Comparative characteristics of building materials

Checking cement for quality, you should squeeze a handful with your hands. Fanding cement has high quality. If lumps are formed during the compression process, then concrete on this basis will not be strong. When choosing cement, be sure to look at storage periods. Over two years of storage, the quality of binders decreases by 50%. Slate. The darkening of the slate means that it was stored for a long time in the open air and that its strength is significantly reduced. High -quality solitary sheet of slate without cracks withstands human weight.