%0 Generic
%A Frías, M.
%A Rodríguez, O.
%A De Rojas, M. I.Sánchez
%A Nebreda, B.
%A Vegas, I.
%A Urreta, J.
%A García, R.
%A Vigil, R.
%T Reuse of waste paper sludge as supplementary cementing material
%J Proceedings of the 2008 Global Symposium on Recycling, Waste Treatment and Clean Technology, REWAS 2008
%D 2008
%U https://hdl.handle.net/11556/1608
%X This paper shows the possibility of reutilize paper sludge waste as supplementary cementing material for the cement manufacture. This industrial waste consists essentially of a mixture of organic matter (30%) and inorganic compound, such as calcite and clay minerals. The raw paper sludge does not present pozzolanic properties, but once calcined at 650°C during 2 hours, exhibits high pozzolanic activity, similar to silica fume at 28 days, as a consequence of the transformation of kaolinite into metakaolinite. Calcined paper sludge was used as partial Portland cement replacements of 0, 5, 10 and 20%. Enhancement in compressive strength was appreciably obtained for 10 and 20% substitution levels from 7 days on. Furthermore, calcined paper sludge slightly reduces the initial and final setting times of cement paste.
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