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Explosives
Published in Michael L. Madigan, First Responders Handbook, 2017
Brisance is the shattering capability of a high explosive, determined mainly by its detonation pressure. The term can be traced from the French verb “briser” (to break or shatter), ultimately derived from the Celtic word “brissim” (to break). Brisance is of practical importance for determining the effectiveness of an explosion in fragmenting shells, bomb casings, grenades, structures, and the like. 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).
Explosives and blasting
Published in Ratan Raj Tatiya, Surface and Underground Excavations, 2013
These explosives are less sensitive to impact and shock compared to dynamites. They show high brisance or shattering effect. Brisance is described as the ability of explosive to shatter and fragment steel, concrete and other very hard structures. Their velocity of detonation is in the range of 7000 to 9000 m/sec. comparing the same for the commercial explosives, which is up to 5000 m/sec. These are known by the names such as: TNT, PETN, RDX, TETRYL etc. They have high detonation pressures of the order of 17 million p.s.i (117.1 million kps (1 p.s.i. = 6.89 kps (kilopascal). The components are either melted or poured or casted into shells or suspended. These explosives feature following characteristics: Maximum power/unit volumeMinimum weight/unit powerHigh velocity of detonationLong term stability under adverse storage conditionsInsensitivity to shock on firing and impact.
Shock Waves and Detonations, Explosive Performance
Published in Per-Anders Persson, Roger Holmberg, Jaimin Lee, Rock Blasting and Explosives Engineering, 2018
Per-Anders Persson, Roger Holmberg, Jaimin Lee
It is well known in the rock blasting industry that explosives with a high brisance (or a high shock energy), such as a high density, high detonation velocity dynamite, are well suited for blasting in hard competent rock. A low brisance explosive such an ANFO (which produces a lower shock wave energy, but a relatively high bubble expansion or heave energy) is better suited for soft, porous, or heavily fractured rock. The best matching for optimum shock wave transmission to the rock occurs when the detonation impedance ρaD equals the impedance of the rock material ρbcb, i.e., when μ for the explosive/rock combination equals one.
Experimental investigation of RC slabs under air and underwater contact explosions
Published in European Journal of Environmental and Civil Engineering, 2021
Xiaohua Zhao, Gaohui Wang, Wenbo Lu, Guangdong Yang, Ming Chen, Peng Yan
Rock emulsion explosive with a material density of 1.05 g/cm3 and a brisance of 12 mm is used in the tests, as shown in Figure 1(a). The charge is placed on the top center of the slabs, and the weights of the charge are from 6 g to 50 g. The electric detonator is inserted at the top of the explosive and used to detonate the explosive (Figure 1(b)). It should be noted that the shape of the explosive is not absolutely cubic or cuboid. This is because the rock emulsion explosive has good liquidity, and the weight of the charge using the explosion tests is very little (only 6–50 g). It is very difficult to ensure the explosive charge with a regular shape. However, this charge shape effects on the experimental results can be ignored (Zhao et al., 2018). The explosive in the electric detonator is Hexogen with rock emulsion explosive equivalence of 1 g (Li et al., 2016). Due to the minimum charge mass in the tests is 6 g, the effects of the electric detonator cannot be neglected. Hence, one electric detonator without any rock emulsion explosive is also used in the current tests.