Acacia
Acacia
Acacia nilotica is truly a multipurpose tree. Its timber is valued by rural folks, its leaves and pod are used as fodder and as tanning material and its gum has a number of uses, including as a substitute for gum arabic. It tolerates extremes of temperature and moisture and can survive both drought and flooded conditions. It is commonly grown in homestead plantation because virtually every part of the tree can be used by the farmer.The sap wood of babul is sharply demarcated from the heart wood and is white or whitish, turning pale yellow on exposure. The heart wood is pinkish brown and turns reddish brown on exposure, often with dark streaks. The grain is fine and straight or slightly twisted.
Babul is a moderate-sized tree with a spreading crown, and height which can reach from 15 m to 25 m and a girth of 2.4 to 3.0 m. It is almost an evergreen tree with a short, thick and cylindrical trunk. The tree has a very clear bole up to a hight of 5 to 6.5 m. In difficult sites, the tree seldom grows more than 10 m.The clean bole in such cases is not more than 3-4 m.There are several varities of babul; the telia and kauria varieties are the best-known. The wood of the telia variety is considered to be of the highest quality.
The wood is very heavy, strong, very tough and extremely hard. It is much stronger than teak and has good shock-absorbing qualities. The average weight is about 785 kg/m3 at 12 percent moisturecontent. It is somewhat coarse-textured and has inter-locked grains. The wood is dull and somewhat rough without any characteristic odour or taste
  • Physical and Mechanical Properties
  • Density, Air-dry 768kg/m3
  • Shrinkage, green to oven-dry Radial Tangential2.76.7
  • Modulus of rupture (MOR) 76 MPa
  • Modulus of elasticity (MOE) 96 MPa
  • Compression parallel to grain 35 MPa
Seasoning
Babul seasons well both by air-drying and by kiln seasoning. It can be air-dried in one year.
Workability
It is an easy wood to convert and resaw when green, but it becomes harder and tougher when seasoned. It works well by hand machines and finishes to a good surface. Its working quality of worked surface and ease of working, is 84compared to 100 for teak.
Durability
The heartwood is fairly durable, though less so than teak. The sapwood is not very durable as it is susceptible to insect attack.