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Recycled concrete and silica fume make calcium silicate bricks

✍ Scribed by Torben C. Hansen; Henrik Narud

Book ID
102999929
Publisher
Elsevier Science
Year
1983
Tongue
English
Weight
240 KB
Volume
13
Category
Article
ISSN
0008-8846

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✦ Synopsis

When old concrete is crushed to coarse aggregate for production of new concrete, approximately 20 weight percent of crusher fines are generated.

It has been shown that calcium hydroxide from hydrated cement of such fines reacts in the autoclave with siliceous particles in the fines to give calcium silicate products.

Such products are similar in nature to sand-lime bricks.

When silica fume is added, the compressive strengths of the products are greatly improved.

It has further been shown that crusher fines from recycled concrete do not qualify as hydraulic cements even when ground to cement fineness.

πŸ“œ SIMILAR VOLUMES

Recycled concrete and fly ash make calci
Recycled concrete and fly ash make calcium silicate bricks
✍ Torben C. Hansen; Henrik Narud πŸ“‚ Article πŸ“… 1983 πŸ› Elsevier Science 🌐 English βš– 153 KB

It has been shown that calcium hydroxide from hydrated cement reacts with fly ash and siliceous particles in the crusher fines of recycled concrete to give calcium silicate products similar to sand-lime bricks when autoclaved. Such products achieved compressive strengths up to 12.5 MPa.

Evolution of porosity and calcium hydrox
Evolution of porosity and calcium hydroxide in laboratory concretes containing silica fume
✍ Dale P. Bentz; Paul E. Stutzman πŸ“‚ Article πŸ“… 1994 πŸ› Elsevier Science 🌐 English βš– 433 KB

Laboratory concretes containing only coarse aggregates and 0, 10, or 20% silica fume as a cement replacement were prepared at a constant water-to-solids ratio and sampled at 1, 7, and 28 days. Scanning electron microscopy was utilized to monitor the progress of the hydration reactions both in the bu