Masonry Magazine June 1972 Page. 24
Cast-in-Place Concrete Floors
The use of cast-in-place concrete floors, because of the time needed for forming, pouring, finishing and curing, requires a building plan which is large enough to permit the masonry work to progress in one part of the structure while the floor in another area is completed. Cast-in-place floors can also be considered where two buildings of sufficient size are being built adjacent to each other; masonry work can alternate back and forth between buildings, the effect being uninterrupted masonry work for the total project.
Connections
Transfer of loads from floor to wall requires proper connection between these elements. Connections are critical to the integrity of a structure and their proper design and detail are particularly important where earthquakes and high wind forces are to be resisted. Examples of several details which have given satisfactory performance are illustrated in Figures 1 & 2.
Non Structural Properties
In addition to their structural qualities, these concrete floor systems possess fire and sound insulation characteristics second to none. Floors having the fire resistance ratings required for fireproof and fire resistive construction are readily obtainable since these properties are inherent; their utilization with concrete masonry walls in constructions not requiring such a high degree of fire resistance provides for savings in insurance costs.
Superior insulation from air-borne and impact noise transmission is another inherent property of the concrete floor system especially when compared to other systems of equivalent cost. Sound Transmission Class ratings generally range from 45 to 55 depending on thickness of floor; and insulation from impact noises as related to thickness of floor structure is decidedly more efficient than other floor systems. Rapid attenuation of impact noises in a concrete floor prevent these noises from being heard or sensed several rooms away from the source.
NATIONAL CONCRETE MASONRY ASSOCIATION
P.O. Box 9185, Rosslyn Station, Arlington, Virginia 22209