Top Methods Used To Improve Pre-Stressed Concrete in the Construction Industry

The Construction concrete Cement industry is constantly evolving. Different methods have been developed to enhance the tensile strength of the concrete so as to come up with structures that last a significant amount of time. One of such different methods is to make use of prestressed concrete in the construction industry. Pre-stressed concrete is a type of concrete that provides additional strength, and this is made possible because of the compression, which is generated by the high strength tendons. This is done to improve the performance of the high-strength mix concrete. In order to build prestressed concrete structures, steel wires are anchored against the concrete, and this introduces pre-stress to the concrete structure.

The pre-stressed concrete can be improved in two ways- either makes use of pre-tensioning methods or post-tensioning methods in order to come up with desired results regarding the performance of high-strength mix concrete. The following is a list of top methods segregated as pre-tensioning methods and post-tensioning methods to improve pre-stressed concrete in the construction industry. Without any further ado, read on to plunge into the details.

Fitness workout program to try for first time exercisers testosterone cypionate vs enanthate bodybuilding bodybuilder flex wheeler returns to the gym after leg amputation

Pre-tensioning system

 The following is a list of points consisting of the most commonly used pre-tensioning system to improve pre-stressed concrete in the construction industry. Without any further ado, read on to plunge into the details.

Hoyer System

 The most widely used pre-tensioning system is the Hoyer system, which is also known as the long-line method. In this system, one needs to anchor two different bulkheads in the ground. Make sure that they are many meters apart from each other along with wire stretched between the two. In order to add tension, most of the time, companies make use of a hydraulic-jack along with split-cone wedges made from tapered conical to grip the bulkheads strongly.

Then, add high-strength mix concrete around the wires after you have placed molds, which serve the purpose of enclosing the wires. This method provides better work ability and is economical when compared to that of the other methods as different members can be created while using a single line. This is the primary reason for the constantly growing popularity of the Hoyer System in pre-tensioning factories.

• Shore System

This system makes use of a central tube of high strength steel. The purpose of it is to direct the pre-stress from the wires and the complete assembly in a concentrated and controlled manner so as to provide you with the best possible results. However, after a sufficient period of time, the central tube is removed, and the hole obtained from removing the tube is grouted. 

Advantages offered by the pre-tensioning system

• It is very much inexpensive when compared to that of the post-tensioning system.
• It offers certainty with regard to the prestressing force.

Post-tensioning system

This system does not require minimal joints as it eliminates any chance of shrinkage cracking and holds any cracks even if formed somehow. This system makes use of a metal tube that is to be placed inside, and concrete is laid around it. After a sufficient amount of time when the concrete mix gains enough strength, the tube is removed and replaced with a steel cable. The following is a list of different methods of post-tensioning systems. Without any further ado, read on to plunge into the details.

• Freyssinet system

The Freyssinet system consists of high strength steel wires, helical springs, a concrete cylinder with a concentric conical hole. In this method, several wires are stretched at the same time. The high strength steel wires of different sizes are coupled together in a cable—the cable has a helical spring, which prevents the high strength steel wires from intervening. The concrete cylinder serves as an anchorage. The wires are then anchored and pulled to a point where they reach the required length. The plug is pushed into the cylinder with the help of an inner piston. This is done so as to grip the wires properly.

• Magnel Blaton system
  Unlike the Freyssinet system, the Magnel Blaton system stretches only two wires at a given point of time. In this system, two wires of size 5mm or 7mm are stretched. The anchorage device consists of a sandwich plate. The plate has grooves that serve the purpose of placing the wires and wedges right in place. The wedges used are grooved a well. Every plate is capable of carrying eight wires, and the wires are separated with the help of spacers.

• Gifford-Udall system
  The Gifford-Udall system uses a single wire where each one of it is stressed separately with the help of a double acting jack. This method does not restrict the number of wires which can be coupled together to come up with a cable. However, there are two different types of anchorage devices used, one being tube anchorages, while the other is plate anchorages.
  
  A bearing plate, anchor wedges, and anchor grips comprise the tube anchorage. It can be either square or circular depending upon your choice, and the number of tapered holes can range between 8 to12 so that prestressing can be adjusted well within the system. Finally, the anchored wedges are used to lock the wires into that of the tapered hole. Other than that, for grouting purposes, there is a grout entry hole in the bearing plate.
   
• Lee-McCall system
  This method is most commonly used for the prestressing of the steel bars. The diameter of these bars ranges from 12mm to 28mm. The end anchorage system for the Lee-McCall system comprises a nut, bearing plate, washer, and a steel bar. The steel bars have threaded so as to accommodate the nut, which helps in further tightening of the bar after they have been stretched to the required length.

Hopefully, the article was helpful enough to walk you through top methods of improving the pre-stressed concrete so as to provide additional strength to the concrete structures. Consider the implications of each method before you opt for one.