History of construction – a backdrop for the innovations of the past century

The history of building is marked by a number of trends. One is the increasing durability of the materials used. Early building materials were perishable, such as leaves, branches, and animal hides.

Later, more durable natural materials such as clay, stone, and timber, and, finally, synthetic materials, such as brick, concrete, metals, and plastics were used.

Another is a quest for buildings of ever greater height and span; this was made possible by the development of stronger materials and by knowledge of how materials behave and how to exploit them to greater advantage.

A third major trend involves the degree of control exercised over the interior environment of buildings: increasingly precise regulation of air temperature, light and sound levels, humidity, odors, air speed, and other factors that affect human comfort has been possible.

Yet another trend is the change in energy available to the construction process, starting with human muscle power and developing toward the powerful machinery used today.

Why reinforced concrete matters so much

Reinforced Concrete played an important part in building America and It’s Industry

Concrete and steel in useful, economic quantities were first developed in the 1800s.

Joseph Monier obtained his second patent related to reinforced concrete in 1877. He used it in the making of flowerpots. Specifically, before concrete is poured into a form, rebar is added inside the form where the resulting structure would experience tensile forces. The rebar is a twisted spiral rod so that the concrete can “grip” it better after it sets. (Other types of reinforced concrete that use other tension resistant materials are being developed, but steel is still the most typical companion material.)

Steel and concrete have similar coefficients of thermal expansion so internal stresses remain low as the temperature of the reinforced concrete changes. The concrete must be mixed correctly to make sure the steel does not rust. Rust expands, and it will crack the concrete.

When the Delaware,viaduct Lackawanna & Western Railroad built a 28.5-mile cutoff between 1908 and 1911, it used reinforced concrete for all of its structures.

The Paulinskill Viaduct was 115 ft tall and, at the time it was built, the world’s largest reinforced concrete structure.

The weld – unseen and underappreciated?

Imagine what we would NOT have today if not for electric welding.

electric weldingIn the 1860s an Englishman named Wilde successfully used the earlier theories of Volta and Davy and the primitive electric sources of the time to make “Joins” and received a patent for the earliest form of the art now known as “electric welding”.

Edmund Davy of England is credited with the discovery of acetylene in 1836. The production of an arc between two carbon electrodes using a battery is credited to Sir Humphry Davy in 1800. In the mid-nineteenth century, the electric generator was invented and arc lighting became popular. During the late 1800s, gas welding and cutting was developed. Arc welding with the carbon arc and metal arc was developed and resistance welding became a practical joining process.

Imagine how the growth of the iron and steel industry was impacted by electric welding that is used for “joins” as well as cutting metals.

It was Iron and Steel that defined our growth

The 19th century is sometimes described as the age of coal, iron, and steel, with the United States emerging as a leading nation in that epochal age. At the beginning of the century, the great bulk of manufactured iron was produced by smelting and refining.

Small iron-works, found in every state, were based upon ore from a nearby mine or bog and relied on charcoal for fuel. In the 1820s, with the emergence of small factories, specialization appeared in the manufacture of iron products. The manufacture of farm machinery and implements, followed by household products, provided the major market for the iron industry.

The development of rolling mills was a major factor in the iron industry’s expansion. The first angle iron, and probably the first regular bars, were rolled in the United States in 1817.

By 1830 the manufactublast_furnacere of rolled and hammered iron products amounted to 113,000 tons. During the following two decades, the production of rolled iron would expand rapidly, totaling more than 500,000 tons by the outbreak of the Civil War.

In 1860 almost one million tons of iron ore were .produced. In that year there were 256 iron-works in 20 states producing bars, sheet, and railroad iron.

Almost 60 percent of the country’s iron ore in 1860 came from Pennsylvania, followed by Ohio and New York. The Empire State’s output totaled 74,645 net tons from 15 furnaces. Most of the ore was found in two localities, the southern highlands and the area around Lake Champlain. New York’s rise to distinction in iron manufacturing dates from the 1830s. By 1840 New York emerged as the leading producer in bar, sheet, and railroad iron, with 195 establishments turning out more than four million dollars’ worth.

“When the timbers start talkin, the miners start walkin”

Abandoned coal mines tell a story.

When you enter one of these derelict mines you often see these sections of trees that are referred to as timbers or props.

Contrary to popular mine timbersbelief these timbers offered little or no roof support.

Instead, these timbers were used as a warning, “when the timbers start talkin, the miners start walkin”.

If a section of the roof began to sag, the wieght would press down on these timbers, they would begin cracking, popping, and sweating as the pressure squeezed the sap out.

When these warning signs were observed, the area was hopefully evacuated until the section of roof fell in a controlled or uncontrolled manner. Wedged at the top, tapered and set on the bottom, they were set very snug to prevent kicking out if pressure was applied.