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Construction is an ancient human activity that began at around 4000 BC as a response to the human need for shelter. [1] It has evolved and undergone different trends over time, marked by a few key principles: durability of the materials used, increase in building height and span, the degree of control exercised over the interior environment ...
In order to strengthen the concrete containers, he experimented with embedded iron mesh. He was not the first to experiment with reinforced concrete, but he saw some of the possibilities in the technique, and promoted it extensively. Monier exhibited his invention at the Paris Exposition of 1867. He obtained his first patent on 16 July 1867, on ...
The underside of a waffle slab, showing the grid like structure. A waffle slab or two-way joist slab is a concrete slab made of reinforced concrete with concrete ribs running in two directions on its underside. [1] The name waffle comes from the grid pattern created by the reinforcing ribs.
Two-man saws were known to the ancient Romans, but first became common in Europe in the mid-15th century. In America, crosscut saws were used as early as the mid-17th century, but felling saws only began to replace axes for felling trees in the late 19th century. [2] Some Japanese saws are used by two persons, although they are of a different ...
A one-way slab has moment-resisting reinforcement only in its short axis, and is used when the moment in the long axis is negligible. [23] Such designs include corrugated slabs and ribbed slabs. Non-reinforced slabs may also be considered one-way if they are supported on only two opposite sides (i.e. they are supported in one axis).
This list excludes tools and tool use attributed to non-hominin species. See Tool use by non-humans. Since there are far too many hominin tool sites to list on a single page, this page attempts to list the 6 or fewer top candidates for oldest tool site within each significant geographic area.
The history of mobile food in America dates back to the 17th century and has some surprising (and yummy) turns along the way. Digital Public Library of America 1691: The First Food Trucks
Stone tools are still one of the most successful technologies used by humans. [28] The invention of the flintlock gun mechanism in the sixteenth century produced a demand for specially shaped gunflints. [31] The gunflint industry survived until the middle of the twentieth century in some places, including in the English town of Brandon. [32]