Search results
Results from the WOW.Com Content Network
Portland cement is the most common type of cement in general use around the world as a basic ingredient ... Portland cement is caustic, so it can cause chemical burns ...
Calcium silicate hydrate (also shown as C-S-H) is a result of the reaction between the silicate phases of Portland cement and water. This reaction typically is expressed as: 2 Ca 3 SiO 5 + 7 H 2 O → 3 CaO · 2 SiO 2 · 4 H 2 O + 3 Ca(OH) 2 + 173.6 kJ. also written in cement chemist notation, (CCN) as: 2 C 3 S + 7 H → C 3 S 2 H 4 + 3 CH + heat
The resulting hard substance, called 'clinker', is then ground with a small amount of gypsum (CaSO 4 ·2H 2 O) into a powder to make ordinary Portland cement, the most commonly used type of cement (often referred to as OPC). Portland cement is a basic ingredient of concrete, mortar, and most non-specialty grout. The most common use for Portland ...
Cement chemist notation (CCN) was developed to simplify the formulas cement chemists use on a daily basis. It is a shorthand way of writing the chemical formula of oxides of calcium, silicon, and various metals.
Tricalcium aluminate hydrates in the process of forming Portland cement. Using X-ray diffraction, two hydrates form, the hexahydrate abbreviated C3AH6 and a nonadecahydrate abbreviated C4AH19. In the presence of gypsum, a component of typical clinkers, the sulfate (S) forms with the formula C4ASH12. [1]
The characteristic greenish-gray to brown color of ordinary Portland cement derives from a number of transition elements in its chemical composition. These are, in decreasing order of coloring effect, chromium, manganese, iron, copper, vanadium, nickel and titanium. The amount of these in white cement is minimized as far as possible.
Portland cement clinker is made by heating a homogeneous mixture of raw materials in a rotary kiln at high temperature. The products of the chemical reaction aggregate together at their sintering temperature, about 1,450 °C (2,640 °F).
An AFm phase is an "alumina, ferric oxide, monosubstituted" phase, or aluminate ferrite monosubstituted, or Al 2 O 3, Fe 2 O 3 mono, in cement chemist notation (CCN). AFm phases are important hydration products in the hydration of Portland cements and hydraulic cements.