Abstract: A method for determining the passivating properties of a mixture (11) containing at least two components, which are cement and water, including the steps of: taking three elements, each made up of an electrically conductive material, these elements being referred to as first electrode (2), second electrode (4) and third electrode (5), fixing at least one these three electrodes on a support (3) in such a manner that they are electrically insulated reciprocally, and the mixture (11) is able to come in contact with at least one predetermined face situated on each electrode, these faces being referred to as first face (20), second face (40) and third face (50), selecting the first electrode (2) and the third electrode (5) and applying between these two electrodes, a direct current, referred to as first direct current, of predetermined intensity value, referred to as first intensity value, and predetermined polarity, referred to as first polarity, resulting in electrolytic reactions on the third electrode (

Abstract: The invention relates to a corrosion protection system for a stay cable construction including a multiplicity of tension members made of parallel steel tensile elements, extending between a first anchorage and a second anchorage, and comprising two opposite ends, the first end co-operating with the first anchorage and the said second end co-operating with the second anchorage. The corrosion protection system involves the use of tensile elements which are not provided with a permanent corrosion protection during their fabrication. This corrosion protection system includes: a plurality of stay pipes, each freely surrounding a tension member made of unprotected tensile elements, a dehumidification device which produces dry air, supply pipes supplying the dry air to predetermined points situated on the first anchorage, the second anchorage, and the stay pipes, a ventilation device pushes the dry air in the supply pipes, surveying, measuring, controlling and testing facilities.

Abstract: A method impedes transverse relative displacements of a pipe (2) and at least one cable (3) which extends in this pipe (2), and doing so with a certain transverse play (4). The method has the steps of: selecting at least one portion (8), of a predetermined longitudinal dimension (L8), of pipe (2), and, then, with the cable (3) inserted in the pipe (2), locally constructing between the cable (3) and said pipe (2) at least one wedging element (9) adapted to suppress the transverse play (4) existing between the cable (3) and the pipe (2) in said at least one selected pipe portion (8).

Abstract: Connecting element for joining two support members (2, 3) absorbing tensile forces, which connecting element (1) comprises at least a first and a second casing body (5, 6) with a through-hole (7) for receiving the respective support members (2, 3), which casing bodies (5, 6) can be joined together by way of a joining section (9) at a first end (11) of each casing body (5, 6), the opposing second end (13) of each casing body (5, 6) being provided with locking members (15, 16) for holding the support members (2, 3) fast. In a working position the locking member (15, 16) of at least one casing body (5, 6) produces an axial locking of the support member (2, 3) running through the casing body (5, 6) by way of a stop part (20) created on the support member (2, 3) within the area of the second end (13) of the casing body (5, 6).

Abstract: A method impedes transverse relative displacements of a pipe (2) and at least one cable (3) which extends in this pipe (2), and doing so with a certain transverse play (4). The method has the steps of: selecting at least one portion (8), of a predetermined longitudinal dimension (L8), of pipe (2), and, then, with the cable (3) inserted in the pipe (2), locally constructing between the cable (3) and said pipe (2) at least one wedging element (9) adapted to suppress the transverse play (4) existing between the cable (3) and the pipe (2) in said at least one selected pipe portion (8).

Abstract: A device (1) is disclosed for anchoring one end (2A) of a stay (2) to a base (3), this end (2A) of the stay (2) comprising at least two strands (2B) which diverge from its longitudinal axis (2C) in such a way as to come to be anchored in the device (1), these strands (2B) each being made up of a core wire (2D) and a protective sheathing (2E), the device itself being intended to be positioned and immobilised in translation in a bore (3A) provided in the base (3), this device (1) comprising a first rigid unit (4), which: is delimited transversally by a cylindrical face (4A) and longitudinally by two opposite faces (4B, 4C) substantially orthogonal to the longitudinal axis (4D) of said first unit (4), is traversed by perforations (4E) which, made substantially parallel to its longitudinal axis (4D), are each intended for passage of one end (2F), devoid of sheathing (2E), of a strand (2B) of the stay (2), and each including a bearing surface (4F) intended to co-operate with an immobilisation piece (4G) of such

Abstract: A device (1) is disclosed for anchoring one end (2A) of a stay (2) to a base (3), this end (2A) of the stay (2) comprising at least two strands (2B) which diverge from its longitudinal axis (2C) in such a way as to come to be anchored in the device (1), these strands (2B) each being made up of a core wire (2D) and a protective sheathing (2E), the device itself being intended to be positioned and immobilised in translation in a bore (3A) provided in the base (3), this device (1) comprising a first rigid unit (4), which:

Abstract: An anchoring device not accessible from one of its sides can be produced by making a cavity (11) of a particular shape and using tendons (4), each of which has an end portion (41) of adapted shape. The cavity may be made in different ways, especially by concreting an anchor member (1) having an opening (12) at one end, the anchor member and the cavity it contains each having an adapted shape. After the anchor member has been concreted and the tendons inserted in the cavity, the cavity is filled with an embedding mortar in order to block the ends of the tendons therein.

Abstract: An anchoring device not accessible from one of its sides can be produced by making a cavity (11) of a particular shape and using tendons (4), each of which has an end portion (41) of adapted shape. The cavity may be made in different ways, especially by concreting an anchor member (1) having an opening (12) at one end, the anchor member and the cavity it contains each having an adapted shape. After the anchor member has been concreted and the tendons inserted in the cavity, the cavity is filled with an embedding mortar in order to block the ends of the tendons therein.

Abstract: An anchoring device not accessible from one of its sides can be produced by making a cavity (11) of a particular shape and using tendons (4), each of which has an end portion (41) of adapted shape. The cavity may be made in different ways, especially by concreting an anchor member (1) having an opening (12) at one end, the anchor member and the cavity it contains each having an adapted shape. After the anchor member has been concreted and the tendons inserted in the cavity, the cavity is filled with an embedding mortar in order to block the ends of the tendons therein.

Abstract: An anchor head assembly comprising a main body member with a plurality of cavities having the shape of a frustum of a cone in an exterior section and a corresponding number of cavities which may also have the shape of a frustum of a cone in an interior section. The cavities are orientated such that the narrow ends of those in the exterior section are of a different diameter than and face the narrow ends of those in the interior section. The interior section is dome-shaped so as to facilitate the fabrication of the cavities therein and to facilitate the splaying of strands or tendons as they are passed into and through the cavities in both the interior and exterior sections. The dome-shaped section also facilitates self-centering of the anchor head assembly in a bearing plate. Wedge members are used for capturing the strands and tendons in the cavities in the exterior section of the anchor head assembly.

Abstract: In a stressing anchorage for prestressing elements (2) in part of a structure, at least one part of an anchor head (4) consists of a mortar-like mass in the area in which bores (3) are disposed to accept frustoconical wedges (8). The frustoconical wedges (8) are made of steel. Since the mortar-like mass on which the frustoconical wedges are supported is more ductile, i.e., more workable than the wedges (8), the distribution of load from the wedges (8) to the anchor head (4) takes place in such a fashion that marked peaks of the load are considerably reduced.

Abstract: For a stressing anchorage for a tension element running inside an encasing tube, a bearing plate with an annular opening is set up on an outer wall of a structural part. In an area of the opening turned away from the structural part there is a cone opening outward. A trumpet of plastic is bonded to the encasing tube, likewise of plastic, at its end situated in the structural part. The outer end of the trumpet is more or less flush with the face of the bearing plate turned away from the structural part. A transition piece projects into the trumpet with a projection leading in whose surface area is shaped frustoconically. Owing to the truncated cone, the outer end of the trumpet is pressed against the cone of the bearing plate, and is held firmly in an annular gap between the said truncated cone and the said cone after the anchor head is placed on the transition piece and the tensioning strands of the individual tension elements are pre-stressed and are held with the wedges.

Abstract: The force transfer body comprises a first, essentially annular partial body, preferably of cast steel, and a second partial body, preferably of a castable mortar mass capable of hardening. The second partial body is cast in one piece with the first partial body. An inner conical aperture is lined with a funnel-shaped plastic part, which overlaps at least a section of the first partial body. The first partial body has an abutting surface, turned away from the part of the structure, serving the firm contact with an anchor head containing individual members. The prestressing forces arising concentratedly with the anchorage are conveyed from the anchor head via the first partial body into the second partial body, and from there into the part of the structure. The second partial body is designed essentially frustoconical, the truncated cone extending, tapering, away from the first partial body. In the area of the outer generated surface of the second partial body there is a circumferential constriction.

Abstract: To connect two sheaths (1a, 1b), used in prestressing cable technology for concrete supporting structures, there is a coupling element (19) which is fitted with chamfered flanges (6). The sheaths (1a, 1b), which have protrusions (2a, 2b), are each inserted into the coupling element (19) with a tubular element (4) which forms the end of the sheaths (1a, 1b). A sealing ring (7) is inserted between each of the flanges (6) and protrusions (2a) of the sheaths (1a, 1b). The flanges (6) and the protrusions (2a) are held together by sloping surfaces (10a) and (10b) of a groove worked in each socket (8). Each of the sockets (8) consists of two half portions (8a) and (8b), which can be connected together.

Abstract: The tension part (1), which can be extracted from the earth after use, comprises a central member (2) and a plurality of outer members (3). At least one (3') of the outer members is completely servered. Pressed on radially about the tension part is a tubular supporting element (5). The point of severance (4) is situated in the entry region of the supporting element. Disposed between the supporting element and the tension part is an insert (11) having inner teeth (13) for a secure grip. Through the severance of one of the outer members, substantially greater ductility is achieved before breakage takes place. This in turn allows better monitoring of soil anchors produced with such tension parts.

Abstract: The prestressed concrete lining has several reinforcement elements (32) distributed around the circumference and along the length of the pressure tunnel. There are prestressing elements (38, 39, 40, 41) which encompass at least a part of the circumference of the pressure tunnel. A bottom part (35) is disposed within the pressure tunnel, formed of several elongated anchorage bodies (15) in series. Each of the anchorage bodies (15) has an essentially U-shaped cross section. In each of the arms (2, 3) of the anchorage bodies turned towards the inside of the tunnel there are first means (5) for passing through at least one of each of the prestressing elements (38, 39, 40, 41). An bearing plate (8) is disposed on each of the facing inner surfaces of the arms in the region of each of the first pass-through means (5). Second means (10) for passing through at least one of each of the prestressing elements (38, 39, 40, 41) are foreseen in the base arm of the anchorage body 15.

Abstract: The wall (5) of the encasing tube (1) includes spiralling protrusions (3, 4). First protrusions (3) and second protrusions (4) run either in different directions or in the same direction but at different pitches. The encasing tube is used for enclosing tensioning cable (2) in concrete structures. By means of the particular arrangement of the protrusions, the flow properties of the grout are improved, air bubbles are virtually eliminated during injection, and the bonding properties of tensioning cables are improved by means of large bonding zones while respecting the required high fatigue strength.

Abstract: In order to make a tension member (1) substantially removable from the ground or from a structure, a central element (2) thereof is completely severed. If the tension member is to be further weakened, at least one outer element (3) is also severed besides the central element. A supporting contrivance (5) is applied to the tension member either around the point of separation (4) of the central element or around both points of separation (4, 6) of the central element and of the outer element. By application of a load, the tension member is torn apart near the point or points of separation so that the major part of the tension member can be pulled out of the ground or structure and, if need be, reused.

Abstract: A prestressing anchor is embedded in concrete in part of a concrete structural component, and after setting of the concrete, a prestressing element extending through the prestressing anchor is prestressed and held by clamping wedges disposed in a frustoconical portion of a passage running through the prestressing anchor. Thereafter, a spacer element and an associated or integral further prestressing anchor provided with clamping wedges are pulled onto the prestressing element. With the aid of screws passing through flanges of the prestressing anchors, the further prestressing anchor is held to the first prestressing anchor, the spacer element resting snugly against the end faces of the clamping wedges. The second phase of construction is then carried out, at which time the further prestressing anchor is also embedded in concrete. After setting of the concrete, the following section of the prestressing element is prestressed to about the same value as the preceding section.