Abstract: Tooling for facing a wall includes a plurality of cavities which are formed by four blades, each of the cavities corresponding to various brick sizes. Six lines of interconnected cavities are attached to a cross beam. Adjacent cavities and lines are spaced from another by a predetermined dimension. Unset settable building material is mixed with appropriate coloring and waterproofing agent and is applied to a wall to form an outer layer. The surface thereof is sponged to produce a brick like surface relief. The tooling is pressed into the outer layer to impress a pattern resembling brickwork. Unset material is sucked from the joint line space between adjacent cavities and the layer is allowed to set. Then, mortar is added to the joint line. Once the mortar has set, the final outer layer has a true brick finish that resembles a real brick wall. The unset settable material can be applied to damaged or wood walls so that a true brick finish can be given to a wall in a quick, simple and cost effective manner.

Abstract: Disclosed is a process for recrystallizing materials that are ordinarily difficult-to-comminute. The process utilizes supercritical fluids and gasses at conditions near their respective vapor pressures which have the ability to dissolve in and expand liquid solutions. The process has been shown to be particularly effective at separating HMX and RDX thereby resulting in a precipitate of RDX which is essentially free of HMX.

Abstract: Explosive grade ammonium nitrate (EGAN) prills are made by a process comprising the steps of:a. continuously spraying a 95 to 98% by weight solution/melt of ammonium nitrate (or a mixture of ammonium nitrate and minor proportions of one or more other EGAN--acceptable nitrates) in/with water under spray-head conditions causing the emergent jets to break into cascades of substantially mono-sized droplets;b. allowing the formed droplets to fall within a vertical duct;c. continuously feeding a stream of cooling gas upwards through the duct to effect cooling and solidification of the falling droplets and some removal of moisture so as to form substantially mono-sized EGAN prills of up to about 4 mm diameter, andd.

Abstract: A quasi-isostatic pressure-forming methods for the production of precision explosive charges consists of the pre-heating of the explosive mass to be pressure-formed is now preheated to 100-120.degree. C. with subsequent forming in an autoclave at pressures of an order of magnitude of 3500 bar during 0.5-5 min. After pressure relief during a further phase of 10-180 min, the mass is cooled down at pressures of 50-500 bar. In a further elaboration of the invention, two autoclaves, one high pressure and one low pressure, may be utilized.

Abstract: A method and apparatus are provided for introducing a flammable powder such as red phosphorus into a hot melt such as an extrudable polymer which is in motion at the point of introduction of the flammable powder.

Abstract: An aggregate floor including terrazzo and the like and a method for forming the floor on a supporting surface, the floor including a layer of flexible compound applied to the surface, a reinforcement mesh positioned between divider strips and adjacent the compound and supporting a layer of compacted aggregate forming a substantially level surface. The divider strips are selectively positioned in desired configurations on the flexible compound layer to divide the mesh and aggregate into discreet and crack controlled sections. A mixture of composite cement, water and, in some cases, sand is applied to the surface of the aggregate layer in such a viscosity as to gravitate completely through the aggregate layer and make contact with the underlying layer of flexible compound. Such permeation fills and replaces the air pockets between the aggregate particles and deposits sufficient top coating on the surface of the aggregate to be polished to a finished surface.

Abstract: A method for the fabrication of a composite structure made from a profile plate and concrete. The relatively lightweight steel profile plate is placed at the building site. At the building site the concrete is sprayed on the surface of the profile plate to form the composite structure. The profile plate can be sprayed with concrete, layer by layer, with each layer being allowed to at least partially set between sprayings. Thus, the inherent load-bearing capacity of the structure increases as the layers are applied and the weight of the structure increases.

Abstract: A method for constructing a concrete building having a plurality of stories in which walls and floors of the concrete building are formed by means of modular form assemblies which can be used repeatedly without disassembling and reassembling includes (a') forming concrete surrounding wall structures of the stories one after the other by elevating a modular inner form assembly to a level of each story from a level of a lower story until the concrete surrounding wall structure of an uppermost story is formed; and (b') forming floors of the stories one after the other by lowering a floor form assembly from the level of the uppermost story.

Abstract: A structural joint is sealed with the aid of an injection hose including a substantially liquid-impermeable base body which envelops a passage channel and which has exit openings distributed over the length of the base body for passage of injection liquid from the passage channel into the joint to be sealed. The exit openings open under internal excess pressure and I close under internal negative pressure. Following injection of the injection liquid into the joint to be sealed, the injection liquid remaining in the injection hose is drawn off from the passage channel.

Abstract: A system for constructing concrete culverts is disclosed wherein reusable outer form and rebar supporting assemblies are set in place in an excavation and are used to form outer portions of the floor and outer walls of the culvert. Forming the outer walls of the culvert is facilitated by anchoring the lower regions of the form assemblies in the outer region of the floor as it is being poured by means of concrete anchors, which remain set in the concrete but are removable from the form assemblies. As a particular feature of this invention, the form assemblies are each provided with a protective wall spaced from the form assembly and adjacent walls of the excavation, forming a protective space where workers may work while being protected from collapse of walls of the excavation.

Abstract: A method of installing a post in a post hole includes the steps of providing a dry fast setting cementitious composition having a set time and in the form of finely divided particles of at least one cement binder, and pouring an amount of the dry cementitious composition into a volume of water located in a post hole without any type of physical mixing of the cementitious composition and water other than the mixing which occurs merely by applying the cementitious composition into the water. The major portion of the particles of the cementitious composition have approximately the same drop rate through the volume of water. The water contacts the dry cementitious composition when poured into the volume of water to hydrate the particles of the dry cementitious composition, the particles of cementitious composition dropping through the water to displace excess water and form the hydrated cementitious composition into a substantially non-segregated mass.

Abstract: The coacervation of ferrocene and ferrocene derivative is carried out in a ater-soluble polyol, coacervation mixture at a reaction temperature from about 40.degree. C. to about 55.degree. C. The coacervation mixture is comprised of about 70 to about 80 parts of a 1:1 ratio of water and a water soluble polyol selected from glycol, a glycerol, and an erythritol, a urea derivative selected from melamine and triazine, and an aldehyde or ketone selected from the water soluble aldehydes or ketones consisting of methanal, ethanal, propanal, propanone, and 2-butanone. Micro-droplets of the ferrocene derivative, 2,2-bis(ethylferrocenyl)propane, are formed by vigorous agitation of the coacervation mixture containing the ferrocene derivative. A polymeric coating on the outer surface of the micro-droplets produces a coacervate which is separated from the coacervation mixture.

Abstract: A method for producing foam-filled stud walls includes introducing at least a portion of an unfilled stud wall between a backplate, with the sheathing against the backplate, and a dam having a compressible membrane draped over one face thereof and a non-adhering sheet draped over the compressible membrane for presenting to the studs; moving the dam against the bottom portion of the open side of the stud wall; introducing foam between the backplate and the dam to fill the stud wall therebetween; moving the dam while unrolling the non-adhering sheet and compressible membrane; introducing additional foam to fill a further portion of the stud wall; repeating the two preceding steps on to completion of filling; moving the dam away from the stud wall; and advancing the filled portion of the stud wall from between the backplate and dam.

Abstract: The invention relates to a method of and an apparatus for producing tribasic propellant charge powders. An operationally safe and continuous course of the production process is obtained according to the invention by first preparing a fully gelatinized dibasic intermediate product of nitrocellulose and a blasting or explosive oil, without solvent, in a shearing mill (1). The intermediate product is granulated and supplied to an extruder (4) into which the third crystalline energy carrier and solvents are introduced. There the pulverous mixture is homogenized and extruded to form powder strands which are moist with solvent.

Abstract: A prestressed concrete tank includes a pair of generally parallel, laterally spaced, straight concrete wall sections which are preshrunk by the application of compressive forces. Straight wall sections are constructed on top of a footing covered with a plurality of plastic sheets to reduce friction so that limited longitudinal movements of at least portions of each wall section are facilitated during the preshrinking operation. The ends of the tank comprise semicircular walls which are prestressed using wire tendons extending peripherally around the wall and tightened to impose centripetal forces on the wall and thereby place the same into circumferential compression. The walls each comprise a substantially vertical steel shell diaphragm with a layer of cementitious material such as shotcrete on each side thereof.

Abstract: The present invention is a contoured wall and method for creating the contour and appearance of a wall formed from individual assembled units such as stones. The wall is formed from a plurality of interlocking wall portions that each have at least two non-linear mating surfaces. Each of the wall portions further has a lateral face contoured to resemble the stone wall. The wall is formed from hardenable construction material such as concrete poured between two mold members. Each of the mold members has a lateral mold face with at least one of the lateral faces having a plurality of interlocking contoured relief portions to provide a molded surface having the contour of a stone wall. In one embodiment, at least one of the mold members includes a plurality of individual form liners, or mold modules, each of which includes two non-linear mating edges and a lateral relief mold face.

Abstract: To rehabilitate an internally corroded underground pipeline, excavations are made at its opposite ends to which launching and receiving pipe structures are then secured. Various pig member sets, with appropriate treatment fluids carried thereby, are air-driven through the entire length of the pipeline to successively acid clean, etch, and neutralize its interior surface. The interior pipeline surface is then thoroughly dried by flowing dehydrated air through the pipeline. Specially designed leading and trailing extruder pigs, with 100% solid, high viscosity, solvent-free epoxy coating material therebetween, are then air-driven through the pipeline to extrude a first protective coating layer onto its interior surface. The first layer is then dried with dehydrated air.

Abstract: The present invention is a contoured wall and method for creating the contour and appearance of a wall formed from individual assembled units such as stones. The wall is formed from a plurality of mating form liners each having a reciprocal contoured surface to that of the desired stone wall. The wall is formed from hardenable construction material such as concrete poured between two mold members with the form liners attached to at least one of the mold members. Each of the form liners has a lateral relief mold face adapted to provide a molded surface having the contour of a stone wall. Each lateral relief mold face of the form liners has a latticework non-linear mortar-forming interlocking portion surrounding stone-forming recessed portions. The form liners ar positionable in a plurality of arrangements wherein the interlocking portions and recessed portions along the mating edge of each form liner mate along the mating edge of the adjacent form liner to form a continuous lateral relief mold face.

Abstract: Multiple processes and apparatuses for improving the prior system of making gas generant pellets or tablets made of sodium azide, molybdenum disulfide and sulfur wherein powdered ingredients thereof are slurried in water, subjected to wet grinding, spray dried to a powdered material which is molded into pellets or tablets which find use in vehicle crash bags or inflators.The first improvement to the old process and apparatus involves adjusting the basicity of the water to a pH of greater than 8.0 up to about 12.5 via the addition of sodium hydroxide, followed by the addition of sulfur and molybdenum disulfide and finally the sodium azide whereby azide addition is made to a basic mixture of the other ingredients thereby keeping hydrazoic acid concentration levels below about 3.times.10EXP(-3) moles per liter.

Abstract: A method of providing a very strong mechanical interlock between the insuor and propellant of an interceptor rocket motor by employing a first lay-up material comprised of a cloth mat of woven cotton cloth (muslin) over a release liner with bleeder which covers a mandrel shell with a boss and a second lay-up material of an uncured vulcanizable rubber insulator, e.g., ethylene-propylene-diene-monomer (EPDM) with additives and curatives. The lay-up materials are subjected to a vacuum bag and autoclave curing environment to complete a vulcanization cycle to vulcanize and consolidate the insulator to the cloth mat. The vulcanized insulator/cloth mat is installed in a rocket motor case. The muslin cloth mat has many protruding microfibers which will be in the interface section when an uncured propellant composition is cast onto and cured to the vulcanized insulator/cloth mat. A very strong mechanical interlock is achieved which exceeds breaking strength of propellant and insulator.

Abstract: A method of repairing an underground large-diameter pipe having an inner surface includes first supporting with props inside the pipe spaced inward from its inner surface a lining having a shape conforming to that of the inner surface and then injecting a hardenable mass into the space between the inner surface and the lining and substantially completely filling this space with the mass. The mass is then cured and the props are removed. Then the cycle can be repeated for the next lining section. The lining is made of a durable synthetic resin, polyvinylchloride or high-density polyethylene.

Abstract: Mobile structural unit molding and assembling apparatus includes a support portion, a raw material supplying portion, a molding portion, a unit transferring portion and a control portion. The support portion includes at least one base section with a wheeled carriage. The raw material supplying portion includes a plurality of reservoirs disposed on the base section. The molding portion includes at least one rotatable mold assembly disposed on the base section including at least two separable mold sections. A mixing chamber adjacent the mold assembly connects with raw material reservoirs through independent conduits. The unit transferring portion includes a tiltable unit positioning assembly selectively movable with respect to the molding portion. The control portion includes a programmable memory, a coordinator, sensors, actuators, a unit orienter and circuitry therefor.

Abstract: A depositing method of wall concrete, in which unset concrete is deposited in a form, includes the step of disposing a non-hygroscopic soft sheet which has a large number of hollow projections or ridges on an inner surface of the form being deformable when lateral pressure is applied thereto by the hardening of the concrete.

Abstract: A method for improving the disperion of particulate materials in intermollar explosive compositions which comprises dry blending at least one fuel compound and at least one oxidizer compound, a viscosity modifier and a dispersable particulate material, melt blending the resulting dry blend, and thereafter casting the melt into a suitable form, casing or mold. The viscosity modifier suitable for use in the invention is a cationic salt of carboxymethylcellulose ether. The viscosity modifier is added in an amount sufficient to achieve a desired melt viscosity.

Abstract: A stable extrudable non-azide crash bag propellant composition for generating high quality nitrogen gas and a low temperature process for producing the same from an extrudable mass containing an effective amount of a cellulose-based binder.

Abstract: A method of sealing a concrete joint formed between a pair of concrete castings by creating an injection hole wherein a removable frame member can be attached to the bottom surface of the first concrete casting so as to form obtuse angles with the concrete casting surface. The other concrete casting is then cast around the frame member. The frame member is then removed to form the injection hole of the desired configuration, and sealing material can then be inserted into the injection hole for feeding into, and sealing of, the joint.

Abstract: Fluid products, particularly highly filled materials, are manufactured and cast in a continuous system utilizing feedforward composition quality control and plug flow. Liquid and solid raw are supplied to, and combined in, a continuous fluid flow system in which plug flow is established. Quantities of materials supplied are measured and averaged over time to determine composition proportions, which are compared to specification. Running averages are maintained for successive serial portions of the continuous plug flow stream. In-specification product is diverted to casting and off-specification to waste, after a time delay so that appropriate diversion is accomplished for each particular, composition-determined serial portion of the product flowstream.

Abstract: Dry cementitious compositions and packages and methods for their application. The dry compositions do not have to be mixed with water but instead are poured, sprayed or troweled onto a substrate which contains water in an amount in excess of that necessary for the hydration of the cementitious materials. These compositions can be applied by layering, dropping through a conduit, or preferably, merely dropped into the water.

Abstract: An insulated concrete building panel having an internal slab of insulating material, layers of concrete on each of the slab faces, and a concrete frame around its edges. One face of the slab has a pattern of grooves into which concrete is cast to provide ribs that are cast integral with the outer layer on that face. The other face has ridges, preferably of trapezoidal cross section that, when placed upon a bottom layer of cast but uncured concrete, become intermeshed with the bottom layer. The panels are prepared by first casting a layer of concrete on a horizontal surface, placing the slab, grooved face up, on the cast but uncured layer, and casting concrete over the grooved face, into the grooves and around the slab edges. Panels having this structure are useful for constructing buildings such as warehouses where long panel lengths of concrete inner face and internal insulation are needed.

Abstract: An improved dome structure on a base is disclosed comprising, in the preferred embodiment, of a membrane sandwiched between layers of rigidifying material such as shotcrete or reinforced composite which also serve to embed radial wires and circumferential tensioned prestressing. Various types of circumferential tensioned prestressing can be applied to minimize bursting stresses and can consist of steel wire as well as fiber or steel-reinforced tape. Further layers of rigidifying material can then be applied over the circumferential prestressing as a final protection and cover. The radial wires can contain spacers or hooks to preclude the circumferential prestressing from riding up on the structure. The lower portion of the dome can include a reverse curvature to minimize stresses and stabilize the structure. The rigidifying material may be composite which can be hardened by light curing. A second outer membrane can also be used for weather protection.

Abstract: A method for mounting floors in a shell whose concrete wall is erected by a continuous self-climbing shuttering installation and a continuous self-climbing shuttering installation for implementing the method, includes appropriate vertical and horizontal movements of certain assemblies (I.sub.1 -I.sub.2), (I.sub.3 -I.sub.4) of self-climbing brackets (2) and of their shuttering and concreting walkways (P.sub.1, P.sub.2, P.sub.3) so as to provisionally align the brackets (2, 2b) vertically in twos, and thus reduce the number of peripheral clearances to be provided in the floors to be laid at intervals inside the wall of the shell to be erected. The installation includes lateral transfer carriages (14, 14') providing the horizontal lateral transfers of the brackets, the vertical transfers being provided by the normal self-climbing system.

Abstract: A process for making a body of gas generating material comprising the steps of preparing a slurry of the ingredients of said gas generating material; extruding said slurry into a plurality of extrudate; forming the extrudate into spherical granules; and pressing a plurality of granules to form a unitary body.

Abstract: Procedure for the construction of a concrete shaft for a platform or similar structure, where one of several of the shafts will be outfitted with relatively much equipment. The shafts are constructed of prefabricated sections which are consecutively installed butt-in-butt on top of each other and which are left in the shaft as an internal fully shaped shaft component, as the sections internally contain associated equipment and externally feature bodies for the installation of easily removable formwork elements, preferably easily mountable slipforms, while the space between the formwork elements and a prefabricated section is filled with reinforcement and concrete. The formwork elements, after the hardening of poured concrete, by a per se known procedure, are moved to a higher level.

Abstract: A method for forming cementitious material, such as gunite or the like, to a desired cross-sectional profile for an interior structure such as a swimming pool, skateboard bowl or the like. A forming assembly includes a cutting edge, which is formed so as to correspond to the final desired profile of the structure. The forming assembly is mounted so as to be pivotable about a pivot axis substantially coincident with the center of the structure being formed. In this manner, when the cementitious material is applied to the side walls and bottom of the excavation to a depth slightly greater than that as finally desired, and the forming assembly pivoted 360.degree. about its pivot axis, the final desired cross-sectional profile of the structure is attained due to the action of the forming assembly striking off the excess material applied to the excavation.

Abstract: A gas generating grain has a water-based particulate booster coating thereon. The coating comprises an alkali metal azide, a water-soluble inorganic oxidizer in approximately a stoichiometric ratio of oxidizer to azide, and a nucleating amount of a small particle size metal oxide. The inorganic oxidizer is potassium perchlorate. A preferred metal oxide is selected from the group consisting of iron oxide, nickel oxide and aluminum oxide. The coating is applied to the grain from a water slurry and dried.

Abstract: The present invention relates to a method for producing, by means of working, mixing and homogenizing, castable explosive substances of high viscosity containing crystalline and/or particulate explosives and, if appropriate, other action-enhancing additives and such small quantities of binder and other viscosity-reducing agents that the mixture in the unworked state virtually feels like and behaves like a dry powder. In order to achieve the desired working, mixing and homogenizing, use is made of an arrangement which is known per se.

Abstract: A gas generating grain has a water-based particulate booster coating thereon. The coating comprises an alkali metal azide, a water-soluble inorganic oxidizer in approximately a stoichiometric proportion of oxidizer to azide, and a nucleating amount of a small particle size metal oxide, preferably selected from the group consisting of iron oxide, nickel oxide and aluminum oxide. The coating is applied to said grain from a water slurry and dried, and when dried has an average particle size of less than about 50 microns.

Abstract: A stabilized high energy explosive, e.g. hexogen (RDX), octogen (HMX) or the like, as a component of NC or plastic-bound propellant charge powders (Lova-TLP) or plastic-bound explosives (PBX) has a particle size up to 5 .mu.m and a stabilizer incorporated into the explosive particles. In order to produce such an explosive, it is proposed that the explosive in the dissolved form and with the stabilizer in the liquid phase is mixed with a proportion of up to approximately 6% and the mixture is brought by flash drying into the solid phase with a particle size of up to 5 .mu.m.

Abstract: Rammed building walls having an earth core and integral cement jackets are formed by placing a rectangular earth hopper within a rectangular wall moulding cavity that is defined by formwork members which are aligned with an underlying foundation. The hopper is filled with earth while outside of the moulding cavity and has a trapdoor as its bottom. The moulding cavity has a substantially greater width than the width of the hopper so that jacket cavities are formed on either side of the hopper. A pair of tiltable cement hoppers, filled with concrete or a sand and cement mix, are mounted on the earth hopper and are tiltably unloaded into the jacket cavities. The trapdoor is then released so that the earth slides downwardly and laterally, and the hoppers are lifted as a unit out of the moulding cavity while the earth fills a core cavity between the mix-filled jacket cavities. Both the earth and mix are then rammed simultaneously.

Abstract: Multiple processes and apparatuses for improving the prior system of making gas generant pellets or tablets made of sodium azide, molybdenum disulfide and sulfur wherein powdered ingredients thereof are slurried in water, subjected to wet grinding, spray dried to a powdered material which is molded into pellets or tablets which find use in vehicle crash bags or inflators.The first improvement to the old process and apparatus involves adjusting the basicity of the water to a pH of greater than 8.0 up to about 12.5 via the addition of sodium hydroxide, followed by the addition of sulfur and molybdenum disulfide and finally the sodium azide whereby azide addition is made to a basic mixture of the other ingredients thereby keeping hydrazoic acid concentration levels below about 3.times.10EXP(-3) moles per liter.

Abstract: An improved process for constructing a multiple-story, reinforced concrete building, in which a central core tower is first erected on a conventional foundation by moving concrete forms incrementally upwardly. A work platform is mounted for self-propelled movement along the top side of the core forms, to move men and equipment to selected locations on the core tower as it is being erected, thus simplifying the construction and substantially reducing costs. Afer the core tower has been erected, floor slabs and integral, underlying walls are constructed from the uppermost floor downwardly using slab/wall forms that can be moved repeatedly downwardly without requiring disassembly and reassembly for each story. The integral, underlying walls associated with each floor slab provide the support structure for each story, thus permitting the slab/wall forms to be lowered without the need for re-shoring.

Abstract: A wet mixture of a metal azide having a predetermined average particle size and a metal oxide is prepared. The wet mixture is ground to reduce at least the average particle size of the metal azide. Thereafter, the wet mixture is directed through a chamber containing grinding media. The grinding media is agitated as the mixture flows through the chamber to further reduce the average particle size of the metal azide to a desired particle size.

Abstract: A raw material composition for igniters, etc. which may ignite or explode can be safely mixed with high homogeneity by dissolving or dispersing a raw material composition of a highly ignitable or explosive material in a solvent or a dispersion medium, applying the resultant dispersion on a heated plate to form a thin film, and drying said thin film.

Abstract: A collection of sheet-metal, flanged, arcuate panels is provided which panels can be assembled in belts of generally circular cross-section commencing from the bottom of the manhole to provide a complete form structure for casting a concrete liner with a minimum thickness of about three inches and including openings created by sectional cylindrical inserts, all of which can be assembled, then disassembled after the concrete liner has set. An extensive variety of panels to accomodate different shapes of manholes includes panels for forming right conical belts, for forming offset conical belts, and for forming wedge-shaped belts to make transitions between vertical and tilted sections of the manhole. A key-panel for these various belts is provided to prevent capture of the panels by the poured concrete liners which includes a relatively narrow portion with vertical flanges fixed at an angle to one another which angle diverges toward the center of the form structure.

Abstract: A process for manufacturing a gas generating material includes preparing a wet mixture of a metal azide and a metal oxide without prior mixing of the metal azide and metal oxide in dry form. The metal azide content of the gas generating material is controlled and the possibility of forming hazardous hydrazoic acid fumes is minimized by maintaining the temperature of the wet mixture of gas generating material between 20.degree. C. and 30.degree. C. The possibility of forming hydrazoic acid fumes is further reduced by maintaining the pH of the wet mixture of gas generating materials at or above 10.5. Excess liquid is removed from the wet mixture of gas generating materials so that the wet mixture has a moisture content of approximately 9%. The excess liquid from the wet mixture is recycled and used the formation of additional gas generating material.

Abstract: The invention provides shaping apparatus for an explosive charge, particularly for use with plastic explosive in forming shaped charges. The shaping apparatus comprises a hollow cylindrical body (1), a substantially conical partition (2) within said body for shaping an explosive charge (3) inserted into the body on one side of said partition (2) and means (5) on the other side of said partition (2) for supporting a detonator (6).

Abstract: The disclosure relates to a method and a device for producing compositions comprising fine-grained crystalline explosive substances with the aid of a steam-driven ejector (22). The expression explosive substances is here taken to mean both low and high explosives.

Abstract: After a mortar layer is formed on the surface layer of placed concrete, an ultrasonic vibrator is caused to vibrate while being pressed against the mortar layer surface, and a thin surface layer is scraped off, obtaining a dense water-shielding layer. Mortar with a low water-cement ratio is spread onto the surface of the water-shielding layer, and adhesion between the mortar and the water-shielding layer is strengthened by using the ultrasonic vibrator. The pressing force of the ultrasonic vibrator is then increased to make the mortar and the water-shielding layer densely integrated together, thereby forming a hard concrete surface excelling in abrasion resistance.

Abstract: A tracer composition with a relatively high luminous output and a moderate burn rate includes from 35 to 47% by weight magnesium; from 40 to 53% by weight strontium nitrate, from 2 to 10% by weight magnesium carbonate, from 0 to 6% by weight color intensifier; from 0 to 6% by weight retardant and from 3 to 8% by weight of a synthetic polymer binder selected from the group consisting of (i) a terpolymer of vinylidene fluoride, hexafluoropropylene and polytetrafluoroethylene and (ii) a copolymer of vinylidene fluoride and hexafluoropropylene.

Abstract: An extrudable plastic bonded explosive molding powder is provided and conns about 20 percent by weight ethylenevinyl acetate copolymer and 80 percent by weight PETN.