Using equal cross-section theory to investigate bending properties of cellulosic fiber reinforced cement panels

摘要

Cellulosic fibers, which are widely available in Iran, can be used as convenient materials for cement panel matrix reinforcing with respect to adequate mix design. This paper at the first stage presents a simple model for predicting the fiber reinforced cement panel behavior during flexural loads by implementing Equal Cross-section Theory. At the second stage, experimental study was carried out to validate the proposed theory. In order to do the experiment, different types of cellulosic fibers were used as cement replacement of 1% by weight. In addition, to solve the problem of swelling of cellulosic fibers within cement matrixes, fibers were treated by UV/ozone and coated with sodium silicate. Compressive strength, flexural strength and density of cement composite samples were investigated in terms of different cellulosic fiber types including viscose, Leafiran, milkweed and hemp and the sodium silicate consumption amount. The results revealed that the use of cellulosic fibers diminished the density and compressive strength of the cement panel specimens. Improvement of flexural strength was only achieved by adding the hemp fibers into the cement panels which showed a good agreement with Equal Cross-section Theory outputs. Moreover, the reductions in the compressive and flexural strength of cement panels contained sodium silicate were much smaller than the cement panels with uncoated fibers.