Fast and efficient design of posttensioned beams, oneway and twoway slabs and mat foundations. Post tensioned foundations are designed using the post tensioning institute pti method first published in 1980 and recently updated with its 3rd edition. The post tensioning institute designed post tensioned foundations. Part three continues with the study of twoway, posttensioned slab systems, including. Course content this spreadsheet program provides for the design and analysis of post tensioned concrete oneway beam and slab systems and twoway flat plate slab systems. Post tensioned slab design, supply, install tensioned concrete. Once the concrete has gained strength to 2000 psi, typically within the 3 to 10 days recommended by pti, the tendons are stressed. Built on adapts unique truestructure modeling and analysis technology, this software provides a powerful, yet easy to use tool for the analysis of all types of slab systems. A residential post tensioned concrete slab will typically be 8 inches thick and use 3000 psi concrete.
The recommendations derived from these and other studies vary from extremely light to extremely heavy. Posttension basics how posttensioned slabs are built the. What is the best software to design a post tension slab. Written by structural engineers who design posttensioned concrete buildings for a living and teach how to design them at the university level, there has simply never been anything like this book. Once the slab cures, qualified personnel apply tension and grout the cables. A residential posttensioned concrete slab will typically be 8 inches thick and use 3000 psi concrete. Slabonground posttensioned slabsonground provide a costefficient, highperformance solution for problems associated with groundsupported residential foundations on shrinkswell soils.
A post tension slab is a concrete slab or foundation that contains high tension cables running through the concrete to increase strength and reduce cracking typically in areas with poor soil conditions. Whether you choose a posttension or rebar slab nortex has the experience and expertise to design a foundation suitable for all your construction and design needs. Posttensioned, reinforced concrete slab design software ram. In this section several typical slabongrade sections are illustrated and described. Calculation and the theory by which the software works are attached with this softwares index, this thing is not seen. As with any type of foundation or foundation pier, there are pros and cons associated with the slab option. Cypecads posttensioned concrete slabs for buildings module has been designed to carry out the design of the passive reinforcement of posttensioned slabs, using the forces that have been obtained from analysing the posttensioned tendons bonded or unbonded, whose properties have been introduced by the program users posttensioned technology has different degrees. The compressive stresses resist the anticipated tension stresses induced by the soil movements, enhancing the performance over a nonprestressed foundation. Reinforced concrete and posttensioned foundation mat. Homeowners are getting crushed by flawed posttension cable. Apr 29, 2019 post tensioned analysis and design spreadsheet. Posttensioned concrete slabs in buildings have many advantages over reinforced concrete slabs and other structural systems for both single and multilevel structures.
This spreadsheet program provides for the design and analysis of posttensioned concrete oneway beam and slab systems and twoway flat plate slab systems. Figures 49 through 411, and 415 show configurations with insulation on the exterior surface of the foundation. What is post tensioning introduction post tensioning is a method of producing prestressed concrete, masonry and other structural elements. Post tensioned foundation information for the homeowner. Adaptsog produces effective, accurate designs with confidence. The foundation gains tensile strength when the cables are tightened after the slab has been cast. Homeowners are getting crushed by flawed posttension. The tricky part comes when concrete is poured into the forms. The example presented is taken from the book posttensioned concrete principles and practice by k. Although some post tensioned slab structures had been constructed in europe quite early on, the real development.
Structural function of pt foundation acts as a buffer between the soil below and the superstructure above to prevent unacceptable deformations in superstructure. The term prestressing is used to describe the process of introducing internal forces or stress into a concrete or masonry element during the construction process in order to. Slab modeling, analysis, and design procedures feature a suite of sophisticated tools and applications, couple with post tensioning, punchingshear, and beam detailing, and integrate the influence of soils, ramps, columns, braces, walls rectilinear. Threedimensional 3d finite element software for analysis and design of concrete and posttensioned floor and foundation systems. Slab onground post tensioned slabsonground provide a costefficient, highperformance solution for problems associated with groundsupported residential foundations on shrinkswell soils. Overview safe is the ultimate tool for designing concrete floor and foundation systems. Do not alter the drainage pattern of the site provide a minimum of 3%.
Posttensioned slab design manual otte group software. A post tensioned foundation is a concrete slab foundation that is reinforced with stranded steel cables that are tensioned after. Fundamentals of posttensioned concrete design for buildings. Standard requirements for design and analysis of shallow post tensioned concrete foundations on expansive soils. Calculation and the theory by which the software works are attached with this softwares index, this thing is not seen on other softwares. Fundamentals of posttensioned concrete design for buildings part one a. Many houston area structural engineers feel that the inherently weaker residential posttensioned slab are at risk from two major factors first, the nonuniform weight distribution of the house puts great stress on the slab foundation.
Suspended slabs can include flat, twoway, waffle, and ribbed framing systems. Post tensioned concrete design limit is the tensile strain in the reinforcement at the balanced strain condition, which is taken as the yield strain of the reinforcement, f e aci 10. In this post, well discuss these advantages and disadvantages, as well as the reason why its common for foundation piers to be installed late in the life of a. Sep 09, 2016 course study on post tension slab design. An alternative to a traditional foundation is known as a slab foundation. The home builders theory is that they can achieve a minimum of 50 psi pounds per square inch compression throughout the slab and most importantly, at the middle of the. This course provides the documentation to enable the use of a posttension design spreadsheet program for oneway concrete beam and slab and twoway. Slabongrade and posttensioned slab software adaptsog. For general design philosophy and analysis of post tensioned concrete, the reader should refer to pdhonline course s127. Safe technical knowledge base computers and structures, inc.
A posttensioned foundation is a concrete slab foundation that is reinforced with stranded steel cables that are tensioned after. Usually a sign in the garage or stamp in the slab will indicate if. The program is divided into three separate screens, which correspond to the three major areas of concern in the design of a post tensioned member. The following table of prestress losses is recommended for the design of posttensioned members, and does not include friction or wedge set losses. Post tensioned concrete slabs in buildings have many advantages over reinforced concrete slabs and other structural systems for both single and multilevel structures. A posttension slab is a slab of concrete that has been prestressed using a specific method to increase the strength of the concrete. Adaptsog software for the design of posttensioned slabs on grade foundations on expansive and compressible soils.
Posttensioned slab ongrade foundation 3d fem design software adaptsog product overview adaptsog is a complete threedimensional 3d finite element fem analysis and design tool for the analysis and design of post tensioned foundations slabs on expansive soils. Want to design concrete floors economically, with exceptional visibility into compliance, and efficiency while designing slabs, mats, and rafts. Post tensioning tensioned concrete offers a wide range of post tensioning solutions from mono strand systems typically used in house slabs where the ground is highly reactive, slab systems 12. Its more user friendly compared to other pt design softwares.
Posttension cables are steel wires inserted into plastic sheathing laid in place while pouring the concrete slab. Analysis of a slabs capacity to support on interior line load or concentrated point load. Design floors and foundations reliably and efficiently, saving time and money, and overcoming the most common concerns you face as a designer. The following table of prestress losses is recommended for the design of post tensioned members, and does not include friction or wedge set losses. Design and analysis of slabonground foundations on both expansive and compressible soils. To get the excel sheet join as loving fansub member to this channel.
Jul 07, 2017 how to build and setup a concrete foundation for garages, houses, room additions, etc part 1 duration. Calculation and analysis of uniform thickness slabs, sometimes referred to as california flat slabs. The posttensioning institute designed posttensioned foundations. Construction maintenance of post tensioned slab on ground. A properly designed post tension slab can design around expansive soils, high water tables, etc. Second, the nonuniform thickness of fill soil under the foundation can be a major contributing factor in damaged slab foundations. A 2 2area 2 a c 2 2 posttensioned concrete design table 11 list of symbols used in the aci 31808 code cp area enclosed by the outside perimeter of the section, in a g gross area of concrete, in a 2 l total area of longitudinal reinforcement to resist torsion, in a o area enclosed by the shear flow path, sqin a oh area enclosed by the centerline of the outermost closed. Onscreen warning messages for out of compliance conditions. Adapt corporation specializes in structural concrete design software for post tensioning, reinforced concrete, and prestressed beam, slab, foundation. Pt designer design of posttensioned concrete floors. While doing all that dirt work is viable on commercial property, the economics dont work on spec homes. Structural engineers design concrete slabs with posttension cables to obtain greater span lengths between supporting columns and to allow thinner slabs. Sep 18, 2006 typical post tensioned ribbed foundation for residential construction with tendons placed in the center of the slab at approximately 48 inches on center in each direction. Actual losses, whether greater or smaller than computed values, have little effect on the design strength of the member but do affect service load conditions i.
Whether you choose a post tension or rebar slab nortex has the experience and expertise to design a foundation suitable for all your construction and design needs. Pt slabs offer the thinnest slab type, as concrete is worked to its strengths, mostly being kept in compression. In the case of a post tension slab, steel cables are laid out in grid fashion inside the forms. Durability aspects of present pt systems, key design concepts, code requirements, and practical design and construction tips will also be discussed. Design publications and software for post tensioned slabs on grade design publications and software for post tensioned slabs on grade josecastjr structural op 14 nov 06 22. Economically design post tensioned and reinforced concrete floors including slabs, mats, and rafts, with exceptional visibility into compliance, efficiency, and practicality. Posttension basics how posttensioned slabs are built. A psc is applied with a compressive stress on the cross section in advance before the application of loading on. Installed correctly post tension cables have proven to be stronger and more reliable in high stress situations while reducing overall materials and construction time. And from what ive seen the cost of conventional vs post tension is about a wash. Although some posttensioned slab structures had been constructed in europe quite early on, the real development. Slabs or foundations can be of any shape, and can include edges shaped with circular and spline curves.
Twoway posttensioned design amsysco post tensioning. Foundation is designed to resist or span over moistureinduced deformations in the soil below, while still maintaining its top surface within permissible level tolerances. Posttensioning may be included in both slabs and beams to balance a percentage of the selfweight. This tension makes the concrete slab and foundation much stronger than concrete without reinforcement and helps reduce cracking. Typical posttensioned ribbed foundation for residential construction with tendons placed in the center of the slab at approximately 48 inches on center in each direction. Economically design posttensioned and reinforced concrete floors including slabs, mats, and rafts, with exceptional visibility into compliance, efficiency, and practicality. Fundamentals of posttensioned concrete design for buildings part one.
Design softwares slab and beam design software service. Figures 412 through 414 show variations where the slab is the primary location for insulation. Safe is a software tailored for the engineering of elevated floor and foundation slab systems. General overview of post tensioned concrete design. A combination of these values will determine the slab stresses at the time of stressing and at service loads. Whether the project is local or overseas, design codes from around the globe are available for reinforced concrete and post tensioned slab design.
Jul 21, 2017 rapt is a two dimensional post tension beam slab design software. It is an outstanding textbook with a crystalclear presentation of indeterminate design and analysis fundamentals. Presentations will focus on design, analysis, and construction of post tensioned buildings and will include handson training on the design and analysis of new post tensioned building structures. Sections are tension controlled when the tensile strain in the extreme tension. Suspended slabs can include flat, twoway, waffle, and. Design publications and software for post tensioned slabs on. Reinforced concrete and post tensioned foundation design software adaptmat product overview adaptmat is a versatile threedimensional 3d finite element fem analysis and design software for any configuration of conventionally reinforced or post tensioned foundation system.
Reinforced concrete and posttensioned foundation design software adaptmat product overview adaptmat is a versatile threedimensional 3d finite element fem analysis and design software for any configuration of conventionally reinforced or post. By simplifying slab reinforcement at column locations and eliminating column capitals, stirrup cages, or i beam shear heads, they enable efficient design and rapid. How to build and setup a concrete foundation for garages, houses, room additions, etc part 1 duration. The first edition of the posttensioning manual was published in 1972, and as of the time of this writing 2018, they are up to their 6th edition. Posttensioned foundations are designed using the posttensioning institute pti method first published in 1980 and recently updated with its 3rd edition. Presentations will focus on design, analysis, and construction of posttensioned buildings and will include handson training on the design and analysis of new posttensioned building structures. Posttensioned concrete design spreadsheet program a pdh. Rapt is a two dimensional post tension beamslab design software. Campbell, the posttension cable system for concrete slab foundations that has and is replacing the standard steel rebar system has a fundamental flaw. Whether the project is local or overseas, design codes from around the globe are available for reinforced concrete and posttensioned slab design. Posttensioned pt slabs are typically flat slabs, band beam and slabs or ribbed slabs. Design publications and software for post tensioned slabs.
It was actually the widespread use of the posttensioned slabonground which induced this interest in design procedure and in many studies of reported slab failures. Need suggestions for a good pt software and design books with examples of post tensioned slabs on grade. What is the difference between normal slab and post. Design seminar descriptions posttensioning institute. The program is divided into three separate screens, which correspond to the three major areas of concern in the design of a posttensioned member. Written by structural engineers who design post tensioned concrete buildings for a living and teach how to design them at the university level, there has simply never been anything like this book. The pti design procedure is used to design a slabon grade foundation that will respond.
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