Ordinary Portland Cement (OPC)
is the most expensive and energy intensive ingredient in concrete. Due to the manufacturing process associated with
cement production, for every tonne of cement produced almost as much CO2
can be released into the atmosphere. Therefore, it is imperative that
alternative cement replacements are developed that produce either less
greenhouse gas emissions in their production or are waste and/or by-products.
study investigates the use of two fly ashes from the combustion of peat and the
co-firing of peat with wood, which are currently waste products, as alternative
binders to OPC. These materials are cost-effective and their use in concrete
can benefit the environment, as the alternative may be to dispose of them in
landfills. The effects these ashes have on the properties of fresh and hardened
concrete is investigated.
with a cement replacement level of 10% and 20% of both materials is tested in terms
of workability and strength at 3, 7, 14 and 28 days. All results are compared
to a control mix. Compressive strength testing was carried out on 100mm cubes,
150mm cubes and 150mm x 300mm cylinders. Correlations between compressive
strength results from the three different types of specimens are presented. The
findings from this study suggest that there is potential for peat fly-ash to be
used as a cement replacement.