Particle Sizes and Wood/Cement Ratio Effect on the Production of Vibro-compacted Composites

Castro, Vinicius; Parchen, Carlos; Iwakiri, Setsuo

doi:10.1590/2179-8087.021315

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Original Article, Wood Science and Technology • Floresta Ambient. 25 (4) • 2018 • https://doi.org/10.1590/2179-8087.021315 copy

Particle Sizes and Wood/Cement Ratio Effect on the Production of Vibro-compacted Composites

Authorship SCIMAGO INSTITUTIONS RANKINGS

ABSTRACT

The aim of this study was to evaluate the influence of particle size and the wood/cement ratio on the physical and mechanical properties of vibro-compacted wood-cement composites. The effects of three different particle sizes (diameter between 1.4-2.36 mm; 2.36-4 mm; and 4-9.56 mm) and wood:cement ratios of 1:2.75, 1:2 and 1:1.5 on wood-cement composites produced with the Amazonia species Swartzia recurva Poepp. and Portland cement type II-Z were analyzed. All evaluated properties were influenced by the particle size used in the mixture; however, the wood:cement ratio only affected the final density of the composite, internal bond and water absorption properties. Composites produced with particles that pass through a 2.36 mm screen but were retained with a 1.4 mm screen showed average values of modulus of rupture and higher modulus of elasticity than composites produced with bigger particles. The use of a 1:2.75 wood:cement ratio resulted in composites with higher density and dimensional stability than composites produced with a lower amount of cement.

Keywords:
Amazonian species; Swartzia recurva; wood-cement composites

Variation source	Degrees of freedom	Density	Water absorption
Variation source	Degrees of freedom	Mean square	2 hours		24 hours
Particle size (A)	2	0.040 ^ Significant at 1% (p < 0.01);	292.290 ^ Significant at 1% (p < 0.01);		289.777 ^ Significant at 1% (p < 0.01);
W/C ratio (B)	2	0.035 ^ Significant at 1% (p < 0.01);	5.8524^NS		20.766 ^* * Significant at 5% (0.01 > p < 0.05); NSNot significant at 5% (p > 0.05); IB = internal bonding; MOR = modulus of rupture; MOE = modulus of elasticity.
(AxB)	4	0.027 ^ Significant at 1% (p < 0.01);	45.819 ^ Significant at 1% (p < 0.01);		22.260 ^ Significant at 1% (p < 0.01);
Residue	39	0.003	2.015		2.531
Variation source	Degrees of freedom	Thickness Swelling	2 hours		24 hours
Variation source	Degrees of freedom	Mean square	2 hours		24 hours
Particle size (A)	2	0.106 ^* * Significant at 5% (0.01 > p < 0.05); NSNot significant at 5% (p > 0.05); IB = internal bonding; MOR = modulus of rupture; MOE = modulus of elasticity.		0.130 ^* * Significant at 5% (0.01 > p < 0.05); NSNot significant at 5% (p > 0.05); IB = internal bonding; MOR = modulus of rupture; MOE = modulus of elasticity.
W/C ratio (B)	2	0.008^NS		0.002^NS
(AxB)	4	0.010 ^ Significant at 1% (p < 0.01);		0.181 ^ Significant at 1% (p < 0.01);
Residue	39	0.022		0.027
Variation source	Degrees of freedom	IB	MOR		MOE
Variation source	Degrees of freedom	Mean square	MOR		MOE
Particle size (A)	2	0.150 ^ Significant at 1% (p < 0.01);	6.844 ^ Significant at 1% (p < 0.01);		7273992 ^ Significant at 1% (p < 0.01);
W/C ratio (B)	2	0.031 ^* * Significant at 5% (0.01 > p < 0.05); NSNot significant at 5% (p > 0.05); IB = internal bonding; MOR = modulus of rupture; MOE = modulus of elasticity.	0.010^NS		18869^NS
(AxB)	4	0.036 ^ Significant at 1% (p < 0.01);	0.128^NS		510991^NS
Residue	39	0.008	0.205		254740

	Wood/Cement ratio	Particle size
	Wood/Cement ratio	P1 (1.4-2.36mm)	P2 (2.36-4 mm)	P3 (4-9.52 mm)
Density (g cm^-3)	1:2.75	1.14^Aa (4.52)	1.09^ABa (4.42)	1.03^Ba (7.20)
	1:2.0	0.90^Ab (4.64)	0.91^Ab (5.13)	0.76^Bb (11.01)
	1:1.15	0.70^Bc (5.55)	0.83^Ab (3.13)	0.77^ABb (8.30)

Mechanical Properties	Wood/cement ratio	Particle size
Mechanical Properties	Wood/cement ratio	P1 (1.4-2.36mm)	P2 (2.36-4 mm)	P3 (4-9.52 mm)
Internal Bonding (MPa)	1:2.75	0.60 ^Aa (22.78)	0.55 ^ABa (17.85)	0.38 ^Ba (31.49)
	1:2.0	0.67 ^Aa (5.36)	0.64 ^Aa (14.98)	0.25 ^Ba (38.22)
	1:1.15	0.55 ^Aa (11.52)	0.51 ^Aa (22.12)	0.31 ^Ba (6.82)
MOR (MPa)	1:2.75	3.21 ^a (18.86)	1.73 ^bc (38.81)	1.53 ^bcd (37.03)
	1:2.0	2.19 ^b (19.67)	1.47 ^cd (26.97)	0.78 ^d (39.22)
	1:1.15	1.29 ^cd (21.41)	1.05 ^cd (25.54)	0.95 ^cd (40.61)
MOE (MPa)	1:2.75	2631 ^a (33.02)	930 ^bc (50.87)	709 ^c (67.38)
	1:2.0	1477 ^b (49.68)	813 ^bc (35.08)	248 ^c (43.97)
	1:1.15	658 ^c (21.09)	529 ^bc (44.16)	420 ^c (50.81)

Physical properties	Wood/cement ratio	Particle size
Physical properties	Wood/cement ratio	P1 (1.4-2.36mm)	P2 (2.36-4 mm)	P3 (4-9.52 mm)
Water absorption after 2 hours (%)	1:2.75	16.69 ^Ca (6.98)	14.19 ^Bb (9.86)	14.77 ^Bb (10.90)
	1:2.0	23.35 ^Ba (9.58)	23.46 ^Aa (14.14)	20.13 ^Aa (15.61)
	1:1.15	37.10 ^Aa (6.20)	22.55 ^Ab (7.41)	19.07 ^Ac (7.75)
Water absorption after 24 hours (%)	1:2.75	19.43 ^Ca (5.46)	16.62 ^Cb (8.46)	16.97 ^Bb (11.43)
	1:2.0	26.24 ^Ba (8.13)	23.44 ^Ba (4.06)	23.29 ^Aa (11.67)
	1:1.15	39.56 ^Aa (9.53)	26.22 ^Ab (5.36)	23.79 ^Ab (7.71)
Thickness swelling after 2 hours (%)	1:2.75	0.36 ^Aab (52.83)	0.25 ^ABa (50.15)	0.12 ^Bb (57.24)
	1:2.0	0.19 ^Aa (32.36)	0.20 ^Aa (53.38)	0.41 ^Aa (53.57)
	1:1.15	0.58 ^Aa (30.82)	0.21 ^Ba (70.80)	0.25 ^Ba (64.19)
Thickness swelling after 24 hours (%)	1:2.75	0.45 ^Ab (27.74)	0.34 ^ABa (36.15)	0.24 ^Bb (54.68)
	1:2.0	0.36 ^Ba (44.68)	0.43 ^ABa (45.14)	0.77 ^Aa (27.18)
	1:1.15	0.87 ^Aa (14.73)	0.29 ^Ba (37.17)	0.57 ^Ba (44.51)

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[1] *Vinicius CastroUniversidade Federal Rural do Semi-Árido – UFERSA, Av. Francisco Mota, 572, Bairro Costa e Silva, CEP 59625-900, Mossoró, RN, Brasil e-mail: vinicius.castro@ufersa.edu.br