1. ERDC Knowledge Core
2. Pre - Engineer Research and Development Center (ERDC)
3. Structures Laboratory - (4/16/1978 - 2/22/2001)
4. Publication
5. Miscellaneous Paper

Title:	Factors affecting sulfate resistance of mortars
Authors:	Mather, Katharine.
Keywords:	Cements Mortar Portland cements Concrete Sulphate resistance Concrete chemistry
Publisher:	Structures Laboratory (U.S.) Engineer Research and Development Center (U.S.)
Series/Report no.:	Miscellaneous paper (U.S. Army Engineer Waterways Experiment Station) ; SL-80-17.
Description:	Miscellaneous Paper Abstract: The ability of a mortar made using portland cement, fine aggregate, and water to resist attack by sulfates is affected by the proportions of the mortar (water-cement ratio and cement content), by the maturity, by the amount of tricalcium aluminate in the portland cement, by the presence of tricalcium aluminate-sodium oxide solid solutions with different structures and reactivities, and by the composition, reactivity, and amount of pozzolan used together with the portland cement. Cements investigated included portland cements of Types I, II, III, and V meeting ASTM C 150, blended cements including Type IP's meeting ASTM C 595 that were made from the same clinkers as the Type I's, and Type I's blended with pozzolans including fly ashes produced by burning bituminous, subbitumous, and lignitic coals, calcined natural volcanic glass high in silica, and silica fume. Silica fume forms glassy microspheres that may contain over 90 percent SiO2; it is a by-product of the production of silicon metal. Some of the fly ashes produced from subbituminous and lignitic coals replacing 30 percent by volume of cements increased the expansion of mortars containing the blends when stored in sulfate solutions. This behavior reflects SiO2 below 50 percent, Al2O3 16 to 26 percent, and CaO 5 to 30 percent. Other investigations show that Al2O3 and CaO in the fly ash glass are readily available to combine with sulfate to form ettringite. With cement of lower C3A content, some of the subbituminous and lignitic fly ash blends improved tne sulfate resistance of mortars, except when SiO2 in the fly ashes was 38 percent or less. Type IP blended cements made with portland-cement clinkers containing up to 11 percent calculated C3A and about 20 percent fly ash show substantial improvement in sulfate resistance of mortars compared with Type I cements made from the same clinkers.
Rights:	Approved for public release; distribution is unlimited.
URI:	http://hdl.handle.net/11681/11016
Appears in Collections:	Miscellaneous Paper