Open AccessSite Trials of Recycled and Secondary Aggregates in Concrete and Concrete Blocks in Qatar
Author(s) -
K.E. Hassan,
M. S. Kuwari,
J M Reid
Publication year - 2014
Publication title -
forum
Language(s) - English
Resource type - Journals
eISSN - 2051-8242
pISSN - 2051-8234
DOI - 10.2478/ijpeat-2013-0011
Subject(s) - aggregate (composite) , demolition waste , subbase , demolition , economic shortage , excavation , environmental science , california bearing ratio , road construction , waste management , civil engineering , engineering , geotechnical engineering , mining engineering , materials science , subgrade , composite material , linguistics , philosophy , mathematics , discrete mathematics , general topology , topological space , government (linguistics) , extension topology
A major construction programme is underway in Qatar. A shortage of local aggregate is focusing attention on the use of recycled and secondary aggregates. Site trials using locally available materials in structural concrete and concrete blocks were carried out in three small buildings. By far the largest source of recycled and secondary aggregates in Qatar is construction, demolition and excavation waste, which is generally crudely separated into excavation waste (EW) and construction/demolition waste (CDW). The other material investigated was incinerator bottom ash (IBA). The EW was used to replace 50% of the coarse aggregate in structural C40 concrete, with the CDW replacing 50% and IBA 20% of the coarse aggregate in non-load bearing concrete blocks. The control was 100% imported gabbro coarse aggregate. The trials also incorporated replacement of 60% of the local washed sand with imported crushed rock fines; this was investigated because the reserves of suitable concrete sand in Qatar are limited. Results after one year show the materials giving equivalent or better performance than the primary aggregate controls. The Qatar Construction Specification will be updated to permit greater use of recycled and secondary aggregates (RSA) and further trials are planned in a range of applications, including unbound subbase and pavement concrete. Wider use of these materials will reduce reliance on imported aggregates. The site trials won an award for the most innovative project from the Qatar Contractors Forum 2013.