PRODUCTION AND EVALUATION OF CEMENT-BONDED PARTICLE BOARD USING COGON GRASS AS CONSTITUENT

J. A. TAGAL1 and J. D. CATAYTAY2

1Student Researcher, Bachelor of Science in Agricultural EngineeringUniversity of Southeastern Philippines, Tagum-Mabini Campus

Apokon, Tagum City, Davao del NorteEmail: jobelle_tagal@yahoo.com

2Adviser and Professor, Department of Agricultural Engineering,College of Agriculture and Related Sciences,

University of Southeastern Philippines, Apokon,Tagum City, Davao del Norte

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ABSTRACT

The possibility of using cogon grass as constituent of cement-bonded particle board (CBPB) was evaluated in this study.

The study started with the collection of cogon grass, cement, and other materials used in the production of cement-bonded particle board. The cogon grass was chopped and cut then dried and weighed to desired quantities corresponding to cement to cogon grass ratios by weight.

A preliminary evaluation was conducted on the amount of cogon grass to be used in the production of CBPB. After evaluation, it was found out that the amount of cogon grass should not exceed 15 percent of the total weight of the produced CBPB.

After determination of the amount of cogon grass, three treatments were formulated, 85:15, 90:10, 95:5 cement and cogon grass ratio respectively. Each mixture was glued together. After 28 days of curing. The density and specific gravity of the boards were determined. The boards were also subjected to modulus of rupture, the 95:5 cement/cogon grass ratio was superior to that 85:15 and 90:10 cement/ cogon grass ratio. Water absorption result showed that the 90:10 and 95:5 cement/ cogon grass ratio were comparable with each other and were less absorbent than that of the 85:15 cement/cogon grass ratio. Cement-bonded particle board made from cogon grass can therefore be used for housing materials.

INTRODUCTION

Grasses are particularly growing everywhere. The first thing that comes into our mind is the picture of weeds growing profusely in the open fields. The grass family includes plants that we do not normally think as grasses like sugar canes and bamboos. The grass family contains 635 genera’s and 9,000 species, making it as the fourth largest plant family after the legumes, orchids and composite flowering plants. Grass belongs to the family of graminea, a large family of monocotyledoneae, the subclass of monocots or those flowering plants that have single cotyledon or seed leaf.

Cogon grass is recently used as a potential export item in the neighboring nation of the Philippines. It serves as feedstuff in cattle fattening operations, at the same time development arouse the interest of enterprising groups and individuals, it also cause apprehension among ecologist and citizen

concerned with protective, productive and sustainable use of the natural environment.

The benefits of cogon grasses are not only limited to the export of feeds but most importantly it serves as prevention of soil erosion resulting in the siltation of dams. Thus, a structure would normally be constructed to catch silt in dams so as not hamper the operational life of dams.

The uncontrollable growth of these grasses can be a threat to our farmer’s life in the field. Cogon grasses are like silent robbers who slowly rob the land to the extent they reduce the quality of the crops. Cogon grass, Imperata cylindrica (L.) has been ranked as one of the ten worst weeds of the world. In tropical and subtropical regions around the globe, this aggressive, rhizomatous perennial is generally considered a pernicious pest plant due to its ability to successfully disperse, colonize, spread, and subsequently compete with and displace desirable

vegetation and disrupt ecosystems over a wide range of environmental conditions. These characteristics and consequences of cogon grass infestations are similarly evident even within the native or endemic range in the Eastern Hemisphere, as it has long been considered one of Southeast Asia’s most noxious weeds (Brook, 1989).

Significance of the Study

Chronic shortages of suitable housing exist throughout the developing nations of the world. Reasons for these shortages vary, but lack of planning, exploitation of natural resources, and rapid population growth has greatly exacerbated the problem. The need for low-cost housing specifically suited to the needs of these people has long been recognized by essentially all world bodies concerned with humanitarian issues along with those governments concerned with global political stability. Given the practical financial constraints that exist in these countries, however, it is evident that the solution to world housing problems lies largely in the development of low-cost building materials that are able to satisfy the production, construction, economic, cultural, safety, and health requirements imposed by the natural barriers, lack of infrastructure, and lack of community services in developing nations.

This study would make this cogon grass a useful constituent on producing alternative construction materials. CBPB had been successfully used in a variety of climatic condition where its unique characteristics make it an ideal building material. It would introduce the important uses of cogon grass.

Objectives

Generally, the study aimed to produced and evaluate Cement Bonded Particle Board (CBPB) using cogon grass as constituent for its production.

1. Produce CBPB, using different proportion of cogon grass and cement.

2. Determine the modulus of rupture (MOR) and water absorption (WA) capacity of the produced cement-bonded particle board.

3. Determine the density and specific gravity of CBPB constituted by cogon grass.

4. Select the best mixture of cement and cogon grass ratio with high MOR value.

5. Determine the cost of production of the produced CBPB.

Scope and Limitations

The study was limited only to production, evaluation and selecting of best CBPB mixture which have the highest MOR value. Evaluation was limited to determine its density, specific gravity, MOR value and water absorption value. MOR value was obtained by determining the maximum load that the board can with stand per unit area for three cement/cogon grass ratios: 85:15, 90:10, 95:5.

Data gathering and experimentation was conducted from October 2010 to January 2011 at Maco, Compostela Valley Province.

MATERIALS AND METHODS

Materials

The materials used for the production of cement-bonded particle board (CBPB) using cogon grass as constituent were:

3 kilogram of cogon grass 20 kilogram of Portland cement mat forming frame (dimension: 8in X 5in) bolo large plastic basin water weighing scale spring balance 1 piece plywood Oven

Collection of Materials

Cogon grass was collected at the grassland. Cement, nails and plywood were purchased from the hardware. Other materials were collected according to their availability.

Frame Construction

The frame (Figure 1) was constructed from wood having 1 in X 1 in dimension and a length of 8 in (2pcs.) and 5 in (2pcs.). These four pieces of wood was nailed to form a rectangular frame. The bottom of the frame was attached to a piece of plywood.

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Figure 1. Constructed frame

Preliminary Evaluation

To know the possible amount of cogon grass used in the study for the production of cement-bonded particle board, a preliminary evaluation was conducted. Three pieces of CBPB with different ratios of cement and cogon grass were formulated. The ratios of cement and cogon grass used were 60:40, 70:30, 80:20 respectively. After 28 days of curing, the strength of produced CPBP was tested. Also the appearance of the boards was examined. The appearance and the strength were then used as the basis in formulating the treatments used in the study.

Procedure for CBPB Production

1.) The collected cogon grass (Figure 2) was manually cut into small pieces.

2.) The cut cogon grass was sun dried.3.) The dried cogon grass was weighed

according to the 85:15; 90:10; 95:5 cement to cogon grass ratio (Figure 3).

Figure 2. Collected cogon grass

4.) The dried cogon grass, water and cement were mixed manually until the cogon grass will be coated with cement.

5.) The mixture was spread out in a mixture forming frame previously constructed. It was sure that the mixture will be properly level up to a thickness of ½ inch.

6.) The mixture (Figure 4) was dried for 24 hours and left to stand for 27 days to cure completely.

7.) After curing, the produced CBPB was subjected to evaluation by determining its density, specific gravity, MOR test and water absorption test.

Figure 3. Weighing of cogon grass

Figure 4. Mixing of cogon grass and cement

8.) Three replications for each treatment were also performed for each test mention above.

Formulation

Each treatment has a dimension of 8 in. X 5 in. X ½ in. was subjected for evaluation. Three treatments were used in this study. Each treatment

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represents different mixing proportions. Proportion for treatment 1 (T1) was 85:15; for treatment 2 (T2) was 90:10 and for treatment 3 (T3) was 95:5 cement to cogon grass respectively.

Statistical Tools

The analysis of variance (ANOVA) following CRD design was used in the study to determine significant difference. Duncan’s Multiple Range Test (DMRT) was used to identify the significant difference per treatment.

Density Computations

The width and thickness of the board develop was determined. After measuring, each of the board was weighed (Figure 5). Density was computed using the formula:

DPB=W PB

V PB (equ.1)

Where: DPB = is density of particle board (g/cm3)

WPB = is weight of particle board (g) VPB = is volume of particle board (cm3)

Where: VPB = L x W x t

Where: L = length of particle board (cm)W = width of particle board (cm)t = thickness of particle board (cm)

Figure 5. Weighing of produced cement-bonded particle board

Modulus of Rupture (MOR) Test

Modulus of rapture was the maximum load applied per unit area of the board that can withstand without breaking. The formula used in determining MOR values for these three different mixing proportions was:

MOR=3PL (equ.2) 2bd2

Where:MORfs = modulus of rapture for flexural

strength.P = load applied L = length of CBPBB = base d = thickness

Water Absorption Test

Water absorption test was the property of cement-bonded particle board to hold water. To start the test the initial weight of particle board was determined. The CBPB was then soaked into water for 24 hours. After soaking (Figure 6), final weight of CBPB was recorded. This weight was compared with the initial weigh of the particle board.

Formulated in Bato Balani Magazine, 1998-99 for water absorption is:

WA = W ¿

At¿ (equ.3)

Where: WA = water absorption (g/cm3)Wf = weight of CBPB after soaking (g)Wi = weight of CBPB before soaking (g)A = area of CBPB (cm)t = thickness of CBPB (cm)

Figure 6. Soaking of produced cement-bonded particle board in water

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Specific Gravity Computation

As applied to CBPB, the ratios of the oven dry weight of sample to the weight of volume of water equal to volume of the sample at specified moisture content.

The boards was oven dried as a temperature of 101 to 104oC as specified by the American Standard Testing Materials (Bato Balani, 1999)

Sg = W PB

W H 2 O (equ.4)

Where: Sg = specific gravityWpb = weight of oven dried CBPB (g)WH2O = weight of water equal to volume of

CBPB tested (g)

RESULTS AND DISCUSSIONS

Cement-bonded particle board (CBPB) is composed of small wood particles of other fibrous materials. Relatively cheap and highly versatile, it competes closely with plywood as a prime panel material.

Cogon grass is commonly discarded in the Philippines. However, it embedded with silica and contains a durable fiber. Silica is usually used as additives in concrete to add strength to it. Due to its light weight, high strength to weight ratio, corrosion resistance and other advantages, natural fiber based composites are becoming important composite materials in building.

The prospects for CBPB production are bright; more so as the price of lumber and plywood is increasingly steadily. This research would make this cogon grass as the primary material for cement-bonded particle board.

Preliminary Evaluation

During the preliminary evaluation conducted, as the appearance of the produced CBPB was shown, it was found out that the three ratios being formulated were not possible because the cement was not enough to coat the cogon grass. After the preliminary evaluation, production of the cement-bonded particle board (CBPB) followed. Three treatments (Figure7) were prepared with treatment 1 as 85:15, treatment 2 as 90:10, treatment 3 as 95:5 cement and cogon grass ratio respectively. Three replications were also prepared for each treatment.

Figure 7. Produced cement-bonded particle board.

Density of Produced CBPB

Table 1 shows that the produced CBPB different from the average board density which ranged from 1.097 to 1.533 g/cm3. It was found out that the average density of some produced cement-bonded particle board far exceeds with the standard density of CBPB which is 1.25 g/cm3

(http://www.eltomation.nl/page 5.html). Among the three treatments, treatment 1 had the lower density and treatment 3 had the higher density. Statistical test using the Analysis of Variance (ANOVA) test at 5% and 1% level of significance, comparing the computed F (Fc) and tabular F (Ft) in Table 1, result showed that the density of produced CBPB was affected by the proportion of cement and cogon grass. It was also found out that treatment 2 and treatment 3 were not significantly different. Only treatment 1 had significant difference with treatment 2 and treatment 3.

Table 1. Observation data for the density of produced CBPB, g/cm3.

Treatment Observation Total Mean

R1 R2 R3

1 1.55 1.11 1.08 3.29 1.097b

2 1.25 1.25 1.30 3.8 1.267a

3 1.53 1.53 1.54 4.6 1.533a

Grand 11.69 3.897

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Cv=3.14%Mean numbers with different letters has significant difference at 5% level of significance using DMRT.

Specific Gravity of Produced CBPB

The produced CBPB were oven-dried at a temperature of 104oC for 24 hours as specified by the American Standard Testing Materials (Bato Balani, 1999). The boards withstand the extreme temperature. Table 2 shows the specific gravity of produced CBPB. Treatment 3 had the higher value and treatment 1had the lower specific gravity. Statistical test using the analysis of variance (ANOVA) at 5% and 1% level of significance showed that there was a significant among treatment means. Treatment 1 and treatment 2 were not significantly different, only with that of treatment 3.

Table 2. observation data for the specific gravity of produced CBPB, g/g

Treatment Observation Total Mean

R1 R2 R3

1 1.05 1.07 1.05 3.17 1.06b

2 1.16 1.17 1.20 3.53 1.18b

3 1.46 1.44 1.50 4.4 1.47a

Grand 11.1 3.71

Cv=1.82%Mean numbers with different letters has significant difference at 5% level of significance using DMRT.

Water Absorption of the CBPB

The produced CBPB were subjected to water absorption test by soaking the boards in 24 hours. Table 3 shows the water absorption capacity of the produced CBPB. Among the treatments, treatment 1 (85:15) has the higher water absorption capacity and treatment 3 (95:5) has the lower water absorption capacity. The water absorption capacity of the produced CBPB was subjected to statistical analysis using the Analysis of Variance (ANOVA) at 5% and 1% level of significance. Result showed the water absorption capacity of the boards was significant. The CBPB were greatly affected by the proportion of cement and cogon grass. It was also found out that treatment 2 and treatment 3 were not

significantly different. Only treatment 1 had significant difference with treatment 2 and treatment 3.

Table 3. Observation data for water absorption of the produced CBPB, g/cm3.

Treatment Observation Total Mean

R1 R2 R3

1 0.184 0.171 0.175 0.53 0.177a

2 0.153 0.147 0.13 0.43 0.143b

3 0.132 0.151 0.127 0.41 0.137b

Grand 1.37 0.461

Cv = 7.21% Mean numbers with different letters has significant difference at 5% level of significance using DMRT.

Modulus of Rupture of Produced CBPB

The produced CBPB were subjected into a test to determine its modulus of rupture. Modulus of rupture was the maximum load the board can withstand per unit area. Table 4 shows the MOR value of the produced CBPB. Results showed that the treatment 3 (95:5) had the highest MOR,at 908.91 N/cm2. The lowest MOR mean was from treatment 1(85:15), which was only 268.28N/cm2. Among the treatments, treatment 3 exceeded the standard value of MOR for CBPB which is 9 N/mm2. Statistical test using Analysis of Variance (ANOVA) at 5% and 1% level of significance of MOR of produced CBPB showed that there was significance among treatment means. It was also found out that treatment 2 and treatment 3 were not significantly different. Only treatment 1 had significant difference with treatment 2 and treatment 3.

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Table 4. Observation data for modulus of rupture of produced CBPB, N/cm2.Treatment Observation Total Mean

R1 R2 R3

1 261.35 277.46 266.46 804.85 268.28b

2 582.31 624.76 569.76 1776.83 592.28b

3 920.31 860.79 945.64 2726.74 908.91a

Grand 5308.42 1769.47

Cv = 5.17% Mean numbers with different letters has significant difference at 5% level of significance using DMRT.

Cost Estimates

For every piece, cement bought including miscellaneous, labor for hauling the grass and other material used was recorded for cost estimates. Each item cost was estimated using the particle dimension of 8in x 5in x ½in.

The Table 5 comprises the cost of production of cement-bonded particle board (CBPB).

Table 5. Cost of the produced CBPB of dimension (8in x 5in x ½in)

Treatment Total Cost (Php.)

1 13.40

2 14.20

3 15.10

The computed cost and estimates for the three treatments of cement-bonded particle board were used in order to know the cost of producing a CBPB using cogon grass as constituent. For treatment 1, the cost of production was 13.40 Php.; for treatment 2 was 14.20 Php.; and for treatment 3 was 15.10 Php. for a 8in x 5in x ½in. The estimated price per square inch ranges from 0.67 to 0.76 Php.

SUMMARY, CONCLUSIONS, AND RECOMMENDATIONS

Summary

The study started with the collection of materials used; cogon grass, cement and other materials used. The cogon grass was chopped and cut into tiny pieces. It was then sun dried.

In order to determine the possible amounts of cogon grass to be used in the study, preliminary evaluation was conducted. 60:40, 70:30, 80:20 were the ratios of cement and cogon grass preliminary used. After evaluation, it was found out that the amounts of the grass used were not possible because the cement was not enough to coat the fiber. After preliminary evaluation, production of CBPB followed. Three Treatments are being formulated, T1 as 85:15, T2 as 90:10, and T3 as 95:5 cement and grass ratios relatively. Each mixture were glued together and cured for 27 days.

After the production of CBPB, the density and specific gravity were determined. The CBPB also undergoes Modulus of Rupture (MOR) and water absorption (WA) tests.

Some of the produced CBPB exceeds from the standard density of CBPB because of the treatments composed mainly of cement. The specific gravity of the produced CBPB was determined after oven-drying for 24 hours at 104oC as specified by the American Standard Testing Materials (ASTM). Only treatment 3 exceeded the standard specific gravity of CBPB, which is 1.25. Among the treatments, treatment 1 and treatment 2 were not significantly different, only with that of treatment 3.

The produced CBPBs were subjected to water absorption and modulus of rupture tests. Statistical test shows that the water absorption capacity of the boards was greatly affected by the proportion of cement and cogon grass. Treatment 1 and Treatment 2 do not vary considerably. In terms of modulus of rupture, Treatment 3 has a higher strength compare to treatment 1 and treatment 2. The mean MOR of treatment 3, 9.08 N/mm2, exceeds the standard MOR for CBPB which is 9N/mm2

(Eltomation, 1996).The estimated cost of the produced cement-

bonded particle board ranges from 13.40 Php. to 15.10 Php. It is cheaper compared to a commercial price of CBPB which is 15.73 Php.

Conclusion

The produced CBPBs were denser than the standard CBPB. Treatment 1 was less dense than

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treatment 3. Result showed that the density of the boards increased as the proportion of cement increased. The specific gravity of the board also increased as the amount of cement increased. The produced CBPB had a better water absorption compared to the standard CBPB. Among the treatments, treatment 3 has the higher MOR value which exceeded the standard MOR for CBPB. Its price per square inch is cheaper than a commercial CBPB.

Therefore, treatment 3 was the best treatment and had the best proportion of cement and cogon grass for cement-bonded particle board production.

Recommendations

Based from the study the following are recommended for further study:

1. Add some additives to improve the strength of the produced cement-bonded particle board.

2. Use a suitable adhesive as binding material for the production of cement-bonded particleboard like plastic resin.

3. Use the finest chop of cogon grass to enhance the binding properties.

4. Use different thickness of the produced cement-bonded particle board for evaluation.

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LITERATURE CITED

Bato Balani for Science and Technology (Senior Ed.) Vol. 18 No.1 SY 1998-99

Bato Balani for Science and Technology (Senior Ed.) Vol. 18 No.3 SY 1998-99

CATOERA, DEXTER,2010. Production and Evaluation of Cement-Boned Particle Board Using Chicken Feather As Constituent.

ERELLANA, ISMAEL CONSENCINO,2006. Production and Evaluation of Cement-Boned Particle Board Using Coconut Coir As Constituent.

MILLER, R.1991. Carpentry and Construction.

World Wide Web: http://en.wikipedia.org/wiki/Cement. Accessed online on October 17, 2009

World Wide Web: http:// www. bmtpc. org/pubs/papers/ paper 1.htm. Accessed online on October 17, 2009

World Wide Web: http://www.eltomation.nl/cbpb.html. Accessed online on October 17, 2009

World Wide Web: http://www.fao.org/docrep/r6560e/r6560e05.htm. Accessed online on October 17, 2009

World Wide Web: http://www.nps.gov/plants/alien/fact/imcy1.htm. Accessed online on October 17, 2009

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