ez Why
ane
sedimentary sacks nat used for
Iconstruction?
Answers
Answer:
Explanation: 1. In addition to the pond soil itself, you might use a range of different materials for the fish farm, for example for foundations, water supply and water control devices. The choice ranges from locally available materials such as bamboo and wood to bricks, cement blocks, concrete and plastics (for pipes), for which you may have to go to specialized dealers.
Selecting materials
2. The choice of construction materials essentially depends on their suitability, their local availability and the amount of money you are prepared to invest.
3. If you are a beginner fish farmer and your farm is very small, it is best to use simple structures and not to spend too much on materials. As you gain experience and wish to expand, your investments may increase, and more permanent, better structures may be built.
4. It you plan to build a large fish farm, you should select the most suitable permanent structures from the start.
Weight per unit volume of materials
5. The materials generally have to be transported to the construction site. To plan this properly and help estimate the cost of transport and handling, use Table 5, which gives the weight per unit volume (kg/m3) of common basic materials.
TABLE 5
Specific mass of various construction materials
Material
Specific mass (kg/m3)
Bamboo
Wood
300-500
500-1100
Bricks
Cement blocks
Crushed bricks (for foundation)
1500-1800
1500-2000
950-1250
Building stone, dry loose
Earth, dry loose
Earth, moist rammed
Gravel
Sand, dry to wet
Cement
Clay, dry compacted
1400-1600
1300-1500
1750-1850
1300-1500
1450-2000
1250-1400
1400-1500
Cement concrete
Cement mortar
Reinforced concrete (5% steel)
2100-2400
2000-2200
2600-2700
Reinforcement steel bars
(see also Chart in Section 3.5)
Diameter (mm)
Weight (kg/m)
6
0.222
8
0.395
10
0.617
12
0.888
Note: for granular materials, these figures are bulk densities, i.e. including the pore space between the particles. The actual density is higher
3.1 Bamboo and wood
Special characteristics of bamboo
1. Bamboo is a wooden perennial grass that lives for an indefinite number of years. It grows fast, occurring naturally throughout the world, but particularly in tropical Asia. The Chinese bamboo or "yellow bamboo" (Bambusa vulgaris) has been introduced in several African and Latin American countries where it is now found widely at altitudes between sea level and 1500 m.
2. Lengths of bamboo wood, or culms, are cylindrical and divided at intervals by raised nodes from which the branches grow. At each node there is a partition wall that completely separates the cavity of one internode from the next. Culms are covered outside and inside by hard waxy cuticles that offer considerable resistance to the absorption of water, particularly when properly dried out. Bamboo is strongest at the age of three to four years. Because of its versatile characteristics, bamboo has numerous uses, for example as a construction material, for water pipes and for erosion control.