from The American Heritage® Dictionary of the English Language, 5th Edition.
- noun A siliceous volcanic ash used to produce hydraulic cement.
- noun Any of various powdered substances that react with lime to form strengthening or enhancing compounds in cement.
from Wiktionary, Creative Commons Attribution/Share-Alike License.
- noun Any material which, when combined with
calcium hydroxide, exhibits cementitiousproperties; often used as an extender with Portland cements.
from The American Heritage® Dictionary of the English Language, 4th Edition
from Wiktionary, Creative Commons Attribution/Share-Alike License
Chemical analyses of various samples of the ash material show that while its composition does vary, its content of silica, alumina, and iron oxides does meet the minimum ASTM chemical requirements for a cement binder (known technically as Type N or F pozzolan), and compares favorably with such materials used in the concrete for many Corps of Engineers construction projects in the Pacific
Pozzolan (or pozzolana) is an Italian word, named from Pozzuoli, the place near Naples where pozzolan was first mined and used as cement, during Roman times.
The largest producer is Italy, which dominates pozzolan production and also produces some pumice.
Efficient and low-cost local lime production is essential to keep the cost of pozzolan cement low.
Although some grinding is required to make it fine enough to work with, the pozzolan mix does not require firing which reduces production costs.
In Guatemala, pozzolan cement currently costs approximately 60% of the cost of portland cement.
Mixed with lime at a ratio of 80: 20 or 70: 30 (pozzolan: lime), natural pozzolan behaves like cement.
The Centro de Investigaciones de Ingeniera at the Universidad de San Carlos de Guatemala and the Department of Civil Engineering at the University of Calgary are testing pozzolan cement as a substitute for portland cement in such applications as blocks and masonry mortar.
Twenty-five percent of Guatemala is in a volcanic zone that contains large surface deposits of a volcanic ash called pozzolan.
Four demonstration houses will be built using pozzolan and workshops are being used to encourage small pozzolan cement production plants in rural areas near pozzolan deposits.