Hydration and mechanical properties of Portland cement containing eloxal waste from aluminium industry: Fid-Bau Portal

Hydration and mechanical properties of Portland cement containing eloxal waste from aluminium industry

Erdem, E. / Günay, M.E. / Donat, R.

Eloxal waste is obtained during the production of aluminium tube and decorative profile. It is composed mainly of aluminium oxide, aluminium hydroxide and other substances. In this study, ability of using eloxal as an additive for rapid hardening of Portland cement is investigated. For this purpose eloxal whose alkalinity was removed by partial refining with water. Then, it was dried following its mixture with Portland cement at different ratios. The development of hydration of cement mixes was examined by using setting times, flexural-compressive strengths, volume expansion, X-ray diffraction and scanning electron microscope (SEM) techniques. It was observed that setting times were slightly shortened gradually whereas the flexural and compressive strengths were increased for cements which was prepared by adding eloxal to Portland cement at various ratios up to 4% in weight. It is determined that setting times of prepared cement mixtures are slightly shortened gradually by the effect set accelerator effect of eloxal. Flexural and compressive strengths are increased by eloxal up to a ratio of 4% in weight Portland cement. Therefore, optimum mixing ratio can be 4% eloxal and 96% OPC. The results of volume expansion tests varied totally about 0.0-2.5 mm, the obtained results were in TS 19 limits and eloxal did not have any negative effect in volume expansion. X-ray patterns and SEM micrographs are characterised by hydration products such as calcium silicate hydrates, ettrin-gite and hydrogranate phase and eloxal. These results vary accordingly with the increasing strength and shortening of setting times. Therefore, eloxal can be used in Portland cement which acts as an additive where rapid setting and high strength is required. At the same time it is concluded that eloxal can also be used directly without feeling the need for some treatments like grinding, cooking and mining which have considerably important shares in product unit cost. By this way environmental pollution and source squandering caused by eloxal will be removed and prevented, respectively, and a more enduring building material can be produced.