排序方式: 共有12条查询结果,搜索用时 15 毫秒
11.
Dede Hermawan Toshimitsu Hata Shuichi Kawai Wakatsu Nagadomi Yasuo Kuroki 《Journal of Wood Science》2002,48(1):20-24
This study dealt with the effects of a curing method that uses gaseous and supercritical CO2. Its effects on the properties of oil palm fronds cement-bonded board manufactured by the conventional cold-press setting method were recorded. The effect of MgCl2 as an accelerator of cement setting was also investigated. The hydration of cement was examined using X-ray diffractometry, thermal gravimetry, and scanning electron microscopy. The results are as follows. (1) High-performance cement-bonded boards made from oil palm fronds were successfully manufactured using the CO2 curing method. (2) The curing method using either gaseous or supercritical CO2 resulted in accelerated curing of cement (within several minutes). Accelerated formation of the hydration products (e.g., calcium carbonate and calcium silicate) is the main reason for the high strength of CO2-cured boards. (3) The CO2 curing technology does not require setting accelerators, which cause a decrease in the dimensional stability of cement-bonded board. 相似文献
12.
This study was designed to reveal the role of the cement/wood ratio in a hydration test of wood-cement mixtures. The compatibility of oil palm (Elaeis guineensis Jacq) fronds-cement mixtures was tested in the hydration test, with the addition of magnesium chloride as an accelerator at different water/cement ratios. To prove the findings on the hydration behavior of components, the cement-bonded boards were manufactured using a conventional cold-pressing method at different cement/wood ratios. Results indicated that the optimum weight ration of cement/wood increased with decreasing wood powder size based on the equal specific surface area ratio of cement/wood in the hydration test and board manufacturing. The addition of magnesium chloride improved the compatibility of oil palm fronds with cement; the compatibility factor (C
A) increased by more than 90% with the addition of 5% magnesium chloride. TheC
A factor increased proportionally with a higher magnesium chloride content and a higher water/ cement ratio. The addition of magnesium chloride also enhanced the cement hydration and ultimate board strength properties. However, the addition of 5% magnesium chloride did not improve the properties of boards sufficiently at a cement/wood ratio of 2.21.0. 相似文献