The main reasons for the following reasons:
1, in order to complete the hydration of cement, stirring too much water (10% to 15%) caused by ceramic refractory castable significantly higher porosity, density decreased.
2, calcium aluminate hydrate in the middle temperature stage has a strong dehydration and recrystallization effect, destroying the hard material in the castable structure, so that refractory castable in the temperature stage of the sharp decline in strength.
3, cement binder will be more calcium into the castable, resulting in ceramic refractory castable load softening temperature drop, thermal shock stability performance deterioration. In view of the problem of poor performance of ordinary refractory castable, low cement refractory castable effectively avoids the regret of high temperature performance. The so-called low-cement refractory castables, which contain less than 8% of the cement content, and less than 4% is called ultra-low cement refractory castable. In contrast, the general Refractory company castable above mentioned deficiencies are converted into low cement refractory castable advantage. Its structure is dense. Low porosity, high refractoriness, high softening temperature, high temperature strength, good thermal shock stability. But because of its low cement content, resulting in a long time of condensation, early strength in the winter and low temperature conditions, construction is particularly unfavorable. So in the masonry, to give full attention.