We have given the basic information on what cement is along with a straightforward idea of how it works. However, did you know that there are several different types of cement? Each type has its own attributes, uses and chemical formulae. Some types are general purpose while others are deeply specialised and refined for use in specific fields.
Today we look at Portland Cement, a type of cement that was first patented in 1824. Currently the basic chemical compounds of Portland Cement include Calcium, Silicon, Aluminium and Iron. Originally, Portland Cement was made from a ground mixture of calcined limestone and argillaceous earth or clay, (argillaceous meaning that it is very clay like in nature). Modern Portland Cement uses limestone, marly limestone, chalk, coral limestone, marble, lime sand and shell deposits to get its calcareous compounds i.e. to provide lime, CaO, as the Calcined Limestone did. Portland Cement now also uses clay, shale, marl, marly clay, ash and slate for its argillaceous compounds, to provide silica, aluminium and iron which are gained from argillaceous earth or clay.
Portland Cement is a general purpose cement and is not specialised for any specific fields or uses, although it does produce a fair amount of heat during its hydration process.