Can I use PFA and/or FBA in Foamed Concrete without any risk of an explosion?
In November 2009 a foamed concrete containing Incinerator Bottom Ash (IBA) as a coarse aggregates was associated with an explosion. This was the result of elemental aluminium reacting with calcium hydroxide, a by-product of the reaction of Portland Cement with water, producing hydrogen gas. Normally this gas would simply disappear to atmosphere, but if the gas is trapped in a confined area as in this incident, an explosion may occur. IBA is a very different material than PFA or FBA due to the fuels combusted and the furnace operating temperature. Pulverised Fuel Ash (PFA) and Furnace Bottom Ash (FBA) are from the coal fired power stations and the UK power station operators do not burn waste materials. This is primarily because the stations are not registered as Waste Incinerators. The fuels that are used do not contain elemental aluminium, therefore, the resulting PFA or FBA never contains elemental aluminium and there is no risk of release of hydrogen gas from PFA (or FBA) produced fr
