To best comprehend Post-tensioning, it is excellent to contemplate the main difference between pre-stressed and reinforced concrete. Both reinforced and pre-stressed concretes make use of the structural capabilities of concrete and steel. Concrete is very strong in compression but quite weak in tension. Reinforced concrete beams supports loads towards the top but because it cannot resist the tension towards the bottom, it easily cracks.
Steel bars in reinforcement are utilized to place within the tension zone to control the cracking. Pre-stressed concrete entails the application of forces that often bend and compress a concrete structure in counteractive bending that are caused by loading. The force applied is the tensioning from 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 used in stressing all strands in pc steel wire simultaneously. The main benefit of this really is its high-speed and precise stressing operation in the cables in a single trouble-free step.
Single Strand Mono Jacks are of three basic models; 10T mono jack is meant for the mining industry, and can be used as overhead works. 17T mono jack can be a designated .5 strand in the lightweight steel model; it really is double acting and uses 3-piece reusable wedges. Lastly, the 25T mono jack that is capable of doing stressing 5mm wire up to 15.2mm strand using the easiness of exchanging two components together with the stokes of 6, 8, 12,18 and 24.
Grout Pumps are commonly useful for leveling concrete slabs, for filling cracks, for raising sunken concrete, sealing concrete holes, and then for repairing tunnels, parking structures and bridges. The sort of grout pump is founded on the complexity of your job, either air-powered or manual dependant upon what grout pump is required.
Staple machines are no ordinary stapling machines. This really is utilized for attaching strands for prestressing concrete. Manually operated staple machines may be used in sites which are isolated sites to where high air pressure systems will not be accessible.
Onion Jacks are utilized to eliminate the use of anchor plates or wedges. It generates anchor point for pc strand. The device forms an onion contour around the final of 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 towards the end from the prestressing cable to make angle point. This jack is lightweight and power-driven by machine or a hand pump.
Inappropriate handling and care of prestressed anchorage can result to harm to property or even physical injuries. Only qualified and well-trained personnel can operate the machine during use. Personnel doing the stressing along with the inspectors must always remain clear of the tendons being stressed every one of the times. Jacks must be positioned on the strand being stressed. It is not necessarily preferable to adjust the position of the jack by striking or pushing after any load continues to be already applied. Tend not to go higher than the intended capacities of your tendons or perhaps the jacks being stressed, excess pressure can result to accidental injury. To keep jacks, it is required to used only approved clean hydraulic fluid and alter it if needed. Jacks needs to be cleaned immediately when it is in contact with air, rain and also other corrosive environments after exposure. Tend not to stress any tendons which have concrete slurry inside the anchor cavity, this will delay appropriate seating from the wedges.