Modern concrete can break up within 50 years. However, Roman concrete structures last for thousands of years because they used volcanic ash, which slowly transforms into aluminum tobermorite. 1)
The world's tallest building, the Burj Khalifa, is made of 330,000 m³ of concrete reinforced with 55,000 tonnes of steel. 2)
Three Gorges Dam in Hubei, China, is the largest and heaviest concrete structure, build using 28,000,000 m³ of concrete and 463,000 tonnes of steel. Its reservoir contains 39.3 km³ (9.43 cubic miles) of water, weighing more than 42,000,000,000 tonnes. 3)