Dimensional stability of wood wool cement board

Eusebio Dwight A., . (2006) Dimensional stability of wood wool cement board. [Proceedings Paper]

Wood excelsior or wood wool bonded with a general purpose portland is referred to as wood wool cement board WWCB. Several studies on the utilization of varoius wood species for WWCB have been conducted and results showed that the basic properties of WWCB are largely dependent on the wood species used as well as some manufacturing variables. However there are still peripheral questions that remain unanswered. One question often asked by some WWCB manufacturers and end-users is whether WWCB shrinks either in width thickness or length. When WWCB is used either as exterior or interior panelling there were observations that cracks occur in the cement plaster after sometimes and has been speculated that this is due to board shrinkage of cement plaster or due to the drying of WWCB components such as cement and wood. In this study WWCB with a thickness of 8 mm were produced at wood/cement ratios WC of 50/50 40/60 and 30/70 using yemane Gmelina arborea Roxb and general purpose portland cement as raw materials. The boards were cured under shade US and without shade i.e. exposed to sun and rain WS. Thickness swelling TS and water absorption WA were tested every week for 6 consecutive weeks from the time WWCB were produced. On the other hand dimensional changes in terms of length width and thickness were measured after 6 weeks from the time WWCB were produced. There was no definite trend that TS would be lower as affected by the 2 curing conditions at all levels of WC. The TS values obtainded were all below 1 for all boards from the 1st week until the 4th week curing. WA values of boards cured US were almost the same after the 1st wek or curing until the 4th week while boards cured WS showed a decreasing trend during the 4th week period. The dimensional changes of the boards in terms of length. width and thickness were significantly affected by curing condition and WC ratio but not curing period.

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Abstract

Wood excelsior or wood wool bonded with a general purpose portland is referred to as wood wool cement board WWCB. Several studies on the utilization of varoius wood species for WWCB have been conducted and results showed that the basic properties of WWCB are largely dependent on the wood species used as well as some manufacturing variables. However there are still peripheral questions that remain unanswered. One question often asked by some WWCB manufacturers and end-users is whether WWCB shrinks either in width thickness or length. When WWCB is used either as exterior or interior panelling there were observations that cracks occur in the cement plaster after sometimes and has been speculated that this is due to board shrinkage of cement plaster or due to the drying of WWCB components such as cement and wood. In this study WWCB with a thickness of 8 mm were produced at wood/cement ratios WC of 50/50 40/60 and 30/70 using yemane Gmelina arborea Roxb and general purpose portland cement as raw materials. The boards were cured under shade US and without shade i.e. exposed to sun and rain WS. Thickness swelling TS and water absorption WA were tested every week for 6 consecutive weeks from the time WWCB were produced. On the other hand dimensional changes in terms of length width and thickness were measured after 6 weeks from the time WWCB were produced. There was no definite trend that TS would be lower as affected by the 2 curing conditions at all levels of WC. The TS values obtainded were all below 1 for all boards from the 1st week until the 4th week curing. WA values of boards cured US were almost the same after the 1st wek or curing until the 4th week while boards cured WS showed a decreasing trend during the 4th week period. The dimensional changes of the boards in terms of length. width and thickness were significantly affected by curing condition and WC ratio but not curing period.

[error in script]

Item Type:	Proceedings Paper
AGROVOC Term:	WOOD
AGROVOC Term:	WOOL
AGROVOC Term:	CEMENT
AGROVOC Term:	CORK
AGROVOC Term:	SAWNWOOD
AGROVOC Term:	DRYING
AGROVOC Term:	PROCESSING
AGROVOC Term:	SWELLING
AGROVOC Term:	ABSORPTION
AGROVOC Term:	SHRINKAGE
Geographical Term:	MALAYSIA
Depositing User:	Ms. Norfaezah Khomsan
Last Modified:	24 Apr 2025 05:28
URI:	http://webagris.upm.edu.my/id/eprint/16923

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