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Brisance
Brisance (; ) is the shattering capability of a high explosive, determined mainly by its detonation pressure. Application Brisance is of practical importance in explosives engineering for determining the effectiveness of an explosion in blasting and quarrying, and in weaponry such as fragmenting shells, bomb casings, grenades, and plastic explosives. The sand crush test and Trauzl lead block test are commonly used to determine the relative brisance in comparison to TNT (which is considered a standard reference for many purposes). The value of brisance depends on the application. At one extreme, if an explosive is to be used for propulsion, e.g. by driving a piston or a bullet, brisance is likely to be undesirable, because the objective will be to ''move'' the load, not to shatter it or the engine or firearm, nor to produce a loud report. Such propulsive charges are designed to burn controllably, such as carburetted fuel/air mixes in vehicle piston engines, or nitrocellulos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
High Explosive
An explosive (or explosive material) is a reactive substance that contains a great amount of potential energy that can produce an explosion if released suddenly, usually accompanied by the production of light, heat, sound, and pressure. An explosive charge is a measured quantity of explosive material, which may either be composed solely of one ingredient or be a mixture containing at least two substances. The potential energy stored in an explosive material may, for example, be: * chemical energy, such as nitroglycerin or Dust explosion, grain dust * pressure, pressurized gas compressor, gas, such as a gas cylinder, aerosol can, or boiling liquid expanding vapor explosion * nuclear weapon, nuclear energy, such as in the fissile isotopes uranium-235 and plutonium-239 Explosive materials may be categorized by the speed at which they expand. Materials that detonate (the front of the chemical reaction moves faster through the material than the speed of sound) are said to be "high ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blasting Powder
Gunpowder, also commonly known as black powder to distinguish it from modern smokeless powder, is the earliest known chemical explosive. It consists of a mixture of sulfur, charcoal (which is mostly carbon), and potassium nitrate (saltpeter). The sulfur and charcoal act as fuels while the saltpeter is an oxidizer. Gunpowder has been widely used as a propellant in firearms, artillery, rocketry, and pyrotechnics, including use as a blasting agent for explosives in quarrying, mining, building pipelines, tunnels, and road#Construction, roads. Gunpowder is classified as a Explosive#Low, low explosive because of its relatively slow decomposition rate, low ignition temperature and consequently low brisance, brisance (breaking/shattering). Low explosives deflagration, deflagrate (i.e., burn at subsonic speeds), whereas high explosives detonation, detonate, producing a supersonic shockwave. Ignition of gunpowder packed behind a projectile generates enough pressure to force the shot fro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Table Of Explosive Detonation Velocities
This is a compilation of published detonation velocities for various high explosive compounds. Detonation velocity is the speed with which the detonation shock wave travels through the explosive. It is a key, directly measurable indicator of explosive performance, but depends on density which must always be specified, and may be too low if the test charge diameter is not large enough. Especially for little studied explosives there may be divergent published values due to charge diameter issues. In liquid explosives, like nitroglycerin, there may be two detonation velocities, one much higher than the other. The detonation velocity values presented here are typically for the highest practical density which maximizes achievable detonation velocity.Cooper, Paul W. (1996). ''Explosives Engineering'', New York: Wiley-VCH. The velocity of detonation is an important indicator for overall energy and power of detonation, and in particular for the brisance or shattering effect of an explosi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quarry
A quarry is a type of open-pit mining, open-pit mine in which dimension stone, rock (geology), rock, construction aggregate, riprap, sand, gravel, or slate is excavated from the ground. The operation of quarries is regulated in some jurisdictions to manage their safety risks and reduce their environmental impact. The word ''quarry'' can also include the underground quarrying for stone, such as Bath stone. History For thousands of years, only hand tools had been used in quarries. In the eighteenth century, the use of drilling and blasting operations was mastered. Types of rock Types of rock extracted from quarries include: *Chalk *China clay *Scoria, Cinder *Clay *Coal *Construction aggregate (sand and gravel) *Coquina *Diabase *Gabbro *Granite *Gritstone *Gypsum *Limestone *Marble *Ores *Phosphate rock *Quartz *Sandstone *Slate *Travertine Methods of quarrying The method of removal of stones from their natural bed by using different operations is called quarryin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Firearm
A firearm is any type of gun that uses an explosive charge and is designed to be readily carried and operated by an individual. The term is legally defined further in different countries (see legal definitions). The first firearms originated in 10th-century China, when bamboo tubes containing gunpowder and pellet projectiles were mounted on spears to make the portable fire lance, operable by a single person, which was later used effectively as a shock weapon in the siege of De'an in 1132. In the 13th century, fire lance barrels were replaced with metal tubes and transformed into the metal-barreled hand cannon. The technology gradually spread throughout Eurasia during the 14th century. Older firearms typically used black powder as a propellant, but modern firearms use smokeless powder or other explosive propellants. Most modern firearms (with the notable exception of smoothbore shotguns) have rifled barrels to impart spin to the projectile for improved flight stabili ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Relative Effectiveness Factor
TNT equivalent is a convention for expressing energy, typically used to describe the energy released in an explosion. A ton of TNT equivalent is a unit of energy defined by convention to be (). It is the approximate energy released in the detonation of a metric ton (1,000 kilograms) of trinitrotoluene (TNT). In other words, for each gram of TNT exploded, (or 4184 joules) of energy are released. This convention intends to compare the destructiveness of an event with that of conventional explosive materials, of which TNT is a typical example, although other conventional explosives such as dynamite contain more energy. A related concept is the physical quantity TNT-equivalent mass (or mass of TNT equivalent), expressed in the ordinary units of mass and its multiples: kilogram (kg), megagram (Mg) or tonne (t), etc. Kiloton and megaton The "kiloton (of TNT equivalent)" is a unit of energy equal to 4.184 terajoules (). A kiloton of TNT can be visualized as a cube of TNT on a si ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
C-4 (explosive)
C-4 or Composition C-4 is a common variety of the plastic explosive family known as Composition C, which uses RDX as its explosive agent. C-4 is composed of explosives, plastic binder, plasticizer to make it malleable, and usually a marker or odorizing taggant chemical. C-4 has a texture similar to modelling clay and can be molded into any desired shape. C-4 is relatively insensitive and can be detonated only by the shock wave from a detonator or blasting cap. A similar British plastic explosive, also based on RDX but with a plasticizer different from that used in Composition C-4, is known as PE-4 (Plastic Explosive No. 4). Development C-4 is a member of the Composition C family of chemical explosives. Variants have different proportions and plasticisers and include compositions C-2, C-3, and C-4. The original RDX-based material was developed by the British during World War II and redeveloped as Composition C when introduced to the U.S. military. It was replaced by Composition C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Detonation Velocity
Explosive velocity, also known as detonation velocity or velocity of detonation (VoD), is the velocity at which the shock wave front travels through a detonated explosive. Explosive velocities are always higher than the local speed of sound in the material. If the explosive is confined before detonation, such as in an artillery shell, the force produced is focused on a much smaller area, and the pressure is significantly intensified. This results in an explosive velocity that is higher than if the explosive had been detonated in open air. Unconfined velocities are often approximately 70 to 80 percent of confined velocities. Explosive velocity is increased with smaller particle size (i.e., increased spatial density), increased charge diameter, and increased confinement (i.e., higher pressure). Typical detonation velocities for organic dust mixtures range from 1400 to 1650m/s. Gas explosions can either deflagrate or detonate based on confinement; detonation velocities are ge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Explosives Engineering
Explosives engineering is the field of science and engineering which is related to examining the behavior and usage of explosive materials. Topics Some of the topics that explosives engineers study, research, and work on include: * Development and characterization of new explosive materials in Use forms of explosives, various forms * Analysis of the physical process of detonation * Explosive generated shock waves and their effects on materials * Safety testing of explosives * Analysis and engineering of rock blasting for mining * Design and analysis of shaped charges and reactive armor * Design, analysis and application of military explosives such as grenades, Land mine, mines, Artillery shell, shells, aerial bombs, missile warheads, etc. * Bomb disposal * Drilling and blasting * Demolition Organizations * International Society for Explosive Engineers, International Society of Explosives Engineers (ISEE) * Missouri University of Science and Technology http://explosives.mst.e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drilling And Blasting
Drilling and blasting is the controlled use of explosives and other methods, such as gas pressure blasting pyrotechnics, to break rock for excavation. It is practiced most often in mining, quarrying and civil engineering such as dam, tunnel or road construction. The result of rock blasting is often known as a rock cut. Drilling and blasting currently utilizes many different varieties of explosives with different compositions and performance properties. Higher velocity explosives are used for relatively hard rock in order to shatter and break the rock, while low velocity explosives are used in soft rocks to generate more gas pressure and a greater heaving effect. For instance, an early 20th-century blasting manual compared the effects of black powder to that of a wedge, and dynamite to that of a hammer. The most commonly used explosives in mining today are ANFO based blends due to lower cost than dynamite. Before the advent of tunnel boring machines (TBMs), drilling and b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Slate
Slate is a fine-grained, foliated, homogeneous, metamorphic rock derived from an original shale-type sedimentary rock composed of clay or volcanic ash through low-grade, regional metamorphism. It is the finest-grained foliated metamorphic rock. Foliation may not correspond to the original sedimentary layering, but instead is in planes perpendicular to the direction of metamorphic compression. The foliation in slate, called " slaty cleavage", is caused by strong compression in which fine-grained clay forms flakes to regrow in planes perpendicular to the compression. When expertly "cut" by striking parallel to the foliation with a specialized tool in the quarry, many slates display a property called fissility, forming smooth, flat sheets of stone which have long been used for roofing, floor tiles, and other purposes. Slate is frequently grey in color, especially when seen ''en masse'' covering roofs. However, slate occurs in a variety of colors even from a single locality; for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
