Prestress posttensioning in lusas is suitable for beams, slabs and. Impact of deterioration of post tensioned tendons in bridges. The article describes some of the commonly used techniques and precautions for detensioning tendons, repairs and restressing of tendons. Conventionally without post tensioning concrete would have to be poured very thick to handle loads, in addition, the size and length of concrete structures. Post tension slab although concrete is a strong material for construction, it is not resistant to breakdown especially where longer concrete slabs are required like in a bridge or a length of a beam. Economically design posttensioned and reinforced concrete floors including slabs, mats, and rafts, with exceptional visibility into compliance, efficiency, and practicality. Adapt corporation specializes in structural concrete design software for posttensioning, reinforced concrete, and prestressed beam, slab, foundation. Bbr contech is nzs specialist in concrete posttensioning. Post tensioning the program enables the user to define and design posttensioned concrete beams and slabs for any strap model.
If these cables are cut, nicked or in any way compromised, they can rip through the concrete and render the slab useless, or seriously injure someone. Halfen hsdld lockable dowels have been designed for use in temporary movement joints, most commonly found in post tension concrete slabs. See the adjacent software information links for general details regarding lusas. This course provides the user with a fundamental understanding of posttensioned concrete design to enable the use of a spreadsheet program. Posttensioned foundation a typical posttensioned foundation with the forms set and ready for concrete. Digital concrete scanning services construction of posttensioned slabs on grade is very similar to using reinforcing steel, except for the tensioning step. Our innovative approach and extensive experience dealing with concrete and steel strand tensioning systems allows us to provide our customers with excellent pt concrete engineering results. These dowels allow for initial shrinkage to take place and then are locked in position with a mechanical plate and a controlled amount of epoxy resin. 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. Design posttensioned and conventional systems design elevated concrete slabs with or without posttensioning.
Most precast, prestressed concrete is actually pretensionedthe steel is pulled before the concrete is poured. Nov 19, 2016 the alternative to pretensioning is post tensioning. And while code allows a licensed design professional ldp to delegate the design of the general anchorage zone to the contractor, we dont recommend taking that route. Design and software expertise in post tensioning and prestressed concrete for over 30 years, adapt corporation has provided a full range of software products and engineering services for the modeling, analysis and design of prestressed pre or post tensioned concrete structures. Jul 21, 2017 rapt is a two dimensional post tension beamslab design software. Post tensioned concrete is accomplished by tension ing high strength steel cables within the concrete mass. Post tensioning chucks post tension accessories post tensioning strand post tensioning jacks post tensioning rams. Adapt corporation specializes in structural concrete design software for post tensioning, reinforced concrete, and prestressed beam, slab, foundation. Post tensioning pt is one of the most advanced and efficient technologies used to reinforce concrete. Consider all major aspects of slab design including service, ductility, and strength limit states, codeprescribed requirements, longterm deflections, punching shear, and walking vibration. The program enables the user to define and design post tensioned concrete beams and slabs for any strap model. The compressive stresses resist the anticipated tension stresses induced by the soil movements, enhancing the performance over a nonprestressed foundation. Cables are arranged as indicated by the engineer and chaired to run through the center of the slab.
For general design philosophy and analysis of posttensioned concrete, the. Posttension cables are used in concrete construction to allow thinner slabs and greater span lengths between support columns. Software pt designer is a computer program for the design and analysis of linear posttensioned concrete floor systems. In 1971, hugh oneil created posten to enable rapid, detailed and efficient designs of post tensioned and reinforced concrete structures. Post tensioned slabs are becoming a larger part of the design and construction mix here. Posten post tensioned and reinforced concrete design. The program is divided into three separate screens, which correspond to the three major areas of concern in the design of a post tensioned. The program is developed around the robust computational core of two popular programs ptdata.
Structural calculations for posttensioned beam and oneway. Use the tabs in the component dialog box to load a previously saved pt post tensioning 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. Posttensioning concrete increases the many benefits associated with a concrete framed building. Over tensioning, bad prepration design layingcuring of concrete, bad structural design, bad load estimation and temperature, right. Post tensioned concrete design table 11 list of symbols used in the aci 31808 code m bal design moment resistance of a section with tendons and the necessary mild reinforcement to reach the balanced condition, nmm m u factored moment at section, lbin n c tension force in concrete due to unfactored dead load plus live load, lb p. Post tension slab design software mck26 structural. Software for posttensioned or prestressed structures adaptbuilder structural concrete design suite 3d fem design adaptedge analyzes complete concrete buildings for gravity and lateral loads. Eriksson software precastprestressed concrete design and. Post tensioning is a method of reinforcing strengthening concrete or other materials with highstrength steel strands or bars, typically referred to as tendons.
While concrete is strong in compression, it is weak in tension. The design of general anchorage zones is critical to the integrity of any posttensioned concrete structure and we recommend that the ldp complete this task personally. Economically design posttensioned and reinforced concrete floors including slabs, mats, and rafts, with exceptional visibility. Given the early age strength requirement, post tensioned concrete is classified as a special class concrete by as79. In this article, ill be giving homeowners some necessary information about the characteristics, advantages, disadvantages, and common questionsconcerns that i receive regarding posttensioned foundations.
Post tensioning 61 component enables tekla structures to accurately model most post tensioning profiles and attributes. Posttensioning is a method of reinforcing strengthening concrete or other materials with highstrength steel strands or bars, typically referred to as tendons. Homeowners are getting crushed by flawed posttension cable. Sep 09, 2016 course study on post tension slab design. The program provides for the ultimate strength and service stress design and analysis of oneway beam and slab and twoway flat plate systems. Our future vision pti envisions a future in which post tensioning is the first choice for reinforcing all structures. Pt designer, our latest post tensioned design software for more. Post tensioning can be used for repairs, modification and strengthening of reinforced concrete and post tensioned structures. Posttensioning methods for reinforcing concrete the. Aug 30, 2017 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 tension pt tendon systems are primarily used for large slab construction projects. Post tensioning can help create innovative concrete components that are thinner, longer, and stronger than ever before. Prestressing post tensioned concrete software design. List of contents structural design criteria for the project submitted in a separate package input data.
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. The program enables the user to define and design posttensioned concrete beams and slabs for any strap model. Founded in 1904 and headquartered in farmington hills, michigan, usa, the american concrete institute is a leading authority and resource worldwide for the development, dissemination, and adoption of its consensusbased standards, technical resources, educational programs, and proven expertise for individuals and organizations involved in concrete design. Posttensioning institute education pt applications. Top 10 biggest mistakes made in posttensioned concrete design. The rise of elevated, posttensioned concrete slab systems as our communities infill and become more dense, more multilevel structures will be introduced. Posttensioned concrete portland cement association. Post tension slab advantages and disadvantages of post. Eriksson software is an engineering software development firm located in tampa, florida. The use of post tension tendons allows the engineer to design for larger slab construction spans typically used in parking structures or high rise. The program enables the user to define and design post tensioned concrete beams and slabs for any strap model the user has full flexibility in defining the number of the cables and their shape.
Posttensioning and prestressed design and software. Highstrength steel tendons are positioned in ducts or sleeves before the concrete is placed. Net, which many engineers have come to trust over the years for its accuracy and flexibility. Post tensioned foundation information for the homeowner. Replacing it will be the first building in new zealand constructed with posttensioned lvl frames and posttensioned lvl walls. Its more user friendly compared to other pt design softwares. 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. 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. Software pt designer is a computer program for the design and analysis of linear post tensioned concrete floor systems.
Tendons today are seven highstrength steel wires wound together and placed inside a plastic duct. Posttensioned slabsonground provide a costefficient, highperformance solution for problems associated with groundsupported residential foundations on shrinkswell soils. In posttensioning it is necessary to use some types of device to attach or anchor the ends of the tendons to the concrete section. This spreadsheet program provides for the design and analysis of post tensioned concrete oneway beam and slab systems and twoway flat plate slab systems. Once the concrete has gained strength, tension is then applied, pulling the tendons and anchoring them against the outer edges of the concrete, before service loads are. Post tension cables pt cables are drawn tight with thousands of pounds of pressure. Suncoast posttension is north americas largest unbonded post tension specialist. Posten engineering systems provides the tools you need to design your structures efficiently, quickly and correctly. Posttensioning and prestressed design and software expertise. In addition, post tensioning requires tendons, which are steel wires, bars or strands with a higher tensile strength than conventional reinforcement. Since the early 1950s, post tension tendons have been used in the design of concrete structures.
Posten engineering systems structural engineering is. Demolition of post tensioned concrete structures presents the contractor with unique issues. Pt designer is a computer program for the design and analysis of linear post tensioned concrete floor systems. Whats the solution of cracks in the post tensioning slab. If you want the latest theory get gilbert and ranzis book on long term effects in concrete. Top 10 biggest mistakes made in posttensioned concrete. The forces contained within post tensioning tendons demand that owners, designers and contractors who maintain these structures have a high level of technical knowledge and skills to ensure the safety of the structure and of individuals working on, near or in the vicinity of a post. Ram concept is a software application for the structural analysis and design of conventionally reinforced and post tensioned concrete floors, mats, and rafts. In a post tensioned beam, the tendons are stressed and each end is anchored to the concrete section after the concrete has been cast and has. Once the concrete has gained strength to 2000 psi, typically within the 3 to 10 days recommended by pti, the tendons are stressed. For an excellent overview of pt, visit the post tensioning institute.
Post tensioning is the primary method of prestressing, where the tendons are stressed after the masonry has been placed. While trimble navigations christchurch officewarehouse survived the 2010 and 2011 earthquakes, it wasnt destined to last for long. Posttensioning and prestressed design and software expertise for. Pt designer design of posttensioned concrete floors. Posttensioned concrete design spreadsheet program a pdh. Design floors and foundations reliably and efficiently, saving time and money, and overcoming the most common concerns you face as a designer. Posttensioned concrete means that the concrete is poured and then the tension is appliedbut it is still stressed before the loads are applied so it is still prestressed. Economically design post tensioned and reinforced concrete floors including slabs, mats, and rafts, with exceptional visibility into compliance, efficiency, and practicality. Post tensioning is a method of reinforcing concrete. For residential construction, tendons at 48 inches on center are common.
These devices are usually referred to as end anchorages. The systems used to post tension concrete and masonry consist of prestressing steel that is housed inside a duct or sheath, which allows. 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. The rise of elevated, posttensioned concrete slab systems. Download free, highquality cad drawings, blocks and details of post tensioned concrete organized by masterformat. What is the best software to design a post tension slab. 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. For the repair and modification of post tensioning pt systems as well as post tensioned concrete structure repair and protection, structural technologies offers highly specialized products and services including investigation, repair design support, repair and replacement components, corrosion protection products, strengthening solutions as well as new or replacement post tensioning systems. Post tension slab design software structural engineering.
We specialize in analysis and design software for precastprestressed concrete in both the transportation and commercial markets. Reinforced concrete and partially prestressed concrete members to various design codes. Any software that uses long term multipliers like 2 with a compression reinforcement factor is effectively useless for. Posttensioned, reinforced concrete slab design software ram. This tek focuses on the design of concrete masonry walls constructed with vertical post tensioned tendons. Eriksson software precastprestressed concrete design. A residential post tensioned concrete slab will typically be 8 inches thick and use 3000 psi concrete. Beam line, shell surface and solid volume modelling of concrete is supported. Nov 25, 2008 post tensioned concrete is a term heard more and more in the construction industry today. New zealands leading provider of concrete post tensioning solutions. Post tensioned concrete means that the concrete is poured and then the tension is appliedbut it is still stressed before the loads are applied so it is still prestressed. Ram concept contains an advanced feature set that allows for the design of a wide variety of floor systems including post tensioned, reinforced concrete and hybrid systems, elevated slabs and mat.
This method is achieved in a process where metal or plastic tubes which contain loose tensioning cables or rods are cast into the concrete. Our future vision pti envisions a future in which posttensioning is the first choice for reinforcing all structures. Post tensioned wall construction uses standard materials. There is currently debate on how best to assess post tensioned concrete in terms of early age strength measurement and also how best to optimise mix designs for constructional applications. For this, the concrete slab is tensioned with a process called prestressing and the slab of concrete which comes out after this process is known. The results of this program have been compared to other proprietary software that. Bbr contech offers advisory, design and construction services for structural and civil engineering projects of any size and scale, including retrofitting and strengthening weakened and damaged structures. Calculation and the theory by which the software works are attached with this softwares index, this thing is not seen on other softwares. These cables, composed of steel wires inserted into a plastic sheath, are subsequently tensioned and grouted after the concrete is poured. Software for posttensioned or prestressed structures.
The purpose of this publication is to widen the understanding of posttensioned floor construction and show the considerable benefits which include minimum storey heights, rapid construction, economy. Whether you are doing a residential or commercial project, we have everything you need to get the job done. Adaptbuilder structural concrete design suite 3d fem design. Prestressing post tensioned concrete software design workshop the workshop this new pt software workshop will allow structuralcivil engineers to design pt structures quickly whilst still understanding the processes involved via a more interactive input of data and output of results. Steel is strong under forces of tension, so combining the two elements results in the creation of very strong concrete components.
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