Masonry

• Masonry is the word used for construction with mortar as a binding material with individual units of bricks, stones, marbles, granites, concrete blocks, tiles etc.
• Mortar


  A mixture of binding material with sand. Binding materials can be cement, lime, soil or any other.
• Components of masonry

  • Mortars
  • Bricks or Concrete Hollow Blocks
• Mortar


  • It cushions the masonry units, giving them full bearing against one another despite their surface irregularities
  • It seals between the units to keep water and wind from penetrating
  • It adheres the units to one another to bond them into a monolithic structural unit
  • It is important to the appearance of the finished masonry wall
• Lime


  Produced by burning limestone or seashells (calcium carbonate) in a kiln to drive off carbon dioxide and leave quicklime (calcium oxide)
• Type N mortar


  A general-purpose mortar with a balance of good bonding capabilities and good workability. Recommended for exterior veneers, nonloadbearing exterior walls, parapets, chimneys, and interior loadbearing walls.
• Type S mortar


  Has a higher flexural bond strength than Type N mortar. Recommended for exterior reinforced masonry, exterior loadbearing masonry walls, and veneers and walls subject to high wind forces or high seismic loads
• Type O mortar


  A low-strength mortar recommended mainly for interior nonloadbearing masonry and historic restoration work
• Type M mortar


  A high-strength mortar with less workability than Type S or N mortars. Recommended for masonry construction below grade, masonry subject to high lateral or compressive loads, or masonry exposed to severe frost action.
• If the mortar was mixed less than 90 minutes prior to its stiffening, it has merely dried and the mason can safely retemper it with water to make it workable again.
• If the unused mortar is more than 2.5 hours old, it must be discarded because it has already begun to hydrate and cannot be retempered without reducing its final strength
• Masonry types

  • Clay Unit Masonry
  • Concrete Unit Masonry
  • Glass Unit Masonry
  • Adobe Unit Masonry
  • Stone /Bricks Masonry
• Clay brick units


  • Typically composed of soft clay extruded into shapes in a manufacturing plant, and are available in various colors, sizes and textures
  • There are two methods of manufacture: extrusion and pressing. The extrusion method produces a denser brick, whereas the pressing method results in a smoother, more accurately shaped brick.
• The type of shale and clay, the plasticity of the mix, and the pressure under which the material is forced into shape all contribute to the character of each individual brick.
• The term brick is used to denote solid clay masonry units. Cored units are still considered solid if cores do not exceed 25% of total cross sectional area.
• The cores reduce weight, increase bond to mortar, and allowing faster drying during fabrication.
• Concrete Masonry Units


  • They can provide the structural frame of a building and they can also serve as a strong backup system for many types of veneer systems
  • Concrete Masonry Walls can even be the veneer system itself with options such as smooth face, split-face, ground face, polished face & glazed face units
• Concrete Masonry Walls used in a single Wythe application
• Concrete Masonry Units


  One of the most versatile products in the construction industry
• Concrete Masonry Units


  • Can provide the structural frame of a building
  • Can serve as a strong backup system for many types of veneer systems
  • Can be the veneer system itself with options such as smooth face, split-face, ground face, polished face & glazed face units
• Concrete Masonry Walls


  • Can serve in both a structural capacity and also be the finished face of the wall
  • Can provide the thermal mass necessary to help reduce heating and cooling costs
  • Can provide redundancy for increased fire-safety in the event sprinkler systems malfunction during a fire
  • Can provide an inordinate amount of sound control wherever used
• Common size of concrete blocks

  39 cm x 19 cm x (30 cm or 20 cm or 10 cm) or 2 inch, 4 inch, 6 inch, 8 inch, 10 inch and 12 -inch unit configurations
• Ingredients used to prepare concrete blocks

  Cement, aggregate, water
• Aggregate composition in concrete blocks

  60 % fine aggregate and 40 % coarse aggregate
• Minimum strength of concrete blocks

  About 3 N/mm2
• ASTM C- 90 - 91 specifies the compressive strength requirements of concrete masonry units
• Density classifications for CMU

  Lightweight (less than 105 lbs./cf.), Medium Weight (105 to less than 125 lbs./cf.), Normal Weight (125 lbs./cf. or more)
• The minimum net area compressive strength of all 3 densities is the same at 2000 lbs./in2 according to ASTM C90
• Solid concrete blocks


  Are commonly used, which are heavy in weight and manufactured from dense aggregate. They are very strong and provides good stability to the structures.
• Hollow concrete blocks


  Contains void area greater than 25% of gross area. Solid area of hollow bricks should be more than 50%. They are manufactured from lightweight aggregates. They are light weight blocks and easy to install.
• Types of Concrete Hollow Blocks

  • Stretcher block
  • Corner block
  • Pillar block
  • Jamb block
  • Partition block
  • Lintel block
  • Frogged brick block
  • Bull nose block
• Stretcher blocks


  Widely used concrete hollow blocks in construction, laid with their length parallel to the face of the wall
• Corner blocks


  Used to join the corner in the masonry, arranged in a manner that their plane end visible to the outside and other end is locked with the stretcher block
• Jamb blocks


  Used when there is an elaborated window opening in the wall, connected to stretcher and corner blocks, provide space for the casing members of window
• Pillar blocks


  Also called as double corner block, generally used when two ends of the corner are visible, in case of piers or pillars these blocks are widely used
• Lintel blocks


  Used for the purpose of provision of beam or lintel beam, generally provided on the top portion of doors and windows to bear the load coming from top
• Partition blocks


  Used to build partition walls, have larger height than its breadth, hollow part is divided into two to three components
• Bullnose blocks


  Similar to corner blocks but with rounded edges at the corner
• Frogged brick blocks


  Contains a frog on its top along with header and stretcher, helps the block to hold mortar and to develop the strong bond with top laying block
• Steel reinforcement in masonry structure

  • Involves reinforcement bars, joint reinforcement, and deformed reinforcing wire
  • Steel bars are utilized to improve both tension and compression strength of masonry structure
  • Maximum reinforcement steel bar size is No.11 as per ACI 530.1-11
  • Epoxy coated and zinc coated steel bars are permitted to use in masonry structures and they may be utilized when corrosion protected reinforcement are specified as per the design