Concrete Masonary Unit & Lintel Opening

Campion College concrete masonry unit (CMU) - partial wall removal and lintel installation

The Campion College is a five-storey building, with a three-storey chapel tower to the south. The superstructure is cast in place concrete and in general, the structural slabs are one-way slab systems. For the main north building portion, on the first floor through to the roof level between Grids A to K, and Grids 1 to 4, the one-way slab has slab bands supported on columns. Outside of these gridlines a concrete slab with either concrete beams or concrete joists were used. The exterior wall load bearing system is constructed of cast-in-place concrete. The foundation is comprised of concrete foundation walls on belled concrete piles.

The proposed opening located on CMU wall running in the north-south direction is expected to be 1200mm wide. The top of the opening is proposed to be located approximately 4 concrete block courses below the top of the CMU wall. A loose lintel is required to support the existing CMU above the new opening.

The steel loose lintel shall be a L152x152x9.5 steel angle member, with the bottom leg slotted into a cut in the mortar bed joint (located between concrete block courses). The length of the member is to be the opening width plus 200mm on each side for bearing length. For example, for the opening width of 1200mm, the steel loose lintel should be 1600mm long, to have 200mm extending past the opening on each side. The loose lintel shall be installed before the CMU is removed beneath the lintel at the proposed opening location.