 110 Type II: “Shotcrete with a Steel Diaphragm,” together
with linear and circumferential prestressing. Over the years CROM®
ELONGATED PRESTRESSED CONCRETE TANKS have become
noted for their outstanding concrete crack control, watertightness,
appearance, longevity and very low maintenance requirements.
City of DeLand, Florida
Two Oxidation Tanks/Clarifiers
Outer Wall 153’10” x 11'6”
Inner Wall 75' x 14'
Consulting Engineers:
Jones Edmunds & Associates, Inc.
(formerly Smith & Gillespie Engineers)
City of Daytona Beach, Florida
Two-Train Elongated 5-Stage
Treatment Basin
538’8” long x 243' wide x 17’9” wall
height
Consulting Engineers:
McKim & Creed Engineers, P.A.
City of Alachua, Florida
One 1,200,000-Gallon Elongated
Oxidation Tank
233'3" long x 51' wide x 14'6"
wall height
One 5,000,000-Gallon Reclaimed
Water Tank
150’ x 37’-10” with dome (not shown)
Two 450,000-Gallon Clarifiers
70’ x 15’8” (not shown)
Consulting Engineers:
Jones Edmunds & Associates, Inc.
Page 25
(Left)
City of Bunnell, Florida
500,000-Gallon Elongated
Oxidation Tank
132' long x 36' wide x 14'10" wall height
990,000 Reuse Water Tank
80' x 26'4” (not shown)
Consulting Engineers:
Mittauer & Associates, Inc.
(Right)
Town of Callahan, Florida
One 820,000-Gallon Elongated
Oxidation Tank
206'3” long x 40'6” wide x 13'9"
wall height
Two 110,000-Gallon Clarifier Tanks
35' x 15'8”
One 170,000-Gallon Digester
45’ x 15’ (not shown)
Consulting Engineers:
Mittauer & Associates, Inc.
City of Fort Payne, Alabama
One 2,240,000-Gallon
Elongated Oxidation Tank
301'4” long x 144'8” wide x 14'6"
wall height
Two 745,557-Gallon Clarifier Tanks
90' x 15'8”
Consulting Engineers:
Ladd Environmental Consultants, Inc.
City of Plant City, Florida
Three 4,000,000-Gallon
Elongated Aeration Basins
262' long x 117' wide x 22'6" wall height
Three 1,500,000-Gallon
Clarifier Tanks
130' x 15'11”
Consulting Engineers:
Arcadis
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Page 26
Tanks for Industrial
Applications
The problem of maintenance is particularly severe in many
industrial installations. The corrosive atmosphere in chemical plants
and paper mills requires great care in the selection of construction
materials and techniques that will not be susceptible to deterioration.
PRESTRESSED CONCRETE vessels built with composite walls have
performed well as mill water treatment tanks and reservoirs, chemical
processing basins, and pulp storage chests lined with tile or fiberglass.
Industrial plants build effluent water treatment facilities to combat
stream pollution. As part of these installations, effluent treatment
tanks are ideally built by the CROM® system.
Chicken Processing Plant
Central Georgia
3,000,000-Gallon Wastewater
Treatment Tank
175’ x 18’
400,000-Gallon Wastewater
Treatment Tank
75’ x 17’2”
500,000-Gallon Wastewater
Treatment Tank
75’ x 18’
40,000-Gallon Wastewater
Treatment Tank
20’ x 18’
Consulting Engineers:
Chas. N. Clark Associates, Ltd.
Copper Recycling Plant
South Carolina
21,000,000-Gallon Stormwater
Collection Tank
378’2” x 26’
Consulting Engineers:
URS (formerly B.P. Barber &
Associates) and Energaes
Consulting; A Joint Venture
Page 27
Citrus Processing Plant
Leesburg, Florida
1,400,000-Gallon Digester
100' x 24'6"
6,700,000-Gallon Wastewater
Treatment Tank
215'6" x 24'6" with concentric
clarifier wall 74'9" x 24'6"
Consulting Engineers:
U.S. Filter
Central Alabama Chemical Plant
One Clarifier Tank
25’ x 15’
One Clarifier Tank
40’ x 15’6”
One Stormwater Tank
65’ x 18’
One Equalization Tank
78’ x 20’
Two Aeration Tanks
65’ x 18’
Consulting Engineers:
Atkins
Nebraska Bioclean-Mead LLC
Mead, Nebraska
Two 4,000,000-Gallon Digesters
131’ x 40’ with domes
Two 500,000-Gallon Effluent Tanks
65’ x 20’6” with domes
Consulting Engineers:
Biothane Corporation
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Page 28
Tanks for Thermal
Energy Storage
Thermal energy storage is a process whereby electric power
costs for cooling can be shifted from high demand to low
demand periods. This is accomplished by producing and storing
chilled water during times of low cost/low power demand and
using it later at the time of peak demand and high cost.
PRESTRESSED CONCRETE TANKS built by The Crom
Corporation are particularly well suited for these applications.
CONCRETE is the ideal material for chilled
• PRESTRESSED
water storage tank construction.
may be partially or completely buried without
• Tanks
concern for maintenance.
pleasing insulation systems may be added
• Aesthetically
economically.
free-span concrete dome can be designed to support
• The
the loads of internal piping.
surfaces do not require costly coatings or
• Interior
maintenance.
Devon Consolidated Data Center
Oklahoma City, Oklahoma
80,000-Gallon Chilled
Water Storage Tank
30’ x 15’ with dome
Consulting Engineers:
Franfurt-Short-Bruza
Associates, P.C.
Nielsen Media Research
Oldsmar, Florida
Two 750,000-Gallon Chilled Water
Storage Tanks
46’ x 60’ with domes
Consulting Engineers:
Alfonso Architects and Engineering
Matrix
Page 29
(Left)
Walgreen Company – Warehouse
& Distribution Center
Williamston, South Carolina
1,610,000-Gallon Chilled Water
Storage Tank
65’ x 65’ with dome
Consulting Engineers:
The Korte Company
(Right)
Dupont Fabros ACC4 Data Center
Ashburn,Virginia
Two 500,000-Gallon Chilled Water
Storage Tanks
40’ x 53’2” with domes
Consulting Engineers:
CCG Facilities Integration Inc.
St. Mary’s Hospital, Inc.
West Palm Beach, Florida
1,400,000-Gallon Chilled Water
Storage Tank
69’ x 53’ with dome
Consulting Engineers:
Johnson, Levinson, Slider & Davila,
Inc.
U.S. Army
Fort Jackson, South Carolina
2,250,000-Gallon Chilled Water
Storage Tank
98’ x 40’ with dome
Consulting Engineers:
U.S. Army Corps of Engineers
Savannah District
Broward Community College
Central Campus
Davie, Florida
750,000-Gallon Chilled Water
Storage Tank
68’ x 27’6” with dome
Consulting Engineers:
Engineering Matrix
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Page 30
Prestressed Concrete
Wall Design - AWWA D110
Type III Tanks: “Precast Concrete
with a Steel Diaphragm”
The Crom Corporation has a history extending in excess of a half
century during which time the design and construction of high quality
PRESTRESSED CONCRETE TANKS has been its chief goal and
aspiration.
CROM® has built more AWWA D110 tanks than any other copmany
in the world.
In addition to our standard Type II tanks, we are fully qualified and
experienced in designing and building prestressed concrete tanks
under Type III of AWWA Standard D110. This Type III designation
states that the tank core wall shall consist of “precast concrete with a
steel diaphragm”. The difference is that Type II uses shotcrete together
with diaphragm, whereas Type III uses precast concrete together with
diaphragm.
As described earlier in this brochure, in the case of Type II, the steel
diaphragm is vertically erected full circle on supporting form work, the
mild reinforcing steel is placed, and shotcrete is applied to the desired
thickness of the corewall.
The Type III methodology involves precasting the tank wall panels and
then lifting them into position. The photographs shown on the opposite
page illustrate the Type III procedure.
1 After the tank floor has been cast, panels of steel diaphragm are
placed in preformed casting beds. Mild steel reinforcement is added per
design.
2
3
Panels are cast in multiple layers to insure a consistent radius.
After the concrete is cured, the precast panels are tilted up.
Vertical joints between panels are sealed, and shotcrete is applied to the
steel diaphragm along the exterior of the wall.
4 High strength prestressing wire is placed to provide the desired wall
compression, then shotcrete is applied to bond wires to the wall.
5 This Type III tank has a flat roof using cast in place reinforced concrete.
6 This view of the tank interior shows the vertical columns required to
support the flat roof.
Type II or Type III tanks can be built with a self supported free-span
concrete dome roof or a column supported concrete flat roof or an
aluminum dome.
Page 31
AWWA D 110 Type III Core Wall Construction
1
2
3
4
5
6
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Page 32
Prestressed Concrete
Tanks with Embedded
Poly-Liner
Since 1953, The Crom Corporation has been designing and
building PRESTRESSED CONCRETE TANKS for water storage
and wastewater treatment, all built using a concrete core wall
with an embedded steel diaphragm and single wire circumferential
prestressing. It is a proven design. The Crom Corporation has
over 4000 tanks presently in service.
When a storage project contains aggressive materials, CROM®
offers a PRESTRESSED CONCRETE TANK with a permanently
EMBEDDED POLY-LINER which provides protection against
corrosive liquids and gases. The poly-liner eliminates the need for
coating or re-coating the interior surfaces of the tank. The most
common application is to cast a standard concrete dome over a
thermal seamed HDPE liner. CROM® also has experience in designing
and building PRESTRESSED CONCRETE TANKS where the entire
interior (floor, wall and dome) has an embedded poly-liner. Consulting
Engineers may specify different liner materials (HDPE - High Density
Polyethylene; LLDPE - Linear Low Density Polyethylene;
PP - Polypropylene); depending on the application’s requirements.
COMPLETE TANK CONSTRUCTION
The Crom Corporation provides the design and complete
construction of the tank, including the poly-liner and all tank
accessories such as ladders, vents and overflows. There is no
division of responsibility.
1
2
1. Wall casting bed with poly-liner.
2. Poly-liner in place on dome form.
3. Casting concrete on a
poly-lined dome.
3
Prestressed Concrete Tanks
with Embedded Poly-Liner
Page 33
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®
Page 34
Unique Installations
In the interest of diversification, and in response to the demands
of the market, The Crom Corporation has designed and built some
outstanding and unique structures. Pictured on these pages are
several of these projects.
(Left)
Escambia County Utilities
Authority
Perdido Key, Florida
500,000-Gallon Elevated Water
Storage Tank
46’ x 39’ with dome
125’ to High Water Line
Consulting Engineers:
Barrett, Daffin & Figg
(Right)
City of Boynton Beach, Florida
1,500,000-Gallon Elevated Water
Storage Tank-Night Time View
155’ to Overflow
117’4” to Dome Ring
32’ OD Pedestal
Consulting Engineers:
The Crom Corporation
Murfreesboro Water & Sewer
Department
Murfreesboro,Tennessee
2,000,000-Gallon Elevated Water
Storage Tank
169’ to Overflow
113’4” to Dome Ring
32’ OD Pedestal
Consulting Engineers:
Smith Seckman Reid, Inc.
Page 35
Department of Veteran Affairs
Orlando, Florida
2,000,000-Gallon Bomb Resistant
Fire Protection/Potable Water
Storage Tank
70’ x 71’ with dome
Consulting Engineers:
Roger, Lovelock & Fritz/Ellerbe
Becket
City of Baltimore, Maryland
Black River WWTP
Two 3,000,000-Gallon Egg-Shaped
Digesters
85’ x 139’
Consulting Engineers:
Black & Veatch, Inc.
Seacoast Utility Authority
Palm Beach Gardens, Florida
400,000-Gallon Accelator Tank
60’1” x 19’6”
Consulting Engineers:
Reese, Macon & Associates
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Page 36
The Crom Corporation:
Affiliated Enterprises
THE CROM CORPORATION PARTICIPATES IN THE ACTIVITIES OF:
Copyright © 2012 by The Crom Corportion • All Rights Reserved.