Abstract:
The story of the invention of Portland cement
is, however, attributed to Joseph Aspdin, a Leeds
builder and bricklayer, even though similar
procedures had been adopted by other inventors.
Joseph Aspdin took the patent of portland cement
on 21st October 1824. The fancy name of
portland was given owing to the resemblance of
this hardened cement to the natural stone
occurring at Portland in England. In his process
Aspdin mixed and ground hard limestones and
finely divided clay into the form of slurry and
calcined it in a furnace similar to a lime kiln till the
CO2 was expelled. The mixture so calcined was
then ground to a fine powder. Perhaps, a
temperature lower than the clinkering
temperature was used by Aspdin. Later in 1845
Isaac Charles Johnson burnt a mixture of clay and
chalk till the clinkering stage to make better
cement and established factories in 1851.
In the early period, cement was used for
making mortar only. Later the use of cement was
extended for making concrete. As the use of
Portland cement was increased for making
concrete, engineers called for consistently higher
standard material for use in ma
