Yog tias koj tau sawv ob peb yards ntawm lub tshuab sib tov suab nrov nrov thaum tav su lub caij ntuj sov, koj twb paub cov lus teb yog " kub dua li koj xav ." Feem ntau lub xeev DOT specs xav kom muaj qhov kub sib tov ntawm 275 ° F thiab 325 ° F (135 ° C–163 ° C) ntawm qhov chaw thauj khoom. Hauv lus Askiv yooj yim, qhov ntawd kub txaus kom kib ib daim nqaij nyuj nruab nrab-tsis tshua muaj hauv qab 30 vib nas this. Thiab yog, koj nyeem qhov ntawd yog lawm—275 °F yog qhov tsawg kawg nkaus , tsis yog qhov siab tshaj plaws.
Cov asphalt cement (cov kua nplaum dub uas tuav cov pob zeb ua ke) muaj qhov sib xws ntawm cov kua qaub txias ntawm chav tsev kub. Yuav kom npog txhua lub pob zeb thiab cov xuab zeb, cov khoom sib txuas yuav tsum yog kua. Kev cua sov txo qhov viscosity exponentially: rau txhua 25 ° F nce, cov khoom sib txuas yuav ua li ob npaug ntawm cov kua . Yog li ntawd, cov nroj tsuag thawb lub hnab kom lav tag nrho cov txheej, tshwj xeeb tshaj yog rau cov pob zeb uas muaj qhov dej uas haus cov kua. Cov lus hauv qab: qhov kub dua qhov sib tov, qhov zoo dua qhov txheej, thiab qhov muaj zog dua qhov kev taug kev.
Thaum lub tsheb thauj khoom tawm ntawm lub rooj vag, qhov cua sov poob pib. Kev tshawb fawb los ntawm National Asphalt Pavement Association (NAPA) qhia txog kev poob ntawm 5–7 °F ib mais ntawm 60 °F ib puag ncig hnub. Ntxiv cua, kev thauj mus los ntev dua, lossis kev paving hmo ntuj thiab qhov delta dav dua. Yog tias daim lev tuaj txog hauv qab kwv yees li240 °F (116 °C) , kev sib zog ua rau muaj kev nyuaj siab. Cov log tsheb tsis tuaj yeem kaw cov qhov cua tsis tau lawm, thiab qhov sib tov ua rau tawg, ua rau tawg thiab sib tsoo ua ntej lub sijhawm. Txhais lus : koj qhov chaw nres tsheb tshiab tuaj yeem zoo li kaum xyoo hauv rau lub hlis.
Tsis txhob muab cov khoom tso ua ntau txheej . Muab ib nrab ntawm cov khoom tso pov tseg, tos kaum feeb, tom qab ntawd muab cov seem tso pov tseg yuav ua rau lub plawv txias uas tsis muaj lub log twg kho tau.
Cov nroj tsuag niaj hnub nim no muaj cov koob yees duab infrared nyob saum lub thawv thauj khoom. Cov khoom siv no ntsuas tag nrho qhov chaw ntawm txhua lub tsheb thauj khoom hauv lub sijhawm tiag tiag, cim cov khoom thauj uas poob qis dua qhov teev tseg. Cov ntaub ntawv yuav xa mus rau cov dashboards huab, yog li cov neeg tshuaj xyuas DOT thiab cov neeg saib xyuas kev paving tuaj yeem tsis lees txais cov khoom txias ua ntej nws mus txog txoj kev.
Muaj tseeb tiag. Thaum sawv ntxov caij nplooj ntoos hlav uas kub txog 40 °F, tus neeg ua haujlwm cog qoob loo yuav tsoo lub hom phiaj mus rau qhov chaw uas lawv xav tau.330 °F los them rau cov kev thauj mus los txias. Ntawm qhov tod tes, thaum lub Xya Hli 95 ° F tav su, qhov chaw teeb tsa yuav rov qab mus rau290 °F kom tiv thaiv cov ntawv nplaum kom tsis txhob ntws tawm. Xav txog nws zoo li ua kom koj lub qhov cub sov ua ntej: koj tig lub hau raws li yam uas tab tom ci sab nraum zoov.
Muaj tseeb tiag. Thawb qhov sib xyaw dhau mus350 °F (177 °C) thiab cov asphalt cement pib oxidizing sai sai. Cov binder hloov mus ua brittle, thiab cov pa luam yeeb xiav uas koj pom yog cov roj teeb uas kub hnyiab . Qhov no tsis yog tsuas yog ua rau muaj teeb meem ib puag ncig xwb, nws tseem ua rau txoj kev tsis muaj zog los ntawm thermal cracking thawj lub caij ntuj no. Hauv ntej, kub dua zoo dua - kom txog thaum nws tsis kub.
Cia peb xam cov lej. Qhov kub ntawm lub qhov rooj cog khoom: 315 °F. Qhov kub thiab txias ib puag ncig: 105 °F. Qhov deb ntawm kev thauj khoom: 20 mais ntawm 55 mph. Siv tus qauv txias NAPA, qhov sib xyaw tuaj txog ntawm285 °F —tseem nyob hauv qhov rais compaction. Tab sis ntxiv 15-mph headwind thiab qhov kub tuaj txog yuav poob qis rau270 °F Tam sim no lub tshuab dov tawg tsuas muaj yim feeb xwb kom txog 92% qhov ceev ua ntej daim lev poob qis dua 240 °F. Yog koj tsis nco qab lub qhov rais ntawd ces koj yuav caum cov duab ntxoov ntxoo.
Ib qho khoom thauj 20-tuj uas tuaj txog qis dua qhov teev tseg yuav raug nqi rau tus neeg cog lus:
| Khoom | Tus nqi |
|---|---|
| Kev Tshem Tawm & Kev Hloov Chaw | $1,200 |
| Kev sib tsoo thiab kev npog | $800 |
| Cov kev nplua rau DOT | $500 |
| Tag nrho cov kev raug mob | $2,500 rau ib lub tsheb thauj khoom |
Yog koj muab kaum lub tsheb thauj khoom ntxiv rau ib hnub ces koj yuav tau $25,000 los kho dua ua ntej noj su. Tam sim ntawd, qhov kev hloov kho lub koob yees duab infrared $300 ntawd zoo li nyiaj me me xwb.
Nco ntsoov tias, qhov kub thiab txias yog lub hom phiaj txav mus los . Saib xyuas cov chaw teeb tsa ntawm lub Hoobkas, qhov deb ntawm kev thauj khoom, qhov ceev ntawm cua, thiab qhov kub thiab txias ib puag ncig hauv lub sijhawm tiag tiag. Kho txhua yam khoom zoo li kev xa pizza kub: qhov ceev thiab kub dua nws mus txog tus neeg siv khoom, txhua tus neeg zoo siab dua.