Txiv qaub tau muab faib ua quicklime thiab slaked txiv qaub. Quicklime cov khoom tseem ceeb yog calcium oxide (CaO), tau los ntawm calcining limestone nrog cov calcium carbonate siab (CaCO₃) cov ntsiab lus nyob rau hauv lub qhov dej -ventilated txiv qaub kiln kom siab tshaj 900℃. Nws yog hygroscopic thiab tuaj yeem siv los ua cov desiccant, feem ntau siv hauv kuv lub teb chaws los tiv thaiv cov khoom los ntawm kev ntub dej.
Cov txheej txheem ntawm quicklime (CaO) reacting nrog dej los tsim calcium hydroxide hu ua txiv qaub slaking los yog digestion. Cov tshuaj tiv thaiv no nrog dej (tso tawm ntau lub tshav kub) los yog nqus dej los ntawm huab cua ua rau cov txiv qaub slaked, tseem hu ua hydrated txiv qaub. Slaked txiv qaub dissolves 1.56 grams hauv ib liter dej (ntawm 20 degree). Nws cov tshuaj saturated hu ua limewater, uas yog alkaline thiab absorbs carbon dioxide los ntawm huab cua los tsim calcium carbonate precipitate. Cov khoom ntawm cov tshuaj tiv thaiv, calcium hydroxide, yog hu ua slaked txiv qaub los yog hydrated txiv qaub.
Txiv qaub slaking tso tawm ntau lub tshav kub thiab nce ntim los ntawm 1-2 zaug. Zoo-calcined txiv qaub nrog cov ntsiab lus calcium oxide siab slakes sai dua, tso cua sov ntau dua thiab nce ntim. Ob txoj hauv kev rau slaking txiv qaub ntawm qhov chaw tsim kho yog txoj kev slaked txiv qaub slurry thiab txoj kev slaked txiv qaub hmoov. Nyob rau hauv cov txiv qaub slurry tsim tom qab quicklime slaking, cov txiv qaub particles tsim ib tug calcium hydroxide colloidal qauv nrog zoo heev hais (kwv yees li 1 μm inch) thiab ib tug loj cheeb tsam (10-30 m² / g). Cov yeeb yaj kiab dej tuab yog adsorbed rau ntawm nws qhov chaw, tso cai rau nws nqus dej ntau, yog li nthuav tawm cov dej muaj zog khaws cia. Ntxiv rau cov cement mortar los ua ib qho sib xyaw mortar ua kom cov mortar ua haujlwm tau zoo.
Txiv qaub hardens los ntawm ziab, crystallization, thiab carbonation. Vim tias cov pa roj carbon dioxide tsawg hauv cov huab cua thiab cov tawv tawv calcium carbonate plhaub tsim tom qab carbonation tiv thaiv cov pa roj carbon dioxide nkag thiab dej evaporation, hardening qeeb, thiab lub zog hardened yog tsawg. A 1: 3 txiv qaub mortar muaj lub zog compressive ntawm 0.2-0.5 MPa tom qab 28 hnub. Hauv qhov chaw ntub dej, cov dej hauv cov txiv qaub tsis evaporate, thiab cov pa roj carbon dioxide tsis tuaj yeem nkag mus, txwv tsis pub tawv. Tsis tas li ntawd, calcium hydroxide yog me ntsis soluble hauv dej, ua rau cov txiv qaub tawv tawv kom yaj thiab tawg thaum sib cuag nrog dej. Yog li ntawd, txiv qaub tsis haum rau siv nyob rau hauv ib puag ncig nrog ntev dampness los yog dej immersion.
Thaum lub sij hawm hardening txheej txheem, txiv qaub evaporates ib tug loj npaum li cas ntawm cov dej, ua rau lub ntim loj shrinkage thiab ua rau nws nquag qhuav shrinkage tawg. Yog li ntawd, txiv qaub yuav tsum tsis txhob siv ib leeg; nws yog feem ntau tov nrog cov ntaub ntawv xws li xuab zeb, ntawv pulp, thiab hemp fiber kom txo shrinkage, nce tensile zog, thiab txuag txiv qaub.
Txiv qaub muaj zog alkalinity thiab, nyob rau hauv chav tsev kub, muaj peev xwm hnov mob nrog glassy activated silica los yog activated alumina los tsim hydraulic khoom thiab tsim cov cement. Yog li ntawd, txiv qaub tseem yog ib qho tseem ceeb raw khoom nyob rau hauv lub tsev cov ntaub ntawv kev lag luam.
Txiv qaub slurry feem ntau yog tsim los ntawm kev ntxiv dej rau calcium oxide. Vim tias calcium hydroxide muaj cov solubility tsawg, nws feem ntau ua rau kev ncua ntawm calcium hydroxide (piv txwv li, cov tshuaj aqueous uas tsis muaj calcium hydroxide). Txiv qaub slurry, ntawm qhov tod tes, yog cov kua turbid tau los ntawm diluting txiv qaub nrog dej (kwv yees li 2.5-3 npaug ntawm cov txiv qaub).
