Engineering properties and applications of recycled brick rubble

Recycling and reuse of waste materials is a topic of global concern and of great international interest. The urgent need for recycling is driven mainly by environmental considerations, due to the increase scarcity of natural resources and the increasing cost of land fill in most countries. Construction and demolition (C&D) materials are generated by regeneration of infrastructure such as demolition activities of buildings and construction activities of tunnels and roads. Recycled crushed brick, crushed concrete, crushed basaltic rock are viable substitute materials for natural construction materials in engineering applications such as pavement subbase and other road construction applications. This study focuses on the applicability of crushed brick blends with crushed concrete and crushed basaltic rock in pavement subbase material as well as bedding and backfill material for drainage systems. Construction and demolition materials account for a major proportion of the waste materials present in landfills in Australia. Crushed concrete and crushed brick are major components of demolition materials in Australia. Crushed rock used in this study originates from 'basalt floaters' or surface excavation rock (basalt) which commonly occurs near the surface to the north and west of Melbourne, Australia. The materials for the experimental works were collected from a recycling facility in Victoria, Australia The engineering characteristics of various proportions of crushed brick blends with crushed concrete and crushed rock, obtained from an extensive laboratory testing include high level tests such as static triaxial tests and repeat load triaxial tests are presented in this study. Finite element modelling on pavement application was done by using finite element program 'PLAXIS'. The engineering properties obtained were compared with existing local road authority specifications for pavement subbase or light duty base material and backfill material for drainage systems to ascertain the potential use of crushed brick blends. The research indicates that initially up to 25 % of crushed brick could be safely added to crushed concrete and crushed rock as pavement subbase material. Depending on the results of field trials, it may be possible to increase the percentage of crushed brick added in the future.