Soil Modification by Cement Kiln Dust

Cement kiln dust (CKD) is a waste 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. Dune sand, an abundant marginal soil, was treated by varying amounts of CKD. In addition, 100% CKD was tested. Compacted specimens were tested for unconfined compression (UC) after seven-, 28, and 90-day curing periods at different temperature levels. Further testing was conducted for specimens with CKD percentages that gave satisfactory results for road subbases. These tests included durability, the California bearing ratio (CBR), and split tension. The test results indicated that on the basis of utilization, CKD between 12 and 50% may be satisfactory. Specimens of 75% and 100% CKD gave relatively high strengths but failed the durability requirements.