Concrete is the most widely used construction material in the world. It is made by mixing cement, water, and aggregates such as sand and gravel. The history of concrete spans more than 7,000 years, beginning with early lime mortars and evolving into modern reinforced concrete and sustainable, low-carbon cement technologies.
Concrete is a composite building material made from:
When water reacts with cement through a chemical process called hydration, the mixture hardens into a strong, stone-like material.
Some of the earliest building materials resembling concrete were used in Mesopotamia.
Builders mixed mud, lime, and straw to bind stones together.
The Egyptians used gypsum and lime-based mortars in pyramid construction.
These materials were early forms of cement but not fully developed concrete.
Chinese builders used lime mortars, sometimes mixed with sticky rice, to improve strength and durability in structures such as parts of the Great Wall. These early mixtures were precursors to true hydraulic concrete.
Opus caementicium (Roman concrete) consisted of:
The volcanic ash allowed the mixture to harden even underwater, making it a hydraulic concrete.