lways at the front of new technology,DYK Incorporated has emerged asthe undisputed leader in the design,

construction and post-tensioning of circularconcrete reservoirs using externalcircumferential strandwrapping and verticalthreadbar post-tensioning. DYK’s tanks aredesigned to meet the immediate needs ofthe community as well as the demands offuture generations in the new millennium.

The past seventy years have seen manychanges and innovations in materials,construction, design and technology as theprestressed concrete tank industry hasmatured. Through extensive research anddevelopment, DYK boasts the mostsophisticated finite element design analysisand the most technologically advanced andefficient construction, prestressing andshotcreting equipment in the industry. DYK’scurrent prestressing technology has evolvedto such a high level of maturity that a 100year life span for a tank is consideredconservative.

To utilize DYK’s advanced technology andensure the continued integrity of yourstorage project well into the new millennium,contact a DYK representative today.

PRESTRESSED CONCRETE TANKSP.O. Box 696, El Cajon, CA 92022-0696Phone: (800) 227-8181 • E-Mail dykinc@dyk.comWeb: http:/www.dyk.com

AA

To utilize DYK’s advanced technology for the future,contact a DYK representative today.

I N C O R P O R A T E D

PRESTRESSED CONCRETE TANKSP.O. Box 696, El Cajon, CA 92022-0696Phone: (800) 227-8181 • E-Mail dykinc@dyk.comWeb: http://www.dyk.com

I N C O R P O R A T E D

YK recognizes that remainingsuccessful and competitive in thenew millennium requires being

innovative and environmentallyresponsible today.

To reduce dust associated with typicalmanual sandblasting applications, DYKutilizes a hard, durable slag abrasive in

lieu of sandproducts.Thehardnessand friabilityof the slag,combinedwith theefficiency of

DYK’s automated blasting machinery,produces a superior bonding texture ofthe exterior concrete tank wall surface.DYK’s advanced blasting process farexceeds the performance of antiquatedsandblast systems still in use today.

As part of its aggressive researchand development program, DYK isconstantly evaluating various materialsto ensure that the most environmentally

responsibleproductsavailableon themarkettoday arebeing used.

DDCo

rew

all p

rior t

o bl

astin

g

1

Core

wal

l afte

r bla

stin

g

BEFORE: Surface texture before blasting is smoothand coated with form oil residue thereby inhibiting thebond with the shotcrete.

AFTER: Surface texture after blasting is clean ofresidues and is roughened to provide a superior bondwith the shotcrete.

ertical prestressing tendonducting is pressuregrouted with an approved

2 part water insensitive epoxy byDYK’s technologically advancedepoxy grouting equipment. Epoxywill not settle, has superior flowcharacteristics, is dielectric andhas other advantages whencompared to cement grout. Thisprovides corrosion protection ofthe threadbars well into the nextmillennium.

Epoxy pumping of verticalprestressed tendons ensurescomplete filling of ducting andanchors, penetration of smallvoids and better insulation ofprestressing steel from electriccurrents and potential differences.

VV

10

Each verticalthreadbarassembly isgrouted withepoxy pumpedthrough thebottom valveconnection

I N C O R P O R A T E D

Electronicallyproduced force andelongationrecordings areinstantaneouslyproduced for eachvertical tendonstressingapplication.

YK’s newlydeveloped automatedbeadblasting process

uses steel beads to cleanand etch the tank wall insteadof conventional abrasives likesand. The steel beads arerecycled by the machine andthe dust from the operation iscollected and prevented fromescaping into theenvironment. This processprovides better quality controlthan manual applications andis much quieter thanconventional nozzle blasting.The machinery is interfacedto allow the beadblaster anddust collector to be carried,powered and controlled byDYK’s strandwrappingmachinery for maximumefficiency.

DD

2

Exterior beadblasting of concrete core wallin preparation for shotcrete application andcircumferential prestressing.

he most important qualityassurance tool available toavoid inaccurate stressing is

an instantaneous and simultaneousrecording of the force andelongation of each verticalthreadbar as it is being stressed.This technology immediately andpermanently documents that therequired stress was provided.

If any problems are detected, thethreadbar can easily bedetensioned, the problem correctedand the bar then correctly stressed.Manually measuring the elongationwith a ruler after stressing orrelying on a hydraulic pressuregauge to interpret the force doesnot give the complete information,documented proof and qualityassurance that a permanent forceversus elongation plot provides.

TT

9

Prestressing force = 142,500 lbs

1” = 1,000 lbs Force

3”=

1”

Elo

ngat

ion

I N C O R P O R A T E D

uring the last seventy years, many improvements have been made in the

prestressed concrete tank industry. Asignificant technological advancement has

been the machine application of tensioned,galvanized, multiple-wire strand, in lieu of singlewire, to supply the circumferential corewallcompression. Machine strandwrapping systemshave proven to be an extremely durable andefficient method of circumferentially prestressingtank walls. The benefits of currentstrandwrapping versus wire wrapping includeincreased bond, improved efficiency, higher forcetolerance, electronic spacing, fewer welds andsplices,a greater safety factor and a higherbreaking strength.

The advent of strandwrapped systems has been a necessary improvement in theprestressed concrete tank industry and has

basically made wire wrapped systemsobsolete. Because of the superiority ofstrand, and its predominance of use,many other advancements inprestressing technology have beencoupled to the use of strand. Sincethere are no known patents which existfor the machine application of strand,any competent prestressing companyhaving the necessary resources candevelop strandwrapping technology.

During the last twenty-five years,strandwrapping has become thepreferred method of application foralmost all of the municipalities andconsultants in the West. Just as anOwner would not be expected to acceptsmooth conventional reinforcing steelfrom a mill unwilling to buy equipment toproduce deformed rebar, no tank ownershould be required to lower theirstandards solely to appeaseprestressing companies unwilling tomake the necessary commitmenttowards improved technology.

DD

3

Strandwrapping in progress.

ertical prestressing of tank walls is animportant element of producing adurable, crack-free, leak-free liquid

storage structure. Early tanks thatrelied solely on conventional verticalreinforcing to resist vertical bendingdue to differential dryness wouldfrequently develop horizontal cracksand subsequent leaks. Verticalcompression of the walls has provenextremely effective in preventing

concrete cracking and subsequentdeterioration caused by leakage.

DYK feels that high strength threadbarsmeeting the properties of ASTM A-722Type 2 have the best attributes of any ofthe readily available prestressingmaterial to provide vertical compressionin tank corewalls. Thethreadbar is essentially a highstrength piece of all-thread witha positive screwed-on nut as theanchorage. The nut anchorageeliminates the stressconcentrations typicallyassociated with the razor sharpteeth of wedges used to bite intostrand tendons.

DYK recommends a “ball andsocket” type joint at the end ofthe nut to allow for constructiontolerances during the installationin the field. Without this feature,any misalignment would producebending stresses additive to the

tensile stress therebyoverstressing the bar.With a threadbar, it isalso possible toeliminate any seating loss by

completely tightening the anchorage nutdown. By placing a single bar in a rigidPVC pipe, problems associated with multi-

strand tendons, such as bunching and frictionlosses, are also eliminated.

8

Post-tensioningram

Post-tensioningcontrol box

Verticalthreadbarsencased in PVC tubing

arepositioned

in placeprior to

each wallpour.

VV

Verticalthreadbarassembly

I N C O R P O R A T E D

ontinuous electronicrecording and instantaneousforce application correction is

essential to ensure the properstress is applied to the prestressedmaterials. Over-stressing, althoughnot visually altering its appearance,can result in stress corrosion andhydrogen embrittlement of theprestressing material. Under-stressing the prestressing materialwill make the tank prone to crackingand leakage. To date, the mostsophisticated, reliable and field-proven recording technology isbeing utilized solely forstrandwrapping systems.

CC

4

Electro-servo strandwrapping with continuouselectronic recording.

Close-up of strip chart recording of the applied force whilestrandwrapping is in progress.

Electronic recording of all applied circumferential post-tensioningforces ensures that the allowable design stress tolerances are notexceeded.

he shotcrete curingprocess, utilizing DYK’sinnovative technology,

encapsulates the entire tank wallin plastic sheeting shortly after thefinal shotcrete layer is applied andsoaked with water. The plasticsheeting is lapped and sealed asnecessary to properly cure theshotcrete. This procedure providesa very cost effective cure methodand greatly improves the moistureretention of the shotcrete during itscuring period.

TT

7

The entire tank wall is encased in plastic after the final shotcrete layer has been applied.

I N C O R P O R A T E D

he most significant development in improvingshotcrete quality has been

the introduction of the automatedshotcrete application by DYK.This enhanced technology willpreserve the integrity of DYK’sstructures in the new millennium.

DYK has found that an automated shotcrete application greatlyenhances the protective functionof the shotcrete covercoat whencompared to hand-appliedshotcrete. Hand-applied shotcrete is subject to numerousvariables, such as distance fromwall, applied thickness and theshooting angle up and down andshooting angle side to side, that ifnot correct can only diminish thefinal quality.

TT

5

The only practical method to helpcontrol these variables for the entireproject is an automated shotcreteprocess. The task of properlyapplying shotcrete by hand, especiallywhen considering the large surfacearea and number of layers required forthe typical prestressed concrete tank,is particularly daunting. With hand-applied shotcrete, the tendency is tobuild up thick layers and move on.However with automated equipment,numerous thin layers, as typicallyspecified, can efficiently be built upwhich provides for a better, moreuniform cure. An automatedprocedure also increases productivitythereby protecting the Owner fromoperational problems or penalties ifthe tanks are not completed on time.

DYK pioneered the use of the wet-mix shotcrete system using concretebatched under the tight quality controls of a ready mix plant.

et-mix shotcrete is applied from anozzle mounted on a mechanizedtower which travels around the

circular wall or dome-ring at a controlledspeed. The nozzle, always held at theproper angle and distance, slowly movesaround the tank circumference and up thewall in a uniform spiral path. To obtain auniform cure and prevent shrinkagecracking, the full cover is built up innumerous layers. In addition to improvedstructural quality, a beneficial side effectof the automated application is that theefficiency of the system has reduced cost.

WW

6

I N C O R P O R A T E D

DYK’s sophisticated shotcrete machinery. Continuous nozzle travel ensures uniform coatingthickness and maximum quality control of the shotcrete.

he most significant development in improvingshotcrete quality has been

the introduction of the automatedshotcrete application by DYK.This enhanced technology willpreserve the integrity of DYK’sstructures in the new millennium.

DYK has found that an automated shotcrete application greatlyenhances the protective functionof the shotcrete covercoat whencompared to hand-appliedshotcrete. Hand-applied shotcrete is subject to numerousvariables, such as distance fromwall, applied thickness and theshooting angle up and down andshooting angle side to side, that ifnot correct can only diminish thefinal quality.

TT

5

The only practical method to helpcontrol these variables for the entireproject is an automated shotcreteprocess. The task of properlyapplying shotcrete by hand, especiallywhen considering the large surfacearea and number of layers required forthe typical prestressed concrete tank,is particularly daunting. With hand-applied shotcrete, the tendency is tobuild up thick layers and move on.However with automated equipment,numerous thin layers, as typicallyspecified, can efficiently be built upwhich provides for a better, moreuniform cure. An automatedprocedure also increases productivitythereby protecting the Owner fromoperational problems or penalties ifthe tanks are not completed on time.

DYK pioneered the use of the wet-mix shotcrete system using concretebatched under the tight quality controls of a ready mix plant.

et-mix shotcrete is applied from anozzle mounted on a mechanizedtower which travels around the

circular wall or dome-ring at a controlledspeed. The nozzle, always held at theproper angle and distance, slowly movesaround the tank circumference and up thewall in a uniform spiral path. To obtain auniform cure and prevent shrinkagecracking, the full cover is built up innumerous layers. In addition to improvedstructural quality, a beneficial side effectof the automated application is that theefficiency of the system has reduced cost.

WW

6

I N C O R P O R A T E D

DYK’s sophisticated shotcrete machinery. Continuous nozzle travel ensures uniform coatingthickness and maximum quality control of the shotcrete.

ontinuous electronicrecording and instantaneousforce application correction is

essential to ensure the properstress is applied to the prestressedmaterials. Over-stressing, althoughnot visually altering its appearance,can result in stress corrosion andhydrogen embrittlement of theprestressing material. Under-stressing the prestressing materialwill make the tank prone to crackingand leakage. To date, the mostsophisticated, reliable and field-proven recording technology isbeing utilized solely forstrandwrapping systems.

CC

4

Electro-servo strandwrapping with continuouselectronic recording.

Close-up of strip chart recording of the applied force whilestrandwrapping is in progress.

Electronic recording of all applied circumferential post-tensioningforces ensures that the allowable design stress tolerances are notexceeded.

he shotcrete curingprocess, utilizing DYK’sinnovative technology,

encapsulates the entire tank wallin plastic sheeting shortly after thefinal shotcrete layer is applied andsoaked with water. The plasticsheeting is lapped and sealed asnecessary to properly cure theshotcrete. This procedure providesa very cost effective cure methodand greatly improves the moistureretention of the shotcrete during itscuring period.

TT

7

The entire tank wall is encased in plastic after the final shotcrete layer has been applied.

I N C O R P O R A T E D

uring the last seventy years, many improvements have been made in the

prestressed concrete tank industry. Asignificant technological advancement has

been the machine application of tensioned,galvanized, multiple-wire strand, in lieu of singlewire, to supply the circumferential corewallcompression. Machine strandwrapping systemshave proven to be an extremely durable andefficient method of circumferentially prestressingtank walls. The benefits of currentstrandwrapping versus wire wrapping includeincreased bond, improved efficiency, higher forcetolerance, electronic spacing, fewer welds andsplices,a greater safety factor and a higherbreaking strength.

The advent of strandwrapped systems has been a necessary improvement in theprestressed concrete tank industry and has

basically made wire wrapped systemsobsolete. Because of the superiority ofstrand, and its predominance of use,many other advancements inprestressing technology have beencoupled to the use of strand. Sincethere are no known patents which existfor the machine application of strand,any competent prestressing companyhaving the necessary resources candevelop strandwrapping technology.

During the last twenty-five years,strandwrapping has become thepreferred method of application foralmost all of the municipalities andconsultants in the West. Just as anOwner would not be expected to acceptsmooth conventional reinforcing steelfrom a mill unwilling to buy equipment toproduce deformed rebar, no tank ownershould be required to lower theirstandards solely to appeaseprestressing companies unwilling tomake the necessary commitmenttowards improved technology.

DD

3

Strandwrapping in progress.

ertical prestressing of tank walls is animportant element of producing adurable, crack-free, leak-free liquid

storage structure. Early tanks thatrelied solely on conventional verticalreinforcing to resist vertical bendingdue to differential dryness wouldfrequently develop horizontal cracksand subsequent leaks. Verticalcompression of the walls has provenextremely effective in preventing

concrete cracking and subsequentdeterioration caused by leakage.

DYK feels that high strength threadbarsmeeting the properties of ASTM A-722Type 2 have the best attributes of any ofthe readily available prestressingmaterial to provide vertical compressionin tank corewalls. Thethreadbar is essentially a highstrength piece of all-thread witha positive screwed-on nut as theanchorage. The nut anchorageeliminates the stressconcentrations typicallyassociated with the razor sharpteeth of wedges used to bite intostrand tendons.

DYK recommends a “ball andsocket” type joint at the end ofthe nut to allow for constructiontolerances during the installationin the field. Without this feature,any misalignment would producebending stresses additive to the

tensile stress therebyoverstressing the bar.With a threadbar, it isalso possible toeliminate any seating loss by

completely tightening the anchorage nutdown. By placing a single bar in a rigidPVC pipe, problems associated with multi-

strand tendons, such as bunching and frictionlosses, are also eliminated.

8

Post-tensioningram

Post-tensioningcontrol box

Verticalthreadbarsencased in PVC tubing

arepositioned

in placeprior to

each wallpour.

VV

Verticalthreadbarassembly

I N C O R P O R A T E D

Electronicallyproduced force andelongationrecordings areinstantaneouslyproduced for eachvertical tendonstressingapplication.

YK’s newlydeveloped automatedbeadblasting process

uses steel beads to cleanand etch the tank wall insteadof conventional abrasives likesand. The steel beads arerecycled by the machine andthe dust from the operation iscollected and prevented fromescaping into theenvironment. This processprovides better quality controlthan manual applications andis much quieter thanconventional nozzle blasting.The machinery is interfacedto allow the beadblaster anddust collector to be carried,powered and controlled byDYK’s strandwrappingmachinery for maximumefficiency.

DD

2

Exterior beadblasting of concrete core wallin preparation for shotcrete application andcircumferential prestressing.

he most important qualityassurance tool available toavoid inaccurate stressing is

an instantaneous and simultaneousrecording of the force andelongation of each verticalthreadbar as it is being stressed.This technology immediately andpermanently documents that therequired stress was provided.

If any problems are detected, thethreadbar can easily bedetensioned, the problem correctedand the bar then correctly stressed.Manually measuring the elongationwith a ruler after stressing orrelying on a hydraulic pressuregauge to interpret the force doesnot give the complete information,documented proof and qualityassurance that a permanent forceversus elongation plot provides.

TT

9

Prestressing force = 142,500 lbs

1” = 1,000 lbs Force

3”=

1”

Elo

ngat

ion

I N C O R P O R A T E D

YK recognizes that remainingsuccessful and competitive in thenew millennium requires being

innovative and environmentallyresponsible today.

To reduce dust associated with typicalmanual sandblasting applications, DYKutilizes a hard, durable slag abrasive in

lieu of sandproducts.Thehardnessand friabilityof the slag,combinedwith theefficiency of

DYK’s automated blasting machinery,produces a superior bonding texture ofthe exterior concrete tank wall surface.DYK’s advanced blasting process farexceeds the performance of antiquatedsandblast systems still in use today.

As part of its aggressive researchand development program, DYK isconstantly evaluating various materialsto ensure that the most environmentally

responsibleproductsavailableon themarkettoday arebeing used.

DD

Core

wal

l prio

r to

blas

ting

1

Core

wal

l afte

r bla

stin

g

BEFORE: Surface texture before blasting is smoothand coated with form oil residue thereby inhibiting thebond with the shotcrete.

AFTER: Surface texture after blasting is clean ofresidues and is roughened to provide a superior bondwith the shotcrete.

ertical prestressing tendonducting is pressuregrouted with an approved

2 part water insensitive epoxy byDYK’s technologically advancedepoxy grouting equipment. Epoxywill not settle, has superior flowcharacteristics, is dielectric andhas other advantages whencompared to cement grout. Thisprovides corrosion protection ofthe threadbars well into the nextmillennium.

Epoxy pumping of verticalprestressed tendons ensurescomplete filling of ducting andanchors, penetration of smallvoids and better insulation ofprestressing steel from electriccurrents and potential differences.

VV

10

Each verticalthreadbarassembly isgrouted withepoxy pumpedthrough thebottom valveconnection

I N C O R P O R A T E D

lways at the front of new technology,DYK Incorporated has emerged asthe undisputed leader in the design,

construction and post-tensioning of circularconcrete reservoirs using externalcircumferential strandwrapping and verticalthreadbar post-tensioning. DYK’s tanks aredesigned to meet the immediate needs ofthe community as well as the demands offuture generations in the new millennium.

The past seventy years have seen manychanges and innovations in materials,construction, design and technology as theprestressed concrete tank industry hasmatured. Through extensive research anddevelopment, DYK boasts the mostsophisticated finite element design analysisand the most technologically advanced andefficient construction, prestressing andshotcreting equipment in the industry. DYK’scurrent prestressing technology has evolvedto such a high level of maturity that a 100year life span for a tank is consideredconservative.

To utilize DYK’s advanced technology andensure the continued integrity of yourstorage project well into the new millennium,contact a DYK representative today.

PRESTRESSED CONCRETE TANKSP.O. Box 696, El Cajon, CA 92022-0696Phone: (800) 227-8181 • E-Mail dykinc@dyk.comWeb: http:/www.dyk.com

AA

To utilize DYK’s advanced technology for the future,contact a DYK representative today.

I N C O R P O R A T E D

PRESTRESSED CONCRETE TANKSP.O. Box 696, El Cajon, CA 92022-0696Phone: (800) 227-8181 • E-Mail dykinc@dyk.comWeb: http://www.dyk.com

I N C O R P O R A T E D