Welcome to a new era in Post Tension Design

Kline Engineering introduces the first of its kind – a Post Tensioning (PT) Calculator.  The PT Calculator is a convenient application for quickly estimating concrete dimensions and reinforcement quantities for typical post-tensioned concrete buildings.  The application is designed to aid in schematic design, value engineering, and structural type study comparisons that can be used in the planning process for building construction. The PT Calculator is ideal for owners, developers, contractors, architects, and engineers who need to quickly estimate quantities and concrete sizes.

The PT Calculator can be used for the following building types:

• Office

  • Flat plate

  • Continuous wide shallow drop

• Residential – Multi-Story

  • Flat plate

  • Podium slab with 3 levels of wood construction (4 levels of wood with roof)

  • Podium slab with 4 levels of wood construction (5 levels of wood with roof)

• Parking Structure

  • One-way beam and slab with long-span beams

  • Flat plate

Value Engineering

The PT Calculator is an excellent tool for comparing the relative cost of a PT design versus an alternative construction method. We recommend contractors and owners use the PT Calculator to determine if PT provides a more economical building solution for their project before they enter the construction phase of a build. 

Architectural Planning

The PT Calculator is ideal for architectural planning. If an architect wants to know the concrete floor thickness required for a multi-level residential building, the PT Calculator can provide the answer.  If you are planning to construct multi-level wood framing over a concrete podium slab, the PT Calculator will provide the podium thickness.  In the early planning stages of design, you may not have convenient and low-cost access to structural engineering services; the PT calculator is here to help bridge this gap.

Using the PT Calculator

Using the PT Calculator is easy.  With a few simple inputs, the user is provided with concrete sizes, PT quantities in lb./sq. ft., and rebar quantities in lb./sq. ft.  Below are the steps:

• Select building type from a drop-down menu.

• Input typical span lengths

• Input typical bay widths

• Press “calculate”, and the application provides typical concrete dimensions and reinforcement quantities.

• A data sheet with all of the input and results is available to download and print.

The calculator algorithm is based on the minimum design requirements of ACI 318-14, and on loading in accordance with IBC 2015.  

Limitations of PT Calculator

It is critical for the user to understand that any information provided by the PT Calculator should only be used for conceptual design purposes or for approximate size and quantity comparisons.  The PT Calculator is not intended to be used for design of new buildings or evaluation of existing buildings.  It does not provide detailed design information such as prestress forces, tendon profiles, rebar sizes and lengths, etc.  The application does not consider special design conditions such as concentrated loads, non-typical span lengths, or openings in the slab.  The application also does not check for punching shear resistance in two-way slabs.  Many of the assumptions that form the basis of the PT Calculator are rooted in typical PT design and construction practice in North America.  For example, the user cannot vary design concrete strength.  The application uses f’c = 5000 psi for all computations.  

The PT Calculator should not be relied upon for design purposes or for accurate construction price estimates, and Kline Engineering & Consulting, LLC does not guarantee or warrantee that the information provided by the PT Calculator is accurate.  

If you wish to receive more accurate preliminary design information you are encouraged to contact Kline Engineering & Consulting, LLC.  Kline provides consulting services for all types of PT structures and we provide structural designs from conceptual phase through final design and construction.  For more information, please contact our office.