PEER-REVIEWED ARTICLE bioresources.com Ayrilmis et al. (2017). “Palm & cement composite,” BioResources 12(2), 3583-3600. 3583 Technological Properties of Cement-Bonded Composite Board Produced with the Main Veins of Oil Palm (Elaeis guineensis) Particles Nadir Ayrilmis, a Seyyed Khalil Hosseinihashemi, b, * Marziyeh Karimi, b Abolfazl Kargarfard, c Alperen Kaymakci, d and Homayoun Soleimani Ashtiani b The effects of main veins of palm (Elaeis guineensis) particles and the amount of CaCl2 on the mechanical and physical properties of cement- bonded composite boards (CBCBs) were investigated in this study. Homogenous CBCBs were produced with main veins palm particles content at three levels of 10, 15, or 20 wt.% and CaCl2 at three levels of 0, 3, or 6 wt.%. Other manufacturing parameters consisting of pressure and time for cold-press, material dry weight, and panel dimensions were kept constant. The flexural strength, flexural modulus, internal bonding, water absorption, thickness swelling, and the thickness of CBCBs after 2 and 24 h immersion in distilled water were determined. The results indicated that increased amount of lignocellulosic particles caused a decrease in the mechanical properties of the CBCBs. The increase in calcium chloride up to 6 wt.% improved mechanical properties of the CBCBs. The panels manufactured with 10 wt.% E. guineensis particles and 6 wt.% CaCl2 showed the most favorable physical and mechanical properties. Keywords: Cement-bonded composite board; Palm; Calcium chloride; Physical and mechanical properties Contact information: a: Department of Wood Mechanics and Technology, Forestry Faculty, Istanbul University, Bahcekoy, Sariyer, 34473, Istanbul, Turkey; b: Department of Wood Science and Paper Technology, Karaj Branch, Islamic Azad University, Karaj, Iran; c: Department of Wood and Paper Science, Research Institute of Forests and Rangelands, Agricultural Research Education and Extension Organization (AREEO), Tehran, Iran; d: Kastamonu University, Forestry Faculty, Department of Wood Mechanics and Technology, 37000, Kastamonu, Turkey; *Corresponding author: hashemi@kiau.ac.ir INTRODUCTION Agricultural wastes such as sugarcane bagasse, arhar stalks, date palm midrib, flax, babacu shell, vegetable fibers, vine stalks, wheat straw, and rice husk ash have been used as filler in the manufacture of wood-cement boards (Aggarwal 1995; Almeida et al. 2002; Ntalos and Grigoriou 2002; Papadopoulos and Hague 2003; Roma et al. 2008; Nemli et al. 2009; Nasser et al. 2011; Nasser 2012; Bahurudeen et al. 2015). These raw materials have been used as substitutes for mineral aggregates and solid woods from natural forests (Savastano et al. 2000; Karade et al. 2001; Almeida et al. 2002; Semple et al. 2002; Li et al. 2004; Abdel-Kader and Darweesh 2010). In order to remove chemical substances, pre-treatment of lignocellulosic particles with cold or hot water as well as the addition of CaCl2 or MgCl2 is required (Rahim et al. 1995; Olorunnisola 2008; Ashori et al. 2011; Zhou and Li 2012). Furthermore, there are many factors that affect the properties of cement-bonded composite boards (CBCBs), such as the effect of exothermic behavior during the hydration process (Hachmi et al. 1990; Semple et al. 2002; Okino et al. 2004). Generally, lowering the amount of inhibitory extractives diffuse into the cement paste is beneficial for the wood-cement compatibility.