Dept. of Soil & Water Engineering, Faculty of Agril. Engineering, BCKV, Mohanpur, Nadia.
The dice for making precast concrete half round section was designed, fabricated and tested for its performances. Costly steel reinformcements and stone chips were replaced by bamboo sticks and blust furnace slag chips, respectively. The precast sections were of 50 cm and 36.4 cm diameters, 152.4 cm length, 2.54 cm thickness and the bamboo reinforcement spacing of 10 cm x 10 cm or 15 cm x 15 cm and 5 mm x 7 mm or 7 mm x 10 mm cross section of the bamboo sticks. The precast bamboo-reinforced concrete slabs of breadths 40 cm, 30 cm and 20 cm and the thickness 5 cm, 5 cm or 4 cm and 4 cm or 3 cm, respectively were used in different combinations for making different capacity and geometric shape channels.
The performances of the channels operated in tubewell commands were tested in respect to controlling seepage losses and economy of use. The average seepage through the half rounds, trapezoidals and triangular channels were 10.86, 8.55 and 15.76 cm3/cm2 day which reduced the water losses by 91.68, 93.45 and 87.93%, respectively. The construction costs of the channels reduced by 2.21 to 3.12 times compared to the costs of comparable size brick lined channels.
