SPEC MIX® Setting Bed Mortar is specifically engineered as a thick, solid mortar bed for constructing horizontal surfaces with natural and manufactured paving units. This dry, pre-blended mortar contains cementitious materials and dried aggregates that are mixed with a low water addition rate for a zero-slump dry pack base material. SPEC MIX Setting Bed Mortar can be used as a paving unit base for residential and commercial paving unit applications. It can be used for interior and exterior installations, allowing light and medium traffic. Each SPEC MIX manufacturer certifies that SPEC MIX masonry products are designed to meet applicable ASTM and ACI standards.