Title:
Properties of High-Calcium Dry Bottom Ash for Structural Concrete
Author(s):
Nader Ghafoori and Jeffrey Buchole
Publication:
Materials Journal
Volume:
94
Issue:
2
Appears on pages(s):
90-101
Keywords:
abrasion; bottom ash; compression; concretes; deformation;
physical properties; fine aggregates; modulus of elasticity; shrinkage;
splitting tensile strength; sulphate resistance;
DOI:
10.14359/289
Date:
3/1/1997
Abstract:
A pilot study was undertaken on the use of lignite-based bottom ash as a fine aggregate in structural grade concrete. Bottom ash is combined with portland cement, crushed limestone coarse aggregate, and water to produce concretes with uniform slump of 4±¼ inches (100 mm). Four different mixes with cement contents ranging from 500 to 800 lb/yd3 (297 to 475 kg/m3) are utilized. The bottom ash concretes are studied for fresh properties, hardened characteristics, and long-term durability. The engineering characteristics of mixtures made with bottom ash are compared with those of conventional concretes in order to evaluate the effectiveness and suitability of bottom ash as a viable fine aggregate in portland cement-based mixtures. Laboratory test results conclude that the inclusion of bottom ash increases the demand for mixing water in obtaining the required workability. As a consequence, both fresh and hardened properties are impacted, particularly for mixtures of low cement content. When a water-reducing admixture is used, the engineering properties of bottom ash concretes are similar, and in most cases superior, to those of control concretes.