El tradicional ensayo de Trauzl permite determinar el rendimiento aproximado de los explosivos en aplicaciones de voladura midiendo el aumento de volumen que se produce por la detonación de una carga explosiva en la cavidad de un bloque de plomo. En este documento, los autores buscan reconsiderar la posibilidad de interpretar los resultados de la prueba de Trauzl en términos de parámetros de detonación. Los parámetros de detonación utilizados en el análisis se calculan utilizando el código termoquímico EXPLO5, mientras que el hidrocódigo AUTODYN se utiliza para simular el efecto de la densidad de carga explosiva y la velocidad de reacción en los resultados de la prueba de Trauzl. El aumento en el volumen de la cavidad del bloque de plomo se encontró que se correlaciona mejor con el producto del calor de detonación y la raíz del volumen de los productos de detonación. Simulación de hidrocódigo demostró que la densidad de la carga explosiva y la velocidad de descomposición explosiva afectan la dinámica de la interacción de los productos de la detonación y el bloque, siendo directamente proporcionales al aumento del volumen de la cavidad.
1. Introduction
The performance of explosives (“strength” or “power”) is usually estimated based on the values of the detonation parameters. However, such an approach often does not give the same explosive ranking order. For illustration, when explosives perform strong disintegration work, the most relevant parameters are detonation velocity and pressure. However, for blasting work, the heat of detonation and the amount of gas products are relevant parameters, while the detonation velocity does not play an important role. Thus, the performance of an explosive should be related to the type of work performed by the explosive, and it cannot be judged on a single detonation parameter.
In practice, various experimental tests have been developed to mimic a particular application of explosives. One of such tests is the lead block test, also known as the Trauzl test, which allows the determination of the approximate relative strength of explosives in blasting applications. The test was proposed in the 1880s by Isidor Trauzl, while the standard conditions for performing the test were established in 1930. The test consists in firing 10 g of an explosive charge mounted in a cavity (Φ2.5 × 12.5 cm), drilled along the block axis) within a lead block (Φ20 × 20 cm). After the explosive charge is inserted, the cavity is tamped with quartz sand. The increase in cavity volume (Δ VT) after charge detonation serves as a measure of explosive strength. One of the key features of the lead block test is that it mimics the conditions fairly closely in a borehole, however, the weakness of the test is that it uses a small explosive charge mass. According to Marshall, the lead block test can only give satisfactory comparative results for the same class of explosives, i.e., explosives that behave in the same way. If, for example, the pressure growth rates of the two explosives are very different, then the results of the tests are no longer comparable. Afanasenkov stated that the experimental Δ VT values for ideal explosives were satisfactorily correlated with the product of the heat of detonation and the amount of gases, while the correlation for explosives detonating at low velocities is significantly poorer. The author assumed that a small amount of explosive charge used in the Trauzl test does not allow establishing the steady-state detonation process in such explosives (non-ideal), which results in a poorer correlation. Mayer et al. also thought that reliable Trauzl test results can only be obtained for ideal high explosives.
Fuente: https://www.sciencedirect.com
