NCo CLC Ingredients

Sand: Optimum properties are achieved when selecting the most suitable raw material (Sand,Cement). Preference : River (round) sand, washed and with minimum 20% fines. As in conventional concrete (CC), the sand should be free of organic material or other impurities.

Cement: Portland cement is preferred over other cements, such as pozzolan. For Early stripping and optimum mechanical properties, high- grade (early strength) cement is recommended. Where economical, fly-ash may be added to the mix to substitute some of the cement.

Water: When used to produce foam, has to be potable and for best performance should not exceed 25у. Water to prepare the mix has to conform with general requirements for concrete.

NCo Foaming Agent: The containments holding foaming agent must be kept air-tight and under temperatures not exceeding 25у. This way the shelf-life is guaranteed for 24 months from date of Invoice.

Production Procedure

Preparation of moulds

For smooth surfaces clean moulds completely of remaining concrete, the steel/or wood surface must be oiled/waxed.

Steel reinforcement will be placed in the moulds as usual. No coating of the steel is necessary . In panels of more than 12-15 cm thickness, we recommend the use of a double mesh (100 x 100 or 150 x 150 mm).

The steel connected to the lifting anchors should reach more than half of the width of the panel and should possibly not be connected to the mesh. Ordinary steel is used as in CC when casting densities of 1200 or higher. The high ratio of cement to material in NCo CLC ensures proper protection of the steel against corrosion.

The steel embedded has to be covered by minimum 25 mm of concrete The use of spacers is recommended. To prevent cracking when lifting/tilting, steel rods may be placed across the anchors.

Charging, Mixing and Pouring

Before charging the mixer with material, it must be rinsed, in particular if the concrete produced before, used any additive, which might have adverse reaction on the foam. To obtain optimum performance, sand is first fed into the mixer, first absorbing water left after rinsing or from the previous (NCo CLC-) mix

Keep on mixing, until a homogenous colour of the mix is achieved.

The densities recommended are oven dry, achieved when drying the mix for 24h at 105у. Before adding foam, the water/ cement (w/c) ratio of the mortar must be minimum 0,35. Lower ratios may cause the cement to draw water from the foam, causing it to partly or totally collapse, increasing the density and decreasing the yield.

The weight of the foam should be minimum 80 g/l. Use a containment of as close as possible to 10 liters in volume, to check the weight (density) regularly.

Once set correctly, the foam generator will keep the consistency stable, as long as air-and water-supply remains constant as well. We still recommend to check the weight of the foam once in a week or if the density/consistency of the mix varies.

Gravity mixers (e.g. Ready Mix) take the foam under almost instantly and distribute it homogenously in the mix. It takes more time to achieve a proper distribution when using pan-mixers or similar. In between pours, the mixer should be kept in motion until it is completely discharged.

NCo CLC always should be poured in the shortest possible time. If buckets are used to fill moulds, they should hold as much NCo CLC as possible, possibly even pouring one complete panel in one step. Extended time between pours of one building member might result in the creation of dry-joints as happening in the case with regular concrete as well.

Although NCo CLC does not require vibration - at least not to densify the mix - which is liquid anyhow, vibration of horizontally produced panels will show an even better surface, drawing cement slurry to the mould side. Preference is given to High-Frequency vibrators. Length of vibration 15-20 sec. or until bubbles on the surface appear in large numbers. Use aluminium or other straight and sharp-edged screedslats immediately after pouring the concrete. Delayed screeding might ԳmearԠthe surface. If moulds have to be moved after screeding, this might have to be repeated.


Assembly of panels in NCo CLC happens usually the same way as with CC. Special care has to be taken not to apply any mechanical force to avoid damage. If necessary, panels of NCo CLC may be sawn (no gravel), definitely nailed (without the use of dowels as in AAC), drilled or profiled. In densities of 1200 kg/mӠand higher, where reinforcement is used, NCo CLC requires no special coating/plaster on the outside. Water-repellent paint (dispersion-paint) will be suitable.

Vertical casting

The high fluidity of NCo CLC allows full height walls or complete houses (floor by floor) to be cast in one pour, inclusive the slab. Frames for voids for windows, doors and other opening, or penings therefore are cast in place, together with empty tubes and pipes for power and sanitary. No voids, no sagging (beneath frames). Walls/ partitions may be as slender as 50 mm thick only (!) as no vibration is necessary. With a coarse sand paper stuck to a piece of board, rub the walls immediately after stripping, in circular motion, to eliminate possibly honey-web or ԮosesԠcaused by possible irregularities in the mould or by joints. Perhaps a day after stripping it is recommended to saw imitation joints from both sides of the walls on neuralgic positions to allow possible shrinkage to ԡccumulateԠin the joints and not show on the walls, as also done in CC when casting in situ.

Detailed drawings - according ICBO - upon request. As with all lightweight concretes (lesser with CC) hair-cracks might appear but have no adverse effect on the reinforcement, and usually disappear when painted. This way one complete house is cast each day with every set of vertical mould. Where applicable even the gable can be cast at the same time with appropriate modification to the mould.