Title: Compressive Strength of Municipal Sludge Ash Mortars

Author(s): Javed I. Bhatty and Kenneth J. Reid

Publication: Materials Journal

Volume: 86

Issue: 4

Appears on pages(s): 394-400

Keywords: aggregates; compressive strength; fly ash; limes; sludge; mortars (material); portland cements; Materials Research

DOI: 10.14359/2170

Date: 7/1/1989

Abstract:
Sludge ashes produced by the incineration of municipal sewage wastes are becoming increasingly difficult to dispose of in landfills and there is a resulting increase in interest in disposal by incorporation in building materials. In the present study, a comprehensive test program was developed to examine the potential for using the ash as a fine aggregate in mortar. The strength characteristics of mortars prepared from sludge ash with addition of fly ashes (both Classes C and F) and varying amounts of cement and lime were determined. The test samples, cast in cylindrical molds, were cured under standard laboratory conditions for periods of 1, 3, 7, 14, and 28 days before testing for compressive strength. The results indicate that the addition of sludge ash adversely affects the strength behavior of mortars. Although partial substitution of sludge ash with fly ash gave improved results, strengths were always less than those obtained from control mortars using sand. Addition of fly ashes also improves mortar workability. The addition of lime in place of cement reduces strength.