Posttensioned prestressed concrete bridge assignment design a posttensioned prestressed concrete bridge of a threespan arrangement. This report presents the structural engineering calculations of a post tensioned floor using parallel beams and oneway slab construction. Design of straddle beam by spreadsheet the creation of this spreadsheet was very involved and required a significant time investment once completed, it facilitated design well, since adjustments could be made from the summary tab, making it relatively simple to determine the required post tensioning quantity and tendon path. A more detailed guide to the design of pt floors can be found in the concrete societys technical report 43 tr43.
Caprani post tensioned in this method, the concrete has already set but has ducts cast into it. Pdf posttensioned concrete girders yatniel bustamante. A 2 2area 2 a c 2 2 post tensioned 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. The general criteria used for the design, such as details of material. Now optimum efficiency is obtained because the posttensioned reinforcing is located in the tension zones, the concrete is being compressed, and the posttensioned reinforcing is creating an uplift force in the. It is the intent of this chapter to establish the practices and specific requirements of the structure and bridge division for the design and detailing of prestressed and posttensioned concrete members. It is the intent of this chapter to establish the practices and specific requirements of the structure and bridge division for the design and detailing of prestressed and post tensioned concrete members. For post tensioned concrete bridges we need the construction stages for the evaluation of different cross section properties based on the open and filled ducts for the tendons as well as for. To validate the post tensione d glass beam concept, two 0.
Post tensioning in buildings is not limited to floor slabs. Post tensioning of foundations, transfer beams and plates, post tensioned masonry and the combination of precast elements with castinplace concrete by means of post tensioning offer other interesting opportunities. Tensioning building structures miroslav vejvoda, p. Post tensioned and reinforced concrete slab and beam design software adaptptrc product overview since 1981, adapt softwares proven reliability and easeofuse have made it the most widely used software for the design of post tensioned slabs and beams worldwide. Pretensioning and posttensioning in prestressed concrete design pretensioning in prestressed concrete. Precast post tensioned segmental construction is defined as a method of construction for bridges, buildings, tanks, silos, cooling towers, tunnels and other structures in which primary load carrying members are composed of precast concrete segments post tensioned together. Precast posttensioned concrete structures amazing facts about us since the 1980s, dutchland has been specializing in the design, manufac turing and construction of precast posttensioned concrete structures for. A detailed explanation will be given of the checksto be carried out, the aspects to be considered in the design and the construction procedures and sequences of a post tensioned slab. Distribute the positive moment reinforcement uniformly across the slab beam width and as close. Design of posttensioned girder anchorage zones by w. Post tensioned concrete beam bridge sofistik tutorials. The program is developed around the robust computational core of two popular programs ptdata. Post tensioned concrete beam bridge sofistik tutorials 2018.
Pretensioning is accomplished by stressing wires or strands, called tendons, to predetermined amount by stretching them between two anchorages prior to placing concrete as shown in fig. Guidelines for the design of post tensioned floors by bijan o. Posttensioned box girder design manual now available. The execution of the design will be explained with reference. Structural calculations for posttensioned beam and oneway. 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. Posttensioning of foundations, transfer beams and plates, posttensioned masonry and the combination of precast elements with castinplace concrete by means of posttensioning offer other interesting opportunities. Jun 22, 2016 the purpose of the initial tension is to control minimise cracking while the concrete is gaining strength. Post tensioned prestressed concrete bridge assignment design a post tensioned prestressed concrete bridge of a threespan arrangement. 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 analytical model of the bridge consists only of beam elements superstructure and columns. The anchorages to post tensioned members must distribute a large load to the.
Design of straddle beam by spreadsheet at the time of design, a midas license was not consistently available, so i ended up performing the design using a large spreadsheet the spreadsheet consisted of one tab for each construction stage, including steps for adding new structural components, aging of concrete, and placing of additional loads. This report presents the structural engineering calculations of a posttensioned flat slab supported on columns, using hong kong building code hkcop 2004 and its amendment of june 2007. The alternative to pretensioning is post tensioning. Tensioned bonded strands bonded tendons unbonded tendons internal internal external. The design steps for a post tensioned composite bridge girder were prepared with the help of several sample design calculation demonstrated.
In pt design, it is preferable to draw moment diagrams to the tensile face of the concrete section. The posttensioned system was designed to span the same lengths as the composite system while maintaining a relatively thin. Pt designer design of posttensioned concrete floors. Pdf experimental and numerical assessment of bonded and. A detailed explanation will be given of the checksto be carried out, the aspects to be considered in the design and the construction procedures and sequences of a posttensioned slab. The characteristic feature of a bonded tendon is that, by design, the. Sep 10, 2016 course study on post tension slab design. Posttensioned concrete design spreadsheet program a pdh. In simple span beams the primary post tensioning pt moments induced by the prestressing force are. What is the difference between pretension and post tension. This spreadsheet program provides for the design and analysis of posttensioned concrete oneway beam and slab systems and twoway flat plate slab systems.
In post tensioned structures, the strands are contained within ducts, except at their ends where the strands are anchored into the concrete. Structural calculations for posttensioned beam and. Post tensioned concrete design for aci 31808 slabstitch. Pdf prestressed and posttensioned concrete yatniel. Pretensioning and posttensioning in prestressed concrete. Load and resistance factor design design live load. Bonded posttensioned concrete is the descriptive term for a method of. The tensile face indicates what portion of the beam requires. Fundamentals of posttensioned concrete design for buildings part one a suncam online continuing education course. In our case we are interested only in the beam results for further design of the composite cross sections. Pt designer is a computer program for the design and analysis of linear posttensioned concrete floor systems. Posttensioned psc box girder bridge using fcm as per eurocode. This report presents the structural engineering calculations of a posttensioned floor using parallel beams and oneway slab construction.
This tutorial deals with a simple 2span post tensioned concrete beam bridge. Recommended practice for precast posttensioned segmental. The following table of prestress losses is recommended for the design of post tensioned members, and does not include friction or wedge set losses. General objectives in the design of building structures. Structural calculations for posttensioned beam and one. Pretensioning and posttensioning both method are used under prestressing process which have few edge over the orthodox nonstressed structures like more span to depth ration, higher moment and shear capacity. Caprani posttensioned in this method, the concrete has already set but has ducts cast into it. One of these issues is the lack of guidelines for the design and detail ing of the posttensioning anchorage zones. Posttensioned pt concrete floors are now widely used in the uk, particularly for highrise buildings. In pt design, it is preferable to draw moment diagrams to. The design live load hl93 consists of a design truck or design tandem and a design lane load, and a nm permit design live load p327 dead loads. The following table of prestress losses is recommended for the design of posttensioned members, and does not include friction or wedge set losses. Posttensioning in buildings is not limited to floor slabs.
Optimized posttensioning anchorage in prestressed concrete 1. Design report select the desired uls and sls enter the partial factors flexure design torsional design shear design. Follow the 10 steps of design for efficient of pt floors and beam frames learn to use the latest us and european pt design codes find out about deflection calculations which is. Fundamentals of posttensioned concrete design for buildings. Indications are given concerning preliminary design and indirect control of deflections in posttensioned flat slabs. Final post tensioning is applied after concrete reaches its design strength. The anchorages to posttensioned members must distribute a large load to the. Pti 3 structural material types structural steel prestressed concrete reinforced concrete pre. Developers, architects, engineers, contractors, educators and. The strands or tendons are fed through the ducts stage 1 then tensioned stage 2 and then anchored to the concrete stage 3. General overview of posttensioned concrete design pdh online.
Twoway posttensioned design amsysco post tensioning. In post tensioning method, tendons are coated with grease or. Exterior posttensioned band beam to column connections under. 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. This spreadsheet program provides for the design and analysis of post tensioned concrete oneway beam and slab systems and twoway flat plate slab systems. Deflecuon limits prestressing in posttensioned slabs fundamentally influences the behaviour of the structure under service loads. Continuous posttensioned beam neutral axis pt tendon aend e aint l1 l2 l3. Posttensioned and reinforced concrete slab and beam design. Posttensioned concrete is a variant of prestressed concrete where the tendons are tensioned after the surrounding concrete structure has been cast 25 the tendons are not placed in direct contact with the concrete, but are encapsulated within a protective sleeve or duct which is either cast into the concrete structure or placed adjacent to it. General overview of posttensioned concrete design instructor. This course is intended to be an introductory course for structural engineers new to post tensioned. Net, which many engineers have come to trust over the years for its accuracy and flexibility. Edition published in 1980, 2nd edition in 1996 incorporated into model building codes ubc 1997, ibc 2000 used to design millions of existing foundations.
The tensile face indicates what portion of the beam requires reinforcing for strength. Manual for refined analysis in bridge design and evaluation. Structural calculations for posttensioned beam and oneway slab construction. In the design of prestressed concrete beams, calculates and reports the required areas of reinforcement for flexure, shear, and torsion based on the beam. When moment is drawn on the tension side, the diagram. 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 attained sufficient strength to safely withstand the prestressing force as shown in fig. Guidelines for the design of posttensioned floors by bijan o. This method will be used exclusively in this course. Posttensioned buildings design and construction hardcover january 1, 2014. Tensioning building structures march 12, 2020 2020 educode las vegas. To provide a complete idea, the stress computation, the reinforcement. Posttensioned and reinforced concrete slab and beam.
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. Includes powerpoint picture presentation of examples of post tensioning from my projects. Jurgens his article presents a set of guidelines intended to t assist designers in routine post tensioning design, beginning with a discussion of the initial decisions that must be made to design post tensioned floor members. What is the difference between pretension and post tension in. Pretensioning and posttensioning in prestressed concrete design. To meet the design requirements, a low value for post tensioning had to.
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. A basic design for a posttensioned glass beam has been made. In simple span beams the primary posttensioning pt moments induced by the prestressing force are directly proportional to the eccentricity of the tendons. Includes powerpoint picture presentation of examples of posttensioning from my projects. Posttensioned and reinforced concrete slab and beam design software adaptptrc product overview since 1981, adapt softwares proven reliability and easeofuse have made it the most widely used software for the design of posttensioned slabs and beams worldwide. Posttensioned prestressed concrete bridge assignment. The construction is prestressed at the age of 7 days and put into operation at the age of 100 days. Jurgens his article presents a set of guidelines intended to t assist designers in routine posttensioning design, beginning with a discussion of the initial decisions that must be made to design posttensioned floor members. This article provides information on how to scheme a pt slab and how the use of posttensioning affects the rest of the structure. The design is based on hong kong building code hkcop 2004 and its amendment of june 2007. Posttensioned psc box girder bridge using fcm as per. When moment is drawn on the tension side, the diagram matches the general drape of the tendons. Fundamentals of posttensioned concrete design for buildings part one. This article provides information on how to scheme a pt slab and how the use of post tensioning affects the rest of the structure.
Experimental and numerical assessment of bonded and unbonded posttensioned concrete members article pdf available in aci structural journal 1126. Aci3182002 for the design of prestressed concrete sections. Tn342 design example 2way mondada 093090 adapt corporation. The following table of prestress losses is recommended for the design of post tensioned members, and does not.
887 1549 1609 902 1234 125 1003 1071 535 342 114 1423 1377 345 839 1489 1532 1597 677 98 38 1202 393 1233 416 1431 508 494 1063 1151 1498 1400