AbstractThe main theme of this research was to investigate the durability of concrete made using waste materials as a cement replacement. This is a method to produce green sustainable concrete. The objective was to use locally available wastes to produce a concrete that could be used by the local authority.
The mechanical, physical and chemical properties of concrete made predominantly with IFA as a partial cement replacement have been tested. The IFA was won locally from the domestic waste incinerator at Coventry, UK. The other materials used in the mixes included Ground Granulated Blast Furnace Slag (GGBS), silica fume and by-pass dust, which was used as an activator and was also won locally from the Rugby cement plant.
Compressive strength and tensile strength, workability, corrosion of embedded steel, shrinkage and expansion, freeze and thaw, corrosion and chloride ingress were studied. Water permeability was studied by the author on mortar samples during one year and on concrete samples during the following. Carbonation was studied on concrete samples and finally mechanical experiments were carried out on concrete beams and slabs. Two further experiments were carried out to complete the study of durability of concrete made with waste materials being, the ASR (Alkaline Silica Reaction) and sulphate attack experiments.
One main physical experiment, in the form of a trial mix, was carried out in one of the waste recycling sites of Warwickshire in September 2013. Subsequent to observations during the site trial, the author compared results of setting time, heat of hydration and strength of the trial mix and control mixes.
The outcome of this research was a novel mix that had more than 30 percent waste material and a further 40 percent of secondary materials, making it as sustainable as possible. Both laboratory and site trial results have achieved compressive strength which are higher than 30 MPa, indicating that the novel mix concrete could be used for structural purposes.
Most of the durability results of the novel mix were comparable with the control OPC mix and the novel mix concrete, in terms of transport properties, induced less electrical current seepage. Furthermore the tensile strength of the novel mix concrete was higher than the control OPC concrete and this is due to the higher ductility index of the novel mix.
|Date of Award
|Peter Claisse (Supervisor)
- Incinerator Fly Ash Concrete