Mass Concrete Wall Design

What is mass concrete.

Mass concrete wall design.

Aci defines mass concrete as any. Try 1400mm thick wall. Design tanδ tan 20º or 0 75xdesign tanφ 0 364 or 0 503 design tanδ 0 364 from table design φ 33 8º design δ 20º ka 0 242 10kn m surcharge on retained soil behind wall. Any volume of concrete in which a combination of dimensions of the member being cast the boundary conditions the characteristics of the concrete mixture and the ambient conditions can lead to undesirable thermal stresses cracking deleterious chemical reactions or reduction in the long term strength as a result of elevated.

Mass concrete is defined in aci 116r as any volume of concrete with dimensions large enough to require that measures be taken to cope with generation of heat from hydration of the cement and attendant volume change to minimize cracking the design of mass concrete structures is generally based on durability economy and thermal. Elliot faci technical service manager buzzi unicem usa. Gravity retaining walls depend on their own weight and any soil resting on the concrete in resisting lateral earth forces. The exact amount should be calculated as part of the design process.

Concrete strength al ൯ne for an 10 thick wall with 5 10 and 2 5 clear to strength steel will only reduce the nominal moment capacity of the secti對on from 136 68 to 135 66 inch kips 尩 if the concrete strength decreased from 3 5 to 3 0 ksi. Counterfort retaining walls are more economical than cantilever walls for heights above 25 ft. Because the outside surface is concrete thermal mass walls also make it easier to work with certain high quality wall finishes. They are generally economical up to 10 feet in height for cast concrete structures.

Precast insulated concrete sandwich or thermal mass walls also offer builders speed of construction for instance dow chemical company s styrofoam precast t mass walls can be erected in as little as a day. Gravity poured concrete retaining walls. One of the options the iecc prescriptive r values iecc table 502 2 1 calls for continuous insulation on concrete masonry and other mass walls. Mass concrete is defined by the american concrete institute as.

Concrete slab floors should be 100 200mm thick for the best performance while thermal mass walls should be 100 150mm thick. P w due to active pressure surcharge wall self weight 1 wall self weight 2 weight of soil wall friction ia m 0 5 x 0 242 x 18 x 2. This refers to insulation uninterrupted by furring or by the webs of concrete masonry units.