Post Tension Slab Cutting

It should be kept in mind that no cutting or drilling should be done to post-tensioned concrete slabs, because once a tendon is cut, it becomes complicated to repair. TendonScan ® is a comprehensive post tension tendon inspection service that utilizes the latest in non destructive evaluation (NDE) and nondestructive testing (NDT) technologies to locate and assess voids, water, bleeding grout (grout not cured) as well as section loss (loss of metallic area) and corrosion in external tendons of segmental structures. (PTSI) provides cutting-edge engineering solution. One contractor. Post-tensioned concrete means that the concrete is poured and then the tension is applied-but it is still stressed before the loads are applied so it is still prestressed. Termite problem solved. " Our recent article in Master Builder Magazine on "Combination of Unbonded Post-Tensioning with Void Slab". Question of anchoring gunsafe to post tension slab I searched on this and didn't find anything in this forum and not too much with a google search. Bonded and unbounded post-tension structures present unique challenges for maintenance and repair. We were recently contracted to locate and identify post-tensioned cables in a structural slab on the top floor of a parking garage. For slabs, it’s best to cut through the top inch, then use a sledgehammer to break off the rest. I have the cables marked already. Is this a code requirement (code and section please), good. You may not know it but if you own a modern home you probably have a post-tension slab. Although some post-tensioned slab structures had been constructed in Europe quite early on, the real development. Certification. Tensioned Concrete specialises in providing efficient design alternatives to fully reinforced slabs, equating to cost savings by simplifying formwork, decreasing reinforcement, reducing concrete thicknesses, and cutting overall project time. Post-Tensioned Box Girder Section 13. In Post-Tension slabs construction, is there a code requirement (IBC, ACI, etc. After relaxation and other losses, stress in the strands is ~65% of their ultimate tensile strength. Many post-tensioned slabs are often stamped to alert workers, as well as owners, in case any renovations take place in the future. Tendons today are seven high-strength steel wires wound together and placed inside a plastic duct. Working with light and versatile stressing tools enables site operators to increase stressing efficiency and productivity. However, because the continuous two-way tendons had to be placed in a draped parabolic profile -near the top of. 2mm) suitable for suspended high rise construction, to complex multi strand systems used in heavily profiled transfer slabs. If you have 2" PVC, chip away enough concrete to replace the drain and go from there. Just fill it !. The Fonterra Co-Operative Group Ltd's milk powder storehouse in Te Rapa incorporates the largest post-tensioned concrete slab constructed in New Zealand, with a combined area of 50,000 m2. Other stroke lengths are available on special order. Is it safe to cut the post tension concrete slab foundation to fine sewer line for bathroom addition? No, You must first locate the P. Keep current and future building owners and tenants from damaging post tension slabs along with the structural integrity of your work. Pre-Tensioning b. Post tension slab is the foundation of choice around Texas with the exception of few enclaves and the older homes. PT slabs offer the thinnest slab type, as concrete is worked to its strengths, mostly being kept in compression. Background: The building is a 3-story building for elderly and handicapped on the Mississippi coast that was built in the early 1980's. T cables, and because you said it is to find a sewer line im. Table of Contents General Post-Tensioning Manual, 5th Edition 1. All deeper than the cables. The shrinkage and creep losses are also more in pre-tensioning system. tensioned phrase. Post-tension and pre-tensioned (PT) cables are commonly used in concrete construction to facilitate thinner slabs and greater span lengths between support columns. A thin rubber pad placed in the joints between slabs minimizes stress concentrations due to surface irregularities. If larger openings are essential in post stressed accessories, they can often be treated in the same way as traditional reinforced concrete slabs because the outcomes of cutting through a bonded tendon remain localised and also the rwkhni redevelops its bond each side of the cut, typically within 1m. University of Houston Master Construction Specifications Insert Project Name AE Project Number: Post Tensioned Concrete 03 38 00 – 3 Revision Date: 1/29/2014 1. Post Tension Cable Suppliers Ready to Support Your Project. PT slabs provide the leaner slab type, as concrete functions to its strengths, mostly being maintained in compression. Keep current and future building owners and tenants from damaging post tension slabs along with the structural integrity of your work. The benefit associated with the added cost of post-tensioning a reinforced concrete stiffened slab is not clear. TYPES OF SLABS CCL post-tensioned slab systems can be integrated into any type of slab, including flat, ribbed or waffle slabs, which may include drop caps, drop panels or band beams to produce optimal configurations. Detensioning Unbonded Post-Tension Tendons Posted on July 28, 2011 by Neel Khosa On rare occasions, the ironworker/installer will need to detension an already-stressed post tensioning tendon. I have to access some plumbing in my home, and I would like to know what the proper way is to cut into the post tension concrete slab that my home sits on? What would be the proper materials to use to fill in the area that was cut out when finished?. Post-tensioned slabs use high-strength tensioned steel strands to compress the slabs, keeping the majority of the concrete in compression. tendons anchored in block-out at the edge of top slab cantilever wing. It is supplied with a connection with the greased strand covered in polyethylene, the corrosion protection is provided by means of passivation while grouting. Originally post-tensioned, two-way slab framing systems were constructed with column and middle strips, similar to those used in conventionally reinforced two-way slabs. Re: Post-tensioned slab demo The "risks" in demo'ing a PT slab are two things- death and dismemberment. Tendons, reinforcement bars and services can be easily located and marked on the surface of the slab using radar or x-ray. Now that being said, you still need to take precautions, but post tension slabs are usually 10"+ thick. If your location is an area with expansive soils, always assume the slab is post tensioned. The hazard exists when workers cut into the slab and rupture the. It is a recognized leader in the field of concrete construction and has grown to become one of. To create shorter members, dividing plates can be placed at any point along the member which, when removed, permit the cutting of the wires. flush into slab edge The Po st Tension Plug is used at the stressing end of a Post Tension cable after the cables have been stressed, cut, and the grease cap has been applied. 0 INTRODUCTION Post-tensioned floor slabs in Australia and South East Asia are now universally regarded as the most cost effective form of construction for shopping centres, office buildings, and carparks where spans exceed 7. Its not easy to cut one of these cables. Bryce, because of the age of your rental house, I don't think you are going to encounter a problem with post-tension cables. Termite problem solved. Post tensioning is a tehnique for reinforcing concrete. All relevant post-tensioning design documentation should cross reference to this CARES Model Specification 4th edition and in particular to the requirements of Clause 1(a). Surfaces are stained or coated. cable that ran through the concrete slab when the concrete fractured and the post-tensioning device lost its base. Any misalignment of duct shall be rectified. This can reduce congestion in members. One contractor. A pioneer in prestressing, Freyssinet offers a cutting edge post-tensioning system combining performance and durability. (Unbonded post-tensioning) Active 1E15-A1 assembled anchorage The anchorage: active and unbonded, "1E15-A1" type. Localized corrosion may require splicing and re-stressing a strand. ***** PART 1 GENERAL 1. Although some post-tensioned slab structures had been constructed in Europe quite early on, the real development. The work was completed with the assistance of Conset Construction. In a single strand, called monostrand post-tensioning system, the tendon consists of a single 7-wire steel strand, P/T coating, fixed end anchorage, stressing end anchorage. April 15, 2020. The pad and nominal post-tensioning stress level prevent water. I was on a hotel project, where all the floors were post cable tensioned, and a separate Xray company wall called out for Xrays for before any coring / cutting in slab. Post-tensioning utilizes high quality high strength steel such that 1 kg of post-tensioning strand may replace 3 or 4 kg of ordinary non-prestressed reinforcement. Unfortunately, when the plumber was cutting holes for the new plumbing, he hit a pair of post-tension tendons. Often it is necessary to cut holes in concrete floor slabs. It should be kept in mind that no cutting or drilling should be done to post-tensioned concrete slabs, because once a tendon is cut, it becomes complicated to repair. Updated March 8th, 2019RCC slab can be various types depending on various criteria. My plumber cut a post tension cable when jack hammering my concrete slab to install new bathroom drain lines. He was releasing the pressure on the 1/2 in. It is supplied with a connection with the greased strand covered in polyethylene, the corrosion protection is provided by means of passivation while grouting. Concrete scanning to locate reinforcing, tension cables and in-slab services is essential prior to cutting, coring and drilling in concrete structures. In the case of a post tension slab, steel cables are laid out in grid fashion inside the forms. CCL Post-Tensioned Slabs show reduced cracking. Thanks TXStructural for your post. We offer our post-tensioning products and services to single family homes, multi-family housing, tennis courts, commercial slabs on ground, and high-rise commercial structures. Satish Jain, PE, SE Managing Director Satish Jain Consulting Engineers Pvt. To assist in the design of these structures the Highways. Anchor castings are available for strand Sizes 600", 1/2", 7/16" and 3/8". He says if cut it would move about 3 inches in the slab and not go shooting out the side of the foundation. The cable is going to be in the centre of the slab. I assume that you known about RCC now what happens in prestress structure intensionally stresse. Post Tension Cable Warning Markers Recommended for Post-Tension Concrete Contractors. Post-tensioned slabs can be installed much faster than reinforced slabs. KingFlor® KF40® Fielders KingFlor® KF40® SquashCut™ is a revolutionary steel formwork product highly suitable for all types of concrete slab construction. Moment ® Corrugated Duct is used as a duct former for a variety of precast and cast-in-situ concrete work. Post-tensioning of foundations, transfer beams and plates, post-tensioned masonry and the combination of precast elements with cast-in-place concrete by means of post-tensioning offer other interesting opportunities. Sections are tension-controlled when the tensile strain in the extreme tension. The alternative to pre-tensioning is post-tensioning. Post tension slab construction is common in areas with expansive soils. Generally, post-tensioned (PT) slabs belong to flat slabs, band beam and slabs or ribbed slabs. Post-tensioning provides high strength and stability, but looks just like any other concrete slab. Contractors sometimes need to drill or cut into a post-tensioned slab for repair or renovation work. Slab is approx. The low-stress way to find your next post tensioning engineer job opportunity is on SimplyHired. recommendations to accomodate the use of post-tensioned slab foundations for the eight single-family homes to be constructed for the subject project. KingFlor® KF40® Fielders KingFlor® KF40® SquashCut™ is a revolutionary steel formwork product highly suitable for all types of concrete slab construction. I can't imagine that the post-tension cables will even enter into the equation. c) Supporting the nearby area of slab which is to be cut by help of structural steel members. This method is a better way than using a basic rebar grid to construct a slab foundation to be more resistant to cracking and deflection. Slabs - Design Strips. To minimise. We had to use a specialty contractor to cut through the tendons of the original post tension deck for the main elevator core that includes the central wrap stair. It is a recognized leader in the field of concrete construction and has grown to become one of. Concrete Services. Here, in chapter 18, which is exclusively for Prestressed Concrete, all the aspects related to unbonded post-tensioned system are nicely described which includes criteria for P-T slab as well as P-T beams. Generally, post-tensioned (PT) slabs belong to flat slabs, band beam and slabs or ribbed slabs. Post Tension Cable Locators, Inc. Although some post-tensioned slab structures had been constructed in Europe quite early on, the real development. Post-tension and pre-tensioned (PT) cables are commonly used in concrete construction to facilitate thinner slabs and greater span lengths between support columns. VSL has more than 50 years experience in designing, manufacturing and installing durable, state-of-the art post-tensioning systems. I have the cables marked already. Tunnel leaves your home's interior is not subject to possible mold or gasses under the slab. They allow increased spans to be achieved with thinner concrete sections. Post-tensioned concrete slabs in buildings have many advantages over reinforced concrete slabs and other structural systems for both single and multi-level structures. 6-8 inches thick with rebar. If you’re after a cost-effective tension kit then look no further. AEC Construction Details - AutoCad. 03365 POST-TENSIONED CONCRETE ***** SPECIFIER: CSI MasterFormat 2004 number 03 38 00. The post-tensioning of the foundation slab with installed longitudinal and transverse tendons had to be carried out within a very short period of time, since the concrete had cured after three days. Generally, post-tensioned (PT) slabs belong to flat slabs, band beam and slabs or ribbed slabs. TN340_beam_slab_shell_082509 STRUCTURAL CALCULATIONS For Post-Tensioned BEAM AND ONE-WAY SLAB CONSTRUCTION ROYA CONSTRUCTION Building Division Technical Services Unit Kowloon August 16, 2009 - revised. Whether you need assistance with a concrete foundation, concrete reinforcement, post-tension concrete repair or concrete construction in general, we can help. Constructing on top of an existing structure has brought many unique challenges not normally faced when building a typical parking garage. Our slab post-tensioning system offers all the stakeholders in a building project many benefits including reduced structure depth, greater clear spans, design flexibility, formwork versatility, reduced construction costs, enhanced construction speed, improved durability, minimum maintenance costs and reduced carbon footprint due to less concrete and steel required. Three ultimate tests were carried out by Patrick and Lloyde to compare the structural response of a composite slab, a post-tensioned solid slab and a post-tensioned composite one prepared with KF57 steel deck produced by Fielders. FULL-SCALE FIRE TESTS OF POST-TENSIONED TIMBER BEAMS Phillip Spellman1, David Carradine2, Anthony Abu3, Peter Moss4 and Andrew Buchanan5 ABSTRACT: This paper describes a series of full-scale furnace tests on loaded post tensioned LVL beams. Post tension slab construction is common in areas with expansive soils. In Post-Tension slabs construction, is there a code requirement (IBC, ACI, etc. Using cutting-edge technologies, CCL Scandinavia specializes in the design, supply and installation of vertical post-tensioning systems, post-tensioned slabs and post-tensioning for civil structures. • External post-tensioning: External PT is mostly used in strengthening existing structures or for replacement applications where previous designs do not meet updated standards. Alibaba offers 151 Post Tensioning Machines Suppliers, and Post Tensioning Machines Manufacturers, Distributors, Factories, Companies. US5044139A - Method of replacing post tensioned beams - Google Patents FIG. Contractors responsible for the renovation of the slab have to avoid cutting any of these. CONCLUSION RTS (along with tendon corrosion) is one of the two biggest problems ever faced by the post-tensioning industry. The main reason for using post-tensioned slabs on ground is to eliminate joints. There is inherent risk of striking rebar, electrical and communications conduits, and post tension cables during cutting, coring or drilling process. For this, the concrete slab is tensioned with a process called pre-stressing and the slab of concrete which comes out after this process is known. Halfen Moment is a leading provider of post-tensioning and prestressed system throughout Asia and Middle East over the past 25 years. SAFE is a software tailored for the engineering of elevated floor and foundation slab systems. post-tensioning can be used in substructures. If your location is an area with expansive soils, always assume the slab is post tensioned. Originally post-tensioned, two-way slab framing systems were constructed with column and middle strips, similar to those used in conventionally reinforced two-way slabs. Photo Album Gallery Place Holder - Please wait while the Photo Album loads. The entire dinner was so awkward you could cut the tension with a knife. Prestressed Cable Pusher Machine, PC Strand Pusher, PC Strand Pusher Machine manufacturer / supplier in China, offering Prestressed Cable Pusher Machine for Post-Tensioning Concrete Slab, Beautiful Blasting Chamber Automatic Sandblaster Room Price, Automatic Abrasive Sandblaster Cabinet Cleaning Equipments and so on. The different forms of construction used in a number of more or less conventional structures built during the last few decades will give rise to a variety of problems when the time comes for them to be demolished. I went into a garage during an inspection yesterday. post-tensioned reinforcing is installed in a draped profile instead of running in a straight line. Post-tensioning provides high strength and stability, but looks just like any other concrete slab. With new build construction and renovation projects, the likelihood of needing to cut or core a concrete slab is high. Is this a code requirement (code and section please), good. Turek said. advantages of post tensioned slabs. Post-tension cable is stretched after the concrete hardens. This allows us to avoid rebar, post tension cables, conduit, pipes, and wires to provide the safest and most precise cut. Post-tensioning acts on the concrete structure or elements by compressing. Its not the same as rebar. If the moment varies along the length of a Design Strip then the individual design cuts will show a varying amount of moment demand at each section. Moving a drain with a Post-Tensioned slab? Not a good idea if you're talking about saw cutting and breaking up enough of the slab to inset one. The original installer of the post-tension strands came out and repaired it under the supervision of the original engineer. With new build construction and renovation projects, the likelihood of needing to cut or core a concrete slab is high. Bryce, because of the age of your rental house, I don't think you are going to encounter a problem with post-tension cables. 2mm) suitable for suspended high rise construction, to complex multi strand systems used in heavily profiled transfer slabs. It can be a hassle figuring out what to do and how to approach the break. Wolf Concrete Construction strives to provide customers with high quality products, safely and at a competitive price. Freyssinet’s technical services design anchors, jacks and installation equipment, and operate a laboratory and test centre for the formulation of grouts. A post-tensioning anchor 14 is disposed at the inside face of the pocket. University of Houston Master Construction Specifications Insert Project Name AE Project Number: Post Tensioned Concrete 03 38 00 – 3 Revision Date: 1/29/2014 1. The bridges listed here have been identified by their respective states as having some exceptional quality and consequently will continue to be considered individually pursuant to Section 106 of the National Historic Preservation Act, as will those post-1945 common. Precast Concrete Pavement Systems Save Time, Cut Congestion on Highway Repair Portland Cement Association / May 10, 2010 Precast concrete pavement systems—cast off-site and installed quickly when traffic volume is low—have the potential to transform highway renewal and repair in high-traffic areas. of tension. If the concrete slab has a reasonable amount of compression for its full depth, theoretically it can never crack (see previous crack discussion). , Winnipeg, Manitoba. I want to sound somewhat educated when talking with contractors. Precast post-tensioned segmental construction is defined as a method of construction for bridges, build-ings, tanks, silos, cooling towers, tunnels and other structures in which primary load carrying mem-bers are composed of precast con-crete segments post-tensioned to-gether. 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. We are dedicated to expanding post-tensioning applications through marketing, education, research, and code development while advancing the quality, safety, and use of post-tensioning systems. According to Concretenetwork " Post tensioning is a technique for reinforcing concrete. Power Team Monostrand Stressing Jacks are the most durable in the industry. The cost of such mistakes can be prohibitive. Rebar reinforcement in this case is technically allowed by code but in our experience, a properly designed post-tensioned concrete slab will minimize cracking due to shrinkage. 1 SUMMARY A. This guide is applicable to PT flat slabs, PT beams and PT band beam slabs. 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 cast-in-place method of. cable that ran through the concrete slab when the concrete fractured and the post-tensioning device lost its base. There is an existing garden tub and an adjacent shower stall. “Do not core holes or saw-cut through existing post-tensioned slabs, for example when relocating net posts or adding a shelter where foundations are required,” adds Wright, “as there is danger if cables are cut. The hazard exists when workers cut into the slab and rupture the. MODULE 3 - BREACHING-BREAKING-CUTTING- BURNING SM 3 3 Types of concrete nPeople often misuse the word cement and concrete. We now apply this post tensioning expertise to the construction of specialised containment structures. • Grout tendons. These options should be decided before the construction and could increase the initial cost of the project. Surfaces are stained or coated. Bijan O Aalami Reviewed by : Russell Price Peter Reinhardt SYNOPSIS This Technical Note presents the layout and profile of post-tensioning tendons, and the layout of supplemental non-prestressed (passive) reinforcement for post-tensioned floor systems. On August 12, 1999, Employee #1 was operating an Owatonna post-tensioning device, model B, serial # 333487D, at 5,600 psi on a concrete slab. If you really want to move the drain then have someone come in and x-ray the slab. The effect is a spring-loaded slab that is resistant to any movement and most cracks. This structural solution is commonly used in concrete construction where the post-tensioned composite slab spans between reinforced or prestressed band beams, as illustrated in Fig. As a result of the GPR survey, no rebar or post tensioning cables were cut during the coring activity. This is particularly true for post tension cable systems. Manufactured using high quality ductile iron and meet or exceed the requirements of the Post Tension Institute and International Building Code. e) Cutting the slab area with Saw cutting machine. I called the local building dept to check if our client’s home had Post Tension Cables in the concrete slab. Southern Post Tension provides the highest level of post tension repair and construction service. Construction of (B1+G+9) Post Tensioning Slab under supervision of Inam Construction LLC, Muscat, Oman (Area – 15000 Sqm. Can A Post-Tension Slab (in DFW homes since mid 1990's) Be Cut For Under Slab Repairs?. STRENGTHENING TECHNIQUES Slab Sl One cantilever of Slab S 1 was strengthened using near surface mounted Leadline CFRP bars while the other cantilever remained unstrength­ ened. Post tensioning is the prestressing of a concrete member by tensioning the reinforcing tendons after the concrete has set What is difference between pre tension and post tension precast girders of. Regarding the possibility of re-bar in the slab, my advice is to call a good concrete or plumbing subcontractor for their appraisal. Surfaces can be stained or overlaid. The cable tension literally squeezes the concrete together and, if a cable is cut, the release of the tension unleashes an explosive force, like cutting a taut elastic rope, that damages the slab and may cause injury to anyone nearby. The real neat thing with top-side insulation of a slab is that you get to deal with the thermal bridge problem of brick veneers. If you hit a cable, you will know it. A pioneer in prestressing, Freyssinet offers a cutting edge post-tensioning system combining performance and durability. Is it safe to cut the post tension concrete slab foundation to fine sewer line for bathroom addition? No, You must first locate the P. Detail horizontal curvature of tendons at block-outs, openings and. In these areas, constructing a post-tension slab instead of a traditional slab is a good choice, because post-tensioning strengthens the foundation, allowing it to resist the effects of shrinking and swelling soil. Ideally suited for work on slab-on-grade where dirt, heat and high volume use take their toll. The strength and durability of concrete depend chiefly on the amount of water used. If it is a post tension slab you are referring to and NO you cannot cut through it without VERY careful planning. Looking back over the growth of post-tensioned concrete for 5 decades, and the early efforts to solve the shortening problems, it. If larger openings are essential in post stressed accessories, they can often be treated in the same way as traditional reinforced concrete slabs because the outcomes of cutting through a bonded tendon remain localised and also the rwkhni redevelops its bond each side of the cut, typically within 1m. Locating and cutting of post tension cables for the installation of a storm shelter How to Safely Fell or Cut Down a Tree ‫‬Very good video showing step by step Post tension slab. Post-tensioning method. Home is slab on grade, no evidence of post tensioning, nor any existing cracks in drywall. Ready Cable engineers and fabricates rebar and post tension cables. However, Concrete X-RAY technology is still useful in some rare cases. The used method. April 15, 2020. Another advantage of this post-tensioning system for this type of application, is that it can be used on site with low labour requirements and precisely defi ned results. Some post-tensioned structures were built in Europe quite early on but the real. They allow increased spans to be achieved with thinner concrete sections. Southern Post Tension provides the highest level of post tension repair and construction service. 1 January, 2017 37 After Post-Tensioning After Post-Tensioning • Inspect structure for damage priorto cutting strands. POST-TENSIONING ASSOCIATION. " Our recent article in Master Builder Magazine on "Combination of Unbonded Post-Tensioning with Void Slab". The cost of such mistakes can be prohibitive. Slab is approx. The main reason for using post-tensioned slabs on ground is to eliminate joints. post-tensioning for strengthening of structures are diverse and only limited by imagination. Post-Tensioning Tendon Type Prestress Loss-PSI Slabs Beams & Joints Stress Relieved 270K Strand 30,000 35,000 Low Relaxation 270K Strand 15,000 20,000 Bars 20,000 25,000 The diagram on this slide illustrates the impact of friction and wedge set (i. Benefits of using GPR: GPR is a real-time NDT technique that quickly locates the position of post tension cables, rebar, and electrical conduits embedded in concrete, eliminating dangers associated with cutting or drilling and the high costs required for their repair if cut or damaged. What Are Post Tension Cables & What Are Their Benefits? Post tension cables are used in concrete construction to add strength to thin and long slabs. Using the post-tensioning method of prestressing enables a builder to get all the advantages of prestressed concrete or masonry while still enabling the freedom to construct the member (slab, wall, column, etc,) on the job site in almost any shape or configuration imaginable. I have to access some plumbing in my home, and I would like to know what the proper way is to cut into the post tension concrete slab that my home sits on? What would be the proper materials to use to fill in the area that was cut out when finished?. pression stress in the concrete under full design loads. He received his PhD from the University of London, England, and is the author of the ADAPT Post-Tension-ing Software System. Homeowners can maintain the value of their homes with this High Quality repair method. It is a post tension slab; however, I've got that covered. Post-tensioning utilizes high quality high strength steel such that 1 kg of post-tensioning strand may replace 3 or 4 kg of ordinary non-prestressed reinforcement. << Return to Program Comment for Common Post-1945 Concrete and Steel Bridges page. Water entering the sheathing may cause corrosion in multiple locations. Working for client accross Malaysia, Singapore, India and Philippines, we supplies a cutting-edge post-tensioning system & accessories combining performance, durability and more environmentally friendly solution. Metro Testing + Engineering’s scope of service for a typical post tension concrete slab or beam of concrete includes observation and review of material handling and storage and assisting with the flow of Post Tensioning information and compatibility for all materials. Post-tensioning is a special form of prestressed concrete in which the prestressing tendons are stressed after the concrete is cast. This is a typical concern for those purchasing new construction who are not familiar with post tension cable reinfored foundation construction methods and soils conditions in our area. Such as ribbed slab, flat slab, solid slab, continuous slab, simply supported slab etc. On August 12, 1999, Employee #1 was operating an Owatonna post-tensioning device, model B, serial # 333487D, at 5,600 psi on a concrete slab. At times with out realizing it. Perpendicular to the tendons, the banded tendons run with the columns. If more bearing is needed, it's possible to cut through the slab and pour a pad footing. Surfaces are stained or coated. Many homes and commercial buildings have post tension cables running through the concrete slabs as a reinforcement. This may weaken the structural strength of the slab. The post-tensioning system consists of a flat duct filled in with 4 prestressing strands, and live or dead-end anchorages. May result in serious injury". The work was completed with the assistance of Conset Construction. A residential post-tensioned concrete slab will typically be 8 inches thick and use 3000 psi concrete. Post tension strands require repair for many reasons. He was releasing the pressure on the 1/2 in. VSL has more than 50 years experience in designing, manufacturing and installing durable, state-of-the art post-tensioning systems. CCL Post-Tensioned Slabs show reduced cracking. 3 - OSHA’s Request for Information - Reinforcing Steel and Post-Tensioning Safety Issues Sample Letter to OSHA OSHA Docket Office Docket No. Post tension slab construction is common in areas with expansive soils. HT Strand must be cut by using cut-off wheel/abrasion blade. Our concrete cutting is affordable, fast and accurate. Post-tensioning is a method of strengthening concrete using high-strength steel strands or cables, typically referred to as tendons. Project Value : OMR 69,300. An easy way to verify if the slab is post tension is to look along the concrete below the garage overhead door for a stamp warning "Post Tension Slab Do Not Cut or Drill". I think he was seeing rebar. In Post-Tension slabs construction, is there a code requirement (IBC, ACI, etc. A thin rubber pad placed in the joints between slabs minimizes stress concentrations due to surface irregularities. However, for post-tensioned (PT) slabs, this can be mistakenly regarded as difficult, expensive, and dangerous. The Fonterra Co-Operative Group Ltd's milk powder storehouse in Te Rapa incorporates the largest post-tensioned concrete slab constructed in New Zealand, with a combined area of 50,000 m2. 0 INTRODUCTION Post-tensioned floor slabs in Australia and South East Asia are now universally regarded as the most cost effective form of construction for shopping centres, office buildings, and carparks where spans exceed 7. If the tendons are bonded, then holes can be cut without much hassle, maybe just resulting in a bit of cracking at reentrant corners. Reduced the cap step height detailed on the Bents and modified the Approach Slab concrete quantities to account for the adjustment in the asphalt wearing surface on the bridge. Products of Iron castings for Post Tension System. Pre-Tensioning b. 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. Converting the structure involved creating a new grid on top of the existing podium structure, and to accommodate offsets between tower and podium grids, crews erected a 60-inch thick, two-way post-tension transfer slab on the structure’s 30th floor, an undertaking involving 2,253 cubic yards of 6,000-psi concrete and two continuous pours. 13' thick slab? I assume you mean 13", a perimeter beam could be 13' deep. research objective was to build the slab without saw-cut shrinkage control joints; pre-stressing would compress the concrete to prevent shrinkage cracking. First get clear with that normal slab is reinforced concrete(RCC) structural element whereas post-tension slab is prestressed concrete (PSC) structure. If the concrete slab has a reasonable amount of compression for its full depth, theoretically it can never crack (see previous crack discussion). Post-tensioned concrete is accomplished by tension-ing high strength steel cables within the concrete mass. Particularly in the 1970s and 1980s, many buildings in Calgary were built with post-tension cable construction in one or more of the horizontal concrete slabs. If you have 2" PVC, chip away enough concrete to replace the drain and go from there. PT slabs on ground can be placed and stamped just like with any other concrete slab. STAGES OF POST-TENSIONING. Locating and cutting of post tension cables for the installation of a storm shelter How to Safely Fell or Cut Down a Tree ‫‬Very good video showing step by step Post tension slab. The foundation gains tensile strength when the cables are tightened after the slab has been cast. The project is in the north east where this type of construction is cost effective for poor soild situations when there is a high live load(250psf)on the slab. • Once the grout is set up the bridges will be supported sufficiently to allow for the post-tensioning work to take place. Scoring involves drawing a cutting wheel firmly across the surface of the tile, making a deep incision. Standard single-acting units have a 10" stroke. A thin rubber pad placed in the joints between slabs minimizes stress concentrations due to surface irregularities. See salaries, compare reviews, easily apply, and get hired. Concrete answers on post tensions slabs The tendons are under a lot of tension. Post-Tensioned Slabs 08/09 STRUCTURAL DESIGN Post-tensioning tendons are virtually replaced in the slab by the set of forces they exert on it: compression along the slab perimeter, upward forces in the spans and downward forces over 3D tendon Finite element Stress the supports. Surfaces are stained or coated. e 10/2017 modernization of existing mumbai international cruise terminal (mict) at indira dock, mumbai volume iii - specifications for post tensioned slab and beams civil engineering department third floor, port house, shoorji vallabhdas marg, ballard estate, mumbai - 400 001 telephone no. These cables, composed of steel wires inserted into a plastic sheath, are subsequently "tensioned" and grouted after the concrete is poured. Surfaces can be stained or overlaid. ***** PART 1 GENERAL 1. Moment ® Corrugated Duct is used as a duct former for a variety of precast and cast-in-situ concrete work. My plumber cut a post tension cable when jack hammering my concrete slab to install new bathroom drain lines. It is supplied with a connection with the greased strand covered in polyethylene, the corrosion protection is provided by means of passivation while grouting. Post Tension Cable Suppliers Ready to Support Your Project. The hazard exists when workers cut into the slab and rupture the tensioned cable. Do you have any other known "cracks" (however tiny) anywhere else in your slab that might indicate a weakness in the foundation design?. • Construct barrier walls, railings, curbs after falsework removal. DEVICES FOR POST-TENSIONING The essential devices for post-tensioning are as follows. 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.