Seeing this title, I feel incredible, gypsum has such a role, ah, the original gypsum in the production of aerated bricks as a regulator in the process of gas. It is a commonly used cementitious material. Gypsum not only acts as a regulator of gas evolution process, but also participates in hydrothermal synthesis reaction, which can improve product strength, reduce shrinkage and improve frost resistance. Gypsum in the production of aerated brick mainly has the following aspects:

　　，参加铝粉的发气反应，当有石膏存在时，同铝粉在与水反应时生成的氢氧化铝反应生成硫铝酸钙。因此，在某些加气砖(如水泥-矿渣-砂，水泥-砂)中，水泥中石膏被铝粉的反应消耗过多时，由于水泥中铝酸盐成分得不到石膏的抑制就可能发生快速凝结，这时应补充加入石膏。

　　Firstly, it participates in the gasification reaction of aluminium powder. When gypsum exists, it reacts with aluminium hydroxide formed when aluminium powder reacts with water to produce calcium sulphoaluminate. Therefore, in some aerated bricks (such as cement-slag-sand, cement-sand), when gypsum in cement is consumed too much by the reaction of aluminium powder, rapid setting may occur because aluminate in cement can not be inhibited by gypsum, gypsum should be added at this time.

　　第二，抑制石灰的消化，使其消化时间延长，并降低终消化温度。

　　Second, inhibit the digestion of lime, prolong the digestion time and reduce the final digestion temperature.

　　第三，可以抑制水石榴子石的生成，从而使游离的铝离子进入CSH(I)中，其中部分转化为铝代托勃莫来石，而AI2O3本身也能促进CSH(I)向托勃莫来石转化，阻止其向硬硅钙石转化，因而强度提高，收缩值降低。

　　Thirdly, the formation of hydrogarnet can be inhibited, so that free aluminium ions can enter CSH (I), some of which can be converted into aluminium-substituted tobermorite, while AI2O3 itself can also promote the transformation of CSH (I) to tobermorite and prevent its transformation to anhydrite, thus increasing its strength and decreasing its shrinkage value.

　　第四，提高坯体及制品的强度，改善收缩等性能。石膏在静停过程中的坯体内参与生成水化硫铝酸钙和C-S-H凝胶，使坯体强度提高。增强了坯体适应蒸压时温差应力和湿差应力的能力。在蒸压过程中，石膏可以促进水热反应的进行，使CSH(I)向托勃莫来石转化。

　　Fourthly, the strength and shrinkage of green bodies and products should be improved. The gypsum participates in the formation of hydrated calcium sulphoaluminate and C-S-H gel during the static shutdown process, so as to increase the strength of the green body. It enhances the ability of green body to adapt to temperature and humidity differential stresses during autoclaving. In the autoclave process, gypsum can promote hydrothermal reaction and make CSH (I) transform to tobermorite.

　　看完上面的叙述您是不是明白了，石膏的作用真的很大，用途也是如此的广阔。

　　After reading the above narrative, do you understand that gypsum really plays a very important role and has such a wide range of uses?