Cov teebmeem ntawm overmixing ntawm cov dej txo cov neeg ua haujlwm los ntawm ob peb zaug ntawm cov khoom ntawm pob zeb

Thawj qhov xwm txheej, nyob rau hauv ultra-high lub zog pob zeb, vim hais tias cov dej-cement ratio Tsawg dua los yog sib npaug rau 0.3 los yog tsawg li 0.2, qhov no feem ntau qhia tau hais tias cov Lub xeev ntawm pob zeb tsis rhiab rau cov dej txo tus neeg saib xyuas ntau npaum li cas, txhawm rau ua tiav lub xeev kev txav mus los zoo tshaj plaws, cov dej txo tus neeg saib xyuas ntau npaum li cas yog 5-8 npaug ntawm cov tshuaj ib txwm muaj, piv txwv li, ntau npaum li cas ntawm polycarboxylic acid yuav tsum yog 5. feem pua ​​-8 feem pua. Rau cov pob zeb hauv qab C50, qhov ntau npaum li cas yog qhov tsis txaus ntseeg. Txawm li cas los xij, cov txiaj ntsig kev sim qhia tau hais tias lub zog ntawm pob zeb ntawm qhov ntau npaum no txhim kho zoo nyob rau txhua lub hnub nyoog, thiab nws tau nruab nrog pob zeb nrog 28d lub zog ntau dua 100MPa. Yog vim li cas yog: qhov dispersion ntawm dej txo tus neeg sawv cev ntawm cov cement tsuas yog lub cev adsorption, dej txo tus neeg sawv cev molecules adsorbed rau saum npoo ntawm cement hais, los ntawm lub luag hauj lwm ntawm spatial site kuj thiab electrostatic repulsion, thiaj li hais tias lub flocculation qauv ntawm cement hais disintegrated, tso cov dej dawb uas yog qhwv, thiaj li ua kom cov pob zeb txav tau nce, thiab cov txheej txheem polycarboxylic acid ntawm cov dej txo tus neeg sawv cev, vim tias nws cov qauv zuag tshwj xeeb, nws tuaj yeem tiv thaiv los ntawm coalescence ntawm cov cement hais dua rau qee yam. lub sij hawm ntawm lub sij hawm, yog li Nws muaj qhov zoo slump tuav kev ua tau zoo. Ib zaug ntau tshaj li ib lub sijhawm, cov khoom siv cement hydration yuav adsorbed rau saum npoo ntawm cov cement hais ntawm cov dej txo tus neeg sawv cev molecules tag nrho qhwv, dej txo tus neeg sawv cev molecules yog shielded tom qab dispersion ntawm cov nyhuv kiag li ploj mus, thiab ces tsis muaj. ntev dua muaj kev cuam tshuam thiab cuam tshuam rau cov pob zeb, cov cement yog ib txwm hydration, ib txwm txhim kho lub zog ntawm cov pob zeb. Tau kawg, vim tias cov dej txo tus neeg saib xyuas ntau npaum li cas, qhov concentration ntawm cov dej txo tus neeg sawv cev hauv cov pob zeb loj, tom qab qee cov molecules raug them los ntawm cov khoom siv cement hydration, muaj cov molecules tshiab adsorbed rau saum npoo ntawm cov cement hydration khoom, tiv thaiv. cov cement hais los ntawm kev sib tsoo sai heev los tsim ib lub network, uas rau qee qhov, ua rau lub sijhawm teem sijhawm ntev, tab sis cov cement feem ntau yuav tsis teem rau ntau tshaj 24h.

Qhov xwm txheej thib ob, tus neeg saib xyuas dej txo nws tus kheej muaj qee yam ntawm huab cua-entraining thiab retardation, tom qab ntawd ob peb zaug sib xyaw ua ke yuav muaj kev cuam tshuam ntau dua rau kev ua haujlwm ntawm pob zeb. Feem ntau hais lus, qhov ntau npaum li cas ntawm cov tshuaj tiv thaiv retarder yog nyob ntawm qhov kub thiab txias ib puag ncig, engineering xav tau thiab cov dej txo tus neeg sawv cev ib txwm sib xyaw los txiav txim siab, yog tias cov khoom tiv thaiv retarder yog sib xyaw ntau zaus, vim muaj ntau cov khoom tiv thaiv retarder adsorption ntawm qhov chaw. cov cementitious cov ntaub ntawv hais, cuam tshuam rau ib txwm hydration ntawm cov cementitious cov ntaub ntawv, los yog ua kom lub sij hawm teem sij hawm ntev dua, los yog ua rau cov pob zeb rau ob peb hnub yam tsis muaj condensation los yog mus tas li tsis muaj teeb meem. Feem ntau 2d lossis ntau lub sijhawm los teeb tsa cov pob zeb, vim tias cov txheej txheem hydration qeeb dhau lawm, hom thiab ntau npaum li cas ntawm cov khoom siv dej hloov pauv, uas ua rau txo qis hauv cov pob zeb ua kom muaj zog. Tau kawg, rau lub subway tom pawg (feem ntau xav tau 72-90h pib) thiab pawg hauv paus, bearing platform, pas dej ua ke thiab lwm yam loj ntim pob zeb tsim, nws tus kheej yuav tsum tau siv sij hawm ntev ntawm kev teeb tsa, feem ntau nyob rau hauv kev faib ua feem tsim. tsim nyog nce qib zog, txhawm rau xyuas kom meej tias lub zog 28d kom ua tau raws li cov qauv tsim.