ACI 213R Guide for Structural Lightweight-Aggregate Concrete
Данный раздел/документ содержится в продуктах:
- Техэксперт: Машиностроительный комплекс
- Картотека зарубежных и международных стандартов
- ASTM F2414 Standard Practice for Sealing Sewer Manholes Using Chemical Grouting
- 93
- ASTM F2414 Standard Practice for Sealing Sewer Manholes Using Chemical Grouting
- 93.030
- ASTM F2349 Standard Practice for Operation and Maintenance of Integrated Natural Gas Pipelines and Optical Fiber Systems
- 23
- ASTM F2349 Standard Practice for Operation and Maintenance of Integrated Natural Gas Pipelines and Optical Fiber Systems
- 23.040
- ASTM F2349 Standard Practice for Operation and Maintenance of Integrated Natural Gas Pipelines and Optical Fiber Systems
- ASTM F3092 Standard Terminology Relating to Optical Fiber Sensing Systems
- ASTM F2551 Standard Practice for Installing a Protective Cementitious Liner System in Sanitary Sewer Manholes
- ASTM C1140/C1140M Standard Practice for Preparing and Testing Specimens from Shotcrete Test Panels
- ASTM C138/C138M Standard Test Method for Density (Unit Weight), Yield, and Air Content (Gravimetric) of Concrete
- Картотека зарубежных и международных стандартов
American Concrete Institute
Guide for Structural Lightweight-Aggregate Concrete
N 213R
Annotation
Historical background—The first known use of lightweight concrete dates back over 2000 years. There are several lightweight concrete structures in the Mediterranean region, but the three most notable structures were built during the early Roman Empire and include the Port of Cosa, the Pantheon Dome, and the Coliseum.
Built in approximately 273 BC, the Port of Cosa used lightweight concrete made from natural volcanic materials. These early builders learned that expanded aggregates were better suited for marine facilities than the locally available beach sand and gravel. They traveled 25 mi. (40 km) to the northeast to quarry volcanic aggregates at the Volcine complex for use in the harbor at Cosa (Bremner et al. 1994). This harbor on the west coast of Italy consists of a series of four piers (~13 ft [4 m] cubes) extending into the sea. For two millennia the piers have withstood the forces of nature with only surface abrasion. They became obsolete only because of siltation of the harbor.
Built circa 126 AD, the Pantheon incorporates concrete varying in density from bottom to top of the dome. Roman engineers had sufficient confidence in lightweight concrete to build a dome with a diameter of 142 ft (43 m), which was not exceeded for almost two millennia. The structure is in excellent condition and is still being used today for spiritual purposes (Bremner et al. 1994).
The dome contains intricate recesses formed with wooden formwork to reduce the dead load and the imprint of the grain of the wood can still be seen. The excellent cast surfaces that are visible to the observer clearly show that these early builders had successfully mastered the art of casting concrete made with LWA. The Roman writer, architect, and engineer, Vitruvius, who took special interest in building construction, commented on several unusual features of the Pantheon. The fact that he did not single-out lightweight concrete for comment could imply that these early builders were fully familiar with this material (Morgan 1960).
