THE ECOLOGICAL SOLUTIONS OF THE COMPOSITE FLOOR STRUCTURES AND DENSE PERFORATED CONCRETE WALLS.

Lech Czarnecki, Professor, Warsaw University of Technology;

Jerzy Zdzisław Pluta, Professor, Warsaw University of Technology; Katarzyna Pluta, dr arch., WUT; Aleksandra Pluta, mgr inż. WUT, Warsaw, Poland.

1. Introduction

In the world solutions of environmentally friendly buildings, the walls and the floors have to be designed of ecological materials, as well as they should actively regulate the microclimate of the rooms (constant temperature and humidity). This is possible when the external layer of building elements has a sufficient mass and low vapour infiltration resistance. The vapour condensate is accumulated in porous material and after reaching the sorption equilibrium is given back to the interior’s atmosphere. In contemporary design to achieve self regulation of humidity in the interior there should be used materials such as: ceramics, gypsum, gypsum polystyrene, keramsite aggregate concrete and wood –fibre cement. Disadvantage for microclimate of interior are such materials as: concrete, polystyrene and foil insulation under thin plates of gypsum plaster. In the paper there are presented the new Polish solutions of floor and walls’ structures, which form full ecological interior.

2. The composite multirib JZP -45/28 floor system

In the composite multirib JZP-45/28 system the precast units were divided on upper-structural and down -filled (Fig.1). The structural element has original key edges divergent shear joints and transfers shear forces in the compressive zone, what considerably reduces the negative influence of creep and concrete shrinkage on the beam deflection [1].

Fig.1. Composite multirib JZP-45/28 system

The laboratory tests of JZP -45/28 structure 7,20 m span have showed the increasing of loading capacity and system rigidity as well as very small deformability of the key edges divergent shear joints, what ensured the transfer of horizontal shear forces from the monolithic ribs to the precast concrete upper elements. In the JZP -45/28 structure there were used the down filling elements of keramsite aggregate concrete (Fig.2), gypsum (Fig.3), and gypsum –polystyrene (Fig.4).

Fig2. The down filling elements made from keramsite aggregate concrete

Fig3. The down filling elements made from gypsum

Fig.4. The down filling element made from gypsum –polystyrene

Fig.5. The Centre Kodak building in Konstancin near Warsaw The ecological structur gate filling units was

3. The composite JZP –LC floor plank system (P362237, 17.09.2003)

In the modern design with the application of large spans - the slab -column skeleton structure

Fig.6. JZP-LC composite floor plank system

e JZP -45/28 span 7,20m with keramsite aggreapplied in the Centre Kodak building in Konstancin near Warsaw (Fig.5).

has became too weighty and not economical. At present on the precast floor planks there are placed the thinwalled infill cassette elements.

For the purpose of obtaining the inside space for installation system and the ecological ceiling, authors decided to open the floor and to introduce double material element: structural concrete combined with concrete in situ and porous material as an absorbent of humidity - JZP-LC composite floor plank system (Fig.6) (P.362237, 17.09.2003). For the down layer of the element there are recommended: ceramics, poroceramics, light concrete and wood –fibre cement plates. Especially wood –fibre cement plates have a very low vapour diffusion resistance, and also are an excellent sound insulation. The structure may be applied in unidirectional system as well as in grid system. In the second case the stiffening ribs have to be more dense situated.

4. The dense perforate concrete walls with free vapour diffusion through the wall.

The polystyrene panels have very high infiltration resistance, what makes the vapour diffusion through walls impossible. Authors have introduced in wall’s elements the gypsum -polystyrene’ layer reaching to the mineral thinwalled plaster, what assures the constant vapour transmission (P.362238, 17.09.2003), (Fig.7) [2].

Fig.7. JZP –LC dense perforated concrete walls system

The basic wall element creates the vertical and horizontal concrete ribs as an open bear system. The continuous gypsum –polystyrene layers reaching the thinwalled mineral plaster let to achieve the constant vapour diffusion through the wall, what prevents the development of mould.

5. Conclusions

At present according to the idea of sustainable development of human settlements, including sustainable building and construction there should be used “materials conducive to health and production of a good indoor climate in buildings” (“The European Urban Charter”, adopted by the Council of Europe’s Standing Conference of Local and Regional Authorities of Europe in 1992, Strasbourg) [3].

The examples of such building materials for floors and walls and arrangement of layers are presented in the paper. They could be used by local construction industry. Presented system of multirib floor structure JZP -ECOL - a new element of polish building technology development has been applied in the practice and would be recommended to the modern construction, especially ecological (system has been tested in laboratory and certified by Building Research Institute). The laboratory research has showed very good collaboration of composite elements. The solutions have fulfilled the requirements for an ecological interior and at the same time have ensured high standard of interior’s architecture. Presented solutions are profitable building’ structures owing to reduced dead load, and create the possibilities of leading installation systems in the space inside floors.

The development of new environmentally friendly construction technologies is one of the main problems in achieving sustainable development of the region.

6. References

[1] J.Z.Pluta, K.Pluta. “Ustroje stropowe, ścienne i szkieletowe systemu JZP -ECOL”. Inżynieria i Budownictwo, 7/2000, str.371-373. [2] J.A.Pogorzelski, K.Firkiewicz –Pogorzelska. „Przydatność PN-EN ISO 13788 do oceny wilgotności przegród”. Materiały Budowlane 2/2004, str.47-48. [3] “The European Urban Charter”. Council of Europe’s Standing Conference of Local and Regional Authorities of Europe (CLRAE), 18 March 1992, Strasbourg, str.17.