Slab on grade post tensioning systems tendon systems. Common design methods for these slabs assume an uncracked section, where slab. Design and analysis of a commercial complex by using post. Design publications and software for post tensioned slabs on. 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.
Usually a sign in the garage or stamp in the slab will indicate if your home has a post tension slab. Post tensioned slab on grade construction is common in the west coast. Project examples to illustrate various uses of post tensioning in buildings, tendon arrangement in common floor systems, use of external post tensioning in the retrofit of an existing slab, facts and myths about post tensioned as compared to reinforced concrete slabs. Adaptsog software for the design of posttensioned slabs on grade foundations on expansive and compressible soils. The compressive stresses resist the anticipated tension stresses induced by the soil movements, enhancing the performance over a nonprestressed foundation. Unless otherwise noted, all referenced table, figure, and equation numbers are from these books. Post tensioned slab on grade is more durable and economical than conventional slab reinforcement. Slabongrade and posttensioned slab software adaptsog. Construction maintenance of post tensioned slab on ground.
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. The following example illustrates the design methods presented in aci 31805 and ibc 2003. Pt slabs offer the thinnest slab type, as concrete is worked to its strengths, mostly being kept in compression. Posttensioned slabsonground provide a costefficient, highperformance solution for problems associated with groundsupported residential foundations on shrinkswell soils. Post tensioned concrete slabs on grade offer the building owner large areas up to 4000m2 in single pours and up to 10,000m2 in coupled jointed slabs.
Posttensioned concrete design spreadsheet program a pdh. Post tension slab design software structural engineering. Cracking in groundsupported post tensioned slabs on expansive soils by ken bondy1 1 introduction post tensioned slabs are widely used as foundations for light residential construction in areas of expansive soils. See more ideas about concrete, concrete slab and toronto cn tower. Posttension basics how posttensioned slabs are built. 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. Members of the institute include major post tensioning material fabricators in the u. 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.
Post tensioning is a method of reinforcing strengthening concrete or other materials with highstrength steel strands or bars, typically referred to as tendons. Posttensioned concrete slabs augi the worlds largest. Construction of posttensioned slabs on grade is very similar to using reinforcing steel, except for the tensioning step. A post tension pt slabongrade sog foundation is based on a typical raft sog foundation with. Posttensioning is a method of reinforcing strengthening concrete or other materials with highstrength steel strands or bars, typically referred to as tendons. My background is in structural steel design and construction management. This study found size economies in iowa school districts. Can i install an underground safe room in a post tension slab. The benefits of faster construction schedules while decreasing the quantity of concrete and rebar saves money. Soils are wetter at slab edge than at any point inside. Posttensioning institute s design of posttensioned slabsonground, pti design procedure 3rd edition. The present study focuses on posttensioned flat slab systems with respect to strength, service and cost estimation. Pt slabongrade, concrete slab not shown to see tendons.
Need suggestions for a good pt software and design books with examples of post tensioned slabs on grade. Design floors and foundations reliably and efficiently, saving time and money, and overcoming the most common concerns you face as a designer. Posttensioned pt slabs are typically flat slabs, band beam and slabs or ribbed slabs. Prestress concrete unbonded posttensioning youtube. Economically design post tensioned and reinforced concrete floors including slabs, mats, and rafts, with exceptional visibility into compliance, efficiency, and practicality. In building structures, an initial post tension is applied within 24 hours or so, when the concrete reaches a certain strength about 7mpa from memory. The area within the foundation walls has to be free of vegetation, top soil or other. For a lightly loaded industrial floor, the slab is placed 4 inches thick with tendons in both directions at 2 to 5foot intervals. Pt slabs offer the thinnest slab type, as concrete is worked to its strengths. Post tensioning imparts an internal compressive force into the concrete. View rashid ansaris profile on linkedin, the worlds largest professional community.
Calculation and the theory by which the software works are attached with this software s index, this thing is not seen. 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. Posttensioning institute education education programs. What is the best software to design a post tension slab. Twoway posttensioned design amsysco post tensioning. Code requirements for concrete slabs on grade evstudio. Once the slab cures, qualified personnel apply tension and grout the cables. If you know what year your home was built andor which builder was used, we may be able to help you over the phone.
Us20030233798a1 posttensioned, belowgrade concrete. Jul 21, 2017 rapt is a two dimensional post tension beam slab design software. Superior post tension specializes in fullservice fabrication and installation of slab on grade post tension applications. Inserting tendons in the concrete is a very tedious and timeconsuming procedure, even if we do it just as 2d annotation. 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. As we all know, autodesk revit doesnt provide posttensioned concrete modeling. Shrinkage crack considerations for posttensioned foundations. The entire slab is also bearing on the soil and can distribute a surprisingly large amount of load. The systems used to post tension concrete and masonry consist of prestressing steel that is housed inside a duct or sheath, which allows. A below grade, post tensioned concrete foundation system for use in the construction of residential dwellings and other structures is described. The program is divided into three separate screens, which correspond to the three major areas of concern in the design of a posttensioned member. The purpose of the initial tension is to control minimise cracking while the concrete is gaining strength. An animation movie which illustrates almost all the activities related to mono strand unbonded post tensioning system. Shrinkage crack considerations for post tensioned foundations june 1, 2015 shrinkage cracks in concrete slab on ground foundations are a significant public relations problem to home builders.
Cracking in groundsupported post tensioned slabs on. The present study focuses on posttensioned flat slab systems with respect. There has recently been a lot of discussion regarding to a post tension, or pt slab on grade and a pier and beam foundation. The thin post tension slab on grade is not a good solution for the foundation of light. Several methods exist for prestressing concrete, with post tensioning being a very common one. The designs were analysed using adapt builder software with different panel. Reinforced concrete building design sketch up animation. The foundation includes a post tensioned concrete floor slab formed on the soil base of a below grade excavation. Browse mls listings in lafayette and take real estate virtual tours at realtor. 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. Posttensioned, reinforced concrete slab design software ram.
With capabilities to support residential projects from design through construction, spt provides national home and apartment builders, as well as custom home professionals, with the best protection for their new construction investments. The designs were analysed using adapt builder software with different panel sizes. Posttensioned slabs are typically flat slabs for that reason they are best suited for. Adaptsog slabongrade design software, sog foundation with soil. For residential construction, tendons at 48 inches on center are common. Mar 27, 2018 the international residential code irc lays out a series of requirements for pouring a concrete slab on grade. Doc a study on posttensioning slab ajay nagaraj academia. Grade the lot for positive drainage away from the foundation during and afterconstruction. In a post tensioned slab on grade, a grid of highstrength post tensioning tendons replaces the weldedwire fabric or conventional rebar normally used. Longer spans can be achieved due to prestress, which can also be used to counteract deflections.
Post tension slab design software sethguthrie civilenvironmental 18 aug 16 19. Our future vision pti envisions a future in which post tensioning is the first choice for reinforcing all structures. What is the difference between pretension and post tension in. Post tension cables are steel wires inserted into plastic sheathing laid in place while pouring the concrete slab. Posttensioning institutes design of posttensioned slabsonground, pti design procedure 3rd edition. Information on constructing posttensioned slabs on grade. Contractors sometimes need to drill or cut into a post tensioned slab for repair or renovation work. You may also consider contacting your geotech, he or she could get you more information on other projects they may have down in that area. Structural engineers decision on soil bearing area used for. A square 10,000 sqft slab will require less concrete than an irregularly. Jun 22, 2016 post tension is where the tensioning is applied to hardened concrete. Rashid ansari chamions school of real estate houston. Cables are arranged as indicated by the engineer and chaired to run through the center of the slab.
All concrete will shrink during the curing process which lasts up to a year after the time concrete is placed in the forms. Rapt is a two dimensional post tension beam slab design software. The post tension institute pti has a design manual for a post tensioned slab on grade. Jul 27, 2009 thats how a wall on grade or footing foundation works as the basics learned in school. An installation, stressing and post construction activities such as making a. Before a post tension slab is poured, highstrength steel strands or cables, called tendons, are laid in a tight grid. Its more user friendly compared to other pt design softwares. I too, was looking for the best solution for my home. Slab on grade post tensioned concrete slabs on grade have become an integral part of building large cost effective and durable floor slabs. This spreadsheet program provides for the design and analysis of posttensioned concrete oneway beam and slab systems and twoway flat plate slab systems. The solution for soil stability challenges soil stability must be a consideration in the design and construction of any type of structure, irrespective of the region or surface appearance. The greatest advantages of post tensioned slabs on grade are the considerable reduction of the necessity for expansion joints being the most sensitive part of these structures and no cracks in concrete resulting in longer service life, enhanced quality and considerable lower costs of maintenance. 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.
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