Optimizing the Mechanical Properties of Cement Composite Boards Reinforced with Cellulose Pulp and Bamboo Fibers for Building Applications in Low-Cost Housing Estates

Abstract

Africa is the third-richest continent in the world in terms of bamboo species. Despite these laudable natural resources, most African countries still use asbestos cement board as one of their major building materials. This is chiefly due to the high cost of equipment and technologies associated with non-asbestos-fiber cement board production. The current research seeks to underscore the possibility of utilizing these massive continent resources for non-asbestos-fiber cement board production by employing the existing production process in the asbestos cement industries via an innovatively developed laboratory-simulated Hatschek process. Non-asbestos-fiber cement boards incorporating kraft and bamboo fibers were successfully produced in the laboratory using this innovative method based on Hatschek technology, with natural fibre addition in the range of 2-6 wt.%. Experimental results revealed that the Flexural strength and deflection of the board improved significantly, producing optimum values of 10.41 MPa and 2.0 mm, respectively for composite board reinforced with 10 wt.% and 6 wt.% of kraft pulp and bamboo fibers, respectively. The SEM morphology of the fractured surfaces revealed the mode of composite fracture as well as good interaction at the fiber-matrix interface. Overall, the mechanical properties of the developed composite boards satisfy the minimum requirements of relevant standards based on fiber cement flat sheets and can be employed for internal building applications in low-cost housing estates in developing countries. The outcome of this research indicates that the current industrial production process based on Hatschek technology can be employed for non-asbestos-fiber cement board production using the studied natural fiber.

Keywords: Hatschek process; construction materials; kraft pulp; natural fiber; non-asbestos cement board.

Figure 4

Bending test of specimen in the lab using the Instron 4467 Electromechanical Testing Machine, Norwood USA.

Figure 1

Camera photo of the as-received raw bamboo fiber and the prepared chopped fiber.

Figure 2

Pulping process for producing kraft pulp fiber.

Figure 3

(a) Setup for the lab-simulated Hatschek process. (b) A selection of manufactured specimens in the lab.

Figure 5

TGA curves of bamboo fiber in a nitrogen atmosphere.

Figure 6

Flexural strength of FCBs reinforced with 5–20 wt.% of kraft fiber (7 and 14 days) (the ‘antennae’ indicate a standard error).

Figure 7

Flexural strength of FCBs reinforced by 10 wt.% of kraft pulp and 2–6 wt.% of bamboo fiber (7 and 14 days) (the ‘antennae’ indicate a standard error).

Figure 8

Flexural behavior of FCBs reinforced by 10% of kraft pulp and 2, 4, and 6 wt.% of bamboo fiber (14 days).

Figure 9

Percentage change in length of composite boards exposed to moisture movement (the ‘antennae’ indicate a standard error).

Figure 10

Percentage of water absorption of FCBs submerged in water for 48 h (the ‘antennae’ indicate a standard error).

Figure 11

The density of FCBs reinforced with kraft pulp and bamboo fibers (the ‘antennae’ indicate a standard error).

Figure 12

SEM micrographs of fractured surfaces of samples (a) K10-BB4 and (b) K10-BB6.