Concrete

• Definitions (concepts found in the text)

1) Concrete is a manufactured mixture of cement and water, with aggregates of sand and stones, which hardens rapidly by chemical combination to a stonelike, water-and-fire-resisting solid of great compressive but low tensile strength.

• Look for images of spaces created using: reinforced concrete, pre- cast concrete, prestressed concrete and concrete-shell

The Paulins Kill Viaduct, Hainesburg, New Jersey, is 115 feet (35 m) tall and 1,100 feet (335 m) long, and was heralded as the largest reinforced concrete structure in the world when it was completed in 1910 as part of the Lackawanna Cut-Off rail line project. The Lackawanna Railroad was a pioneer in the use of reinforced concrete.

A vertical cantilever configuration with a portion of the precast concrete panel below finished floor level, tied into the foundation concrete with reinforcing bars.

Sleepers in prestressed concrete

Exhibition hall, La Defense. This huge ribbed concrete shell structure is an equilateral triangle in plan, and supported at the three apexes of the triangle. The clear span is 721 ft. (Near Paris, France)

• What is the difference between tiltwall construction, tilt-up panel construction and pre-cast concrete construction? (see the link for “precast concrete”)

In some regions the term tiltwall is used interchangeably with the term tilt-up. Tilt wall is a compound word using the terms "tilt-up" and concrete "wall" panels. In a tilt-up construction, the building's walls are poured directly at the jobsite in large slabs of concrete called "tilt-up panels" or "tiltwall panels". These panels are then raised into position around the building's perimeter forming the exterior walls. Tilt-up construction allows general contractors to build a wide range of commercial buildings more quickly and with lower construction costs than what is typical for traditional masonry construction projects.

Precast concrete buildings are buildings constructed using precast or prefabricated concrete wall panels. Precast construction is similar to tilt-up construction, except that the concrete wall panels are formed at a manufacturing facility and transported to the job site by trailer, rather than fabricated directly at the site. This prefabricated panel process, provides a more controlled environment for consistent quality, insulated panels and weather protected scheduling. An offset is required close proximity from jobsite to manufacturing site and higher final in-place costs.