Calcium sulfite acts as a retarder for the setting of normal Portland cement, high early strength cement, and blast furnace slag cement. If used with gypsum it is possible to prevent the false setting under the federal test. The mortar strength test for the cement mixed with calcium sulfite and gypsum gave the better results.
The specimens showed the general trend of giving higher bending strength. The cements mixed with calcium sulfite gave a larger expansion and a smaller shrinkage under water than those mixed with gypsum, the specimens showed the larger trend of returning to the original size even after the repeated expansion and shrinkage.