Title:
Improving Lightweight Concrete with Bottom Ash
Author(s):
M. Nisnevich
Publication:
Concrete International
Volume:
19
Issue:
12
Appears on pages(s):
56-60
Keywords:
aggregates; cements; compressive strength; density; durability;
fly ash; lightweight concretes; porosity;
DOI:
Date:
12/1/1997
Abstract:
Lightweight concretes based on highly porous aggregates and made with a low content of cement possess sufficient thermal insulating properties. However, these concretes have drawbacks, such as reduced strength and formation of open air voids in cement stone that allow migration of water and undesirable solutions in concrete, thus lowering its durability. A rational direction towards removal of these drawbacks is the use of a fly ash additive. In this article, the evaluation is given of the possibility of increasing the strength of lightweight concrete and lowering the porosity of hardened cement (cement-fly ash) paste by using concrete with high volumes of fly ash. This evaluation is founded on research with 17 concrete compositions prepared with the broad ranges of varying values of the cement/water ratio (w/c) and the content of cement and fly ash. For the lightweight porous aggregate, furnace bottom ash was used; both materials were selected from one source.