LECA CLS 1400 - LECA CLS 1400Ri
THE FIRST STRUCTURAL LIGHTWEIGHT CONCRETE
PREMIXED FOR REINFORCEMENT CASTING AND
SLABS ACTING COMPOSITELY WITH THE
STRUCTURE, FOR THE RESTORATION OF OLD
WOODEN FLOORS, CONCRETE FLOORS, I-BEAMS
AND CORRUGATED SHEETS. AVAILABLE ALSO IN
THE 1400RI FAST HARDENING VERSION
ADVANTAGES
Lightweight
Safe
Premixed Leca CLS 1400 and Leca CLS 1400Ri weigh 1,400
Kg/m3, a lot lighter than the 2,200 - 2,400 Kg/m3 of traditional
concrete. A reinforcement casting 5 cm thick weighs 70 Kg/m2
against the 110 - 120 Kg/m2 of standard concrete. This reduction of the loads is particularly important in the restoration of
wooden floors.
Leca CLS is a premixed product. It has a granulation curve and
a constant and controlled granular distribution in curve and
binder dosing. The simplicity of the mixture assures, with the
right quantity of water, the performances of the best concrete.
Resistant
Leca CLS although being light has a resistance level similar to
traditional concrete prepared on construction sites. Leca CLS
1400 and Leca CLS 1400Ri have a resistance of 250 Kg/cm2.
Practical
Leca CLS is packaged in practical and easy-to-handle bags that
helps handling and storage operations even in difficult sites and
also simplifies mixing operations because it just needs water. For
an optimal mixture we suggest using mixers with metering screw
(even continuous).
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Incombustible
Leca CLS, prepared with Lecapiù, siliceous aggregates and
watery binders, has an A1 Euroclass level.
“Compliant” with the standards
Leca CLS fully complies with the requirements of the Ministry for
Public Works and uses only cement with Conformity Certificate
as per Decree 12/7/99 n° 314 as binder (for more information
see page 67).
Pumpable
It’s pumpable with the standard pneumatic pumps used for
foundations.
THE LIGHTWEIGHT CONCRETE FOR RESTORATION WORKS
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4
3
2
1
Reinforcement of wooden floor - Alessandro Manzoni house in Milan
1) Structure to reinforce
2) Structure connection system/Leca CLS
3) Leca CLS 1400 or Leca CLS 1400Ri
4) Elastic mat and damp proof barrier
5) Lecamix screed
FIELDS OF USE
Creation of slabs acting compositely with the structure on
wooden, concrete floors, I-beams and corrugated sheets. Ideal
when a lightweight and resistant concrete is needed, even in
short period of time.
Not suitable for:
Thickness lower than 5 cm.
Mixture with “wet-soil” consistency.
Wood floor
Corrugated sheet floor
Consolidation of wooden floors - Viboldone Abbey in Milan
I-beam and concrete floor
Concrete floor
Seismic beam
Structural casting
1
2
3
4
5
6
Leca CLS (1400; 1400Ri).
Metal frame or weldmesh.
Floor or existing structure to reinforce.
Continuous or dotted metal connectors for slabs.
Premixed Lecamix screeds.
Elastic mat for impact sound insulation and/or damp proof barrier.
Restoration of roof – Church of Loreto
LECA CLS 1400 AND 1400Ri: STRU
METHODS OF USE
PREPARING THE SURFACE
The surface must be clean, without any inconsistent parts, dust
or other residues; it must be suitable for reinforced
concrete casting. Therefore, reinforcements, connections,
spacers and/or form release agents must be applied.
PREPARING THE MIXTURE
Tank concrete mixer
• Put one or more bags into the mixer;
• Do not load more than 60% of the mixers capacity and mix
with the rotation axis almost horizontal;
• Add 6.5 litres of clean water for every bag;
• Mix for at least 3 minutes until reaching a “semi-fluid” consistency.
Mixers with metering screw
• Put one or more bags into the mixer;
• Add 6 litres of clean water for every bag;
• Mix for at least 3 minutes until reaching a “semi-fluid” consistency.
For an optimal mixture with high productivity levels, approx. 2 2,2 m3/hour (57÷63 bags/hour) we suggest using the continuous Lecamix mixer.
APPLICATION AND FINISHING
Leca CLS is cast just like traditional concrete. The vibration
phase must be performed very carefully so that the Lecapiù
granules do not rise to the surface.
FINISHING LAYER
A concrete floor is not a foundation and must not be interrupted with the installations (plumbing piping, drains, electric installations, etc.) otherwise the resistance level of the floor itself will
be affected. Hence, an adeguatefinishing screed is necessary
and we suggest the use of lightweight products (Lecamix line).
If the site limitations do not allow for the creation of a proper
foundation it is possible to directly glue the flooring on Leca CLS
1400 and1400Ri, just as on a traditional concrete layer. In this
case, be very careful when preparing the casting surface (planarity and smoothness), and use materials and techniques suitable for the concrete gluing (elastic glues, small formats, large
joint widths).
Also consider the consequences that the deflection of the
layer could have on the flooring and the content of residual
humidity before gluing. To maintain good final resistance
levels, use the right quantity of water in the mixture (do not lay
with a “wet soil” consistency”).
WARNINGS
• Remember that more water is a synonym of less resistance: the product must not become “self-leveling”, while it is being cast: the casting
on site must be achieved through vibration of the casting.
• We do not recommend hand mixing for premixed Leca CLS. Do not
add other inert materials, cement, lime, gypsum, admixtures.
• Leca CLS 1400 and 1400Ri screeds must be protected against
excessive drying especially during summer. Furthermore, be very careful with castings on old, highly absorbing foundations (such as bricks)
and low thickness (risk of “burning”).
• In case of casting on clay bricks which are visible on the ceiling’s
underside it is necessary to foresee a proper protection against possible absorption by support.
• Do not apply with temperatures lower than + 5 °C or higher than + 35 °C.
• The use of anti-freezing additives is appropriate.
• Interventions with reinforced concrete in structural works and/or situations acting compositely with the structure must be performed under
the control of a certified Technician in accordance with the regulations
in force.
• Not appropriate for use with truck mixers or in silos.
• Not appropriate for “facing” applications.
• See “General warnings” on page 67.
UCTURAL LIGHTWEIGHT CONCRETE
TECHNICAL FEATURES
Leca CLS 1400 Leca CLS 1400Ri
Density in bag
approx. 1.150 Kg/m3 approx. 1.150 Kg/m3
Density on site
approx. 1.400 Kg/m3 approx. 1.400 Kg/m3
Application temperature
from + 5 °C to + 35 °C
Treadable after casting
12 hours
8 hours
Dry thermal conductivity
0.42 W/mK
0.42 W/mK
Consumption (floor consolidation) appr. 0.33 bags/m2 for 1 cm thickness
Characteristic compressive
strength
≥ 25 N/mm2
≥ 25 N/mm2
2
(laboratory)* a 28 gg.
(250 Kg/cm )
(250 Kg/cm2)
Average compressive
24 hours 15 N/mm2
strength
approx. 25 N/mm2 3 days 20 N/mm2
(construction site)** at 28 days (250 Kg/cm2)
7 days 25 N/mm2
Characteristic compressive
strength
20 N/mm2 (200 Kg/cm2)
(suggested for calculation)
E (elastic modulus)
approx. 15.000 N/mm2
Fire reaction
Euroclass A1 (Incombustible)
Packaging
Wooden pallets with 40 bags
35 litres/each equal to 1.4 m3
of loose product
(on request 25 bags: m3 0.875)
Preservation conditions
in original packages, in
and duration
covered and dry place with
(as per Min. decree 10/05/04) no ventilation.
Maximum six months from
date packing.
* ** The values of “Characteristic strength (Laboratory)” and “Average strength
(construction site)” refer to parts prepared with the water quantities indicated in
section “Methods of Use”, made, cured and tested according to the UNI standards in force.
Ask for the Safety Sheet.
REINFORCEMENT OF FLOORS
When consolidating wooden floors or in the
creation of new floors, for example in corrugated sheeting, it is necessary to restore
pre-existing structures and adjust them to
the loads required by the standards in
force. This is why a mixed structure is created to obtain T-section beams. Basically
this means casting a new concrete floor
perfectly interconnected with the existing
bearing structures. A new concrete casting
means increasing the weight of the floor and demanding from
the entire building (walls, pillars, foundations) an overload to
transfer and divide over the carrying ground. For the floors this
also means increasing the different deformations of the
structure itself.
Leca CLS 1400 and 1400Ri, designed for this use, thanks to their
low weight assure limited permanent loads, hence limited sinkage/warping. The compressive strength is more than enough in
most of the cases to absorb the compressive stress.
As for the connectors needed for the connection between
the concrete and the existing structure, below are a few suggestions referring to the two main systems and their appliance on wooden floors – dotted connectors
(mechanically fixed or with resins) or continuous, are used
made of galvanized steel profiles, mechanically fixed using
screws fixed to the beams for floors with
I-beams or corrugated: dotted connectors, welded, riveted or
nailed to the existing structure are used. In all cases the
connectors must be checked for the horizontal strength and with
wooden floors, for the punctual streangth. It is advisable to use systems produced by specialized companies that often usually assistance both during the design phase and the implementation phase.
SPECIFICATIONS
Structural lightweight concrete Leca CLS 1400 (or Leca CLS
1400Ri) premixed in bags with water-proof expanded clay
(humidity absorption approx. 1% at 30’ according to EN
13055-1), natural aggregates, Portland cement and
admixtures. Density of concrete at 28 days approx. 1.400
Kg/m3. Average compressive strength at 28 days (at 7 days
for Leca CLS 1400Ri) determined on cubes prepared on job
site 25 N/mm2.
Preparation and casting on site according to the
manufacturer’s indications.
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