large concrete or cement masonry units for building are concrete slab.
large concrete or cement masonry units for building are concrete slab.
large concrete or cement masonry units for building?
concrete slab
blocks of cinder concrete ("cinder blocks" or "breezeblocks"), ordinary concrete ("concrete blocks"), or hollow tile are generically known as concrete masonry units (cmus). they usually are much larger than ordinary bricks and so are much faster to lay for a wall of a given size. furthermore, cinder and concrete blocks typically have much lower water absorption rates than brick. they often are used as the structural core for veneered brick masonry, or are used alone for the walls of factories, garages and other industrial-style buildings where such appearance is acceptable or desirable. such blocks often receive a stucco surface for decoration. surface-bonding cement, which contains synthetic fibers for reinforcement, is sometimes used in this application and can impart extra strength to a block wall. surface-bonding cement is often pre-coloured and can be stained or painted thus resulting in a finished stucco-like surface.
masonry
after examination, the next step is cutting away the old mortar. the old mortar is removed to a depth equal to or slightly more than the width of the joint, or to the point where sound mortar is reached. removal of old mortar between joints is done carefully to avoid damage to masonry units. on buildings with soft materials, such as under-fired brick, lime mortar, or terra cotta, removal by hand is often the most effective to avoid damage. hard portland cement mortar is usually removed with a grinder or power circular masonry blade, taking care not to damage the masonry units. vertical joints or thin joints are done by hand or with small power chisels." if a power saw needs to be used, it's only used on wide and uniform horizontal joints and in the middle of the joint. a hammer and chisel are then used for the rest of the mortar, closer to the masonry units. caulking cutters with diamond blades are an acceptable power tool to remove mortar in wide horizontal joints. they are slow, have no rotation, and vibrate so they are likely to cause less damage to the masonry units.
repointing