Effect Of Some Technological Factors On Some Properties Of Acacia Seyal (Talh) Wood-Cement Aggregates

Abstract

This study investigated the effect of some technological factors on the properties of Acacia seyal (talh) wood-cement aggregate in two separate experiments. Wood was obtained from six trees in Wad Albashir near Alhwata Forest circle in Gadarif State. Commercial cement and sand were used. The first experiment was factorial to study the effect of cement/wood ratio (3.5:1, 3:1, 2.5:1, and 2:1), calcium chloride content (1%, 2% and 3%) and pressure (No pressure and 4 N/mm2) on the properties of wood-cement aggregate. In the second experiment the effect of cement/wood/sand ratios (2:1:1, 2:1:1.5, 2:1:2, 3:1:1, 3:1:1.5 and 3:1:2) and pressure (5, 12.5 and 20 N/mm2) on the properties of wood-cement aggregate at mixed calcium chloride 3% was investigated using metallic mould, 144 block specimens (7×7×7 cm3) were produced. After 24 hours the blocks were removed from the molds and were then cured for 28 days. The wood-cement aggregate were tested for mechanical (compressive strength) and physical (water absorption and density) properties. Analysis of variance and Duncan Multiple Range test were carried out to study of the significance of the treatments and their interactions. The results indicate that the addition of increased amounts of CaCl2 increased the compressive strength and water absorption but did not affect density of talh wood-cement aggregate. Higher compressive strength, density, and lower water absorption were obtained with increasing cement-wood ratio when applying 4 N/mm2 pressure. The compressive strength and water absorption decreased when the pressure was increased over a value of 5 N/mm2. However, compressive strength and density were found to increase with increasing pressure when the sand was added to the mixture.