Mortar – Mortar is a workable paste used to bind building blocks, like brick and stone, together. Mortar is also used to fill and seal the irregular gaps between the building blocks. Sometimes the mortar can be used to add decorative color and textural patterns in masonry walls. In the broadest sense of the term, mortar includes asphalt, pitch, or even the mud or clay used between mud bricks.
The mortar most commonly seen in brick masonry is cement (Portland cement). The cement mortar becomes hard when it cures, resulting in a rigid aggregate structure; however the mortar is intended to be weaker than the building blocks and the sacrificial element in the masonry, because the mortar is easier and less expensive to repair than the building blocks. Mortars are typically made from a mixture of sand, a binder, and water.
A mortar can also be used to de-construct a wall. However, this bomb launcher is an entirely differently type of mortar.