Hamzeh, Y., Pourhoshyar Ziabari, K., Torkaman, J., Ashori, A., & Jafari, M.

Environmental Management 117 (15): 263–267.

2013

This work assesses the effects of white rice husk ash (WRHA) as pozzolanic material, virgin kraft pulp
(VKP), old corrugated container (OCC) and fibers derived from fiberboard (FFB) as reinforcing agents on
some properties of blended cement composites. In the sample preparation, composites were manufactured
using fiber-to-cement ratio of 25:75 by weight and 5% CaCl2 as accelerator. Type II Portland cement
was replaced by WRHA at 0%, 25% and 50% by weight of binder. A water-to-binder ratio of 0.55 was used
for all blended cement paste mixes. For parametric study, compressive strength, water absorption and
density of the composite samples were evaluated. Results showed that WRHA can be applied as a pozzolanic
material to cement and also improved resistance to water absorption. However, increasing the
replacement level of WRHA tends to reduce the compressive strength due to the low binding ability. The
optimum replacement level of WRHA in mortar was 25% by weight of binder; this replacement percentage
resulted in better compressive strengths and water absorption. OCC fiber is shown to be superior
to VKF and FFB fibers in increasing the compressive strength, due to its superior strength properties. As
expected, the increase of the WRHA content induced the reduction of bulk density of the cement
composites. Statistical analysis showed that the interaction of above-mentioned variable parameters was
significant on the mechanical and physical properties at 1% confidence level.