Pneumatic Concrete Placement for Shaft and Adit Closures

摘要

A system was developed to pneumatically seal mine entries with a minimum ofequipment and expense. This system mechanically feeds and pneumatically transports aggregate mixed with the proper amount of water in a 6-in-diameter pipeline, and pneumatically transports a metered amount of dry cement in a 4-in-diameter pipeline. The two pipes join at the delivery end of the pipeline where mixing occurs as the materials are projected at the desired target such as a mine seal location. A seal can also be made by installing a wire mesh in the entry and then projecting the mix onto it, building an effective seal with a substantially reduced amount of material. A boost system was also developed to allow the system to transport the aggregate, water, and cement around corners or to allow transport of these materials over longer distances without losing transport velocity.