Authors:Abbas Al-Hdabi, Mohammed Al-Jumaili, and Huda Abdulzahra
Cold asphalt emulsion mixtures are produced at ambient temperature and it have several advantages i.e., energy savings, safety and reducing CO2 emission during manufacturing and construction, reduction of adverse environmental impact. Cement kiln dust is a fine powdery substance with appearance similar to Portland cement that is generated as a by-product material of cement manufacturing industry. The aim of this research is addition of cement kiln dust instead of Portland cement as filler in asphalt emulsion mixtures. Cement kiln dust was added with 2, 4, 6, and 8% from total weight of aggregate to improve the mechanical properties and durability of this mixture. The results were very positive and encouraging, due to the improvement of the mechanical properties and durability of the mixtures.
Authors:Abbas Al-Hdabi, Mohammed K. Fakhraldin, Rasha A. Al-Fatlawy, and Tawfek Sheer Ali
Ignition of waste paper sludge at elevated temperatures to produce electricity in power generation plants utilizing fluidized bed combustion generates paper sludge ash. Due to the high concentration of lime and gelignite in paper sludge ash, it is expected that it will play a vital role as a cementitious material. This paper investigates the use of paper sludge ash to improve the mechanical properties of the granular materials, which are suitable to subbase course for road and building constructions. Also, a comparison study with the use of Portland cement as an additive to granular materials has been covered. The mechanical properties were evaluated by conducting the California bearing ratio test for the two adopted methods. Moreover, the compressive strength of the samples using paper sludge ash and cement are investigated. In accordance to the California bearing ratio test, 4% paper sludge ash was indicated as the optimum ash content at which the California bearing ratio value increased by 173% and 111% in comparison with untreated material and 6% cement, respectively. On the other hand, and by means of the compressive strength, the granular materials with 4% paper sludge ash has compressive strength higher than those with 6% cement.