Tsement

Tsement, commonly known as cement, is a finely ground powder that serves as a binding agent in concrete and mortar. When mixed with water, cement hydrates and hardens, binding aggregates such as sand and gravel to form a solid construction material.

The most widely used type is Portland cement, consisting mainly of clinker—a nodular material produced by calcining limestone and clay at high temperatures—and a small amount of gypsum to regulate setting. Many cements are blended with supplementary cementitious materials (SCMs) such as fly ash, slag, silica fume, or natural pozzolans to improve performance or reduce cost and emissions.

Manufacture begins with extracting and preparing raw materials, then calcining them in a kiln at about 1400–1500°C to form clinker. The clinker is cooled, ground, and mixed with gypsum to produce cement. The process is energy-intensive and releases carbon dioxide both from fuel combustion and the chemical decomposition of limestone.

Cement gains strength through hydration reactions as water binds with the cement compounds. The resulting cement paste binds aggregates to produce concrete, mortar, or other composites. Properties such as setting time, workability, and long-term strength depend on cement chemistry, curing conditions, and the presence of admixtures.

Historical notes indicate modern Portland cement was patented by Joseph Aspdin in 1824, named for its resemblance to Portland stone. The term tsement is used in Indonesian and Malay to refer to cement.

In recent decades, efforts to reduce environmental impact include using SCMs to replace part of the clinker, developing blended cements, and improving energy efficiency in production.