In horizontal elements, such as floor slabs, excess water rises and causes a weak laitance layer at the top.
在诸如楼板之类的水平构件中，过剩水分增加会导致顶部的薄弱浆沫层。
2
Carry out surface preparation by grinder and dust free self-enclosed portable grinder until to remove surface laitance and provide sound and textured surface.