Assessment of the suitability of cement kiln dust as a chemical stabiliser for clay subgrade soils.

Abstract

Cement kiln dust (CKD) is a by-product of Portland cement manufacture. This material poses a health hazard, storage problem, and a potential pollution source. Consuming such material in civil engineering works to upgrade marginal materials would help solve some of these problems. Clay, an abundant marginal soil, was treated by varying amounts of CKD. Compacted CKD stabilized clay soil specimens were tested for unconfined compression strength (UCS) after 7, 14, and 21-day curing periods. More tests were conducted on soil specimens with varying CKD content that gave satisfactory results for road subgrade. These tests included plasticity index (PI), and the California bearing ratio (CBR). The test results indicated that on the basis of utilization, CKD content of 10% may be satisfactory. Specimens of 20% CKD gave relatively high UCS but failed the CBR requirements for subgrade.