Effects of Cissus populnea gum and rubber latex on physico-mechanical properties of cement-bonded rattan composites

In this study, the effects of partial replacement of ordinary Portland cement with natural polymers on selected physical and mechanical properties of cement-bonded rattan composites was investigated. Fibrous particles of Laccosperma secundiflorum rattan cane species were mixed with cement mortar at two levels, that is, 2.5 and 5.0%. For experimentation, Portland cement was partially replaced at four levels, first with Cissus populnea gum (0, 10, 20, and 30%) and then natural rubber latex (0, 2.5, 5.0, and 10%). All test specimens were prepared and tested in accordance with ISO 8335 standard. Results obtained showed that the moisture content, density, water absorption, thickness, and bending strength of the composites met the minimum standard requirements, except for samples produced using 30% C. populnea and 5% rattan fibre that fell short of the 9 N/mm2 minimum bending strength requirement. Partial replacement of cement with the two polymers resulted in a general increase in density. Analyses of variance showed that C. populnea gum had a significant effect (p<5%) on water absorption after 24 h of immersion, while natural rubber latex and C. populnea gum had significant effects on thickness swelling at 2 and 24 h of immersion, respectively. Also, C. populnea gum and rattan fibre contents had significant effects on the bending strength of the composites. It was concluded that Portland cement could be partially replaced with up to 20% of C. populnea gum or up to 2.5% of rubber latex in rattan-cement composite manufacture without adverse effects on the basic composite properties tested.   Key words: Rattan cane, Cissus populnea, rubber latex, cement, composites.