To best comprehend Post-tensioning, it can be excellent to think about the real difference between pre-stressed and reinforced concrete. Both reinforced and pre-stressed concretes use the structural capabilities of concrete and steel. Concrete is very strong in compression but quite weak in tension. Reinforced concrete beams supports loads at the very top but as it cannot resist the tension in the bottom, it easily cracks.
Steel bars in reinforcement are widely used to place inside the tension zone to manage the cracking. Pre-stressed concrete entails the effective use of forces that tend to bend and compress a concrete structure in counteractive bending that are caused by loading. The force applied is the tensioning of the steel component in the appearance of wires, bars or high tensile strands. As being a typical practice, suppliers calibrate Stressing Equipments to accomplish post-tension installation successfully.
Multi Strand Jacks are being used in stressing all strands in pc strand simultaneously. The advantage of this is certainly its high-speed and precise stressing operation of your cables in a trouble-free step.
Single Strand Mono Jacks are of three basic models; 10T mono jack is intended to the mining industry, and can be used as overhead works. 17T mono jack is really a designated .5 strand in the lightweight steel model; it is actually double acting and uses 3-piece reusable wedges. Lastly, the 25T mono jack that can do stressing 5mm wire around 15.2mm strand with all the easiness of exchanging two components with the stokes of 6, 8, 12,18 and 24.
Grout Pumps are normally employed for leveling concrete slabs, for filling cracks, for raising sunken concrete, sealing concrete holes, as well as for repairing tunnels, parking structures and bridges. The sort of grout pump is based on the complexity from the job, either air-powered or manual dependant upon what grout pump is necessary.
Staple machines are no ordinary stapling machines. This is used for attaching strands for prestressing concrete. Manually operated staple machines can be utilized in sites which are isolated sites to where high air pressure systems usually are not accessible.
Onion Jacks are widely used to eliminate the application of anchor plates or wedges. It makes anchor point for prestressing strand. The appliance forms an onion shape to the final in the cable by 61dexbpky of spreading and separating individual wires.
Swaging Jack is a type of Stressing Equipment that crushes or swages a barrel and wedge setting it on the end in the prestressing cable to generate angle point. This jack is lightweight and power-driven by machine or a hand pump.
Inappropriate handling and proper care of anchorage grip can result to harm to property as well as physical injuries. Only qualified and well-trained personnel may operate the device during use. Personnel doing the stressing plus the inspectors must always remain clear of the tendons being stressed each of the times. Jacks needs to be positioned around the strand to become stressed. It is not necessarily wise to adjust the positioning of the jack by striking or pushing after any load continues to be already applied. Will not go higher than the intended capacities from the tendons or maybe the jacks being stressed, excess pressure might result to personal injury. To maintain jacks, it is actually needed to used only approved clean hydraulic fluid and change it if needed. Jacks has to be cleaned immediately should it be in contact with air, rain and also other corrosive environments after exposure. Will not stress any tendons that have concrete slurry inside the anchor cavity, this will likely put off appropriate seating of the wedges.