Stil Faiba insait long Tanel Sotkrit: Ribaun, Eneji Absorpsen na Nosel Distens

Stori

Jun 15, 2014

Ol i wokim 'shotcrete' bilong kisim pawa, na i no bilong strongim presa. Dispela wanpela samting i soim olsem wok bilong tanel i yusim sotpela 'fiber', bikpela 'dosage' na ol 'glued bundles'.

Samting Shotcrete I Nidim Em Eneji Absopsen, I No Strong

Praimeri tanel sapot i bihainim narapela tingting long ol straksa bilong graun. Taim graun i senis, 'spray layer' i mas senis wantaim em na i no ken bruk wantu tasol, olsem na 'design parameter' em i hamas eneji dispela 'layer' i kisim long wanpela 'deflection'. Yurop praktis i save makim strong bilong eneji o eneji absopsen wantaim tes long EN 14488-3; Not Amerika praktis i save wok wantaim 'flexural toughness'. Dispela em i hap we 'steel fiber' i kisim ples bilong en: 'plain shotcrete' i save lusim strong bilong en taim em i bruk, na wanpela 'fiber-reinforced layer' i save holim bikpela hap bilong strong bilong en bihain long em i bruk, we i save baim taim long rausim na putim sapot.

Ribaun: Longpela Faiba i Ribaun Moa

Rebound em i hait kos senta bilong shotcrete. Ol samting we i no pas i save pundaun i go bek, na 'plein shotcrete' i save pundaun 15% i go inap 25%; 'fiber' i save mekim em i go antap liklik bikos ol 'fiber' i save kalap long 'nozzle'. Longpela em i nambawan samting: 30 mm 'fiber' i save go antap moa long 20 mm. Long dispela as wok bilong tanel i no save yusim 50 o 60 mm 'fiber', maski ol longpela 'fiber' i save strongim gut. Praktikel kompromis em 20 i go long 30 mm wantaim wanpela diamita klostu long 0.55 mm, olsem na 'fiber' i bihainim win i go insait long graun.

20-30 mm em i wok longpela bilong Wet Miks

Wet miks i save pasim longpela bilong ol 'fiber' moa long drai miks. Ol i save pamim ol wetpela samting i go insait long wanpela lain, olsem na ol longpela 'fiber' i save kamap long ol 'bend'; long 'nozzle' em i mas i go nabaut long rot bilong win we i pas. 20 i go long 30 mm i stret long planti wet-miks robot, wantaim 0.5 i go long 0.75 mm diamita, na i givim wanpela 'aspect ratio' bilong 40 i go long 55. Sapos 'specificed energy absorption' i antap, stretpela bekim em i moa 'dosage', i no longpela 'fiber': apim 30 i go long 45 kg/m3 i save apim eneji absorpsen long 40 pesen ova long tupela o 'rebound' tasol tripela pesen poin.

25-45 kg/m3 na ol klas bilong disain

Dos bilong 'tunnel shotcrete' i save pundaun namel long 25 na 45 kg/m3. Ol 25 i go inap 30 mak i karamapim ol 'levelling' leia bihain long gutpela ston; 35 i go long 45 i karamapim ol 'fault zone', ol 'shallow cover' na ol bikpela 'deformation sections'. Antap long 45 kg/m3 wok i save go daun tru na man i wok long en i save putim wara, na dispela i save katim strong bilong en. Em i as tru na planti sait i save ripotim inap marasin tasol strong bilong en i liklik. Ol i mas putim bikpela marasin wantaim ol marasin we i save daunim wara na senisim 'viscosity', na sekim 'slump' na 'cohesion' pastaim long ol i spreim.

Balling: Failure Mode Shotcrete i save pret long en

Wanpela 'fiber ball' insait long 'layer' em i nogut moa long i no gat wok: em i kamapim wanpela 'void' na wanpela 'weak plane' we i kamap olsem wanpela 'crack starter' taim graun i muv. Balling i gat tripela as bilong en: putim liklik hap 'fiber' i go insait long miksa, taim bilong miksim i no inap, na bikpela 'aspect ratio'. Ol i mas kapsaitim o putim ol 'fiber' long wanpela masin bilong givim marasin, na miksim inap 30 i go inap 60 seken antap long simen tasol. Ol 'glued fiber bundles' i save daunim tru hevi: ol i save putim 'row' olsem wanpela yunit, 'water-soluble glue' i save kapsait, na olgeta wan wan 'fiber' i save bruk wanwan, na dispela i save mekim 'uniformity' i kamap gutpela moa long 40% winim ol 'loose fiber'. Long dispela as ol 'wet-mix' robot i save laikim ol 'glued bundles'.

Wok wantaim Mesh na Steel Arches

Ol 'steel fiber' i no save senisim ol 'steel arches'. Long graun klas IV na V, 'arch' i save givim 'global stiffness' na 'fiber' i save givim 'toughness' long 'layer' yet; ol i save mekim ol narapela narapela wok. Tasol, 'fiber' inap long senisim 'mesh' insait long 'layer', na rausim wok bilong hangamap, pasim na putim ol samting na rausim ol spes i stap baksait long 'mesh'. Kombinesen we ol i save bungim long dispela hap em i 'steel arch' na 'fiber-reinforced shotcrete' we i no gat 'mesh'. Em i save givim gutpela pe long senisim ol 'profile', we 'mesh' i no inap bihainim wanpela ston we i no stret tasol 'fiber concrete' inap.

Drai Miks na Wet Miks: Ples we ol 'Fiber Balls' i save kamap

'Rebound' em i nambawan samting we i save soim kos bilong 'tunnel shotcrete', na namba wan samting bilong en i no 'fiber' tasol em i 'process'. Long wet miks ol samting i bruk pinis taim ol i pamim na ol i putim 'accelerator' long 'nozzle', olsem na planti ol 'lumps' em ol giaman bal we ol i holim wantaim long 'paste' na ol i bruk taim ol i flai. Drai miks em i narapela kain: ol i putim wara long 'nozzle', 'hydration' i no wankain, na 'fiber' i bungim i kamap ol 'true balls' long wol bilong hos na long ol 'bend', na wanpela bilong ol i kamap long 'crown' i lusim wanpela spes. Yu ken makim proses long seksen na tiknes. Long wanpela 'permanent lining' bilong 20 i go inap 30 mm long wanwan taim, 'wet mix' i save givim gutpela 'thickness uniformity'; long sapot bilong sotpela taim, imejensi ripea na senis bilong seksen wantu tasol, 'dry mix' i save senis gut na i save kisim bikpela 'rebound'. Wet miks i gat tripela samting. Longpela bilong 'fiber' i no ken winim wanpela hap bilong hul bilong hos, olsem na 50 mm 'fiber' insait long 65 mm hos bai pasim. 'Accelerator dosage' i save bihainim 'seepage' long pes bilong ston, planti tumas i save mekim wanpela 'brittle layer' na liklik tumas i save larim em i pundaun, na long tupela rot 'fiber' i stop long wok. Putim 'nozzle' 1 i go 1.5 mita long pes na spreim stret; 'angled spray' i save stretim ol 'fiber' wantaim 'air stream' na kamapim wanpela 'anisotropic weak plane'. Ol i skelim 'energy absorption' long 'panel test' insait long EN 14488-3, na 'acceptance' em i eria aninit long 'load-deflection curve' na i no wanpela 'peak value' tasol, we kontrak i mas tokaut klia long en.

Tripela Akseptens Sekim long Sait

Pasin bilong kisim 'shotcrete fiber' i lukluk long tripela samting: 'dose', 'distribution uniformity' na 'flexural toughness'. Ol i save sekim mak bilong marasin long rot bilong wasim wanpela 'site sample' na skelim, insait long 'plus' o 'minus' 10%; wankain pasin long rot bilong putim 'coring' na sekim pes we ol i katim, we i mas soim olsem 'fiber' i spred wankain na i no gat ol 'fiber-free patches'; strong bilong en long 'beam test' we i stap insait long disain. Long model, diamita, longpela na rekomended dosis, tanel na maining seksen bilong 'steel fiber' prodak pes i listim ol wankain gret na dosis, we yu ken putim stret olsem wanpela teknikel aneks.