Artificial wood

The apprication of FRP mortars is various construction materials, such as the sidewalk concrete flags (Photo 6), the artificial wood of concrete (Photo 6), the centrifugal concrete pipe with luster surface (Photo 7), and the surface mortar layer on concrete blocksf or retaing wall and revetment, laying blocks (Photo 8). 

Photo 6 The sidewalk concrete flags and the artificial wood of concrete containing FRP fine powder. 

Keywords artificial woods, bulk specific gravity, carbon fibers, FRP powder, hardness, nail withdrawal, strengths... 

High-early-strength portland cement as specified in JIS R 5210 (Portland Cement) was used in all the mortar mixes for artificial woods. 

According to JIS R 5201 (Physical Testing Methods for Cement), mortars for artificial woods were prepared with the mix proportions given in Table 4 by using an ordinary mortar mixer, and their flows were adjusted to be constant at 170 5. Specimens 40x40x 160mm were molded, and then precured at 20°C and 80%R.H. for 24 hours. Immediately after precuring, the specimens were cured in autoclave in which a maximum temperature of 180°C was maintained under a pressure of IMPa for 3 hours. 

Figure 3 shows the carbon fiber content vs. water-(cement+silica fume) ratio of fresh artificial woods with flows of 170 5. As seen in the figure, the water requirement for the given consistency of the fresh artificial woods increases with an increase in the carbon fiber content regardless of the HPMC content and shirasu balloon content. The water requirement increases slightly with raising HPMC content from 0.4 to 0.8wt% irrespective of the carbon fiber content and shirasu balloon content. The inclusion of 14wt% shirasu balloon in the artificial woods causes an increase in the water requirement. 

Fig. 3 Carbon fiber content vs. water— (cement+silica fume) ratio of artificial woods.

Figure 5 represents the flexural load-deflection curves for artificial woods. In general, the maximum flexural load of the artificial woods tends to increase with an increase in carbon fiber content, and the deflection at the maximum flexural load increases with increasing shirasu balloon content and HPMC content. A drop in the post-maximum flexural load shows a more ductile behavior with raising HPMC content from 0.4 to 0.8wt%. From the above-mentioned results, the flexural deformation behavior of the artificial woods is markedly improved by using carbon fibers, HPMC and shirasu balloon. 

Fig. 5 Flexural load-deflection curves for artificial woods.

Figure 8 exhibits the carbon fiber content vs. compressive strength of artificial woods. The compressive strength of the artificial woods decreases with increasing in the carbon fiber content, HPMC content and shirasu balloon content. Such compressive strength decrease may be explained by increases in both water-(cement+silica fume) ratio and voids in the artificial woods according to the water-cement ratio theory and voids theory, and is expressed by the following empirical equation ... 

Fig. 9 Water- (cement+silica fume) ratio vs. compressive strength of artificial woods, where Fc the compressive strength of the artificial woods Vw the volume of water per unit volume of the artificial woods Va the volume of air per unit volume of the artificial woods Vb the volume of cement plus silica fume per unit volume of the artificial woods a and ft empirical constants...

The relationships between the compressive strength and water-cement ratio or voids of the artificial woods by both theories are represented in Figures 9 and 10. 

Figure 11 illustrates the carbon fiber content vs. hardness of artificial woods. The hardness of the artificial woods decreases with increases in the carbon fiber content, HPMC content and shirasu balloon content. 

In Table 5, the wood-processability of artificial woods is evaluated in comparison with natural wood. Like natural wood, all the artificial woods can be sawed easily. The artificial woods without carbon fibers are cracked when nails are driven into them. On the other hand, when the nails are applied in the artificial woods with the carbon fibers,... 

The nail withdrawal of the above artificial woods is over 25N/mm, which is about twice higher than that of Japanese ceder. 

The mix proportions of artificial woods which can be nailed are recommended in 4. From an economical viewpoint, the carbon fiber content in the mix proportions can be reduced to 2 vol%. The optimum mix proportions with a carbon fiber content of 2 vol% is given in Table 7. The bulk specific gravity, flexural and compressive strengths of an artificial wood with the optimum mix proportions are 0.9, 12.0MPa and 19.0MPa respectively. The artificial wood also has good wood-processability like natural wood. 

The bulk specific gravity of an artificial wood with the above optimum mix proportions is larger than that of calcium silicate-based wood-like materials, and their flexural and compressive strength are higher than those of the calcium silicate-based materials. 

In Japan, calcium silicate-SBR latex-glass fiber-based compos-itesi or portland cement-fly ash-SBR latex-carbon fiber-based compos-itesi l have recently received much attention as new artificial wood. Table 8.3 gives die comparison of the properties of the calcium silicate-SBR latex-glass fiber-based artificial wood with natural wood.1 1... 

Table 8.3 Comparison of Properties of Calcium Silicate-SBR Latex-Glass Fiber-Based Artificial Wood with Natural Wood. ( 1986, Cement and Concrete, reprinted with permission.)... 

The method of hydrolysis used in the CUT-method offers an efficient and economical way of processing plastic waste, both post-consumer municipal waste and industrial waste, contaminated with a cellulose component. The presence of cellulose gives a desired stiffness to the final product, as studies have shown [4,5]. Such plastics product can be used in several applications, such as artificial wood. 

In wood, cellulose is present with lignin, a natural phenolic polymer, described in Sect. 8.3. Kobayshi and coworkers [16] grafted phenolic resins onto cellulose to form an artificial wood polymer. 

Artificial wood replacer, multi-layer plywood, heavy-duty... 

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