R.M. Dheilly

Influence of the proportion of wood on the thermal and mechanical performances of clay-cement-wood composites

Abstract The introduction of wood aggregates to produce low density composites is an interesting technique allowing the reuse of wastes from both the aggregate-mining and wood processing industries. This paper describes the influence that the proportion of wood aggregates has on the thermal and mechanical performance of a clay-cement-wood composite. First, the composite material and its production technique are presented. Then, the thermal conductivity, mechanical strengths and the porosity of the matrix are experimentally evaluated. Finally, it is shown that the addition of wood to clayey concrete improves its insulation characteristics, reduces its mechanical strength and increases its deformability.

Influence of storage conditions on the carbonation of powdered Ca(OH)2

Abstract The influence of relative air moisture, temperature and concentration of CO 2 on the carbonation of Ca(OH) 2 have been examined under normal climatic conditions. The calcium hydroxide used for this original work is a granular material. The importance of the hydrated state of Ca(OH) 2 has also been studied in order to obtain complete carbonation. A three steps mechanism of carbonation has been proposed to help explain the observed phenomena. This work was carried out with the view to defining the optimal conditions for the storage of slaked lime.

Hydromagnesite development in magnesian lime mortars

Abstract The bond which develops during curing in lime paste mortars in the presence of Mg(OH)2 or MgO and moisture in lime paste is a result of the growth of a new phase. Scanning electron microscopy studies along with X-ray analyses show this new phase to consist of common hydromagnesite (Mg5(CO3)4(OH)2,4H2O). This development is accompanied by an increase in the mechanical strengths of lime mortars.

PROPERTIES OF WOOD-BASED COMPOSITES FORMULATED WITH AGGREGATE INDUSTRY WASTE

Abstract The option of using vegetable-based materials is not only one potential response to the lack of aggregate resources in certain regions, but also a way of helping to preserve the environment. These reasons have incited some authors to address the issue of waste reuse in the form of insulating composites. The work presented herein, once the influence of components has been examined, will focus on the influence of various processes on the performances of hardened composites. Aggregate processing by boiling water, followed by a hydraulic binder coating, enables the minimization of the composites dimensional variations to a larger extent. This processing technique allows the achievement of an excellent compromise in material properties, although it increases density and, hence, thermal conductivity.

Reuse of waste oils in the treatment of wood aggregates

Abstract In this work, oil intended for disposal is used to impregnate wood shavings at room temperature and atmospheric pressure. Experimental results show a sizable decrease in the absorption of water by these wood shavings and the generation of a wood–cement–mineral fines composite from industrial waste. The composites dimensional variations can be reduced by half without any of the mechanical properties or thermal conductivity being adversely affected. An oil intended for disposal is more efficient than linseed oil in reducing the extreme dimensional variations.