Bouygues

Rhone-poulenc Chimie

Pierre Richard

Jerome Dugat

Evelyne Prat

Laurent Frouin

Marcel H Cheyrezy

Nicolas Roux

Cementation slurries well suited for encasing reinforcing elements therefor, for example prestressed steel cable, while reducing the risk of embrittlement thereof, contain from about 1.5% to 3% by weight of homogenizing and exudation-reducing hydrophilic particulates (e.g., precipitated silica particles) that are inert in respect of liquids, have a specific surface area of greater than about 200 m.sup.2 /g and which are fragmentable during mixing and/or injection into multiple fragments having particle sizes ranging from about 5 to 300 nanometers.

Cementation slurries for improvedly encasing reinforcing elements

A method and composition for preparing concrete elements comprising the steps of mixing a composition comprising the following components expressed in parts by weight (p): a) 100 p of Portland cement; b) 30 p to 100 p or better 40 p to 70 p of fine sand having a grain size of at least 150 micrometers; c) 10 p to 40 p or better 20 p to 30 p of amorphous silicon having a grain size of less than 0.5 micrometers; d) 20 p to 60 p or better 30 p to 50 p of ground quartz having a grain size of less than 10 micrometers; e) 25 p to 100 p, or better 45 p to 80 p of steel wool; f) a dispersing agent; g) 13 p to 26 p or better 15 p to 22 p of water; and after setting, curing the concrete at a temperature of 250.degree. C. or higher, for a length of time sufficient to transform cement hydration products into crystalline hydrates of the xonotlite type; thus eliminating substantially all of the free water and at least the main part of the adsorbed and chemically bonded water.

Method and a composition for preparing concrete elements having

A metal fiber concrete composition for molding a concrete element, the composition being essentially constituted by a Portland cement, granular elements, fine elements for pozzolan reaction, metal fibers, a dispersing agent, optionally other additives, and water. The preponderant granular elements have a maximum grain size D of not more than 800 micrometers. The preponderant metal fibers have individual lengths 1 lying in the range 4 mm to 20 mm. The ratio R of the mean length L of the fibers divided by said maximum size D of the granular elements is not less than 10. The amount of preponderant metal fibers is such that the volume of preponderant metal fibers lies in the range 1.0% to 4% of the volume of the concrete after setting.

Metal fiber concrete compositions for molding concrete elements,

A concrete structure including a rigid three-dimensional lattice of concrete bars which are interconnected at nodes. The lattice is constituted by an assembly of prefabricated cast blocks, in which each block comprises a node and a plurality of arms (14) radiating from the node. Each arm has at least one longitudinal socket with an opening in the free end of the arm, and the arms of two blocks are assembled in aligned end-to end pairs to constitute the bars of the lattice. The sockets of assembled arms are in alignment and contain a common metal reinforcing member, and the junction zone of the arms is surrounded by a clamping sleeve, with the sockets being filled with hardened mortar. The lattice is prestressed by prestress cavles passing outside the bars of the lattice and fixed to some nodes of the lattice.

Method of making concrete structures of prefabricated blocks

Concrete; structural elements having a high permissible working load typically in the range of at least 50-100 MPa. The element includes a block of compressed concrete surrounded by a tubular hoop made of intercrossed wires. Such elements are useful for making beams, posts, cables and the like.

Concrete structural elements, process and device for manufacturing these

A ballastable concrete base for an offshore platform is essentially constituted by a volume formed by a three-dimensional lattice of concrete bars interconnected at concrete nodes. Some of the nodes are interconnected by prestress cables passing outside the bars and optionally past intermediate nodes. The cables three-dimensionally prestress the lattice as a whole, and the base further includes means for making watertight the side and the bottom of the lattice.

Ballastable concrete base for an offshore platform

A concrete structure including a rigid three-dimensional lattice of concrete bars which are interconnected at nodes. The lattice is constituted by an assembly of prefabricated cast blocks, in which each block comprises a node and a plurality of arms (14) radiating from the node. Each arm has at least one longitudinal socket with an opening in the free end of the arm, and the arms of two blocks are assembled in aligned end-to-end pairs to constitute the bars of the lattice. The sockets of assembled arms are in alignment and contain a common metal reinforcing member, and the junction zone of the arms is surrounded by a clamping sleeve, with said sockets being filled with hardened mortar. The said lattice is prestressed by prestress cables passing outside the bars of the lattice and fixed to some nodes of the lattice.

Concrete structure, block for making such structure and method of making

A prefabricated three-dimensional truss structure for a bridge, or the like, the truss formed from bars arranged to define triangular or rectangular patterns. The bars are formed from prestressed, high-strength concrete that are connected at their ends with assembly blocks that are prestressed, the prestress being preferably provided by the cables that prestress the bars, and which terminate at the blocks. A plurality of such unit trusses can be assembled to provide a truss structure for a bridge span, and the trusses can assume a wide variety of configurations.

Bridge truss, bridge span including such trusses, and method of

A bridge has prefabricated sections and is prestressed externally of the concrete of the sections by cables. Each section has upper and lower decks, interbraced by longitudinal oblique webs which form dihedrons. Certain dihedrons are closed by transverse panels. The panels assure the desired deviations of the prestressing cables as well as their anchoring.

Bridge with prefabricated sections and with external prestressing by

This invention relates to a prestressed concrete structure which behaves like a hollowed out slab. The structure combines a lattice work structure and a prestress by external cable, maximally optimizing the advantages of these two techniques. The Figure represents a part of the floor of a bridge according to the present invention. The floor comprises two tables 6 and 7 which are joined by a lattice work composed of pyramids P. Prestressing cables 8, 8' and 9' pass between the tables outside the concrete of the bars of the pyramids. The present invention is used for the construction of bridges, roofings and floors.

Prestressed concrete structure, a method of producing this structure,

This invention relates to a production of a structure by means of arch stones. The arch stones comprise series of mixed steel-concrete arch stones (V.sub.M), each comprising a metal frame of steel integral with an upper concrete slab, these series being separated by interposed concrete arch stones or sections, (V.sub.B), the assembly of the arch stones being reinforced longitudinally by prestress cables which penetrate the metal frames and are attached at their ends to the concrete arch stones. This invention may be applied to bridge floors and similar structures.

Apparatus for the construction of a bridge floor and similar structures,

The invention relates to an apparatus and method for manufacturing concrete structural elements. In order to manufacture the elements, setting of the concrete takes place in a casing (1), while the concrete is compressed with an axial pressure of at least 50 MPa and the casing is surrounded with a hoop (2,3) so as to create transverse planes of pressure.

Process and device for manufacturing concrete structural elements

This disclosure relates to the extension of a portion of a deck using deck segments, by means of a cable stayed beam resting on a front hinged support and on a rear support. In a first phase, the overhanging segments are suspended from the beam in a manner known per se and the part 5a of the beam which is downstream of the front support 6 is maintained substantially steady. In a second phase, the segments are joined to said portion by producing a prestress accompanied by a progressive swinging movement by said rear part of the beam. This invention is used for the construction of the deck of a bridge.

Growing community of inventors

Neuilly Sur Seine, France

Pierre Richard