Construction maintenance of post tensioned slab on ground. Check slab stresses separately calculate the maximum positive and negative moments in the frame for the dead, live, and balancing loads. Safe is the ultimate tool for structural engineers designing concrete floor slabs. We recommend using pt for temperature and shrinkage reinforcement. Calculation and the theory by which the software works are attached with this software s index, this thing is not seen.
Concrete slab design software economically design post tensioned and reinforced concrete floors including slabs, mats, and rafts, with exceptional visibility into compliance, efficiency, and practicality. Suncoast posttension is north americas largest unbonded posttension specialist. Post tensioning institutes design of posttensioned slabs onground, pti design procedure 3rd edition. The following example illustrates the design methods presented in aci 31805 and ibc 2003. The post tensioning institute designed post tensioned foundations. The two options are a cast in place concrete slab or a post tensioned slab. Top 10 biggest mistakes made in posttensioned concrete design. Advantages of using posttensioning for your next slabonground project.
Jun 22, 2017 homeowners are getting crushed by flawed post tension cable foundations the switch from steel rebar to post tension cable by houston area home builders has delivered unmistakable results post tension cable foundations are failing earlier and in far greater numbers than steel rebar foundations. Posttensioned slab on grade 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. Reliance on 3d finite element software for design and drawings. Labor costs are also reduced because less material is used in slab construction and construction times are optimized. Construction of posttensioned slabs on grade is very similar to using reinforcing steel, except for the tensioning step. An experienced post tensioning engineer will probably be able to generate larger capacities depending on concrete strength and force applied from the tendons.
The contract work to be performed under this section consists of furnishing all required labor, materials, equipment, implements, parts and supplies necessary for, or appurtenant to, the site preparation and grading of tennis courts. Part three continues with the study of twoway, posttensioned slab systems, including. This course provides the documentation to enable the use of a posttension design spreadsheet program for oneway concrete beam and slab and twoway concrete slab systems. Posttensioning institutes design of posttensioned slabsonground, pti design procedure 3rd edition. Ptislab can be used to design or analyze both posttensioned and conventionally reinforced slabsonground for single and multifamily residential and commercial foundations on expansive and. Several methods exist for prestressing concrete, with post tensioning being a very common one. In areas with building height restrictions, saving 8 to 12 inches or more of height on each level can add up by the time you reach 10 or 12 levels. 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. Use the tabs in the component dialog box to load a previously saved pt posttensioning tendon scheme, or a new tendon scheme. Post tension cables are steel wires inserted into plastic sheathing laid in place while pouring the concrete slab. Whether the project is local or overseas, design codes from around the globe are available for reinforced concrete and post tensioned slab design. This can help to minimize cracking and differential settlement in adverse conditions. A normal slab is basically a rcc reinforce cement concrete slab where as a post tentioned slab is the psc prestressed concret slab. Twoway posttensioned design amsysco post tensioning.
My background is in structural steel design and construction management. Post tension slab design software sethguthrie civilenvironmental 18 aug 16 19. A square 10,000 sqft slab will require less concrete than an irregularly shaped slab of the same size. Adapt corporation specializes in structural concrete design software for post tensioning, reinforced concrete, and prestressed beam, slab, foundation, building and bridge structures using finite element or equivalent frame analysis. Market for posttensioning tendons over 40% of all pt tendons sold in the usa are for residential foundations. Post tensioned foundation information for the homeowner. In simple span beams the primary post tensioning pt moments induced by the prestressing force are directly proportional to the eccentricity of the tendons with respect to the neutral axis of the member i. The posttensioning institute designed posttensioned foundations. The advantage of posttensioning is the internal compressive force it imparts on the concrete. Design floors and foundations reliably and efficiently, saving time and money, and overcoming the most common concerns you face as a designer. Fundamentals of posttensioned concrete design for buildings part one a suncam online continuing education course.
The building has been named the aqua because of its contoured. Unless otherwise noted, all referenced table, figure, and equation numbers are from these books. The shape of the pt foudation has a significant effect on the amout of readymix used because of the grade beam layout. Adapt software system posttensioned concrete for todays market seattle. Post tensioning imparts an internal compressive force into the concrete.
Posttensioned concrete is a term heard more and more in the construction industry today. Members of the institute include major post tensioning material fabricators in the u. What is the best software to design a post tension slab. A subsequent report established the feasibility of using posttensioning in slabonground construction and verified many of the brab assumptions. Advantages of using post tensioning for your next slab onground project. In this free webinar dirk bondy and bryan allred discusses the latest edition of their book, posttensioned concrete principles and practice 3rd edition as well as present the latest version. Overview safe is the ultimate tool for designing concrete floor and foundation systems. Contractors sometimes need to drill or cut into a post tensioned slab for repair or renovation work. Members of the institute include major posttensioning material fabricators in the u. Most geotechnical reports require a minimum embedment of 12 to 18 inches below the lowest adjacent grade. Thats why builders posttension with increasing frequency in lieu of conventional rebar slabs. Once the slab cures, qualified personnel apply tension and grout the cables.
A psc is applied with a compressive stress on the cross section in advance before the application of loading on. This depth activates the appropriate bearing pressure and provides a partial water stop to minimize moisture intrusion under the foundation. Jul 15, 2016 in this free webinar dirk bondy and bryan allred discusses the latest edition of their book, posttensioned concrete principles and practice 3rd edition as well as present the latest version. Use the tabs in the component dialog box to load a previously saved pt posttensioning tendon reinforcement that represents reinforcing bars, strands, or wires that are used to produce a compressive stress in prestressed concrete besides the actual reinforcing bars. A posttensioned foundation is a concrete slab foundation that is reinforced with stranded steel cables that are tensioned after. General overview of posttensioned concrete design instructor. In below grade structures this can mean less excavation, and in above grade structures it can mean a reduced overall building height. Posttensioning 61 component enables tekla structures to accurately model most posttensioning profiles and attributes. Posttensioned, reinforced concrete slab design software ram. There has recently been a lot of discussion regarding to a post tension, or pt slab on grade and a pier and beam foundation. Rapt is a two dimensional post tension beam slab design software. Post tensioned foundations are designed using the post tensioning institute pti method first published in 1980 and recently updated with its 3rd edition. The commentary is provided to mention the considerations of the committee in developing the criteria. This method of reinforcing concrete enables a designer to take advantage of the considerable benefits provided by prestressed concrete while retaining the flexibility afforded by the castinplace method of building concrete structures.
Slabongrade and posttensioned slab software adaptsog. In this section several typical slab on grade sections are illustrated and described. Adapt corporation specializes in structural concrete design software for posttensioning, reinforced concrete, and prestressed beam, slab, foundation, building and bridge structures using finite element or equivalent frame analysis. This course provides the documentation to enable the use of a post tension design spreadsheet program for oneway concrete beam and slab and twoway concrete slab systems. Posttensioned slab on grade is more durable and economical than conventional slab reinforcement. Figures 412 through 414 show variations where the slab is the primary location for insulation. Concrete slab on grade analysis calculator for post or wheel. Calculators for structural engineers, construction professionals and steel building specifiers. This spreadsheet program provides for the design and analysis of post tensioned concrete oneway beam and slab systems and twoway flat plate slab systems. In this section several typical slabongrade sections are illustrated and described. In 1965 the writer developed a complete, overall design system, later modified to con.
Csis safe software is used in the design of an 87story mixeduse tower in chicago. For residential construction, tendons at 48 inches on center are common. The first edition of the post tensioning manual was published in 1972, and as of the time of this writing 2018, they are up to their 6th edition. What is the difference between normal slab and post. Nov 25, 2008 post tensioned concrete is a term heard more and more in the construction industry today. Post tension slab design software structural engineering. Cracking in groundsupported post tensioned slabs on. The benefits of faster construction schedules while decreasing the quantity of concrete and rebar saves money. Advantages of using post tensioning for your next slab on ground project. An excellent 2page reference on posttensioned concrete is available from, of all places, the posttensioning institute pti. Posttension basics how posttensioned slabs are built. The benefits of faster construction schedules while decreasing the quantity of concrete and rebar saves money posttensioning imparts an internal compressive force into the concrete. Download free, highquality cad drawings, blocks and details of post tensioned concrete organized by masterformat.
Fundamentals of posttensioned concrete design for buildings part one. Online concrete slab on grade analysis calculator for slab subjected to interior concentrated post or wheel loading assuming slab is reinforced for shrinkage and temperature only. Homeowners are getting crushed by flawed posttension cable. A posttension slab is a slab of concrete that has been prestressed using a specific method to increase the strength of the concrete. Before a post tension slab is poured, highstrength steel strands or cables, called tendons, are laid in a tight grid. Here, in chapter 18, which is exclusively for prestressed concrete, all the aspects related to unbonded posttensioned system are nicely described which includes criteria for pt slab as well as pt beams. In continuous or indeterminate post tensioned structures the moments due to the prestressing. Concrete slab design software economically design posttensioned and reinforced concrete floors including slabs, mats, and rafts, with exceptional visibility into compliance, efficiency, and practicality. Design publications and software for post tensioned slabs. Site preparation grade the lot for positive drainage away from the foundation during and afterconstruction. Cables are arranged as indicated by the engineer and chaired to run through the center of the slab. Cracking in groundsupported posttensioned slabs on expansive soils by ken bondy1 1 introduction posttensioned slabs are widely used as foundations for light residential construction in areas of expansive soils.
Posttensioned slabs, however, put the slab in tension after the concrete has cured. Soils are wetter at slab edge than at any point inside. Post tensioned slab on grade 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. A subsequent report established the feasibility of using post tensioning in slab onground construction and verified many of the brab assumptions. Structural engineers design concrete slabs with posttension cables to obtain greater span lengths between supporting columns and to allow thinner slabs. Jul 21, 2017 rapt is a two dimensional post tension beam slab design software. We are dedicated to providing the construction industry with engineering expertise, responsive service and manufacturing excellence to ensure safe, timely and cost effective installations, restorations and repairs. Several methods exist for prestressing concrete, with posttensioning being a very common one. The pti design procedure is used to design a slab on grade foundation that will respond elastically to forces the foundation is exposed to including those that are the consequence of soil pressure and soil deformation. A combination of these values will determine the slab stresses at the time of stressing and. Jan 17, 2019 home articles cast in place concrete vs post tension slab construction cost were currently discussing options for concrete sport courts with a client. Mar 10, 2020 posttensioning 61 posttensioning 61 component enables tekla structures to accurately model most posttensioning profiles and attributes. Post tensioning will reduce cracking and keep any cracks that might. The pti design procedure is used to design a slabon grade foundation that will respond elastically to forces the foundation is exposed to including those that are the consequence of soil pressure and soil deformation.
Need suggestions for a good pt software and design books with examples of post tensioned slabs on grade. Cast in place concrete vs post tension slab construction. Geotechnical evaluation of the design of posttensioned slabs on expansive soils using the pti third edition procedure for arizona conditions. Homeowners are getting crushed by flawed posttension cable foundations the switch from steel rebar to posttension cable by houston area home builders has delivered unmistakable results posttension cable foundations are failing earlier and. The systems used to post tension concrete and masonry consist of prestressing steel that is housed inside a duct or sheath, which allows. Posttensioned concrete design spreadsheet program a pdh. Posttensioned slabongrade 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 posttensioned foundations slabs on expansive soils. Concrete slab on grade analysis calculator for post or. Homeowners are getting crushed by flawed posttension. Top 10 biggest mistakes made in posttensioned concrete. Fundamentals of posttensioned concrete design for buildings. 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.
A square 10,000 sqft slab will require less concrete than an. Originally posttensioned, twoway slab framing systems were constructed with column and. I too, was looking for the best solution for my home. Sep 18, 2006 for example, a 5inch slab can support a 5000pound post load without additional concrete or rebar. Post tensioning is done at a project site and requires little to no modifications of the same forming system that would be used to construct nonprestressed concrete. Contractor will order and coordinate concrete batch and break test for posttension slab. Post tensioned slab on grade is more durable and economical than conventional slab reinforcement. Posttension cables are steel wires inserted into plastic sheathing laid in place while pouring the concrete slab. A post tensioned foundation is a concrete slab foundation that is reinforced with stranded steel cables that are tensioned after. Before a posttension slab is poured, highstrength steel strands or cables, called tendons, are laid in a tight grid. Calculation and the theory by which the software works are attached with this softwares index, this thing is not seen. Cast in place concrete vs post tension slab construction cost were currently discussing options for concrete sport courts with a client.
Apr 05, 2020 a post tension slab is a slab of concrete that has been prestressed using a specific method to increase the strength of the concrete. Figures 49 through 411, and 415 show configurations with insulation on the exterior surface of the foundation. Slab on grade post tensioning systems tendon systems. Its more user friendly compared to other pt design softwares. Rapt is a two dimensional post tension beamslab design software. Posttension basics how posttensioned slabs are built the. Grade the lot for positive drainage away from the foundation during and afterconstruction. Typically maximum fiber stress in tension controls design. Less concrete and steel are needed for the same structural capacity and the slab stiffness is increased so that the slab is better able to resist bending caused by differential soil movements. Economically design post tensioned and reinforced concrete floors including slabs, mats, and rafts, with exceptional visibility into compliance, efficiency, and practicality. Download free, highquality cad drawings, blocks and details of posttensioned concrete organized by masterformat. 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. Construction of post tensioned slabs on grade is very similar to using reinforcing steel, except for the tensioning step.
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