Historical background of light weight concrete
Concrete is referred to as a composite building material made from the combination of aggregate and cement binder. A classical example for the evolution of concrete since the ancient history as reviewed by Chandra (2002), is the use of concrete by Romans in 300 BC when they found that mixing a pink sand-like material which was volcanic ash they obtained from Pozzuoli with their normal lime-based concretes resulted in a far stronger material, this innovative methods was used in preparing concrete mixes with different aggregate materials to suit the structural requirements and strength and these developments in the quality of cement has a direct influence on the development of the concrete technology although the aggregate component of the concrete composition plays an equally important role in various mixes of concrete that serve a desired purpose as argued by Chandra (2002).
The classical examples for the above statement include the use of lightweight aggregates as in the roof of the Pantheon, and embedded reinforcement in the form of bronze bars as argued by Berntsson (2002).
Another element of greater significance to the development of concrete technology in the recent years as early as the 1900s, is the development of concrete boats during the second world war, where the lightweight aggregate concrete played a vital role in the design and construction of the ships itself as argued by Glenn (2004).
It is also interesting to note that, the importance of concrete has increased with the need for refined purpose and specific concrete mixes, which has not only been to provide the structural support but also the desired strength at the required physical conditions in the given geographical location as argued by Glenn (2002), of expanded clay and shale industry. The usage growth and development of lightweight aggregate concrete was accelerated at the dawn of the 20th century, as argued by Glenn (2004),during the second world war, when war ships was constructed from lightweight concrete produced from clay and shale.
In 1984, Thomas A. Holm estimated that there were over 400 LWC bridges throughout the world especially in USA and Canada. The research carried out by The Expanded Clay and Slate Institute proves that, most of the bridges appeared to be in good condition. According to ACI Material Journal by Diona et al; (1994), it was found that in Japan LWC had been used since 1964 as a railway station platform. The study on durability of LWC, carried out in 1983 has proven that LWC exhibitssome cracks, but these posed no structural problems.
References
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ASTM C330-78, “Standard specification for lightweight aggregate for structural Concrete”, Annual Book of ASTM Standards, Vol. 02-04, pp. 190-192, 1989.
ASTM C204-84, “Standard test method for fineness of Portland cement by air Permeability apparatus”, Annual Book of ASTM Standards, Vol. 04-02, pp. 157-162,1989.
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Bondar, D., Lynsdale, C. J., Milestone, N. B., Hassani, N., &Ramezanianpour, A. A. (2011).Engineering properties of alkali-activated natural pozzolanconcrete.ACI Materials Journal, 108 (1), 64-72.
Bondar, A., Bouchard, C. and Bellemare, G. (2011) case studies in construction materials Vol. 1, pp. 1-9, 2014.
BS.882, “Specification for aggregates from natural sources for concrete”, BritishStandards Institution, pp 8,1992.
Chandra, S. and Leif, H.B. (2002) historical background of light weight aggregates concrete, science Technology and application, Vol. 1, pp. 5-19
Dahunsi, B. I. O., Properties of Periwinkle-Granite Concretes, Journal of Civil Engineering
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