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Md. Abdul Ahad12-01-03-104
Presented By
Monisha Podder12-01-03-110
Arafat Chowdhury12-01-03-116
Sabrina Zissan12-01-03-124
Mahbub Al Muhaimin12-01-03-129
Abu bakar Siddik12-01-03-136
Sabrina Mehenaz12-01-03-144
MAT Foundation• Primary shallow foundation;
• Also known as Raft;
• Large footing extended over the whole construction area;
• Supports many columns;
• Foundation for high rise buildings with basement;
• Depth 1~20 feet.
When we construct MaT foundation?
• When the area of individual column footings cover
more then 50% area of total land;
• When the bearing capacity of soil is too weak to
support a structure;
• When the cost of deep foundation is higher then
Raft foundation.
• When the structural load is too high.
Types of MAT
Flat Plate MatTwo-way Beam & SlabFlat Plate Thickened Under
Column
Flat Plate with Pedestals Pile Mat Rigid Frame mat
construction Procedures
Soil test
Shoring & Water
proofing
Partial Excavation
(depending on depth)
Bracing (depending on
depth)
Full area excavation
Soil compaction
BFS & CC or LC layer cover
Reinforcement placing
Shuttering
Casting & Compaction
Shuttering removal
Curing
Soil Test
• Bearing capacity of
soil;
• Soil classification;
• Ground water level;
• Moisture content;
• Appropriation & depth
of MAT.
Shoring• Shoring is commonly used when installing the
foundation;
• Shoring support the surrounding loads until the
underground levels of the building are
constructed.
• Can be of 3 types: Pile shore, steel sheet shore
and timber shore.
Water proofing
• A layer provided over
shoring to prevent
moisture;
• Cement mortar or steel
sheet layer over
shoring;
• Cement mortar layer is
extended over wire
mesh.
Bracing
• A horizontal support for
the boundary shores
during excavation and
foundation;
• Depends on the depth of
foundation;
• Also known as horizontal
shores.
Reinforcement placing
• A batch of horizontal reinforcement placing;
• Another batch of reinforcement placement to complete the bottom mesh;
• Column rod placement;
• Vertical rod (chair) placement over bottom mesh to hold the upper mesh;
• Upper mesh placement.
Important factors
Reinforcement Selection
• 60~72.5 Graded
• 12mm~25mm
Reinforcement Joint
• Heavy Steel wire binding
Chair
• Distance
• Bending
Cast Material
• Mixture ratio 1:2:4;
• Sylhet sand is used
over 50%;
• Stone chips that are
used normally is
½”~¾” in size;
• Stone chips are
preferred than brick
chips.
Precautions for casting
• Materials like piece of wood, polythene etc. must be
removed before casting from that area;
• Shuttering must be leak proof;
• Cast pouring height is less than 5 feet ;
• Pouring and compaction both are done simultaneously.