The use of fly ash to improve the sulfate resistance of concrete

Journal Article · Tue Dec 31 04:00:00 EST 1996 · Waste Management

DOI:https://doi.org/10.1016/S0956-053X(96)00055-4· OSTI ID:464833

Plowman, C; Cabrera, J G ^[1]

---

1. Univ. of Leeds (United Kingdom). Dept. of Civil Engineering

The disposal of fly ash by incorporation in concrete and other cementitious materials is not only environmentally desirable and high energy-efficient, but leads to improvements in the properties of the material, in particular durability. The partial replacement of cement by fly ash is recognized as effective in giving increased resistance to attack by sulfate in groundwater and soils. BRE Digest 363 allows fly ash/cement for almost all groundwater and soil conditions for which sulfate-resisting cement is allowed, and draft ENV 197-X also allows fly ash/cement within defined composition limits. In order to give confidence in the use of fly ash/cement concrete in aggressive conditions, the mechanisms by which resistance is conferred must be well understood. Evidence is presented of a considerably decreased rate of diffusion where fly ash is present, and also of stabilization of the calcium aluminate hydrates, resulting in increased resistance to sulfate attack. The results are consistent for cements with C{sub 3}A contents of 9--12%, but further work is required with lower C{sub 3}A cements. The test method used, developed from the work of Mehta, is considered to offer the most likely route to an acceptable accelerated test which is consistent with long-term data.

• OSTI ID: 464833
• Report Number(s): CONF-9509276--
• Journal Information: Waste Management, Journal Name: Waste Management Journal Issue: 1-3 Vol. 16; ISSN WAMAE2; ISSN 0956-053X
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
36 MATERIALS SCIENCE
CONCRETES
CORROSION RESISTANCE
FABRICATION
FLY ASH
INDUSTRIAL WASTES
MECHANICAL PROPERTIES
SULFATES
WASTE MANAGEMENT
WASTE PRODUCT UTILIZATION