Abstract: This is a device for reinforcing a concrete member (1) in compression, comprising at least one bar (3) housed without adhesion in a channel (2) hollowed out in said member. Each of the two ends of the bar is associated with a device adapted to cause it to bear longitudinally on the concrete of the member. One of these two devices, which is associated with at least one (3.sub.1) of the two ends of the bar (3) is a rigid frame (4) housed in a cavity (5) of the member accessible from the outside. The frame is arranged so as to receive in removable manner a thrust generator (7). One side of this frame having the bar end in question passing through it is arranged so as to interact with a unidirectional element (8) serving successively to cause the end to be pushed back by the thrust generator, and then to lock this end with respect to the frame in the direction corresponding to the return of the end into the frame.

Abstract: A cable-stayed bridge is disclosed comprising at least one pylon (1) and stay cables (2) anchored on this pylon, each stay cable being formed by a bundle of strands or twisted strands (7), the upper portion of each stay cable passing through the pylon from one side to the other and its free end being anchored on a block (3) which bears on the face of the pylon located on the side opposite that where the stay cable is situated. The slightly flared upper portions of two stay cables (2) anchored on the same vertical pylon section (1) and extending on each side of this pylon are crossed with mutual imbrication so that the mean lines of these two portions are both situated in the same vertical plane of the pylon parallel to the longitudinal direction of the bridge.

Abstract: A road joint is disclosed formed by two rigid frames (4) joined together by a flexible strip (2) formed by an elastomer body having in cross section the form of an upside-down truncated V with thick legs and reinforced by a central horizontal rigid plate (1). The frames are disposed on opposing sides of the center of the joint and each include a lower horizontal heel (3) on which a corresponding leg of the elastomer body rests and is adhered. Rigid plate (1) includes two lateral members slanted slightly with respect to the horizontal and the heels of the frames (4) have upper surfaces (8) parallel to these lateral members. The slanted heels (3) of the rigid frames (4) orient the legs of the flexible strip (2) such that vertical deformation of the flexible strip (2) is minimized.

Abstract: For placing a multiple strand cable under tension by successive tightening of the different strands by means of an individual jack, procedure is as follows: the first strand of the cable is tightened, called below "control strand" while keeping possible then measurement of the tension of this strand at any moment, then pulling a second strand until its tension is equal to that of the control strand, measured at the same moment, and then anchoring this second strand so stretched, a third strand is then tightened until its tension is equal to that of the control strand measured at the corresponding moment and then this third strand so tightened is anchored, and so on until the anchoring of the last strand, after which the tension then applied to the control strand is noted and, after having relaxed the latter and having freed from it the measuring means, this control strand is anchored while applying to it the tension thus noted.

Abstract: A device is provided for damping the vibrations of a stay cable (1) comprising an annular gutter (6) surrounding a section of the cable and secured to this cable, an annulus (8) mounted in the gutter, with interpositioning of an annular cavity (7), so as to be able to move transversely with respect to this gutter, substantially indeformable seals (10) providing sealing of the annular cavity with respect to the outside, a cushion (9) made from a material capable of flowing without modifying its overall volume and filling the annular cavity, and a rigid structure (11) connecting the annulus to an appropriate foundation (12).

Abstract: A device is provided for the anchorage of a stretched cable (2,4) on a bearing surface through which this cable passes, comprising a U-shaped body (8) adapted to straddle a section of the cable, the arms of which body are extended by flanges (9) directed towards each other, and a peg (12) adapted to be housed in the U-shaped opening of said body so as to bear against the flanges of its arms, the assembly of the body and the peg being designed so as to define a truncated cone shaped housing for a split truncated cone shaped jaw (14), known per se, adapted for clamping said section.

Abstract: An anchoring device for a tensioned cable comprises a split jaw with a striated inner cylindrical surface and with an outer lateral surface of frustoconic shape, which surrounds one end of the cable and cooperates with a complementary housing hollowed in a rigid part. This housing is so dimensioned so that it surrounds continuously the whole of the tapered end of the jaw. The half-angle at the apex of the outer lateral surface, of frustoconic shape, of the tapered end of the jaw is less than 10.degree.. The radial thickness of the annular terminal section of said tapered end is less than or equal to to 1/10 of the inner radius of said end.

Abstract: To prepare a split frustoconic jaw intended for the anchoring of a cable, a part is first taken bounded externally by a frustoconic surface and hollowed by a cylindrical axial channel whose inner surface is advantageously striated. This part is sawed into by substantially axial and radial slashes leaving bridges to subsist of small thickness at the bottom of these slashes throughout the central channel. An assembly ring is mounted in an outer annular groove and the whole is subjected to cementation treatment so as to surface harden the jaw while making the bridges fragile.

Abstract: To prepare a split frustoconic jaw intended for the anchoring of a cable, a part is first taken bounded externally by a frustoconic surface and hollowed by a cylindrical axial channel whose inner surface is advantageously striated. This part is sawed into by substantially axial and radial slashes leaving bridges to subsist of small thickness at the bottom of these slashes throughout the central channel. An assembly ring is mounted in an outer annular groove and the whole is subjected to cementation treatment so as to surface harden the jaw while making the bridges fragile.

Abstract: The invention relates to the prestressing of a concrete work by means of a relatively long stretched sinuous cable (1) formed by a bundle of several metal strands (2)housed individually in plastic material tubes (3). The different tubes with their strands are positioned without special precautions in a sheath (5) buried in the work then a sufficiently unctuous and fine cement grout (6) is injected into this sheath for filling the spaces in the sheath between the tubes and strands are tensioned individually after solidification of the injected cement grout, by means of relatively light automatically operated actuating cylinders.

Abstract: A tendon for post-tensioned pre-stressed concrete structures in which between the strand and sheath there is provided, in quiescent condition, a latent hardenable material and an activator therefor so that when the strand is tensioned the activator is activated to commence the hardening process of the hardenable material and produce a bonded tendon.

Abstract: The invention provides an anchorage device for a cable with multiple strands (2) comprising a block (1) in which the strands are anchored individually by radially clamping about each strand a split truncated cone shaped jaw (3) surrounding this strand and housed in a complementary housing (4) of the block. This device comprises a single thrust member (6) disposed axially opposite the different jaws (3) and a plurality of spacers (10) each interposed axially between said member (6) and a jaw (3) about the strand end (2) clamped by this jaw, said spacers (10) being identical to each other, formed from a metal or an alloy whose deformation/stress characteristic has a long plastic flow plateau and dimensioned so that at the end of the thrust the deformation of each of them has reached, but not exceeded, the plastic flow stage thereof.

Abstract: To manufacture a bent prestress conduit (5) adapted to receive without damage cables (7) subjected to extremely high pulling forces, one of the faces of a metal strip (1) is coated intimately with a metal phosphate layer (4) itself covered by a soap and this metal strip is wound in helical form so as to obtain a continuous tube whose inner face is formed by the thus coated face of the metal strip.

Abstract: The invention relates to a concrete work prestressed by means of tensioned reinforcements (7) having bell shaped ends (7.sub.1) and formed from an alternate succession of first sections housed, with interposition of an injected cement, in metal sheaths (9) themselves embedded in the concrete and rectilinear sections outside the concrete. For easy replacement of these reinforcements, the first sections have a rectilinear or curved shape of an arc of a circle and they are housed in plastic material tubes (10) adapted to slide against the metal, the tube ends situated at the level of the bell mouthed reinforcement ends (7.sub.1) being themselves given the shape of open mouthed sleeves (11) made from plastic material.

Abstract: For distributing the pressure exerted by a binding cable (2), more especially contained in a sheath (10) with a grease filling, over a tubular body (1), such as a forced duct or a concrete silo, surrounded by this cable, there are inserted between said cable and said body shoes (3) formed by sections of a solid shaped bar of rubber which have the general shape of a C with constricted opening defining a cylindrical groove (4) adapted for jointingly receiving the cable and which are defined, on the side opposite the opening of the C, by a flat rectangular bearing face (6).

Abstract: For joining together two concrete slabs (1, 2) juxtaposed side by side along a crack (3), a cylindrical cartridge with vertical axis is used comprising two half shells (4.sub.1, 4.sub.2) made from cast metal and joined vertically together by a key (11) housed in recesses (10.sub.1, 10.sub.2) each formed in a central projecting step (9.sub.1, 9.sub.2), these half shells being urged mutually horizontally apart by a continuous elastic belt (12) made from an elastomer material adapted to ensure sealed isolation of the inside of the cartridge with respect to the outside.

Abstract: For greasing the end of a reinforcement (2) surrounded by a sheath (3) and retained in a truncated cone shaped ring of jaws (6) coacting with a truncated cone shaped housing (5) formed in an anchorage plate (4), which housing is closed by a cap (11), a longitudinal rectilinear groove (12) is formed in this housing and in this cap is formed an orifice (13) automatically aligned with the groove at the end of fitting of the cap and the inner volume of the assembly is filled with grease through a rectilinear hollow needle (14) passing successively through said orifice and said groove.

Abstract: The invention provides an anchoring device for a pre-stress cable formed from several filaments or strands (4), comprising a bearing plate (1), a block (2) pierced with truncated cone shaped holes (2.sub.1) through each of which passes a filament or strand of the cable, said block resting on said plate and truncated cone shaped jaws (3) for jamming the filaments or strands in their holes. The bearing plate (1) is pierced with multiple holes (1.sub.1) extending those (2.sub.1) of the block (2) so that this plate supports this block over the whole of its non pierced surface.

Abstract: The invention relates to a device for connecting aligned butt ends of isostatic elements (generally girders) of a constructive work. Between the crosspieces connecting the opposite girder butt ends there is disposed at least one tubular cylinder prestressed by clamping screws and by a coaxial tensioned tie rod whose ends bear on the outer faces of the crosspieces. The invention is more particularly applicable to bridges formed by independent isostatic girders.

Abstract: A tie for connecting together parts of a structure, for example a stay for suspending the deck of a bridge from a tower, is constructed so that its length can be adjusted in a simple manner with the tie in service. The tie is made up from several stressed steel tendons, enclosed in a protective sheath filled with hardened material. At its ends the sheath incorporates anchoring devices for the transfer of the pull from the tie to the structure. The sheath forms a conduit whose ends are fixed securely to the anchoring devices. The conduit is isolated, throughout its length, from the structure so as to be capable of sliding longitudinally with respect thereto. At least one of the anchoring devices includes connection means for the active part of a tensioning apparatus and also includes means for bearing against the structure. This bearing means is adjustable on the anchoring device in the longitudinal direction of the tie. .Iadd.