TERIVA ceilings are prefabricated-monolithic multi-rib construction, joist-hollow block ones. These ceilings consist of grid joists, concrete hollow blocks (some of filling components consist of cellular concrete -see annex) and of the concrete developed on the site.
Basic drawing of the TERIVA ceiling
TERIVA ceilings are designed both for real estate and public buildings industry. What highlights these ceilings is the even load-bearing layout over the whole construction weight which is 4,0; 6,0 i 8,0kN/m2.
TERIVA ceilings technical specifications
|Ceiling type||Ceiling span [m]||Joists gauge [m]||Ceiling construction hight [m]||Top concrete layer thickness [mm]||Ceiling construction weight [kN/m2]|
|TERIVA 4,0/1||2,4 ÷ 7,2 *)||0,60||0,24||30||2,68|
|TERIVA 4,0/2||2,4 ÷ 8,0||0,60||0,30||40||3,15|
|TERIVA 4,0/3||2,4 ÷ 8,6||0,60||0,34||40||3,40|
|TERIVA 6,0||2,4 ÷ 7,8||0,45||0,34||40||4,00|
|TERIVA 8,0||2,4 ÷ 7,2||0,45||0,34||40||4,00|
|*) for span over 6,0m, ceiling designed as ribbon development (no less than 2-span)|
Joists and hollow blocks number and concrete amount developed on the site, required to lay out 1m2 ceiling.
|Ceiling type||Joists [m]||Hollow bricks [item]||Monolithic concrete *) [m3]|
|*) without concrete in separating ribs, rims and other supplementing ceiling components, developed from monolithic concrete|
Real Estate Buildings
TERIVA ceilings reinforcement that is the grid joists reinforcement and additional reinforcement on the wall developed on the site determined in accordance with PN-B-03264:2002, with outline assuming of free-supported joist. The exception is TERIVA 4,0/1 ceiling of which length is more than 6,0m and in which assumed outline of partially-installed joist – proper installation conditions are achieved when the ceiling is designed as no less than two-span one, at neighbouring span ratio no less than 0,7. In accordance with PN-B-03264:2002 norm, with all types of multi-rib ceilings (to which TERIVA ceilings are rated) must be applied supporting reinforcement construction. Ceilings with span shown in the below table require reverse ceiling deflection (upwards bending related to constant supports of the ceiling) by 15 mm. Supporting length of joists on constant support (wall, binding) can't be less than 80 mm. In case of real estate buildings ceilings it is recommended of applying higher ceilings, more stiff ones especially if they require reverse bending because in these types of ceilings the a risk of partition walls and plastering damage occurrence will be lower than in case of flexible ones (lower).
Joists length for which reverse deflection is required
|Ceiling type||Joist length [m]|
2. Ceiling load-bearing
Teriva ceilings can carry even load-bearing layout or even substitute one falling to 1 m2 of the ceiling no more than the ones shown in the table:
The most load-bearing of TERIVA ceiling [kN/m2]
|Ceiling type||Characteristic load-bearing||Calculated load-bearing over construction weight|
|over construction weight||whole|
3. Supporting reinforcement
In accordance with PN-B-03264:2002 norm, p. 9.2. each multi-rib ceiling on support should have upper reinforcement of cross-section area no less than 0,2 of cross-section area of lower reinforcement in the span which is able to carry stretching force no less than 40kN/m of ceiling width. It is recommended of applying supporting reinforcement made of A-III N class steel as welded flat grid in accordance with the drawing or bent one as shown in the drawing.
Flat grid is laid out along all constant supports of the ceiling on which joists are supported. On central supports grid P-1 is laid out and on outermost ones – P-2 grid. Bent grid is laid out in all ceiling ribs; on central supports – Z-1 bent grid and on outermost ones – Z-2 bent grid.
The range of flat and bent grid application
|Ceiling type||Ceiling span l [m], at which is applied|
|flat grid||bent grid|
Layout grid examples:
4. Installation supports
During joists development on the site should be applied installation supports laid out at the span no more than 2,0m, that is at.:
- ceiling modular span l <= 4,0m - 1support,
- ceiling modular span 4,0m < l <= 6,0m - 2 supports,
- ceiling modular span 6,0m < l <= 8,0m - 3 supports,
- ceiling modular span l > 8,0m - 4 supports.
During joists layout installation the supports should be laid out to enable reverse deflection of the ceiling by 15 mm.
On the ceiling outermost edges, on construction walls and the ones parallel to joists should be developed horizontally the reinforced rims at the hight no less than the hight of ceiling construction and at the width at least 100 mm. Rims reinforcement should consist of at least three rods. It is recommended the application of four 10 mm diameter rods made of A-III class steel. The 4,5 mm diameter shackle bolts should be laid out at 250 mm span.
It is recommended that the rims reinforcement should be designed in such a way so that upper longitudinal rods of the rims can be placed about 30 mm below upper ceiling surface. It enables support reinforcement layout and its proper concrete facing.
On the walls made of poor durability materials (e.g. cellular concrete, hollow brick) the lowered rims development is recommended. Lower surface of lowered rim should be placed 40 ÷ 70 mm below lower ceiling surface. Ceiling joists supporting on load-bearing walls is recommended by means of reinforced concrete prefabricated components so called rim profiles which on outermost walls at the same time is the lost shuttering of ceiling rims.
Rims should be concreted along with ceiling concreting, especially paying close attention to perfectly filling with concrete mixture of all spaces including the ones under joists in lowered rims.
6. Separating ribs
In case of ceilings span over 4,0m separating ribs should be applied. If the ceiling span is less than 6,0m at least one separating rib should be applied designed near ceiling span centre. In case of ceiling span more than 6,0m at least two separating ribs should be applied and the distance between constant supports and ribs should be about 1/3 ceiling span. Separating rib width should be 70 ÷100 mm and its hight should be the same as the hight of the ceiling.
Separating rib reinforcement should consist of two rods (upper and lower one) at diameter no less than ø12 linked by ø4,5 shackle bolts, spanned every 0,6m. Reinforcement rods of separating ribs should be bolted in rims or bindings at the right angle to these ribs of the length no less than 0,5m. Separating rib cross-section is shown in the drawing.
7. Ribs under partition walls parallel to joists
Under partition walls situated parallel to ceiling joists should be developed reinforced ceiling ribs. Reinforced ceiling ribs can be developed by layout of two neighbouring grid joists or – if required – by development in reinforced joist ceiling with the reinforcement according to static calculation (example solutions of ribs under partition walls parallel to ceiling joists).
8. Ceiling concreting
Ribs among hollow blocks, slab and hollow blocks of 30 mm thickness with TERIVA 4,0/1 ceilings or 40 mm with the other ceiling types should be developed of concrete no lower then B20 class, corresponding requirements of PN-88/B-06250 norm or C16/20 one with the PN-EN 206-1:2003 norm. Aggregate granularity should be no bigger than 10 mm. Ceiling concreting can be developed after joists layout (on constant supports and installation ones), hollow blocks and after rims reinforcement, ribs and supporting reinforcement layout and correctness checking of all operations should be done. Directly before ceiling concreting, all contamination should be removed and all components (hollow blocks, joists) should be watered.
Ceiling concreting should be done moving progressively at the right angle direction to joists. If concrete is delivered by means of the pomp the even layout across all ceiling surface should be done, preventing against its excessive gathering. In case of concrete delivering on the ceiling in a way that burden its construction, the horizontal transport of the concrete on the ceiling can be delivered by means of wheelbarrows at capacity no more than 0,075 m3 by back and forth system on hard platforms laid out at the right angle to the ceiling joists. Platforms should be made of 38 mm thickness boards at least and 200 mm of width. Platform edges should be secured by skirting boards against wheelbarrow off-rolling.
During concreting close attention should be paid to carefully filling with concrete mixture of all spaces among hollow blocks, aligned joists heads, rims and separating ribs, proper concrete consolidation and its proper treating especially in the season of high or low air temperature. During concreting its samples should be taken in order to control its quality in accordance with PN-88/B-06250 or PN-EN 206-1:2003 norm.