Use of colliery spoil for infilling mine workings

Colliery spoil has been used as a major constituent of rock paste, a controlled low-strength bulk infill material, to infill abandoned limestone mines in the West Midlands of England since the early 1980s. During this time the design of colliery spoil rock paste has been modified and improved to ensure that strengths are achieved and consolidation is minimised. This paper describes the methods used for measuring and monitoring the development of the strength of rock paste used to infill the Littleton Street Mine in Walsall, England. The mine had a volume of about 500,000 m3 and is possibly the largest underground void to be infilled with rock paste.