BILAT LEI

Kum 1957 daih tawh khan Rev. Zairema’n ‘Bilat lei (cement) hnathawh dan’ tih lehkhabu a ziak a, a ziah chhan chu Zoram dung leh vanga sawrkarin tuikhur a siamah phui lo a tam vang nia sawi a ni. Tun dinhmunah erawh chuan concrete phui ṭha lo hi la awm mah se, kan harsatna ber zawk chu cement concrete-in chhiatna laka kan himna tura chakna a neih zat tur a nei pha lo ṭhin hi a ni. Cement concrete hian a tlem berah milimetre (mm) khat bialah (chhunhan tiat vel) kg 2 rihna a la zo tur a ni a, he rihna hi a lâk zawh loh chuan lirnghing lakah a him lo a ni. Hemi atan hian balu, rora leh tui inchawhpawlh te, bilât lei hmanga concrete chakna tihpun theih dan tarlan kan tum dawn a ni.

Rora: Lung fang len zawng inchawhpawlh dik (well gradation) hi balu leh roar-ah kan hman chuan concrete chakna kan tisang sawt thei. Tun dinhmunah balu leh rora bikah hian len zawng inang khat (single size) kan hmang nasa hle a, hemi avang hian concrete-ah kar awl a lo tam phah a, chu chuan concrete mukna a tihhniam avangin concrete-in chakna a lo neih tlem phah ṭhin. Entir nan, marble len zawng inang hi darthlalang no-ah han dah ta ila, kar âwl (gap) tam tak kan hmu ang; chutih laiinm, marble lenzawng inang lo zung han dah leh ta ila, kar âwl a lo tlem sawt ang. A lema kan hmuh ang hian, kar âwl a zim phawt chuan a muk tihna a ni a, thil muk reng reng hian rihna a la sang thei tih kan hre ṭheuh awm e.

Kan quarry aṭanga rora kan neih len zawng, mm 20 leh mm 10 te hi 70: 30 ratio hmanga kan chawhpawlh hian, lung fang te rualkhai taka an inchawhpawlh leh an inkamki ṭhat avangin concrete chakna a san phah ṭhin.

Balu: Aizawla in sak nan balu kan hman tlangpui Bagha leh Langkaih balute hi a sîn lam mah mah an nih avangin concrete chakna sang zawk mamawhna heng–lei (bridge) leh cement concrete road-ah te hi chuan duhthusam an ni lo. Balute hi an sîn zawng tehkhawnga tehin zone I, II, III-a an awm theih nan balu sînte chu balu hraw zawk nen chawhpawlh a ngai ṭhin. Balu hi an len dan azirin zone 4-ah ṭhen an ni a, balu zone I, II, III te hi in sak nan hman tlak an nih laiin, zone IV erawh hi chu an sîn em avangin a hman tlak ngei dawn em tih fiah phawt loh chuan chuan hman loh tur a ni. Langkaih leh Bagha balute hi Tlawng balu fai hraw lam deuhte nen 50:50 ratio-a chawhpawlh hian zone II-ah an awm thei a ni.

Balua lei (silt) a tam hian pawi a khawih thui thei hle. Silt te hian rora leh balu te an tuam a, cement-in balu leh rora a châr dawn hian silt hi an inchârna tur lo dâltu niin, cement-in balu leh rora a char khawm ṭhat theih loh phah ṭhin. Amaherawhchu, Tlawng balu hi a fai ṭhat phawt chuan a hman tlak em em. Tin, balu fai hraw kan hmu remchang lo a nih pawhin stone chip-te nena chawhpawlh hian gradation a tidik a, concrete chakna a tam phah ṭhin.

Tui: Concrete-a tui pawlh tlem hian concrete chakna hi 10-15% laiin a tisang thei a, tui kan pawlh hian a hul mah mah em aw tih tur hi a tawk chiah zawk ṭhin. Concrete chawh sa hi kan kuttumin han hûm ila, darh huk loa a inhlâwm theih chuan a tui mamawh zat chiah kan pawlh tihna a ni. Mahse, a hul hian chawh kâwi a hahthlak ṭhin avangin chawh tinuamtu chemical plasticizer hrang hrang–Sika, Frostroc leh a dangte pawlh ṭhin tur a ni. Kan sawi takte khi kan tih theih chuan concrete ṭhat loh avanga sak sa chhut chhiat ngai leh ṭhin hi kan pumpelh thei ang.

In sak dan ruahmanna (building design philosophy)-ah chuan kan inte hi lirnghingin thawklehkhatah tichhe rup lo tura duan a ni. Beam leh slab te an khi hmasa ang a, in chim hma ngeiin kan insaseng hman tura ngaih kan ni. Chutihlaiin, mithiamte’n lirnghing laka kan himna tawk tur concrete chakna ngai zat an chhût chhuah hi kan neih phak loh chuan kan chim rual huk ang a, inchhan chhuak tur awm ṭha lovin kan phek buai thei a ni. Natnate pawh hi mihringah a lo thlen hian mihring taksaa râl veng khawl chak leh chak loh azirin kan chhiatpuiin kan chhiatpui lo ṭhin a nih hi. Chutiang bawkin, kan in sakte pawh hian chhiatna lo dâwl zo tur chuan tichhetu thahrui lo chhat a, lo do let thei ruhrel ṭha kan siam a ngai a ni.

- H Laldintluanga, MZU, 7005899512