Reuse of Paper Mill Ash in Plaster Blends

Saveria Monosi, Daniela Sani*, Maria Letizia Ruello
Universita Politecnica delle Marche, Department of Physic and Engineering of Materials, Italy.

© 2012 Monosi et al.

open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International Public License (CC-BY 4.0), a copy of which is available at: This license permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

* Address correspondence to this author at the Università Politecnica delle Marche, Department of Physic and Engineering of Materials, Italy; Tel: +39 071 2204726; Fax: +39 071 2204627; E-mails:,


This work is part of a broad research conducted to study the re-use of industrial wastes in an economical and environmentally sustainable manner. Re-use of lightweight ash from the paper mill industry in the manufacture of plaster blends is examined in this study. Lightweight ash is produced during the combustion process of de-inking sludge. Studies demonstrate that lightweight ash is an excellent ingredient in the production of cement mortars and/or pozzolanic mortars to be used as plaster. In this research, ash valorization was researched by investigating the efficacy of the ash as it is, as a substitute for very fine sand.

If properly mixed at an optimal mix proportion, the mechanical strength ranges from 4÷10MPa with specific gravity between 1150 and 1350 Kg/m3. Water absorption may be reduced to a very low level with silane-based surface treatment.

Keywords: Paper mill ash, de-inking ash, plaster, mortar, aggregate replacing, permeability, water absorption, compressive strength.