Mild Steel Bars in Cement Concrete

Cement concrete is strong in compressive strength but weak in tensile strength. To increase tensile strength we use mild steel bars in cement concrete. Steel bars used in cement concrete provide good strength to the structure. A strong building structure is what all need for their homes, offices and steel is the best option used with cement concrete.

1) Overlapping in Steel Bars in Reinforced Cement Concrete

There should be no joints in steel bars used for RCC work. If it is necessary to use small length steel bars, proper overlap should be given.

• Steel bars are clear, free from loose mil scales, dust, loose rust and any oily materials.
• The bars used at site are manufactured from reputed brand and have a full length.
• Use full length steel bars in beams, slabs etc if not possible, proper overlap should be given in steel bar and overlap should be staggered.
• Tor, ribbed and twisted steel bars are used as they have more tensile stress. Also they are economical and have more strength in cement concrete.
• The bars must be in full length according to the design.
• Proper sizes/ height of crank bars are given in slab and beams etc.
• Proper support under crank bars of beams and slabs must be given.
• Steel bars are not disturbed while lying cement concrete.
• If steel bars are more in number in beams, the bars are placed in two layers by giving spacer between the layers.

3) Checklist/Points before Laying Cement Concrete

• Form work /shuttering should be checked for line, level and its strength.
• Steel bars and their placing should be checked.
• Proper cover to steel bars and adequate numbers of sports/chairs under crank bars must be checked.
• Proper planks or plates provided for walking over reinforcement are not disturbed during working.
• Raw materials should be proper and sufficient in quantity.
• Electrical pipes, fan box etc. should be laid before lying cement concrete.
• Gap in shuttering plates is sealed properly by jute bags /mortar /rubber etc.
• Shuttering plates are properly oiled.
• Curing arrangement must be checked in advance for smooth curing after laying RCC slab.
• Precautionary arrangements are taken in case of rains etc.

Mass Concrete
Mass concrete means cement concrete used for constructions of dams, massive structures, raft slabs and heavy structure beam foundation. There should be rigid/strict control on concrete work with view to ensure durability, strength, and uniformity. In big projects detailed specification is issued separately for individual project according to site requirement and other situation at site of work. Mass concrete is used in important project having heavy load and different types of stresses. Any small deviation in specifications or any irregularity omitted or committed may cause failure of the structure.