The general function of a lintel is to support the masonry wall above the openings (window and door frames) and transfer its load to side walls. Generally, reinforced concrete lintels can be made in 4” and 5” thicknesses.10mm Tor steel bars and 6mm mild steel bars can be used for reinforcement work. And 1:2:4 cement, sand, and metal (20mm) mixture can be used for concrete placement work.
Mostly lintels can be pre-casted because it’s easier than in-situ casting. It’s cast separately somewhere on the floor. When the wall is ready to place the lintel, then it’s just placed on both side walls opening. Here it’s required to erect formwork above the lintel level. That reduces the time taken to make lintel and it will be cost-effective. But the bond between the cast-in-place RCC lintel and masonry wall is very well. But pre-cast lintel doesn’t make any strong bond with a masonry wall.