The influence of compaction and saturation on the compressibility of colliery waste

Abstract

Using colliery waste to produce building materials, especially in earthworks to build different types of road and railway embankments, or to fill cavities and open-pit mines, requires us to determine the value of the settlement and the ability of fly ash to reduce its volume about its usability for mentioned purposes. Economic benefits and the need to protect the environment are the main reasons for using fly ash as secondary raw material. The purpose of this paper is to determine the effect of initial compaction and water conditions on the process and values of settlement as well as oedometric modulus of primary compression, decompression and secondary compression of fly ash. The tests were carried out in oedometers. The subject of the research was fly ash from Skawina Power Plant. Literature analysis covers the processes of waste production and management, types of waste depending on the grain size and composition, as well as the methods and ways of testing the compressibility of mineral and anthropogenic soils. The results of the tests allowed formulating conclusions on the influence of compaction and water conditions on the possibility of settling, consolidation and the values of compressibility moduli of the tested material. They also allowed determining the usability of the material for earth constructions and other purposes.