The Effect Of Natural Fibers on The Properties of Cement Bricks

The main objective of this research is to study the effect of use the natural fibers in cement bricks, where the used natural fibers here are palm fibers and flax fibers. Also, this study presents an investigation on the use of new lightweight and thermally insulating construction material, composed of cement, sand and natural fibers (palm fibers or flax fibers). Thermal conductivity, compressive strength and bulk density were investigated through the experimental work which was divided into three stages as follows:In the first stage: a study was made to obtain the effect of fiber type, length and volume fraction on physical and mechanical properties of cement bricks reinforced by natural fibers, where palm fibers and flax fibers were added to the control cement brick with different fiber lengths (1cm and 3cm) for both types and fiber volume fractions of 2.5, 5.0and 7.5% for palm fiber, and of 1.5, 2.5 and 3.5% for flax fiberIn the second stage: a study was made to find the effect of coarse aggregate ratio on the efficiency of natural fibers reinforced cement bricks in order to select the optimum mix proportions of the mixes, which give the desired properties in this study. Each mix included constant content of palm or flax fibers, equal 20% as volume fraction, constant water cement ratio (0.5) and constant aggregate volume. However, the dolomite and the sand ratios were varied from mix to another. A technical and economical evaluation was applied on these designed brick types comparing with the control and the foam cement bricks.In the third stage: a development process was applied on the brick with palm fiber and zero percent of dolomite (PD0) in order to produce isolated bricks, where the volume fractions of the used palm fibers were increased to be 30 and 40% beside PD0 (which contained Vf =20%). Finally, the relation between prism to brick strength was investigated.