Abstract:
There are enormous Agricultural Residues (AR) such as Coir Dust (CD), Coir Fibre
(CF), and cashew nut shells, which are sources of environmental pollution in Nigeria.
However, these residues can be deployed in Cement Composite (CC) production as
alternative building material. Ce0ment composites are however susceptible to
unwarranted dimensional instability which can be curtailed by the incorporation of
polymeric substances such as Cashew Nut Shell Liquid (CNSL). Literature on
properties of CCs produced from AR with the incorporation of CNSL is sparse.
Therefore, this study was designed to investigate the properties of CCs made from CD,
CF and CNSL.
Cashew nuts were collected from a local site at Ogbomoso, milled to about 3.35 mm
sizes. The CNSL was chemically extracted from the milled particles using IS methods,
while coconut husk were reduced to obtain CF and CD using IS and ASTM methods.
Cement composites were produced at four levels of CF (5.0, 7.5, 10.0 and 15.0%), four
levels of CD (5.0, 7.5, 10.0 and 15.0%) and four levels of CNSL (2.5, 5.0 7.5, 10.0%)
based on cement weight at 2:1 cement: water ratio following the preliminary tests. A
CC board machine was developed and tested for the production of CC boards using
Schaum’s Machine Design methods. The physical and sorption properties such as
density, Water Absorption (WA), Thickness Swelling (TS) were determined using
ASTM standards. The mechanical properties such as, Compressive Strength (CS),
Modulus of Rupture (MOR), Modulus of Elasticity (MOE), and Impact Strength (IS)
were evaluated using ASTM standards. Data were analysed using ANOVA at 0.05.
A 5.5 kW electrically operated CC board machine developed has an amplitude of 2
mm; frequency of 350 rpm; CC size of and capacity of 360 CCs per
hour. The densities, WA and TS of CF composites without CNSL ranged from
1350.00 to 1690.00 kg/m3, 33.1 to 69.5% and 1.1 to 3.2%, respectively. Their
respective CS, MOR, MOE and IS in Nmm-2 were 5.72–11.43, 4.37–5.34, 813.24–
1428.85, and 1.19–4.35. The densities, WA and TS of CD composite without CNSL
ranged 1030.00–1480.00 kg/m3, 27.5– 69.1% and 1.9–5.1%, respectively. Their
respective CS, MOR, MOE and IS in Nmm-2 were 0.9–11.16, 1.6–3.79, 330.64–
1916.31 and 0.86 – 2.18. However, composites with CNSL had densities, WA and TS
that ranged from 1310.00 to 1510.00 kg/m3, 7.1 to 17.8% and 0.9 to 2.7%,
respectively. Their respective CS, MOR, MOE and IS in Nmm-2 were 2.18–7.25, 1.71–
2.36, 306.01 - 1054.09 and 1.09 to 2.57. The incorporation of CNSL significantly
affected the physical, sorption and mechanical properties of the manufactured CCs and
can be utilised in both indoor and outdoor applications. There was significant
differences in the properties of CC produced from CF, CD and those treated with
CNSL.
Cashew nut shell liquid enhanced the properties and performance of cement bonded
composites made from coconut coir fibre and dust for indoor and outdoor applications.
