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:

　　，參加鋁粉的發氣反應，當有石膏存在時，同鋁粉在與水反應時生成的氫氧化鋁反應生成硫鋁酸鈣。因此，在某些加氣磚(如水泥-礦渣-砂，水泥-砂)中，水泥中石膏被鋁粉的反應消耗過多時，由于水泥中鋁酸鹽成分得不到石膏的抑制就可能發生快速凝結，這時應補充加入石膏。

　　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，使其消化時間延長，并降低終消化溫度。

　　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，從而使游離的鋁離子進入CSH(I)中，其中部分轉化為鋁代托勃莫來石，而AI2O3本身也能促進CSH(I)向托勃莫來石轉化，阻止其向硬硅鈣石轉化，因而強度提高，收縮值降低。

　　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，提高坯體及制品的強度，改善收縮等性能。石膏在靜停過程中的坯體內參與生成水化硫鋁酸鈣和C-S-H凝膠，使坯體強度提高。增強了坯體適應蒸壓時溫差應力和濕差應力的能力。在蒸壓過程中，石膏可以促進水熱反應的進行，使CSH(I)向托勃莫來石轉化。

　　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.

　　看完上面的敘述您是不是明白了，石膏的作用真的很大，用途也是如此的廣闊。

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