Properties of Fiber Cement Board Affected by AFPLF (Abaca Fiber and Pineapple Leaf Fiber)

. At present, the Philippines is the top producer of natural fibers globally. This production of abaca and pineapple leaf fiber increased as time passed by. However, applying these fibers is limited and needs further studies to be efficiently utilized. This study introduced the usage of treated Abaca fiber and Pineapple leaf fiber (AFPLF) by incorporating it to cement boards and evaluate the mechanical and physical properties of fiber cement boards (FCB). This study's experimental results showed a significant increase in compression strength in 5% fiber reinforcement, higher than the compression capacity of cement board without fiber. In addition, the physical properties of the cement board reinforced with Abaca fiber and Pineapple leaf fiber (AFPLF) showed good characteristics in terms of drilling, impact, density, and water absorption tests. The cement board reinforced with 5% Abaca fiber and Pineapple leaf fiber (AFPLF) produces the best results regarding the fiber cement board's physical and mechanical aspects .

showed a significant increase in many engineering properties of Fiber-reinforced polymer composite. Its inherently high mechanical strength, durability, and flexibility. They also stated that it satisfies the ASTM standards, so the materials mentioned could be used as polymer composite [9].
Aside from abaca fiber, the next abundant natural fiber found in the Philippines is Pineapple leaf fiber (PLF) [10]. The Philippines ranks 3 in the world producer of pineapple [11]. In 2020, 66 900 hectares of land were dedicated to pineapple cultivation in the Philippines [12]. Pineapples are produced in the Philippines in approximately 2.7 million metric tons [13]. The Pineapple leaf fiber exhibits excellent mechanical properties that could be used for composite materials [14]. Also, it has desirable textile fiber properties like high cellulose content, good tensile strength, and fiber length [15]. Adding Pineapple leaf fiber to a polymer-reinforced composite increases its tensile strength, and as fiber content increases, the flexural strength gives a higher value [16]. Thus, it could be a potential for polymer-reinforced fiber composite [17].
However, this surprisingly large volume of natural fibers is not utilized and is exported to other countries due to its abundance and limited applications. Ropes, twine, fishing lines, nets, and a flourishing niche market for abaca-made apparel, curtains, screens, and furniture are all made with abaca [18]. In contrast, pineapple leaf fiber (PLF), yarn, woven fabrics, knitted items, non-woven mats, and handcrafted goods are all more environmentally friendly [19]. The advantage of utilizing natural fibers is that they are lightweight and considered lowcost. These properties that natural fibers possess are important in technological advancement. Natural fibers are sustainable materials that might be effortless and feature benefits like renewability, biodegradability, and high properties.
The study aims to determine the physical and mechanical properties of the fabricated fiber cement board (FCB) using Abaca fibers and Pineapple leaf fibers.
The study seeks to utilize the Abaca fiber and Pineapple leaf fiber by incorporating them into fabricating fiber cement boards. Introducing this AFPLF to the cement board will offer a new application to reduce the cost of making the fiber cement board. In addition, this will benefit the construction industry's advancement, producing greener materials.
The application of this research is limited to determining the physical and mechanical properties of cement fiber boards fabricated with both Abaca fiber and Pineapple leaf fiber. In varying percentages of fibers (0%, 5%, 10%, and 15%) will be added to the fiber-cement mix. The 0% fiber-cement mix will be set as the control variable for this experiment. Board sample tests will be limited to Scanning Electron Microscopy with energy dispersive X-ray spectroscopy (SEM/EDX), compression, density, impact, and drilling tests. The expected outcome of this study is to determine the effects of AFPLF fibers on the physical and mechanical properties of concrete.

Research materials
A cementitious matrix and fibers constitute FCB. The following elements constitute the cementitious matrix: (1) ASTM Type I Portland Cement; (2) sand that has a specific gravity of 2.61, an absorption of 4.52%, and a loose and rodded wet unit weight of 1317.44 kg/m 3 and 1518.36 kg/m 3 , respectively, (3) Pineapple leaf and (4) Abaca fiber. . The Abaca fibers were collected at Mercedes, Caraga, Davao Oriental. The Pineapple leaves were collected at Empress, Sasa, Davao City. The collected Pineapple leaves were scraped with a scraper until the non-fibrous material or residuals were removed. The Abaca fibers and Pineapple leaf fibers were cut about 1 inch long. The fibers were cooked in a 12% sodium hydroxide solution for at least 90 minutes. The fibers were washed thoroughly until the sodium hydroxide solution was rinsed. Then the fibers were blended to produce finer fibers. Water was added to the fibers before blending. Then the water was drained from the fibers, ready for mixing.

Mixing process
The design mix ratio used in this study (w/w) is 1:1:0 for sample 1, which is 0% fiber content, 1:0.95:0.05 for sample 2, which is 5% fiber content; 1:0.9:0.1 for sample 3, which is 10% fiber content, and 1:0.85:0.15 for sample 4 which is 15% fiber content, as shown in Table `1. 75 mm x 75 mm x 75 mm cube sizes were prepared to conduct a compressive test, and samples with sizes 200 mm x 200 mm x 10 mm were prepared to conduct drill, impact, absorption, and density tests. Fig. 1 shows the process of fabricating the cement-fiber board. All raw materials, especially the Abaca and Pineapple leaf fibers, must first be prepared to fabricate a cement fiber board sample. In preparing the AFPLF fibers, Abaca fiber and Pineapple leaf fiber were cut into shorter pieces about 1 inch to fit through the mouth of the volumetric flask to cook the raw materials. AFPLF fibers were cooked separately in a sodium hydroxide solution for at least 90 minutes. After 90 minutes, the cooked Abaca fiber and Pineapple leaf fiber were washed and rinsed with water to remove excess sodium hydroxide (NaOH) solution. The Abaca fiber and Pineapple leaf fiber were blended in a blender to produce finer fibers further. Once fibers were prepared, cement and sand were mixed in a dry condition. After mixing the cement and sand, equal portions of AFPLF fibers were added. The ratio of cement, sand, and fibers per sample is 1 :0, 1:0.95:0.05, 1:0.9:0.1, and 1:0.85:0.15, respectively, presented in Figure 1, which is the fabrication of cement fiber boards. It starts with preparing the raw materials such as cement, sand, and water. For the research, treated Abaca fiber and Pineapple leaf fibers were also prepared. Natural fibers are mixed with water until a uniform dispersion is observed. After mixing thoroughly, Portland cement was added with the required percentage until the slurry was obtained. After creating the mix, it will be transferred to forming boards. After sitting in the forming boards for 24 hours, It will be removed from the forms and transferred to the pre-curing zone for 14 hours. In the pre-curing zone, the moisture of the boards is regulated. After 14 hours, the boards will be transferred to the curing tanks and will stay there for 28 days to achieve the required compressive strength and durability. After 28 days, the boards will be subjected to various testing.

Testing methods
For this research, the following testing procedures were conducted: scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM/EDX), compression, density, drilling, water absorption, and impact tests. Sample fibers were analyzed with SEM/EDX to better comprehend the surface structure and division of the fibers. It also aids in determining the effect of the fibers on the morphology of samples containing added fibers. The equipment used was Thermofisher/FEI Quanta 250 EDAX. For the compressive strength test, a representative sample of the fiber cement board is prepared and placed on a testing machine, such as a universal testing machine (UTM), capable of applying a compressive load. The compressive load is applied gradually and continuously at a predetermined rate to the sample. As the load is applied, the testing machine measures and records the compressive force exerted on the sample. The test continues until the sample fractures or fails under the applied load. The compressive strength of the fiber cement board is calculated by dividing the maximum load or the load at failure by the cross-sectional area of the sample. The density of the samples was determined by measuring the mass of the FCB with at least 0.01 grams accuracy and getting the volume of the FCB with the aid of precision instruments. Density is then calculated by dividing its weight by its volume. The first stage of the water absorption test was to weigh the samples in dry conditions. The samples are then placed in a soaking vessel for approximately 12 hours. After the soaking procedure, the samples are weighed again to determine how much weight has been added. The amount of water the samples absorb is then calculated using their weight in dry and wet situations. The impact test used a projectile with a 50mm diameter and 530g mass. In this study, the initial stage is to determine the drop height of the impact ball, which was 1.4 meters. Then, evaluate the impact surface impression and the cracks on both sample surfaces. The drilling test reveals whether the Preparation of raw materials (cement, sand, water, and fibers).
Cement and sand are mixed evenly.
AFPLF is then added to the mixture, constantly mixed until the desired slurry is achieved.
Molds are filled with the prepared mixture.
After 24 hrs., samples are removed from the molds and immersed in water for curing for 28 days.
After 28 days, the samples are removed from the curing tank.
The samples are subjected to various testing.

Results and discussion
3.1 Scanning electron microscopy with energy dispersive x-ray analysis (SEM/EDX).
Scanning Electron Microscope (SEM) is used to see the surface and topography of materials at high magnification. The elongated and cylindrical shape of the abaca fibers was shown in Fig. 2 when examined under the scanning electron microscope. Although there may be some abnormalities due to the surface of the fiber's natural fluctuations, they have a relatively smooth surface. The texture of abaca fibers is layered and fibrous, with minute ridges or scales spanning the length of the fiber; the surface may appear slightly rough or textured. Furthermore, examining the cross-section of an abaca fiber would reveal its internal structure. Abaca fibers comprise several layers of cell walls, providing strength and resilience. Abaca fibers were generally thin, as proved in Fig. 3, showing the average diameter of the abaca fiber of 35.66 ± 1.28 µm. Consequently, the pores and voids on the abaca fibers were natural characteristics that can influence their physical properties, such as moisture absorption.

Fig.3. Diameter histogram of Abaca Fiber
On the other hand, an interesting and complex structure can be seen in the SEM image of a pineapple leaf fiber in Fig. 4. The pineapple leaf fiber is a long, thin, cylindrical strand. The fiber's surface has a textured appearance with various imperfections, lumps, and sporadic fissures. The SEM image indicates that the fiber's surface is covered with small, overlapping scales or ridges resembling fish scales. These scales give the fiber a rough and irregular texture, which may improve its ability to interlock with other fibers and affect its mechanical qualities. The pineapple leaf fiber's diameter seems constant along its length, with sporadic fluctuations suggesting branching or small twists. The fiber's fibrous appearance indicates that it is made up of smaller substructures or fibrils that are arranged parallel to its length. The fiber diameter of pineapple fibers (17.50 ± 5.18 µm), as in Fig. 5, is smaller than that of the abaca fibers. Fiber diameters of materials added to cement mixture may contribute to the changes in mechanical properties of the composites.   Fig. 6 and 7 show the sample's morphology obtained by (SEM) of samples containing the smallest and largest quantity of fibers in the FCB, which were 5% and 15% fiber, respectively. It can be observed that the FCB in Fig. 6 is less in quantity compared to the Fig.  7. It can be stated that the bonding between the FCB in Fig.7 is poor due to larger voids created by a large amount of fiber; hence, resulting in less strength of the concrete. Fig. 6 shows that particles are reduced, and the voids in the sample are lesser compared to Fig. 7. This phenomenon can directly influence the compressive properties of the FCB [17].   It can be observed that the compressive strength of the cement board with fiber is better as compared to no fiber (0%) at all. Cellulose fibers, on the other hand, are primarily included in fiber cement boards to enhance their tensile strength, impact resistance, and dimensional stability. The highest compressive strength can be found at a 5% addition of fiber; a further increase in the percentage would decrease the strength value. Lower fiber content can allow for better packing of the cement particles within the board during manufacturing. This improved particle arrangement can lead to stronger interparticle bonds, increasing compressive strength.

Water Absorption
In Fig.9, the water absorption of all samples with natural fiber content values from 5.97%-11.11%, respectively higher than those without natural fiber content.
This increasing percentage of absorption of the samples with added fibers is mainly due to the abaca fiber and pineapple leaf fiber. These natural fibers absorb more moisture, resulting in higher moisture content than the sample with 0% added fiber content. These results are similar to the study of natural fiber cement board's mechanical and physical properties for building partitions [17].

Drill test
The drilling test reveals whether the manufactured boards are susceptible to cracking and detachment when probed; the experiment used Concrete drilling tools. First, five holes were drilled into the board, fractures were inspected, and observations were recorded [17].
A concrete drill was used to drill four holes in every test sample. The fiber cement board with 0% fiber percentage, shown in Fig. 10, experienced cracks and detachment during drilling. Drilling was stopped after detachment occurred. On the contrary, in Figure 11, all the fiber cement boards with 5%, 10%, and 15% showed no defects during drilling, which means the chance of failure during installation is minimal.
Since the boards with no fiber displayed defects, and the boards with fibers exhibited no cracks and no detachments. Therefore, boards with fiber are more effective in keeping the chances of cracking to a minimum than those without fiber.  Fig. 11 FCB with 5%, 10%, and 15% fiber content experienced no cracks and detachments. Fig. 12 shows the decrease in the mean density of the samples as the fiber content increases. Fiber cement boards with a higher fiber content have a lower density. The fibers used in the board are typically less dense than the cement matrix. When more fibers are added during manufacturing, they displace some of the cement, resulting in a lower overall density. The cement matrix's density is generally higher than the cellulose fibers. Cement is dense, whereas cellulose fibers are lightweight and have a lower density. By increasing the fiber content, the overall density of the board is reduced [17].

Impact test
The impact test used a projectile with a 50mm diameter and 530g mass. In this study, the initial stage is to determine the drop height of the impact ball, which was 1.4 meters. Then, evaluate the impact surface impression and the cracks on both sample surfaces [17]. Fig. 13 and Table 2 show that the 5% and 10% fiber content samples performed well in this test, having more impact resistance. The fibers in the mix act as a reinforcement of the boards, thus making it more stiff and able to withstand more impact with only minimal damage to the fiber cement board. The findings portrayed the same result as the study of the properties of fiber cement boards for building partitions [17].

Conclusion
Based on the findings of the study, adding 5% fiber content to cement fiber boards significantly improved the compressive strength compared to boards without any fiber content. However, beyond 5% fiber will result in a decrease in the compressive strength value. With fewer cellulose fibers, the board has a higher proportion of cement; a high cement-to-fiber ratio can contribute to higher overall compressive strength. Furthermore, additional fiber can decrease the FCB's mean density, making it a good material for lightweight constructional material needs. With more fiber, the boards can absorb moisture much more effectively. The boards with added fiber also exhibited good impact resistance and drilling properties. The high fiber content in these boards provides enhanced structural integrity and reinforcement. The fibers act as a reinforcement matrix, distributing and absorbing the energy created during drilling or impact. The fibers within the cement matrix increase the material's tensile strength as the fibers within the cement board help distribute the stress caused by drilling or impact, thereby reducing the likelihood of cracks or fractures. Consequently, the fibers act as shock absorbers, dissipating the energy and reducing the risk of damage. The high fiber content allows the board to withstand impact without significant deformation or breakage; thus, the FCB with FCB % Indentation diameter(mm) Impact surface. Reverse surface.

0%
--Detachment Detachment 5% high fiber is less vulnerable to damage upon installation. The Fiber Cement Board's characteristics were greatly enhanced by adding fiber; among all the tested samples, the one with 5% fiber content showed the most promising results.
Based on these outcomes, the researchers recommend further investigating the FCBs in terms of thermal conductivity, fire resistance and employing Fourier Transform Infrared Spectroscopy (FTIR) of the FCB.