High alumina cement, also known as aluminate cement, has the advantages of high early strength, high temperature resistance, and strong sulfate resistance. In recent years, due to the rapid growth of the early strength of high alumina cement, it can be demolded as soon as possible, and the construction period is high. The construction of using high alumina cement to prepare concrete is increasing. Due to the unstable strength of high alumina cement in the later stage, there is considerable controversy regarding its application in engineering. Studies have shown that the use of ultrafine powder as a mixture of high alumina cement can improve the later strength of high alumina cement.
BaSO4, commonly known as barite, is a naturally occurring white inorganic salt and a neutral filler. Its relative density is 4.16, and it has the characteristics of light resistance and corrosion resistance, low oil absorption, impervious to ultraviolet rays, X-rays, and radiation protection and so on.
Studies have shown that the use of natural mineral barite as an additive to aluminate cement can reduce the water requirement for the standard consistency of aluminate cement, increase the strength of the cement, and reduce the later strength regression, without affecting the refractoriness of the cement.
Adding an appropriate amount of barite powder to the high alumina cement can not only increase the early strength of the high alumina cement, but also inhibit the late strength shrinkage of the high alumina cement; adding a proper amount of barite powder can promote the hydration of the high alumina cement; The main reason why spar powder inhibits the late strength shrinkage of high alumina cement is that it inhibits the crystal form transformation of CAH10 and C2AH8 to C3AH6 in the hydration products of high alumina cement.