Cement is a fine, powdery substance that, when mixed with water, turns into a paste that hardens over time. It is used to hold concrete together, making it a vital ingredient in construction.

OPC is highly versatile and can be used in various ways. It's ideal for strong RCC works, precast items like tiles and blocks, and projects needing extra strength, like roads and bridges. It’s also used in plastering and flooring.

PPC is great for projects that need long-lasting, durable concrete. It's commonly used in large-scale constructions of dams, hydraulic structures, and marine works. It’s also perfect for masonry work, plastering, and projects in harsh conditions where resistance to chemicals is important. 

OPC: This type of cement is great for projects that need concrete to set up quickly and be strong right away, such as in building structures.
PPC: This type is better for projects where concrete lasts a long time and resists damage from chemicals, making it ideal for large structures and harsh environments.

Choosing the right cement depends on the specific needs of your project, such as strength, durability, and setting time. Refer to project requirements and consult with a professional if needed.

Cement is a powder that acts as a binder, while concrete is a mixture of cement, sand, gravel, and water that hardens into a solid structure.

High-quality cement ensures better strength, durability, and performance in construction projects. It also helps to achieve a smooth finish and reduces the risk of future issues.

Cement itself is not typically recycled, but concrete made with it can be crushed and reused as aggregate for new concrete. This process helps to reduce waste and conserve resources.

Concrete usually begins to set within a few hours, but it can take up to 24-48 hours to fully harden. For best results, avoid heavy use or stress on the concrete until it has cured for at least 7 days.