Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: April 11, 2006
Publication Date: April 24, 2006
Citation: Glenn, G.M., Orts, W.J., Klamczynski, A., Chiou, B., Shey, J., Holtman, K.M., Imam, S.H., Wood, D.F. 2006. Manufacture of biobased building materials. ARS-Mexico Biotechnology Conference, Monterey, Mexico, April 24-28, 2006, Paper No.3. Technical Abstract: Starch aquagel-based lightweight concrete has properties similar to those of other lightweight concrete products. However, starch aquagels are unstable in the strongly alkaline conditions typical of Portland Cement-based concrete and may interfere with the setting process. The effect of alkali treatments on the physical, mechanical, and functional properties of starch aquagels and aquagels from starch/polymer blends was investigated. Starch was blended at 100-115ºC in a twin-screw extruder with five different polymers to determine whether the blends improved alkaline resistance. Polymer blends containing 5, 15, and 30% of the polymer hydrated and formed aquagels when equilibrated in water for 24 hr. However, equilibrium moisture content was lower for the blends compared to the starch control. Aquagels equilibrated in 0.15 N NaOH swelled, lost compressive strength and had greater than 90 % moisture. The blend of starch and 30% PVOH absorbed less moisture and was more resistant to alkaline dissolution in 1 N NaOH than the other blends tested making it a more suitable material for aquagel-based concrete. The moisture content of starch-based aquagels and mixing time were critical factors in determining setting times. The size of aquagel blends had a minor effect on density and compressive strength.