Extensive laboratory work was carried out to investigate the performance of stabilised clay-based target material. Lower Oxford Clay (LOG) was used as the base clay, with and without combining it in equal proportions (50:50) with Pulverised Fly Ash (PFA) an industrial waste from the burning of coal in power stations. The traditional binders of Lime and Portland Cement (PC) were used as controls. In order to enhance sustainability, these two binders were partially replaced with Ground Granulated Blast-furnace Slag (GGBS) an industrial by-product from the manufacture of steel. During the preliminary phase of the research, two different approaches to establishing the moisture demand during compaction of test specimens were investigated, using both LOC and LOC-PFA mixtures at two stabiliser dosages of 10wt% and 20wt%. Results indicated that the approach resulting with a lower compaction moisture content achieved better strength with the lower stabiliser dosage of 10%, while the approach with a higher moisture content was better suited to the higher stabiliser dosage of 20%. With these preliminary results, pilot industrial and commercial trials were then carried out using typical full-size unfired bricks of size 295mm x 140mm x 55mm. These trials demonstrated that all the key parameters of compressive strength, durability and thermal properties were within the acceptable engineering standards for masonry units. Overall, the results suggested that with proper protection against excessive moisture ingress, the use of GGBS and PFA in the manufacture of unfired bricks is a viable alternative to fired bricks, especially in certain applications such as low-bearing load situations. From the environmental and sustainability analysis results, the unfired LOC-PFA bricks showed energy-efficiency and suggested viable economical alternatives to the traditionally fired building components. Using a five-tool environment assessment comparison method, the materials-related inputs were assessed, as criteria for achieving the sustainability rating of a building. The outcome suggested that with the new unfired Clay-PFA technology, innovation and enhanced waste management, the achievement and use of green building materials is real, and thus a great contribution towards the concept of "green building" has been made in this study.
|Date of Award||Jun 2011|
|Supervisor||John Kinuthia (Supervisor)|
- Sustainable buildings
- Design and construction