Where is Portland Pozzolana Cement (PPC) used?
Product17 Mar 2024
Portland Pozzolana Cement (PPC) is a cement type produced by blending Portland cement clinker with pozzolanic materials. There are two types of pozzolana: natural and artificial. Natural pozzolana is made up of calcined materials such as volcanic ash, pumicite, shales, and clay. Artificial pozzolana includes burnt clay, silica fume, fly ash, and blast furnace slag. The primary components of PPC are:
- Portland cement clinker: This is the main ingredient of PPC and is produced by heating a mixture of limestone, clay, and other materials in a kiln at high temperatures of 800-1,000 degrees Celsius. Portland cement clinker blended with gypsum (which controls the setting time) provides the fundamental strength and binding properties to the cement.
- Pozzolanic materials: Pozzolanic materials are finely divided siliceous or siliceous and aluminous materials that react with calcium hydroxide (Ca(OH)2) in the presence of water to form cementitious compounds. Common pozzolanic materials used in PPC include fly ash, volcanic ash, calcined clay, and silica fume.
During the hydration process (when the cement hardens) of PPC cement, the pozzolanic materials react with calcium hydroxide produced during the hydration of Portland cement clinker to form additional cementitious compounds, such as calcium silicate hydrate (C-S-H) gel and calcium aluminate hydrates. These additional cementitious compounds improve the cementitious matrix's strength, durability, and workability.
PPC cement offers several advantages over Ordinary Portland Cement (OPC), including:
- Improved workability: the addition of pozzolanic materials enhances the workability of PPC cement, making it easier to mix, place, and finish.
- Reduced heat of hydration: PPC cement exhibits lower heat of hydration than OPC, which reduces the risk of thermal cracking in large concrete structures.
- Enhanced durability: the pozzolanic reaction leads to the formation of additional cementitious compounds, resulting in improved durability and resistance to chemical attacks, sulphate attacks, and alkali-silica reactions.
- Environmental benefits: using pozzolanic materials in PPC cement reduces the consumption of clinker, reducing carbon dioxide emissions associated with cement production.
PPC, recognized as the best cement in construction boasts several typical applications:
- Concrete production: PPC cement is used for various construction purposes, including residential buildings, commercial structures, bridges, dams, roads, and pavements.
- Masonry work: It is used for bricklaying, blockwork, plastering, and other masonry applications due to its ability to enhance workability and reduce the heat of hydration.
- Precast concrete products: PPC cement is used to manufacture precast concrete products such as blocks, pipes, tiles, and other specialised concrete elements.
- Marine structures: Due to their resistance to sulphate attacks and durability in aggressive environments, PPC cement is suitable for constructing marine structures like ports, harbours, and coastal protection structures.
- Underground structures: Its ability to resist corrosion and sulphate attacks makes PPC cement suitable for constructing underground structures such as tunnels, underground parking lots, and sewage systems.
- Mass concrete structures: PPC cement is used in mass concrete structures such as dams, retaining walls, and heavy foundations due to its low heat evolution and reduced risk of thermal cracking.
Store PPC cement in weather-proof buildings to prevent dampness. Ensure easy access for inspection. Ordinary Portland Cement (OPC) is produced when Portland cement clinker is ground with gypsum. However, when the clinker is ground with pozzolana, it results in the creation of PPC. Similarly, when the clinker is ground with slag, it produces PSC. PPC and PSC are blended cements that enhance the properties of the concrete mix.