Study On Building Gypsum Retarder Of Gel Protein

The gypsum building material has some advantages, for instance, light in quality, a little deformity, low energy expenditure, harmless to person and environment. It also is one kind of green energy-saving building material canonized by international society. But some fatal disadvantages for gypsum material are very short coagulating and hardening times which usually lasts several minutes. It can't meet the requirement for construction operating time, so, the retarder is often added in the gypsum to adjust the setting time. However, when the retarder is playing its part in extending the setting time, it simultaneously causes a great strength loss of gypsum. Therefore, it limits the popularization of gypsum constructive material in some degrees. The Building Gypsum Retarder of Gel Protein studied in the thesis can solve this contradiction effectively.We carried out some experiments in comparison with the building gypsum retarder of gel protein, organic citric acid and sodium polyphosphate: Then we tested that the building gypsum retarder of gel protein effects on the setting time and the strength of gypsum. We also explored that the gypsum categories and gypsum PH value impact on the retarding results of building gypsum retarder of gel protein. The results indicated that the building gypsum retarder of gel protein has a significant impact on the setting time of gypsum, has a little strength and has a perfect adaptability for gypsum in different hydration environments.We analyzed the reason why the microstructure of gypsum is change and the strength is decrease by the means of testing ions super-saturation in liquid phase and observing the crystal morphology microstructure of gypsum during the process of hydration. The retarding mechanisms for the building gypsum retarder of gel protein was also investigated in the thesis.