A new technique to classify the compatibility of wood with cement

Evaluating lodgepole pine (Pinus contorta) affected by mountain pine beetle (Dendroctonus ponderosae) for development of wood-cement board.

“…Weatherwax and Tarkow (1964) proposed samples of mixtures of 200 g cement and 15 g of wood, proportions which would be used by most of the authors. The water ratio was 0.7 ml per gram of oven-dry wood and 0.4 ml per gram of cement; in accordance with the findings regarding the optimization of water-to-type I Portland cement ratio which gave the highest temperature during the hydration of the cement paste (Hachmi et al, 1990).…”

“…However, a recent study showed that the percentage of extractives varied from 1-2% in sapwood and 2-4% in heartwood (Woo et al, 2005), results confirming prior findings of 2.03 % the extractive content of sapwood and 3.30 % the extractive content of heartwood after averaging 54 analyses (Campbell et al, 1990;Koch, 1996).…”

“…Simple inhibitory indices based on temperature figures were calculated and used at the beginning (Weatherwax and Tarkow, 1964;Davis, 1966). More complex equations were developed (Hofstrand et al, 1984;Hachmi et al, 1990) in order to reduce the lack of consistency in the classification of species (Jorge et al, 2004). The newest method was proposed by Karade et al (2003).…”

“…Two inhibitory indices: CA-factor (CA) (Hachmi et al, 1990) and Compatibility Index (Cl) (Karade et al, 2003) are calculated, as a measurement of the compatibility between dead wood and cement. Both methods of assessment are based on the behavior of the exothermic chemical reaction of cement hydration, accounting for the difference between neat cement paste and wood-cement mixtures.…”

“…However, the 3.5-24 hours interval was considered the most significant period of cement hydration, with the high 24 hours limit chosen for practical reasons and the low 3.5 hours limit as the time when the chemical process ended the dormant period and started the initial cement setting period (Hachmi et al, 1990). The data was downloaded into computer through the ACR Application Software.…”