Rau kev txhim khu kev qha thiab ceev nkag thaum lub sij hawm thov, bitumen emulsions tsuas yog diluted bitumen. Nws yog dav siv rau kev siv sib txawv hauv kev tsim kho kev lag luam. Kev kho saum npoo yog ua tiav los xyuas kom meej tias txheej txheej txheej ntawm txoj kev los yog pavement yog khaws cia kom tsis txhob muaj dej los yog noo noo nkag mus. Nws tiv thaiv skis thiab tiv thaiv txoj kev loj. Txawm li cas los xij, qhov kev ua tau zoo yog cuam tshuam los ntawm cov khoom sib sau ua ke, emulsion sib xws, thiab kub.

Bitumen emulsion ua li cas?
Bitumen emulsion yog tsim nyob rau hauv ob kauj ruam yooj yim. Cov dej yog thawj zaug ua ke nrog tus neeg sawv cev emulsifying thiab lwm yam tshuaj. Tom qab ntawd, lub zeb colloidal yog siv los ua ke dej, emulsifier, thiab bitumen. Nyob ntawm qhov kawg-siv ntawm bitumen emulsion, qhov ntau ntawm bitumen yog ntxiv rau qhov sib tov. Thaum lub emulsifier tau ua raws li cov khoom tseem ceeb, nws tuaj yeem siv li ntawm 60-70%.

Tus nqi ntawm bitumen ntxiv rau qhov sib tov yog nruab nrab ntawm 40% thiab 70%. Lub zeb colloidal cais cov bitumen mus rau hauv microscopic hais. Qhov nruab nrab droplet loj yog kwv yees li 2 microns. Tab sis cov tee dej sim daws thiab koom nrog ib leeg. Lub emulsifier, yog li ntxiv, tsim ib txheej ntawm cov nqi saum npoo ib ncig ntawm txhua lub tee ntawm bitumen uas, ntawm qhov tod tes, pab kom cov tee dej kom deb ntawm ib leeg. Cov khoom sib xyaw tau los ntawm cov zeb colloidal yog ua tiav thiab siv raws li cov lus qhia thiab tom qab ntawd muab khaws cia rau hauv lub tank cia.

Hom Bitumen:
Lub bitumen emulsion tau faib ua ob hom:
Raws li lub sijhawm teem sijhawm
Raws li tus nqi saum npoo

Raws li Teem Sijhawm
Yog hais tias emulsions ntawm bitumen ntxiv rau aggregates, dej yog evaporated, thiab cov kuab tshuaj raug tshem tawm. Tom qab ntawd bitumen ntws hla lub hauv paus aggregate, ua haujlwm ua tus neeg sawv cev khi thiab maj mam ntxiv dag zog rau nws tus kheej. Cov txheej txheem no tau muab faib ua peb pawg hauv qab no, nyob ntawm qhov ceev ntawm cov dej evaporates thiab bitumen hais disperse los ntawm dej:
Kev ceev ceev Emulsion (RS)
Nruab nrab Teeb Emulsion (MS)
Slow Setting Emulsion (SS)

Bitumen yog txhais tau tias ua kom tawg yooj yim vim cov emulsion yog ib qho chaw ceev ceev ntawm emulsion. Daim ntawv no ntawm emulsion teeb tau yooj yim thiab kho. Thaum muab tso rau ntawm aggregates, emulsions ntawm nruab nrab qhov chaw tsis tawg poob nthav. Txawm li cas los xij, thaum cov pob zeb ntxhib ntxhib sib xyaw ua ke nrog cov sib xyaw emulsifier sib xyaw, cov txheej txheem tawg pib. Kev teeb tsa emulsions qeeb yog tsim nrog kev pab los ntawm ib hom tshwj xeeb ntawm emulsifier uas ua rau cov txheej txheem teeb tsa qeeb. Cov ntaub ntawv emulsion no muaj zog heev.

Raws li Surface Charge
Bitumen emulsions tau muab faib feem ntau rau hauv peb pawg hauv qab no nyob ntawm seb hom nqi ntawm qhov chaw:
Anionic Bitumen emulsion
Cationic Bitumen emulsion
Tsis yog-ionic Bitumen emulsion

Bitumen hais yog electro-negatively them nyob rau hauv cov ntaub ntawv ntawm anionic bitumen emulsion, whereas nyob rau hauv cov ntaub ntawv ntawm cationic emulsions, bituminous hais yog electro-positive. Niaj hnub no, cationic emulsion ntawm bitumen feem ntau yog siv. Raws li cov ntxhia muaj pes tsawg leeg ntawm cov aggregate siv rau lub tsev, nws yog ib qho tseem ceeb los xaiv ib qho emulsion ntawm bitumen. Qhov sib xyaw ntawm cov aggregates ua electro-negatively them nyob rau hauv cov ntaub ntawv ntawm silica-nplua nuj aggregates. Yog li ntawd, ib qho cationic emulsion yuav tsum tau ntxiv. Qhov no yuav pab kom kis tau bitumen thiab ua ke nrog cov aggregates zoo dua. Rau cov kev daws teeb meem aqueous, non-ionic surfactants tsis nyiam ions. Lub solubility yog nyob ntawm seb muaj pes tsawg leeg ntawm polar molecules. Kev siv cov nonionic surfactants ua ib qho emulsifier, txawm tias tsis yog nyob rau hauv cov txheej txheem dej xwb, tab sis nyob rau hauv lub bitumen theem, raws li tau piav saum toj no, yog qhov zoo txaus siab vim lawv ua raws li tag nrho cov ion surfactants.

Tsis muaj emulsion ntawm txhua yam yog txaus rau txhua txoj haujlwm; nws nyob ntawm acidic los yog qhov tseem ceeb ntawm cov aggregate. Raws li huab cua kub, cua ceev thiab emulsion loj, lub sij hawm teem yuav txawv. Lub peev xwm rau khaws cia yog tsawg heev. Cov kev faib tawm saum toj no yog cov lus qhia los xaiv qhov kev sib tw rau koj cov kev xav tau.