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Hebel Reinforced Fire Walls - Technical |
Select an area from the list below or scroll down to view more:
In addition, Hebel is a natural insulator: in the event of fire, there is no risk of the emission of toxic fumes due to the presence of synthetic insulation. The autoclaved cellular concrete is made up of sand, water and air. Air filled cells form during the manufacturing process. This air, constitutes the best imaginable thermal insulation in this manufacturing context. As a result, Hebel cellular concrete takes on the characteristics of an insulating material. Cellular concrete is an insulant in itself, so it is unnecessary to provide additional insulation. No more problems generated by poor insulation installation, no more thermal bridges. Building with Hebel always results in 100% efficient, durable insulation. Coefficient of thermal conductivity
Coefficient λui: This coefficient is used for materials that are protected against the penetration of rain or moisture, such as, for example, internal or external walls protected by a finishing layer or watertight covering (cladding) Coefficient λue: This coefficient is applied for materials that can be wet by rain or other sources of moisture. Cladding Panels The calculation of U values is based on the λUi values stated above.
Roof Panels The roof insulation value will depend on the density of the cellular concrete, the slab thickness and any additional insulation. To increase the roof insulation value, it is in general more economical to increase the thickness of the cellular concrete than to fit additional insulation.
Floor Panels The measured #Ui values are used for the calculation of U values.
addition to the insulation values and their impact on energy consumed, we must also take into account comfort and well being within the building. Once again, Hebel stands out in this area due to its excellent thermal qualities. During periods of intense heat or solar radiation, a well insulated building with good thermal inertia will remain pleasantly cool during the day and retain a sufficient temperature at night. Obtaining good thermal comfort requires not only external walls with high thermal capacity (that is, with a high mass to be able to “absorb” the heat), but the wall must also be insulating so that the heat does not pass to the other side too quickly. A simple insulant has too low a mass and so cannot store the heat. With a light roof composed of insulation and steel sheet or tiles, a “caravan” effect will arise. This is a rapid heating of the building subject to solar radiation causing discomfort due to excessive heat. The only solution to combat this heating is air conditioning, which is very costly in terms of energy. Hebel has the characteristics of an insulating material and possesses a high mass (between 400 and 700 kg/m3). Hebel meets the conditions for high thermal inertia. Numerous tests have shown the thermal efficiency of Hebel slabs.
Fundamentally, a distinction must be made between airborne noise and impact noise for the sound insulation of building elements. Airborne noise comes from a source that makes the air vibrate directly (e.g. radio, TV). Impact noise of comes from a source that makes part of the building vibrate; the noise is then transmitted to neighbouring rooms and so makes the air vibrate indirectly (e.g. vibration in central heating pipes). Impact noise insulation must be provided for at the design stage. It is very important, from this point of view, to make the necessary arrangements between quiet and noisy premises. The sound insulation that we describe below only takes airborne noise into account and not impact noise. In common usage, “insulation against airborne noise” is often confused with “noise absorption”. These principles are explained below. Sound absorbing products serve to limit the reverberation time and to adjust the acoustic comfort in the room, whereas sound insulation is given to mean the reduction in sound intensity transmitted from one room to another. Insulation against noise In practice, the noise between two rooms does not only propagate directly (meaning through the separating wall), but also indirectly (side walls, ceilings, floors, etc.). More specific sound insulation, which takes both the direct and indirect routes into account, is called overall airborne noise insulation; this is a real value that can be measured on site. In contrast, the transmission loss coefficient of a material is a laboratory-measured value based only on the direct transmission of noise through the separating wall. It is expressed in dB. In accordance with Belgian standard NBN S 01–400, the transmission loss coefficient (R) of a building element is expressed in classes, and Hebel is placed in the following classes:
In accordance with standard DIN 4109, a calculated value of the overall sound insulation (R’w,R) can be deduced from the mass per unit area of single rigid walls or ceilings. It is based on construction with closed joints or a noise proof finish. The table below gives some of these calculated values as a function of mass per unit area.
Noise absorption Sound waves that strike a wall are partly reflected, partly absorbed and partly transmitted.
In accordance with Belgian standard NBN S 01-009, sound absorption is expressed by an absorption coefficient a of between 0 and 1. The value of the coefficient a (sound absorption factor according to Sabine) depends on the frequency of the incident sound and the surface structure of the construction element. The absorption factor (a) of a wall is: α = transmitted sound energy + absorbed incident sound energy α = 1 signifies that all noise is absorbed or transmitted (e.g.: open window) α = 0 signifies that all noise is reflected Reverberation occurs in a room when the incident noise is reflected and absorbed to a lesser extent. The sound absorption of a building element inhibits reverberation in a room. In the event that all the sound energy is completely absorbed, the coefficient value is 1. Due to its cellular surface structure, cellular concrete has a sound absorption capacity 5 to 10 times greater than smooth materials. The graph below shows that Hebel absorbs ± 25% of the noise.
Appearance Texture: smooth structured Colour: white Density
Dimensions Width: the actual width is 600 mm. Thickness: 100 - 150 - 200 - 240 - 300 mm. Length: the length of the panels depends on the thickness, with a maximum of 6,000 mm. Tolerances Length: + or – 3 mm for L <= 1,200 mm + or – 0,0025 L for L > 1,200 mm Width: + or - 2 mm Thickness: + or – 2 mm Shrinkage due to drying For cellular concrete, the shrinkage due to drying does not exceed 0.2 mm/m (see table below). Thermal expansion coefficient The linear expansion coefficient of a material is the variation in length of a 1 metre element per 1°K of temperature variation. The linear expansion coefficient of cellular concrete is 8 • 10-6m/mK (in accordance with standard NBN B 21-004). Compression strength Category CC 3/500: fck >= 3.00 N/mm2 (characteristic value) Category CC 4/600: fck >= 4.00 N/mm2 (characteristic value) (in accordance with standard NBN 21-004) Modulus of elasticity Category CC 3/500.1500 N/mm2 (in accordance with standard NBN 21-004) Bending tensile strength Short term Category CC 3/500: fcflk = 0.81 N/mm2 (charact. val.) Category CC 4/600: fcflk = 1.08 N/mm2 (charact. val.) Long term Category CC 3/500: fcflk = 0.54 N/mm2 (charact. val.) Category CC 4/600: fcflk = 0.72 N/mm2 (charact. val.) (in accordance with standard NBN B 21-004) Aesthetics Cellular concrete is a material made from natural raw materials. Slight differences in shade are therefore possible. Any chips in the panels can be very easily repaired. However these repairs might remain visible. If a perfect finish is required, it is therefore advisable to provide an external and/or internal finish. |
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