Tsiku Lotumiza:11, Sep,2023

Kuyambira 1980s, admixtures, makamaka mkulu-mwachangu kuchepetsa wothandizila madzi, akhala kulimbikitsa pang'onopang'ono ndi ntchito msika zoweta konkire, makamaka mkulu-mphamvu konkire ndi pumped konkire, ndipo akhala zigawo zofunika kwambiri. Monga momwe Malhotra adanenera ku Msonkhano Wapadziko Lonse Woyamba wa Concrete Admixtures: "Kupanga ndi kugwiritsa ntchito zida zochepetsera madzi zogwira mtima kwambiri ndizofunikira kwambiri pakupita patsogolo kwaukadaulo wa konkriti m'zaka za zana la 20." Panali zochepa zochepa zofunikira mu luso la konkire pazaka zambiri, chimodzi mwa izo chinali chitukuko cha mpweya wophunzitsidwa m'zaka za m'ma 1940, zomwe zinasintha nkhope ya teknoloji ya konkire ku North America;Superplasticizerndichinthu china chachikulu chomwe chidzakhudza kwambiri kupanga ndi kugwiritsa ntchito konkire kwa zaka zambiri.

Superplasticizerm'mayiko ena otchedwasuperplasticizer, monga momwe dzinalo likusonyezera, ndiloyenera kwambiri pokonzekera kusakaniza konkire yopangidwa ndi superplasticized. Zoonadi, ndizoyenera kwambiri kusakaniza zosakaniza ndi kutuluka kwakukulu, voliyumu yaikulu ya slurry ndi chiŵerengero chochepa cha madzi-binder, ndiko kuti, kupopera konkire yamphamvu kwambiri.

Komabe, kwa konkire ina, monga konkire yotsanulidwa pomanga madamu a hydraulic, kukula kwakukulu kwa tinthu kophatikizana ndi kwakukulu (mpaka 150mm), voliyumu ya slurry ndi yaying'ono ndipo kutuluka kwake sikuli kwakukulu, ndipo konkire iyenera kupangidwa. pogwiritsa ntchito kugwedezeka kwamphamvu kapena kugwedera kwamphamvu, chochepetsera madzi chapamwamba kwambiri sichingakhale choyenera. Pofuna kusunga chiŵerengero cha madzi-binder osasinthika, kuti akwaniritse zofunikira zamakina zomwe zimafunidwa ndi mapangidwe apangidwe, kuchepetsa madzi ogwiritsira ntchito, ndi kuchepetsa zinthu zomangira simenti monga lingaliro, kumanga madamu ambiri apanyumba a hydraulic amasakanizidwanso ndi mphamvu zambiri. chochepetsera madzi. M'malo mwake, kugwiritsa ntchito kotereku ndizovuta, chifukwa konkire ya hydraulic yoyambirira imasakanizidwa ndi wothandizila mpweya kapena mtundu wa lignin wa chochepetsera madzi wamba, kutsika kwawo kwamadzi kumakhala kochepa, ndipo chifukwa cha kulowetsedwa kwa mpweya kumawonjezera kuchuluka kwa slurry. pamene kumwa madzi ndi kuchuluka kwa simenti kumachepetsedwa panthawi imodzimodzi, ndiko kuti, pamene kuchuluka kwa slurry kumachepetsedwa, kumatha kukhalabe bwino. Kuonetsetsa kuti pali malo okwanira kuti mudzaze aggregate, kukulunga aggregate ndi kupereka workable slurry n'kofunika kuti osakaniza kuti tigwirizane pambuyo kuthira.

Komanso, mphamvu compressive ya osakaniza ndi mkulu dzuwa kuchepetsa wothandizila kuchepetsa madzi binder chiŵerengero akhoza bwino kwambiri pambuyo kuumitsa, koma mapindikidwe mphamvu kukula mlingo nthawi zambiri ndi laling'ono, ndi tilinazo akulimbana adzawonjezeka, kotero ambiri, Kupanga konkriti kapena mlatho kumayenera kukhala kosamala pogwiritsa ntchito njira yochepetsera madzi. M'malo mwake, pokonzekera kuchuluka kwakukulu kwa C30 muzomangamanga ndi zomangamanga (ziyenera kupitilira 1/2 ya chiwopsezo chonse) kapena magiredi otsika a konkire yopopera, chochepetsera madzi mwachangu sichoyenera, kapena si chigawo chofunikira.