Introduction to TechnologyChapter 18:
The World of ConstructionChapter SummariesSection 18.1
Construction occurs at a building site. The first skyscraper was the Home Insurance Building in Chicago. It had a metal frame design. Roads are construction projects. The Romans were the first great road builders. The British developed a material called “macadam” for surfacing roads. The material is called “asphalt” in the United States. The first major all-steel bridge was built across the Mississippi River in St. Louis, Missouri. The first major American tunnel was the Hoosac Tunnel in Massachusetts. Section 18.2
Many structures are built of lumber, which is wood cut into useful shapes. Tall buildings are built with a steel framework. The outside walls, or curtain walls, are hung on the framework. Concrete is a construction material made of cement, sand, stones, and water. Because it can take on any shape, concrete is the most adaptable material used in construction. Structures built in different regions have different requirements. Building codes protect the environment and people’s safety. They vary by region and are regulated by local governments.  | 
