Kwanan Wata: 1, Afrilu, 2024
An yi imani da cewa yawan zafin jiki ya fi girma, yawan ƙwayar siminti za su yi amfani da polycarboxylate mai rage ruwa. A lokaci guda, mafi girman zafin jiki, mafi mahimmancin samfuran hydration na siminti za su cinye wakili na rage ruwa na polycarboxylate. A ƙarƙashin tasirin haɗin gwiwar tasirin biyu, yayin da zafin jiki ya karu, yawan ruwan simintin ya zama mafi muni. Wannan ƙarshe na iya yin bayanin abin da ya faru cewa yawan ruwan siminti yana ƙaruwa lokacin da zafin jiki ya faɗi ba zato ba tsammani, kuma asarar simintin yana ƙaruwa lokacin da zafin jiki ya tashi. Duk da haka, yayin da ake yin aikin, an gano cewa ruwan simintin ba ya da kyau a yanayin zafi mai sauƙi, kuma lokacin da yawan zafin jiki na ruwan da ke haɗuwa ya karu, yawan ruwan simintin bayan na'urar ya karu. Ba za a iya bayyana wannan ta ƙarshen ƙarshe ba. Don wannan, ana gudanar da gwaje-gwaje don yin nazari, gano dalilan da ke haifar da sabani, da kuma samar da yanayin zafi mai dacewa don kankare.
Don yin nazarin tasirin haɗuwa da zafin jiki na ruwa akan tasirin watsawa na wakili mai rage ruwa na polycarboxylate. An shirya ruwa a 0°C, 10°C, 20°C, 30°C, da 40°C domin gwajin dacewa da siminti-superplasticizer.
Bincike ya nuna cewa idan lokacin fita daga na'ura ya yi takaice, fadada simintin slurry na farko yana karuwa sannan kuma yana raguwa yayin da zafin jiki ya karu. Dalilin wannan al'amari shi ne cewa zafin jiki yana rinjayar duka siminti hydration rate da adsorption rate na superplasticizer. Lokacin da zafin jiki ya tashi, saurin adsorption na kwayoyin superplasticizer shine, mafi kyawun tasirin tarwatsawa na farko zai kasance. A lokaci guda kuma, adadin ruwan siminti yana haɓaka, kuma yawan amfani da wakili mai rage ruwa ta hanyar samar da ruwa yana ƙaruwa, wanda ke rage yawan ruwa. Faɗin farko na manna siminti yana shafar tasirin haɗin gwiwar waɗannan abubuwa biyu.
Lokacin da yawan zafin jiki na ruwa ya kasance ≤10 ° C, ƙimar adsorption na superplasticizer da ƙimar hydration na siminti duka ƙanana ne. Daga cikin su, ƙaddamar da wakili mai rage ruwa a kan simintin siminti shine abin sarrafawa. Tun da adsorption na wakili mai rage ruwa a kan simintin siminti yana jinkirin lokacin da yawan zafin jiki ya ragu, farkon raguwar ruwa yana da ƙasa, wanda ke bayyana a cikin ƙananan ƙarancin farko na ciminti slurry.
Lokacin da yawan zafin jiki na ruwan haɗe ya kasance tsakanin 20 zuwa 30 ° C, adadin adsorption na wakili mai rage ruwa da kuma yawan hydration na siminti yana karuwa a lokaci guda, kuma adadin adsorption na kwayoyin masu rage ruwa ya karu da yawa. a fili, wanda ke nunawa a cikin karuwa a farkon ruwa na ciminti slurry. Lokacin da yawan zafin jiki na ruwa ya kasance ≥40 ° C, ƙimar simintin hydration yana ƙaruwa sosai kuma a hankali ya zama abin sarrafawa. A sakamakon haka, adadin tallan tallan na ƙwayoyin cuta masu rage ruwa (yawan adsorption rage yawan amfani) yana raguwa, kuma slurry ɗin siminti kuma yana nuna ƙarancin raguwar ruwa. Sabili da haka, an yi imani da cewa tasirin tarwatsawa na farko na wakili na rage ruwa ya fi kyau lokacin da ruwa mai haɗuwa ya kasance tsakanin 20 da 30 ° C kuma zafin jiki na siminti yana tsakanin 18 da 22 ° C.
Lokacin da lokacin fita daga na'ura ya daɗe, haɓakar simintin slurry ya yi daidai da ƙarshen yarda da gabaɗaya. Lokacin da lokaci ya isa, ana iya sanya wakili mai rage ruwa na polycarboxylate akan simintin siminti a kowane zafin jiki har sai ya cika. Duk da haka, a ƙananan zafin jiki, ƙarancin rage ruwa ana cinyewa don shayar da siminti. Sabili da haka, yayin da lokaci ya wuce, fadada simintin siminti zai karu da zafin jiki. Ƙara da raguwa.
Wannan gwajin ba wai kawai yayi la'akari da tasirin zafin jiki ba, amma kuma yana kula da tasirin lokaci akan tasirin watsawa na wakili mai rage ruwa na polycarboxylate, yana sa ƙaddamarwa ta fi ƙayyadaddun kuma kusa da gaskiyar injiniya. Abubuwan da aka yanke sune kamar haka:
(1) A ƙananan yanayin zafi, tasirin watsawa na polycarboxylate mai rage ruwa yana da tabbataccen lokaci. Yayin da lokacin haɗuwa ya karu, yawan ruwa na simintin slurry yana ƙaruwa. Yayin da yawan zafin jiki na ruwan haɗewar ya ƙaru, haɓakar slurry na siminti ya fara ƙaruwa sannan ya ragu. Za a iya samun bambance-bambance mai mahimmanci tsakanin yanayin siminti yayin da yake fitowa daga injin da yanayin simintin yayin da ake zubawa a wurin.
(2) A lokacin gina ƙananan zafin jiki, dumama ruwan da ke hadewa zai iya taimakawa wajen inganta ƙarancin siminti. A lokacin ginawa, ya kamata a kula da kula da yawan zafin jiki na ruwa. Zazzabi na slurry na siminti yana tsakanin 18 zuwa 22 ° C, kuma ruwa shine mafi kyau idan ya fito daga injin. Hana abin da ya faru na rage yawan ruwan siminti da ke haifar da matsanancin zafin ruwa.
(3) Lokacin da lokacin fita daga na'ura ya daɗe, fadada simintin slurry yana raguwa yayin da zafin jiki ya karu.
Lokacin aikawa: Afrilu-01-2024
