Features of the manufacture of Portland cement
Portland cement firmness with water shutter is conditionally divided into 3 stages.
Liquid phase, colloidation – as a result of which a dough -shaped substance and crystallization are formed – a strong crystalline frame is formed – a stone -shaped substance. After passing these stages, Portland cement acquires its beneficial properties and gains strength.
With hardness of cement, its volume changes: when hardening in the air, the moisture evaporates and it decreases, when connected with water, on the contrary, an increase. Therefore, when using cement -containing materials, it is necessary to take into account the possibility of shrinkage and the appearance of cracks during hardness in the air and mandatory moisturizing with water. To ensure the necessary humidity level, watering the screed is used.