Double Mat Slab Reinforcement

Per code section 7 12 2 2 the bar spacing is limited to five times the slab thickness or 18 in.

Double mat slab reinforcement.

Slabs are constructed to provide flat surfaces usually horizontal in building floors roofs bridges and other types of structures the slab may be supported by walls or by reinforced concrete beams usually cast monolithically with the slab or by structural steel beams or by columns or by the ground. That amount of reinforcement may or may not satisfy the flexural requirement. For walls the minimum area of reinforcement steel shall be as required by 14 3 2 and 14 3 3. Aci 350 10 5 4 for structural slabs mats and footings of uniform thickness the minimum area of tensile reinforcement in the direction of the span shall be the same as required by 7 12.

Mat foundations are often at the basement level of buildings and can be below the water table. Typically reinforced with a double layer of rebar throughout its pad a mat slab is capable of bearing loads at virtually any point and distributing heavy loads across an expanse of weak subsoil. The main reinforcing in a single barrel reinforced concrete box culvert slab is the bottom transverse reinforcing steel. Code section 15 10 4 also sets the maximum spacing of mat reinforcement at 18 in.

What is a slab. If it is a mat on piles the mat is also restrained by the piles. Reinforced concrete box culvert wall is the vertical reinforcing steel on both sides of the wall. To control cracking to make these more watertight it is common to require as much as 0 06 ag reinforcement.

Though little known 10 years ago today mat slabs are a standard solution for building sites with difficult soil conditions.