DuraStor™ Tanks are prestressed concrete storage tanks reinforced with post-tensioning tendons (governed by ACI 350 and AWWA D115). This method actively reinforces the structure and significantly enhances its watertightness and long-term durability. DuraStor™ Tanks can be constructed in many shapes to suit project needs – there are no practical limitations. Tanks have been constructed with capacities up to 30,000,000 gallons. Experience the benefits of prestressed concrete with the geometric flexibility of conventionally reinforced concrete.
Flat Roof Option
Similar to the floor, the roof slab is cast in a single placement with no construction joints. This method results in a watertight slab that eliminates the possibility of substances entering the tank and contaminating the contents. The roof slab is column-supported with typical spans in the 30-foot range each way. Slab thickness is approximately 8 inches. Roof shoring is placed immediately following the column and column footing placement to minimize construction time. Post-tensioning tendons are placed orthogonally as in a typical two-way suspended slab and are "stage stressed" in the same manner as the floor slab tendons. After the tendons are stressed, the shoring is removed through access hatches. Dome roof prestressed concrete tank
Dome Roof Option
Column-supported flat roofs are often chosen for buried tanks or where a less visible tank is desired. A cast-in-place concrete dome is an efficient option for circular tanks where a flat roof is not required
AWWA D110-04 vs. AWWA D115-06 tank roof comparison chart
The wall is composed of full-height segments frequently 12-inches thick. They’re cast in lengths of approximately 75 feet with no horizontal construction joints. Post-tensioning tendons placed horizontally may be tensioned at pilasters or pilasters may be eliminated depending on the project requirements. Tendons are also placed vertically to provide compression to the concrete and accommodate vertical bending moments and thermal stresses.
On large tanks it is possible to place as many as four wall segments per week. Column footings and columns are cast concurrently with the wall to minimize the duration of construction. If required, walls may have any architectural finish, form liner or coating to meet the project’s aesthetic requirements.
AWWA D110-04 vs. AWWA D115-06 tank wall comparison chart
Joints in a floor slab can allow liquids to leak out of a tank – creating the possibility of adversely affecting the environment and/or undermining the structure’s foundation. Joints can also allow substances to seep into the tank and potentially contaminate the contents.
DuraStor™ tank floors are cast in a single placement with no joints or dowels. The floor is a highly reinforced ductile concrete membrane, normally five inches thick, that can tolerate differential movements while maintaining watertightness. The tendons are "stage-stressed" within 48 hours of casting the floor slab to eliminate shrinkage cracks by providing immediate precompression to the concrete.
AWWA D110-04 vs. AWWA D115-06 tank floor comparison chart
Design & Engineering Support
Our skilled, dedicated professionals bring innovation to every project need. STRUCTURAL TECHNOLOGIES provides technical support during the planning and construction phases of projects. Our comprehensive range of services includes feasibility studies, cost estimates, preliminary designs, alternative proposals, detailing, project coordination, contractor consulting, and execution of the work utilizing VSL products and equipment.
Because each project presents a unique opportunity, STRUCTURAL TECHNOLOGIES teams with contractors, owners, and engineers to evaluate projects and determine optimal solutions. Our engineers have extensive experience in structural design and are active members of technical organizations such as the Post-Tensioning Institute (PTI), the American Segmental Bridge Institute (ASBI) and the American Concrete Institute (ACI).
Post-Tensioning Engineering Team Leader
John Crigler, P.E.
With over 30 years of experience at VSL, Crigler is a recognized expert in post-tensioning. He is an active member of several industry associations including the American Segmental Bridge Institute (ASBI), Post-Tensioning Institute (PTI), American Society of Civil Engineers (ASCE) and American Concrete Institute (ACI). In 2008, he received the ASBI Leadership Award given for outstanding leadership for the development of the segmental bridge industry. Crigler received his Bachelor of Civil Engineering from Virginia Polytechnic Institute and is a registered professional engineer in Virginia, as well as numerous other states.
STRUCTURAL TECHNOLOGIES' licensed engineering services are provided by StrongPoint Engineering, LLC - A Structural Group Company, or through other licensed engineers.