Table Of Content

Arktral Engine fami Waller found chat & pti ening 3 tickle nf water at le as 2 goats por inate ean be harem a rr to supply eneugk wate fr 5 head of eal Tit same amount ie Wor thn ficient furaserg homestead requiemeats “Tivonal wate tage Facts have proven ca be expen aad Sndeate, tn fo keaes eal tank wil st und 0 wood took Wl ‘eiesiate, Neithce can be tlle nnderpround. hich Ur exeail fot the peevenion of temperature rt and evaporation. Contes rte bet mute foe Ut baling Wolr forge tau AN vodeeround cencrets Tonk undegres ial danage and evaponsin, ‘iy envi cantribaton cote omer bilder homestead technotoge tng boot. the development of fowcoeealtoonetee ciate ‘Tee feunlativn flor of Ds ta const ofa single concrete slab. The root Bloch (DAS concrete folddglare pouted on expanded-tctal Tah, a itasited in accompanying drawings. An owner-bulder can {ahvicate th tan for about to cents 3 gallon of ater stored GAL TANK AUTHOR SHOWING WALL-BUILDING TECHNIQUE, {SING HORIZONTAL (SPIRAL) SLIDING FORIA % RRS EL ee SN Bee PONS CONCRETE CYLINDRICAL TANK [oyvecrey Ysidle A EEVOWING SLIP-FoeM To Spier PE ACr TRIN WALL MOAGLITHIG CONCRETE Wail 18s? Enea OAL TARE Ms ontural sprog or artesian wall cannot be developed. 2 heme. sender ban the shokse of igen ting, ing. ety OF dla it {he proved fr water Each mcthed, dara bits talow, ha is woe Manages, depeodiog macy upon the cus of penetration into De eat {rman Qne's Sale Celogea Survey officer ast i detecing ‘whe pe of et Fortin one ely ty encovner: jut sbi a eal Uescrnton of your propery "bre the wate ee ful clan to the yr sre, x wel en be adsasagrously dag. Depits ef from 10 to 40 feet are conunon. & ‘evtlac hole, about Sanches ste wl: Bing rund it ess ap (eave a. Except in eats of slid rook, dup wets requie some fom of Perit Hang, Ling preven gp the le ell oppor the pump pltfona and preventing ealrnce of cootaninated wri “tater, One unig and piseie metiod of digning deep wel (ap fo 200 Teeth has Been deloped by toe Wood Heath Orgniracna, The Ge 4S feet castinplace concrete. A ystem of prec eonertteojtinders a then lowered fp the wl nd sere teeter, Trey At 8 cahs008 (regth iy termed, the cabo drop lower, gue by wpperiee cr Teplice ing Tred Wells can abo be consumciad by land Jabot, wing 2 simple ‘arth anger, Tas mximan pracdeal depeh& $0 fst, leg 4 69 ch Alrite wee, ving with 3 get ivoes simply forcing aug odes ins The eo whe Luring the tok. When the pace etwec The aes {GH fest the auger secre rm the hole and emplied. A greater depth aained sets are added to de abe. A pally -ulpped pd iesecenay ax greater depths ae each, oo thatthe eX tad sue tnd ‘Se vera sa evan Gc ele wich ance il coos ‘atthe pipe. 11.2.5 Ferrocement water tanks Ferrocement water tanks are constructed tom cement-rich mortar, plas- tered onto chicken wire reinforced with weld mesh or standard small diam. eter reinforcement bar. Tanks can be built with basic skills using commonly available equipment in a relatively short period. These arc. all advantages over reinforced concrete and masonry tanks. Typically, they may be used to replace Oxfam tanks which can either be dismantled and stored for use elsewhere or used to develop water supplies rapidly in response 10 changing circumstances, Table 11.7 gives comparative dimensions, material requirements and Table 11.7 Dimen: ferrocement tanks ns, materials and construction time for Dimensions Tank volume, m? 1 Base diameter, m a a a 02 410 495 570 630 8. Mesh radius, m 136 191 233 270° 301 Inside radius, m 133° 188 20 267 «298 Wall height, m 180° 180 180 180 1.80 Materials Bage of cement, tank a a | roof 3 5 r a 12 Weld inesh, rolls of 2m x 45m, 2 3 4 > 6 mesh size 150 x 159mm, Chicken we: rolls of tm x 36m, 1 2 26 3 4 2mm mes chicken wire finding wre, 16 gauge, ko 8) 8 6 Clean sand, me 18 2503 4 5 Grave! (< 25min) m3 08 13 20 25 a 200 ire drume of water B 2 30 Construction time, days 8 9 6 mo Source: UNICEF, undated estimated consttuction time for tanks up to 50.000 litres (50m). Tanks over 40.000 litres (40m) require a central column to support the roof, Box 112 outlines the construction proceduze for lerraccment tanks based on a technique developed and successfully used in Kenya. A key aspect of the approach is that rigid shuttering is not required. Adapt the provedure for tank sizes up to 50000 litres (50m). ‘This particular design i not suitable for tanks above this size. All concréte and mortar mix ratios are by volume, Use well graded clean sand Box 11.2 Construction procedure for a 20m? ferrocement tank pay 1 Reterto Figure 11.10. fe) Exeavate a shallow circular level foundation, 100mm deep and 2.05m radius, Prepare weld mesh of 2.05m. ‘adius for floor reinforcement. © Prepare the wall reinforcement by forming 9 12:30m length of weld qesh into an upright cylinder, with overlap, (o give a diametcr of 3.82m. Bend the bottom wires of the mesh at. Bend the top wires inwards at an angle of 45°, @. Prepare the roof reinforcement by forming cut sections of weld mesh, into » 190m racing circle with a 49mm high support at the centre. Day? ; Position any outlet or dain pipe jin a aarrow tench fa the earth foun- dijon under the floor and protrud- ing through it as shown in Figure, A110. Backfill the trench ith concrete. © Cast the concrete floor by laying a SOmm thick concrete hese (1:24 mix) in the prepared foundation. Place the Boor reinforcement on the concrete, Cast another tayer of concrete (1:2:4 mbx) without delay on (op of the reinforcement, working fom the centre up to 400mm from the perimeter. ¢ Position the wall reinforcement ‘without disturbing the reinforcement heady concreted. Pull into shape and bind. Place the remaining con- rete and wamp firmly around the ‘all, Cover the concrete. © Continue preparation of the roof tcinforcement by cutting and placing hicken wire on the prepared roof weld mesh Days # Keep the concrete wet thgh- ute day, * Prepare the wall for plastering: = Tighily wrap the weld mesh from he top to the floor with chicken wire. Gwertap the ends. Tie the chicken wire to the weld mesh in several places, = Tighily wrap 16 gauge binding wire around the wall as follows (see Figure 111) 4 ‘ames around the top weld mesh every 100mm for the top éOOmm; every 8Omm for the next 600m, every SOmm for the next 700mm; 4 times around the bottom and tie to the mesh. = Tie sacking (0 the outside wall Fimly tie two ladders together to straddle the wall. Inspest the tank and pull it into a cylindrical shape using staked ropes or binding wire (Figure 1119), # If it is windy, postpone further vwork until the wind calms. # Plaster the inside wall. Add water toa cement/sand mortar (1:3 mix) un- (1 Lis just workable, The consistency of the mortar is erical. Experiment om a tial scction first and note the water required for a successful mix Start plastering at the bottom and push the plaster into the wire walls from the inside of the tank. Leave a space in the weld mesh for an overflow and amy inlet pipe. © Protect the walls with plastic sheeting. Splash the floor with water. Tay © Remove the sheeting and wet the floor and walls. Keep the concrete wet throughout the day. * Plaster a second layer of slightly welter mortar on the inside wall. Re- move the sacking and plaster a thin layet of mortar (< 10mm thick) over The entside: wall (Continued over) Box 112 (continued) © Cover both the inside and outside walls with plastic sheeting © Wet the floor. Days @ Remove the shecting and wet the oor and walls. Keep the concrete wer thronghoat the day. © Cat the top overflow section of the weld mesh, bend outwards at 90° and wrap in chicken wire, Sup- port and plaster the top of the overflow, ‘© Smooth a 10mm thick layer of plaster on the outside wall and cover. © Prepare the roof for plastering by sewing sacking to the underside of the roof mesh. This may be sup- ported by poles as in a traditional ut. Day 6 ‘© Wer the floor and walls ® Complete the inside wall: Plaster ‘and snioath the iaside wall wo a total ‘wall thickness of 50mm, Make a mix ‘of equal parts of cement and water. ‘Smooth evenly onto the new plasier to within 150mm of the oor, © Complete the floor: Plaster the floor with cement mortac (1:3 mix) to create a slope towards the outlet, Finish the floor and remaining 150mm of wall with a mix of equal parts of cement and water, and cover. Day? © Position and plaster the roof: Phe the roof reinforcement on the tank wall and hind it to the vertical wall wires. Cut an access hole (450m 450mm) fa the roof wires. Support the roof on poles. Plaster the roof with cement mortar (1:3 mix) and cover, (See Figure 11.13). © Cast an access cover in a shallow pit, reinforcing with weld mesh aud chicken wire. Cure for a week. Day 8 © Remove the roof sheeting and wet the roof, floor and walls, © Plaster the roof {10mm thick) and cover with plastic sheeting, © The tank should now be strong ‘enough to hold water. Days © Remove the roof poles and sack: ing, Plaster the underside of the roof, Plaster a piece of galvanized gauze over the overtiow. Afterwards Keep the tank covered in plastic sheet ing andor fil it with water to cure for at least two weeks,