Testing and Enhancing The Compatibility of Five Saudi Wood Species for Cement-Bonded Particleboard Industry

Document Type : Original Article

Author

Plant Production Department, College of Food and Agricultural Sciences, King Saud University, P.O. Box 2460 Riyadh 11451, Saudi Arabia

Abstract

Cement-bonded particleboard (CBP) panels have excellent sound insulation, highly resistant to water and termites and are excellent for outdoor uses. However not all wood species react favorably with cement. Therefore, the present study was undertaken to test the suitability of some wood species that available in Saudi Arabia for CBP manufacturing. After testing, the study was designed to enhance the compatibility of these wood species with cement using different pretreatments and chemical additives. Buttonwood (Conocarpus erectus), lebbeck (Albizia lebbeck), Council tree (Ficus altissima), leucaena (Leucaena leucocephala), and Madras thorn (Pithecellobium dolce) were collected from Experiment Station near Dirab, Riyadh, Saudi Arabia. The results of this work were compared with the data were obtained from Scots pine (Pinus sylvestris).Portland cement (Type I) is manufactured by Al Yammama Cement Company was used as a binder. The hydration procedure was carried out using Dewar flask. Inhibitory index (I), hydration rate (R), and compatibility factor (CA) were calculated from the hydration data. The results showed that under untreated condition, Scots pine and Buttonwood gave the highest maximum temperature (Tmax), and the lowest time to reach maximum temperature (tmax), and they were compatible with cement and classified as "suitable under limited conditions" for making CBP, while the lowest Tmax and the highest tmax were obtained for the rest wood species and they were classified as "unsuitable" and theyrequire special treatments to reduce their inhibitory characteristics when mixed with cement. Using cold or hot water extraction for the six wood species resulted in an enhancement in their compatibility with cement. Under these pretreatments and with some expansions, all wood species used could be reclassified to “suitable under limited condition” for manufacturing CBP. Council treeand leucaena arestill unsuitable for cement mixture since Tmax is below 50 oC. Addition of either CaCl2 or MgCl2 to the mixture of cement and untreated wood improved the parameters and indices of hydration. All wood species used were reclassified from unsuitable or suitable under limited conditions to suitable for making CBP after treating by different treatments used in this work. Correlation coefficients of the hydration parameters are highly significant, therefore the three indices (CA, R and I) can be used as suitable estimates for the compatibility of the wood-cement mixtures in the current study.

Keywords