engleski

Precast building components made of EPS concrete

Recently, expanded polystyrene (EPS) concrete has become competitive due to several reasons: firstly, large amounts of waste (packing material) has become a cheap secondary raw material for lightweight concrete production. Secondly, small amount of polymer latex prevents segregation of EPS beads. Thirdly, transportation and compaction of plastic or even fluid workable mixture can be performed by means of ordinary site equipments. Admixing of polypropylene fibers results in high toughness of hardened concrete. In hardened state the possible densities range from 600 to 1800 kg/m3 with corresponding strengths, modulus of elasticity and good insulating properties as well as low water absorption. It is possible to reinforce elements with steel (bars, wire mesh, profiles) and also with wood (boards, planks, battens). All this gives possibility to optimize composites for wide variety of precast light concrete components, e.g. single-layer large façade panels instead of many-layers sandwich systems, tilt-up sanitary cabins, precast floor and wall components, composite floor slabs consisting of lightweight concrete precast slabs and in situ normal concrete topping. The methods for analysis and design of components applied so far were chosen in accordance with the results of material tests and studies of structural behavior of corresponding elements. This paper presents several applications of this improved new material with quite a long history. In order to simplify future applications a study of most recent standards for lightweight concrete was made. It was established that European Standard EN 1520 (Prefabricated reinforced components of lightweight aggregate concrete with open structure) together with some 40 supporting standards quoted in “ Normative references” could be applied to components of EPS concrete. Due to special properties of the material (the closed structure, large amount of cement, impermeability and others) some provisions of EN 1520 regarding density, thermal conductivity, improvement of bond between reinforcement and concrete, corrosion protection, and protection against penetration of water could be modified or even canceled.

lightweight concrete; fiber reinforced lightweight concrete; secondary raw material; latex; expanded polystyrene; precast structural members; standards

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