Reinforcement for building elements under tension and installati

Details Reinforcement for building elements under tension and installati Reinforcement for building elements under tension and installati

1996-02-08

1998-02-24

Kent, Christopher

Static structures (e.g., buildings)

With component having discrete prestressing means

Specific prestressing means

522236, 522238, 5274519, E04C 508

Patent

active

057201404

DESCRIPTION:

BRIEF SUMMARY
SPECIFICATION



CROSS REFERENCE TO RELATED APPLICATIONS

This application is a national phase of PCT/DE 94/00788 filed 7 Jul. 1994 and based, in turn, on German national application P 43 22 862.3 under the International Convention.


FIELD OF THE INVENTION

The present invention relates reinforcements for tension-loaded structural parts or installation parts which are characterized by being magnetized, especially magnetized to saturation (remanent magnetization).
Such reinforcements can be used optionally for tension-loaded installations like bridges, tunnels, concrete roofs, conveyor belts or the like of optional structural materials like plastics, concrete, etc. An especially significant use is, however, in reinforced concrete structures with steel reinforcements under tension to which the subsequent description is largely directed.
Such magnetized reinforcements enable a noninvasive monitoring of the integrity of structures and installations equipped with the reinforcements by nondestructive testing processes based upon magnetic-field measurements.
The magnetization of the tensioning steel or reinforcement steel, together with or without a sheathing tube, is effected prior to incorporation in the reinforced structure or installation part and can be carried out by the manufacturer of the reinforcing steel or at the structural site directly prior to the incorporation thereof.
The magnetization is effected in a manner known per se with the aid of correspondingly dimensioned and wound coils connected with a power supply for controllable current supply and corresponding holding and guide elements which enable a passage of the elements to be magnetized through the coil.
The useful life of prestressed reinforced concrete structures is determined largely by the integrity of the tensioned reinforcement. High-strength steels which are used for reinforcing, can break as a result of stress-crack corrosion without warning.
Failures recently have indicated that even in the case of properly applied pressed sheathing tubes and without detectable action of corrosive substances, ruptures can occur decades after fabrication. As a consequence of the resulting insecurity with respect to the useful life of prestressed concrete structures, it has been found to be important to be able to detect ruptures of individual wires promptly.


BACKGROUND OF THE INVENTION

The nondestructive testing of the integrity of steel reinforcements of prestressed concrete structures by magnetic field detection is known in which ruptures in structural members with a direct bond between the concrete and the reinforcement (i.e. with reinforcement wires which are not surrounded by a metallic sheathing type) can be detected by a nondestructive process (magnetic stray field measurement). For structures with an additional bond in which the sheathing effect of the sheathing tube and the neighboring intact steel reinforcement must be considered, a process has been proposed in which the incorporated steel reinforcement is subjected to magnetization initially, for example by the effect of permanent magnets moved along the surface of the prestressed concrete structure and demagnetization follows of the slack reinforcement (DE-OS 40 37 992 and 40 37 993).


SUMMARY OF THE INVENTION

According to the invention the integrity monitoring of the stressing elements of prestressed concrete structures is facilitated and improved substantially by magnetization of the stressing elements before their incorporation since, in this manner, one need not fear any restriction in the magnetization by poorly accessible regions at which reinforcing elements are particularly important.
The prior magnetization of the reinforcement member is apparently advantageous, independently of the nature of its use, in both direct bonding or with a sheathing tube. In the latter case, especially depending upon the sheathing material, a magnetization of the core can be effected together with the sheathing tube. Preferably, however, the magnetization of the reinforcing steel is effected prior

Affiliated with

Also associated with

Rating

Reinforcement for building elements under tension and installati does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Reinforcement for building elements under tension and installati, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Reinforcement for building elements under tension and installati will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-1868755