Properties Of Cement-bonded Particleboard Research Articles

A Comparative Study of the Physico-Chemical Properties of Cement-Bonded Particle Boards from Semi-Pulped Bagasse and Newsprints

The objectives of this study were to compare the compatibility of semi-digested pulp and fully digested pulp with cement and to further determine how appropriate these two samples are for the production of outdoor particle boards using the hydration test to determine the compatibility through the compatibility factor obtained using the area ratio method. The effects of chemical additives on the compatibilities of the samples with cement and the existence of bond formation were also looked into. Stems of sugar cane were obtained from the Sabo market in Ile-Ife, Osun state, Nigeria while newspaper prints were also gathered from Obafemi Awolowo University, Ile-Ife, Nigeria. The samples were converted to mesh, bleached and then converted to pulp. Different tests comprising proximate analysis, phytochemical screening, compatibility test and hydration experiment. The results of physical tests showed that bagasse is light yellow in colour while the newsprint is yellow solid in colour. Phytochemical screening results indicated that saponins, alkaloids, and tannins were present in high concentration. Infrared analysis indicated the notable presence of hydroxyl, ester and carbonyl groups in the samples. Based on the compatibility values, the addition of additives such as CaCl₂ produced higher compatibility values. The study concluded that semi-pulped bagasse and the newsprints are appropriate for the production of the particle boards.

Influences of cement brands and mixing ratios on the physico-mechanical properties of cement bonded particleboards made of wood particles of Gmelina arborea, Afzelia africana and Triplochiton scleroxylon

Cement bonded particleboards (CBPs) were produced of wood particles of Gmelina arborea, Afzelia africana and Triplochiton scleroxylon using two brands of ordinary portland cement manufactured by two different domestic cement companies operating in Nigeria known as Dangote PLC and Lafarge Company. The admixture of wood particles and cement for production of the CBPs were done at mixing ratios of 1:1, 1:1.5 and 1:2 (weight to weight basis). The properties such as water absorption and thickness swelling at 24 hours, density, modulus of rupture (MOR), modulus of elasticity (MOE) and impact bending strength were determined. The results of the study reveal that the density ranged from 0.61 to 0.92 g/cm3. Meanwhile, water absorption and thickness swelling were found to be 30.34 to 72.44 % and 11.43 to 10.77 % at 24 hours, respectively. The bending properties obtained from the laboratory tests ranged from 115.77 to 826.55 N/mm2 and from 1157.70 to 4773.38 N/mm2 for MOR and MOE, respectively, while impact bending strength ranged from 41.70 to 238.49 N/mm2, respectively. As the cementious content increases from 50 % to 66.3 % and wood content decreases from 50 % to 33.4 %, the properties such as density, MOR, MOE and impact bending strength increased, while water absorption and thickness swelling decreases. The statistical results showed that such factors as wood species, cement type and mixing ratio had significant influence on the physical and mechanical properties of CBPs. The study reveals that CBPs made of wood particles of Triplochiton scleroxylon and Dangote cement brand at the ratio of 1:2 were more dimensionally stable, denser and stronger while CBPs of wood particles of Afzelia africana were stiffest and most rigid. As concluded, cement brand had significant importance in qualities of CBPs, which can be attributed to chemical compositions found in materials used. Keywords: cement, physical, mechanical, wood, particleboards, mixing ratio

Utilization of olive mill solid waste in the manufacturing of cement-bonded particleboard

This article investigated the effect of using olive mill solid waste (OSW) residue and cement types on some properties of cement-bonded particleboard (CBPB). Therefore, OSW as the wood replacement at four different rates (0%, 10%, 20% and 30%) based on wood weight, and two cement types [32,5R Portland Cement (PC) and 52,5R Super White Cement (SWC)] were used in the production of CBPB. 1% NaOH extraction was applied to all OSW materials prior to CBPB production. The experimental boards were subjected to moisture content, density, water absorption, thickness swelling, modulus of rupture, modulus of elasticity, and internal bond strength tests according to the relevant EN standards. In addition, thermogravimetric and scanning electron microscope analyses were performed to determine boards' thermal and morphological properties. According to the results, the density values of the boards (SWC-boards) produced by using the SWC were found to be higher. With the increase in the amount of OSW, density values were generally increased. The water resistance was higher in the boards used in the SWC. With the increase in OSW, it was observed that water absorption and thickness swelling increased in both cement types. When the effect of the cement types on the mechanical properties were examined, higher values were obtained from the SWC-boards than PC-boards. In addition, as the use of OSW increased, the resistance properties decreased likewise. In thermal properties, intimate results were obtained in weight loss of the boards, and weight loss was higher in the SWC-boards without adding OSW. In morphological features, the increase in OSW ratio caused the boards to have a more hollow structure. In addition, it was observed that the OSW added boards had fewer hydration products [Ca(OH)2 and C–S–H] compared to the other boards.

The effect of moisture on the properties of cement-bonded particleboards made with non-traditional raw materials

The paper presents research into the changes of properties in cement-bonded particleboards caused by moisture saturation over the course of 504 h. Three particleboard variants were tested, all at the age of 18 months. The first is a standard production-line board manufactured by CIDEM Hranice, a.s. (identified as CP-R). The other two variants were modified by by-products of the particleboard manufacturing process—dust (CP-D) and a particulate mixture (CP-P). The experiment observed changes in the boards’ dimensions, volume, and mass. The effect of moisture on their basic material properties was also investigated. While the boards were being saturated by water, changes in their structure were examined using an optical microscope. It was found that the boards behave differently depending on their composition. Also there were differences in the dynamics of the property changes. The modified particleboards are more susceptible to dimensional and volume changes. Both, volume and mass undergo the most significant changes during the first 24 h. Cracks and air voids inside the wood chips begin to close upon contact with water as a result of swelling. It was observed by optical microscopy that this process occurs within 3 to 5 min since immersion in the water bath. Between 24 and 96 h the rate at which the air voids and pores are closing begins to decrease and there is a difference in the dynamics of mass and volume changes as well. Wet–dry cycling of the boards was analysed as well. Temperature and moisture fluctuations negatively affected particleboard behaviour and properties. Strength dropped up to 50%. Wider cracks in structure of the particleboards were detected by optical microscopy, namely in ITZ (internal transition zone) of cement matrix and spruce chips.

Fiberglass Plaster Mesh as Reinforcement for Cement Bonded Particleboard

The effects of fiberglass plaster mesh (FPM) as reinforcement on some physical and mechanical properties of cement bonded particleboard (CBP) were examined. Experimental CBP with and without FPM were manufactured in laboratory conditions using wood particles, cement, tap water and chemical accelerators. Two plies of FPM, manufactured using fiberglass and polyester resin, were laid within the experimental CBP. The target density of CBP was 1300 kg/m3 in the study. Three different types of chemical accelerators (CaCl2, KCl, DARASET ® 580) were used in the experiments. Properties of CBP evaluated include 2- and 24-hour - thickness swelling (TS), 2- and 24-hour - water absorption (WA) and bending stiffness (MOE) and strength (MOR). The results indicate that all the board properties tested were significantly improved by FPM application. The average MOE values of the CBP boards with FPM was two times higher than those of the boards without FPM. Dimensional stability and MOR of the CBP boards were also significantly improved with the use of FPM. FPM can be used to improve inferior properties of the CBP, so as to make it more compatible with other wood based construction materials.

Physical and mechanical properties of cement-bonded particle board produced from African balsam tree (Populous Balsamifera) and periwinkle shell residues

Reducing the amount of wastes deposited into the environment has become important. A fresh approach in doing this is by recycling them. This paper investigated the physical and mechanical properties of cement bonded particle boards from agricultural wastes. The particle boards were tested for their physical (density, water absorption and thickness swelling) and mechanical (modulus of elasticity and modulus of rupture) properties. Scanning Electron Microscopy (SEM) analysis was carried out to determine the internal microstructure of the boards. The results revealed that periwinkle shell and cement have a great influence on the density of the board, cement and sawdust have a great influence on water absorption and thickness swelling, cement has a great influence on Modulus of Rupture & Modulus of Elasticity for all the combinations tested. The SEM photograph of the cut surface of the boards showed good fibre matrix adhesion at mix ratio of 1:1.5 (cement/waste). At lower fraction of cement matrix to waste ratio, the cement bonded particle board lost its adhesive force. It was concluded that sawdust and periwinkle shells are suitable materials in the production of particle boards.

Effect of CO2 on the degradation of cement-bonded particleboard based on the treatment to conventional cured board

This study aimed to evaluate and clarify the effect of CO2 at either the gaseous or supercritical phase on the degradation of cement-bonded particleboard (CBP) based on the treatment to conventional cured board, while the estimation of long term degradation of CBP is also discussed. The properties of CBP are improved by CO2 treatment in short period in both the gaseous and supercritical phases even after the conventional curing process. These properties, however, over the longer treatment time degraded in rapid rate against CO2 treatment in both the gaseous and supercritical phases. It was considered that the degradation of CBP increased with increasing the CO2 concentration, CO2 pressure and treatment time. With the longer treatment time against supercritical CO2 in higher concentration and pressure, the residual values of mechanical properties (IB strength, MOR, and MOE) were decreased, indicating CBP performance was degraded rapidly compared to treatment in the lower concentration and pressure of CO2 or under gaseous phase. High coefficient determination values between the residual values of CBP properties, and the treatment time and CO2 concentration were observed and the simple linear model was found to estimate the long term degradation of CBP among the properties and affecting factors.

Physico-Mechanical Properties of Cement-Bonded Particle Boards of Bambusa vulgaris and Gmelina arborea Fibres

This study investigated the effect of pre-treatment and particle geometry/stratification on the physical and mechanical properties of cement-bonded particle boards (CBPBs). 6 mm thick homogeneous cement-bonded particle boards were made from Gmelina arborea roxb. sawdust and bambusa vulgaris shard. fibres with type 1 Portland cement. The CBPBs were manufactured at four particle geometry/stratification levels and three pre-treatment levels. The CBPB was manufactured with a cement wood ratio of 3:1, board density of 1500 kg/m3, board size of 350×350×6 mm and a pressing pressure of 1.23 N/mm2. The CBPBs were tested for modulus of rupture (MOR), modulus of elasticity (MOE), thickness swelling (TS) and water absorption (WA). The MOR obtained for each of the 12 factor combinations in this experiment ranged from 2.02 to 11.27 N/mm2 while MOE value ranged from 253.88 to 4942.60 N/mm2. The mean percentage for water absorption (WA) values ranged from 8.78% to 35.66% while mean TS values ranged from 0.16% to 15.71%. Stronger and stiffer boards were produced using the sawdust/fibre/sawdust geometry stratification. Calcium chloride pre-treatment increased the mechanical properties of the boards, while Al2(SO4)3 improved their physical properties. There were significant differences between particle geometry and pre-treatment on both physical and mechanical properties of cement-bonded particle board (p<0.05).

Effect of wood particle geometry and pre-treatments on the strength and sorption properties of cement-bonded particle boards

The effect of particle geometry and pretreatments on the strength and sorption properties of wood particle cement composite boards was investigated. Wood particles (flakes and sawdust) of Gmelina arborea were mixed with cement and water in the production of composite boards. The wood particles were pretreated with hot water, calcium chloride and a combination of both treatments to enhance bonding with cement. The slurry was poured into rectangular moulds for board formation. After demoulding, the boards formed were tested for modulus of rupture (MOR), modulus of elasticity (MOE), water absorption (WA) and thickness swelling (TS). The results revealed that the mean MOR for flakes boards was 3.23N mm-2 while the mean MOR for sawdust boards was 3.01N mm-2. Hot water and calcium chloride treatment produced the best effect in flake composite boards with MOR and MOE values of 6.90 N/mm2 and 1897.36 N mm-2 while sawdust composite boards had mean MOR and MOE values of 5.69N mm-2 and 1664.31N mm-2 respectively. The WA rate after 24 hours of flakes and sawdust boards treated with hot water and calcium chloride was 3.63% and 4.28% while the TS rate was 0.69% and 1.44% respectively. Particle geometry and pretreatments significantly improved strength and sorption properties of wood particle cement composite boards (p<0.05).

The influence of additive content and particle size of bagasse on some properties of cement-bonded particleboard

Agricultural residuals, such as bagasse, are the renewable resources which can be used as raw materials for making cement-bonded particleboard (CBPB). In this study, the effect of sodium silicate (Na2SiO3) as accelerator was evaluated on hydration process of cement paste. Moreover, it was analyzed modulus of rupture (MOR), internal bonding (IB) and thickness swelling (TS) of CBPB manufactured from bagasse as affected by particle size and content of additive (Na2SiO3) through using response surface methodology. It was determined that adding of bagasse meal in cement paste caused to decrease the initial and final setting time. Besides, higher amounts of additives resulted in lower values of hydration temperature peaks (Tmax) and hydration times. Based on central composite design, quadratic models were developed to correlate the preparation variables; particle size (x 1), additive content (x 2), to the responses; MOR (y1), IB (y2) and TS (y3). Analysis of variance indicated that particle size was the most significant variable for responses. The optimum preparation conditions for strength properties and TS were obtained by using particle size of >6.2 mm and additive content of 5.5 %, which resulted in MOR, IB and TS of 9, 0.25 MPa and 18 %, respectively.

Cement-bonded particleboard with a mixture of wheat straw and poplar wood

We investigated the hydration behavior and some physical/mechanical properties of cement-bonded particleboard (CBPB) containing particles of wheat straw and poplar wood at various usage ratios and bonded with Portland cement mixed with different levels of inorganic additives. We determined the setting time and compression strength of cement pastes containing different additives and particles, and studied the effects of these additives and particles on thickness swelling, internal bond strength and modulus of rupture of CBPB by using RSM (Response Surface Methodology). The mathematical model equations (second-order response functions) were derived to optimize properties of CBPB by computer simulation programming. Predicted values were in agreement with experimental values (R2 values of 0.93, 0.96 and 0.96 for TS, IB and MOR, respectively). RSM can be efficiently applied to model panel properties. The variables can affect the properties of panels. The cement composites with bending strength > 12.5 MPa and internal bond strength > 0.28 MPa can be made by using wheat straw as a reinforcing material. Straw particle usage up to 11.5% in the mixture satisfies the minimum requirements of International Standard, EN 312 (2003) for IB and MOR. The dose of 4.95% calcium chloride, by weight of cement, can improve mechanical properties of the panels at the minimum requirement of EN 312. By increasing straw content from 0 to 30%, TS was reduced by increasing straw particle usage up to 1.5% and with 5.54% calcium chloride in the mixture, TS satisfied the EN 312 standard.

Rapid production of high-strength cement-bonded particleboard using gaseous or supercritical carbon dioxide

This study deals with the effects of curing treatment with gaseous and supercritical carbon dioxide on the properties of cement-bonded particleboard (CBP) manufactured by the conventional cold-pressing method. The hydration of cement and the mechanism of improvement were examined using X-ray diffractometry (XRD), thermal gravimetry (TG-DTG), and scanning electron microscopy (SEM) observations. The results are as follows: (1) The curing of cement was accelerated concomitantly with the improvement in mechanical and dimensional properties of CBP significantly by curing with gaseous or supercritical carbon dioxide. (2) Supercritical carbon dioxide curing imparted boards optimal properties at a faster rate than did gaseous curing. (3) Accelerated formation of calcium silicate hydrate and calcium carbonate and the interlocking of those hydration products on the wood surface are potentially the main reasons for the superior strength of carbon dioxide-cured boards.

Optimale Parameter der Wärmebehandlung von zementgebundenen Holzspanplatten

The process of the heat-treatment of cement-bonded particleboards was examined theoretically and experimentally. For the calculation of this process, the physical-mathematical model was worked out and numerically was realized. The heat-physical qualities (heat-conductivity, specific heat-capacity) of the cement-bonded particleboard through experimental and calculation methods were examined. The corresponding generalized calculation-dependences were gotten. The kinetics of the hydratation of cement in the wood-cement mixture according to the different technological factors was examined experimentally. The experiments concerning the influence of the temperature-medium in the area of 323 to 353 K on the early strength properties and the end strength properties of cement-bonded particleboards were carried out.

Effect of flake geometry on properties of cement-bonded particleboard from mixed tropical hardwoods

Laboratory scale cement-bonded particleboards were made from mixed particles of three tropical hardwoods. Boards were three-layered comprising of 2 mm thick sawdust face and 4 mm thick core layers made from flakes of three lengths-12.5 mm, 25.0 mm and 37.5 mm and two thicknesses of 0.25 mm and 0.50 mm. The panels were fabricated at three density levels of 1,050 kg/m3, 1,125 kg/m3 and 1,200 kg/m3. From the statistical factorial analysis carried out, flake length, flake thickness and board density had significant effects at 1% level of propability on the properties of the tested panels. Mean MOR ranged from 5.22 to 11.15 N/mm2; MOE-2,420 to 4,820 N/mm2; water absorption and thickness swelling following 144 hours soak in water, 32.95 to 46.00% and 0.35 to 5.47% respectively. The longer and thinner the flakes, the stronger, stiffer and more dimensionally stable the experimental cement-bonded particleboards. Similarly, the higher density panels generally exhibited higher strength values in terms of MOR and MOE and were more dimensionally stable. MOR, MOE, water absorption and thickness swelling were found to be highly correlated with flake length, flake thickness and panel density. Correlation coefficients (R) for these relationships were 0.888 to 0.986 for the combined variables; and 0.574 to 0.992 for the individual factors. In all the cases tested, the regression relationships were linear.