Table of Contents
What is thrust line in prestressed concrete?
In prestress, the combined effect of prestressing force and external force can be resolved into a single force. The locus of the points of application of this force in any structure is termed as pressure line or thrust line or p-line.
Which is the basic concept used for calculating the stresses in a cross section of prestressed member?
Explanation: The basic concept involved in the analysis of prestressed concrete members is concept of combined direct and bending stresses used for columns whereas principle and shear stresses are formed in case of tensioning the prestressed and reinforced structures, overhead stresses are formed while the stresses in …
What do you mean by loss of prestress explain in brief different types of pre stress?
Elastic Shortening 1. Pre-tensioned Members: When the tendons are cut and the prestressing force is transferred to the member, concrete undergoes immediate shortening due to prestress. 2. Tendon also shortens by same amount, which leads to the loss of prestress. 12.
What are the various steps for design of prestressed concrete structures?
METHOD
- Pre-cast concrete wall elements are usually pre tensioned vertically in the plant and post tensioned horizontally through ducts cast in the panels.
- Vertical pre stressing diminishes vertical bending in the wall and subsequent leakage.
- Circumferential pre-stressing counteracts bursting loads from interior liquid.
What is pressure line explain its significance?
Pressure line means a sanitary sewer through which wastewater must be forced by pumping or gravity pressure to a point of collection.
What is C-line and P-line in prestressed concrete?
Line of action of P-force is called the P-line. The P-line is nothing but the tendon line itself. The line of action of the C-force is called the C-line or Pressure line. Hence in the absence of any external bending moment the P-line and the C-line coincide.
What is pressure or thrust line?
The pressure line (also called thrust line or C-linel•2) is the line of ac- tion of the concrete compressive stress resultant at each section along the beam. Note that in a statically determinate. beam the pressure line departs from the. centroid of the tendons by a distance. MIF, where M is the external moment.
Why do losses occur in prestress structure?
In the case of post-tensioning, the tendons are provided inside the duct of a precast concrete member. So the loss in prestress occurs due to friction between the concrete surface and the tendon in the process of tensioning. The loss of friction is also accompanied by the wobble effect.
What is P line and C line in prestressed concrete?
How does prestressed concrete work?
In pretensioning, the steel is stretched before the concrete is placed. High-strength steel tendons are placed between two abutments and stretched to 70 to 80 percent of their ultimate strength. Concrete is poured into molds around the tendons and allowed to cure.
What is the pressure line?