Introduction of steel and concrete mainly used in Sydney Opera House!

The spire shell is covered with white grid glaze, and the shell-shaped spire roof is made up of 2,194 bent concrete prefabricated pieces weighing 15.3 tons each, which are tensioned by steel cables, and the exterior is covered with 1.5 million white or cream tiles. This building was built in 1964, so it is made of ordinary portland cement, cold-drawn steel bars, bonded with steel bolts and cured with epoxy resin. Because it's a long time ago, it's estimated that all the materials used now are very common, and there are no additives now.