Bina Nusantara - CEMENT - Cement represent the result of very complex industry, with mixture and also different formation. Cement can be differentiated to become two group : –Non-Hidrolik cement. –Hydraulic Cement. 1.Non-Hydraulic Cement. Non-Hydraulic Cement cannot fasten and ossify underwater however can ossify on the air. Special example of hydraulic cement is chalk. Good Chalk type is white chalk, that is consist of high oxide calcium when still in form of chalk of tohor ( not yet related to water ) and will contain many hydroxide calcium when have related to water.
Bina Nusantara Chalk yielded by burning carbonate calcium or limestone with along with materials – its pollutant materials, that is magnesium, silicate, iron, alkali, brimstone and alumina. Process combustion executed in high kiln stove at temperature 800 o -1200 o C. CaCO 3 CaO + CO 2 Formed to be Oxide calcium to be referred by chalk of tohor, and if relating to water will become hydroxide calcium and also heat. CaO + H 2 O Ca(OH) 2 + heat
Bina Nusantara 2.Hydraulic Cement. Hydraulic cement have ability to fasten and ossify in water. Hydraulic Cement example : a.Hydraulic chalk b.Cement of Pozollan c.Cement of terak d.Natural cement e.Cement of Portland f.Cement portland-pozollan g.Cement high kiln terak portland h.Cement of Alumina i.Expansif cement
Bina Nusantara SEMEN PORTLAND Cement of Portland is construction materials which at most used in work of concrete. According to ASTM C-150, 1985, cement of portland defined as hydraulic cement which yielded by milling klinker which consist of hydraulic silicate calcium, which generally contain one or more sulphate calcium form upon which milled addition with – is equal to materials the core important. Special materials cement of portland is chalk (CaO), silika (SiO 3 ), alumina (Al 2 O 3 ), a few magnesia (MgO), and sometimes a few alkali. To control its composition, sometimes added iron oxide, while gypsum (CaSO 4.2H 2 O) enhanced to lead the time to fasten cement.
Bina Nusantara Making the cement of portland executed to pass some step, that is : 1.Mining in quarry. 2.Resolving in plant crushing. 3.Blending 4.Mixing of materials. 5.Ciln 6.Hulling return result of combustion. 7.Addition of additional materials. 8.Packing plant
Bina Nusantara Marginally, there is four especial chemical compound which compile cement of portland, that is : 1.Trikalsium Silicate (3CaO.SiO 2 ),shortened to become C 3 S. 2.Dikalsium Silicate (2CaO.SiO 2 ), shortened to become C 2 S. 3.Trikalsium Aluminat (3CaO.Al 2 O 3 ) shortened to become C 3 A 4.Tertrakalsium aluminoferrit (4CaO.Al 2 O 3.Fe 2 O 3 ) shortened to become C 4 AF.
Bina Nusantara Regulation of concrete 1989 (SKBI.18.104.22.1689) in its divide cement of portland become five type (SK.SNI T-15-1990-03:2) that is : –Type of I, cement portland which in its use do not need special conditions like other type. –Type of II, cement portland which in its use need resilience to hydration heat and sulphate. –Type of III, cement portland which in its use need strength early high in start phase after cordage happened. -Type of IV, cement portland which in its use need low hydration heat. -Type of V, cement portland which in its use need high resilience to sulphate.
Bina Nusantara Percentage Of Composition Cement Portland.
Bina Nusantara WATER Water needed in the making of concrete to trigger process of chemical cement, wetting aggregate and give amenity in work of concrete. Water able to be drinked generally can be used as concrete mixture. The consist of water dangerous compound, impure salt, oil, sugar, or other chemicals, if weared in concrete mixture will degrade the quality of concrete, even can denature – nature of yielded concrete. Because cement pasta represent result of reaction of chemistry between cement with water, hence non comparison of amount irrigate to totalizeing important mixture weight, but exactly comparison of water with cement or which is ordinary to be conceived of Water cement factor.
Bina Nusantara Rule of minimum for the concrete of waterproof. Type Concrete Condition of Environment Relate to Factor Water Cement Maximum Rate Cement Minimum. (Kg/m 3 ) 40mm*20mm* Reinforced Concrete. Freshwater0.5260290 Brackish Water / Water Sea 0.45320360 Prestressed Concrete. Freshwater0.5300 Brackish Water / Water Sea 0.45320360 *) Maximum size Aggregate.
Bina Nusantara Conditions to the Condition of Special Environment. Type Concrete Condition of Environment * Factor Water Cement Maximum, Normal Concrete Content cement minimum ( Kg/m3 ) Maximum Aggregate size measure, mm. 40201410 ReinforcedLight. 0.65220250270290 Middle 0.55260290320340 Heavy. 0.45320360390410 PrestressedLight. 0.65300 Middle 0.55300 320340 Heavy. 0.45320360390410 Non-Reinforced Light. 0.65200220250270 Middle 0.55220250280300 Heavy. 0.45270310330360
Bina Nusantara *) Condition of Environment. –Light : Covert fully from aggresive condition or weather, except momentary when open construction to normal weather. –Middle : Is covert from torrential rains, planted concrete and concrete which is under water forever. –Heavy : Open to sea water, brackish water, hard and close rain, commutation among hard and wet, commutation between dry and wet. Experiencing of heavy condensation or corrosive vapour.