|If this formula is not unified correctly please contact us.|
Manufactured using limestone and shale. Powder is mixed and fired in a rotary kiln to near-stoneware temperatures. The clinker is finely ground to produce a grey powder that reacts with water to form a hydrous calcium silicate with some CaO left over.
Acids do attack cement however as soluble materials are removed less reactive remaining materials are quite stable.
A relatively high-temperature calcinated mix of clay and lime which hardens quickly after wetted with water and left to air-dry. Unlike most natural clay cements, however, Portlands bonding deteriorates under time, stress and weathering. Like all clay cements, Portland, behaving as a calcined calcareous earth, will fuse readily when fluxed and will melt at much lower temperatures than its required high calcinating temperatures. A simple brown glaze, for example, can be obtained at 900º
;C from a thick solution comprising equal parts of Portland and hydroboracite or minium.
typical analyses of compositions, after calcinated at 1300-1500ºC
limestone; 52% lime, 3% silica, 1% slumina, 0.5% iron, 0.5% magnesia, 42% burned away
chalk; 54% lime, 1% silica, 0.5% alumina, 0.2% iron, 0.3% magnesia, 43% burned away
cement rock: 43% lime, 11% silica, 3% alumina, 1% iron, 2% magnesia, 36% burned away
clay: 1% lime, 57% silica, 16% alumina, 7% iron, 1% magnesia, 14% burned away
slag: 42% lime, 34% silica, 15% alumina, 1% iron, 4% magnesia, 0% burned away