The raw material, which includes calcium oxide (CaO), silicon dioxide (SiO₂), aluminum oxide (Al₂O₃), and iron oxide (Fe₂O₃), is first ground into a fine powder and then partially melted to produce a hydraulic binding material with calcium silicate as the primary mineral component. The content of calcium silicate in the final product should be at least 66%, and the mass ratio of calcium oxide to silicon dioxide must be no less than 2.0. This process results in a high-performance cement that offers excellent strength and durability.
Portland Cement (PO)
Strength Grades
The strength grade of Portland cement is divided into six levels: 42.5, 42.5R, 52.5, 52.5R, 62.5, and 62.5R. These grades indicate the compressive strength of the cement after 28 days of curing, with the "R" designation indicating higher early strength.
Ordinary Portland Cement (OPC) has four strength grades: 42.5, 42.5R, 52.5, and 52.5R. It is commonly used in general construction applications due to its balanced performance and cost-effectiveness.
Slag Portland Cement, Pozzolanic Portland Cement, Fly Ash Portland Cement, and Composite Portland Cement are available in three main strength classes: 32.5, 32.5R, 42.5, 42.5R, 52.5, and 52.5R. These types of cement often include industrial by-products such as slag or fly ash, making them more environmentally friendly and suitable for specific construction conditions like sulfate resistance or reduced heat of hydration.
Electric Standing Desk,Height Adjustable Standing Desk,Adjustable Stand Up Desk,Height Adjustable Executive Desk
Changzhou Offistyle Furniture Co., Ltd. , https://www.offistylefurniture.com