MORTAR COMPOSITION FOR ACOUSTIC DAMPING AND FIRE PROTECTION

Abstract

A mortar composition, in particular for preparing a viscoelastic structure and/or a fire barrier, including: a) 15-50 wt.-% of a hydraulic binder, b) 5-35 wt.-% of lightweight aggregates, c) 5-25 wt. % of further aggregates which have a particle density that is higher than the particle density of the lightweight aggregates, and d) 10-50 wt.-% of a polymer.

Claims

1. A mortor composition, comprising: a) 15-50 wt.-% of a hydraulic binder, b) 5-35 wt.-% of lightweight aggregates, c) 5-25 wt. % of further aggregates which have a particle density that is higher than the particle density of the lightweight aggregates, d) 10-50 wt.-% of at least one polymer.

2. The mortar composition according to claim 1, wherein the hydraulic binder comprises Portland cement as well as aluminate cement and/or sulphoaluminate cement with a weight ratio of Portland cement to aluminate cement and/or sulphoaluminate cement from 1-5.

3. The mortar composition according to claim 1, wherein a particle density of the lightweight aggregates is from 100-2,000 kg/m.sup.3 and wherein the further aggregates have a particle density >2,000 kg/m.sup.3.

4. The mortar composition according to claim 1, wherein the lightweight aggregates comprise inorganic particles and wherein a particle size of the lightweight aggregates is from 0.01-2 mm.

5. The mortar composition according to claim 1, wherein the further aggregates are selected from sand, quartz, and/or calcium carbonate, whereby a particle size of the further aggregates is from 0.01-2 mm.

6. The mortar composition according to claim 1 wherein a weight ratio of the lightweight aggregates to the further aggregates is from 0.1-5.

7. The mortar composition according to claim 1, wherein the polymer is a water soluble or water redispersible polymer.

8. The mortar composition according to claim 1, wherein the polymer comprises two different copolymers, a copolymer of vinyl acetate and ethylene and a copolymer of acrylic acid ester and styrene, wherein a ratio of the two different copolymers is from 0.5-10:1.

9. The mortar composition according to claim 1, wherein a weight ratio of the polymer to the lightweight aggregates is from 0.5-10.

10. The mortar composition according to claim 1, comprising: 16-20 wt.-% of Portland cement; 5-10 wt. % aluminate cement and/or sulphoaluminate cement; 5-10 wt. % latent hydraulic and/or pozzolanic binder materials; 10-20 wt. % lightweight aggregates in the form of porous inorganic particles: 10-20 wt. % of further aggregates; 25-40 wt.-%, of at least one polymer with a glass transition temperature of −20-45° C., whereby all amounts are with respect to the total weight of the mortar composition in dry state.

11. A shaped body comprising a mortar composition according to claim 1 after hardening with water.

12. A structure comprising a shaped body according to claim 11 and a support element and/or a cover element being attached to the shaped body.

13. The structure according to claim 12, comprising: a metallic support element; the shaped body; a cover element; an insulation layer; and a deck covering.

14. A method for acoustic damping, comprising applying the mortar composition of claim 1, to a vehicle, a building and/or an offshore installation.

15. A method of forming a fire protection system, comprising: applying the mortar composition of claim 1 to a firewall and/or a fire barrier.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0173] The drawings used to explain the embodiments show:

[0174] FIG. 1A schematic cross-section through the test setup in which the acoustic measurements were performed. The setup comprises two reverberant rooms (1, 2) with a common opening for receiving test decks (2);

[0175] FIG. 2A perspective view of a test deck (2) with a vibration exciter (4);

[0176] FIG. 3A cross-section of a floor structure on a steel deck (4). The floor structure comprises a hardened mortar composition (5) which is covered by steel plates (6);

[0177] FIG. 4A cross-section of another floor structure on a steel deck (7). The floor structure comprises a hardened mortar composition (8) covered by steel plates (9) and a floating floor (10, 11) on top;

[0178] FIG. 5A cross-section of a setup used for fire test comprising a furnace (12) which is covered with a steel deck (13). On top of the steel deck (13), a floor structure (14, 15, 16, 17) is applied;

[0179] FIG. 6 The measured sound reduction indexes R for a mortar composition (closed circles) as well as a bare steel deck (open circles).

[0180] In principle, identical parts are provided with the same reference numbers in the figures.

EXEMPLARY EMBODIMENTS

[0181] 1. Mortar Compositions

[0182] Table 1 shows three mortar compositions M1-M3. The mortar compositions have been prepared by intermixing all of the components in dry state. The mortar composition M1-M3 are present as dry powders.

TABLE-US-00001 TABLE 1 Mortar compositions Component M1 M2 M3 Hydraulic binder [wt. %] Portland cement (CEM I, 52.5N) 18 18 18 Calcium aluminate cement.sup.1) 6.5 6.5 6.5 Anhydrite.sup.2) 2.3 2.3 2.3 Slag 5 5 5 Lightweight aggregates [wt. %] Expanded glass.sup.3) 15 15 15 Further aggregates [wt. %] Sand.sup.4) 14.8 19.8 23.8 Polymer [wt. %] Redispersible copolymer.sup.5) 7.5 7.5 5.0 Redispersible copolymer.sup.6) 27.5 22.5 20.0 Additives [wt. %] Plasticizer.sup.7) 0.08 0.08 0.08 Glass fibres.sup.8) 0.15 0.15 0.15 Polyethylene fibres.sup.9) 0.3 0.3 0.3 Processing additives.sup.10) 2.87 2.87 3.87 .sup.1)Isidac 40, calcium aluminate cement, Cimsa, Turkey .sup.2)Raddipur, CASEA GmbH, Germany .sup.3)Rotocell, particle size 0.09-0.30 mm, Rotec, Germany .sup.4)Quartz sand with particle size 0.1-0.2 mm. .sup.5)Highly flexible dispersion powder based on vinylacetate-ethylene copolymer (Tg = −7° C.) .sup.6)Redispersible polymer powder based on styrene-acrylicacid ester copolymer (Tg = −15° C.) .sup.7)Melflux 5581F, polycarboxylate ether, BASF Germany .sup.8)Cem-Fil, type 70/30, glass fibers, 3 mm length, 20 μm diameter, Owens Corning Composite Materials LLC, USA .sup.9)Fibers F PE 930 T, 0.2-0.5 mm length, 10 μm diameter, Brenntag, Polska .sup.10)Defoamer, rheology modifiers, thixotropic agents, retarder

[0183] Mortar compositions M1-M2 have been mixed with water (weight ratio of water to total weight of dry mortar composition=0.29) in order to obtain processable compositions.

[0184] 3. Processing Properties

[0185] Flow table spread values were assessed according standard EN 12350-5:2009. Directly after preparation values in the range of 176 mm (composition M1) and 173 mm (composition M2) were obtained. Thus, the mortar compositions show a flow behavior which makes processing easy.

[0186] 3. Adhesion Properties

[0187] Mortar compositions M1 and M2 have been applied with a thickness of 2 mm on a cleaned flat steel plate.

[0188] For reason of comparison, a similar system has been prepared with 2 mm SikaFloor® Marine PU-Red (polyurethane based layer) instead of the mortar composition M1.

[0189] Adhesion test carried out similar to standard EN 1348:2007 with the mortar compositions on steel substrates showed bond strengths of: [0190] 0.8 MPa for composition M1 and 1.3 MPa for composition M2 after 7 days; [0191] 1.0 MPa for composition M1 and 1.3 MPa for composition M2 after 28 days; [0192] 0.9 MPa for the comparative composition after 7 days as well as after 28 days.

[0193] Thus, with regard to adhesion on steel, the inventive mortar compositions can compete with polyurethane based systems.

[0194] 4. Acoustic Properties

[0195] 4.1 Test Facilities

[0196] The measurements were carried out in two reverberant rooms as shown in FIG. 1. The rooms are built on two separate foundations made of concrete with a wall thickness of 30 cm. Between the source room 1 and the receiving room 3 there is an opening of 2.99 m×3.37 m, i.e. in the ceiling of the source room 1 and in the floor of the receiving room 3, where a test deck 2 is installed. The volume of the source room 1 and receiving room 3 is 243 m.sup.3 and 230 m.sup.3, respectively.

[0197] Excitation of the test deck 2 with airborne noise and impact noise is carried out with loudspeakers and a tapping machine as stated in standard ISO 10140:2010.

[0198] Excitation of the test deck 2 with structure-borne noise is performed by means of a vibration exciter 4 coupled to a steel plate 5, which is mounted perpendicularly and below the steel deck positioned in the opening, as shown in FIG. 2. By means of this arrangement a reverberant vibrational field is established both in the steel plate coupled to the exciter and the steel deck simulating the real conditions occurring in a ship structure.

[0199] 4.2 Measurements According to ISO 10140:2010

[0200] Measurements according to ISO 10140:2010 were performed as follows:

[0201] During the airborne and structure-borne sound measurements the excitation is performed by means of broadband pink noise in the frequency range 20-10000 Hz.

[0202] The response, i.e. the sound pressure level in the receiving room 3 for the airborne and impact sound insulation measurements or the velocity level on the floor for the structure borne sound measurements, are measured in one-third octave filter bands with center frequencies from 50 Hz to 5000 Hz.

[0203] Measurements in the one-third octave filter bands of 50 Hz, 63 Hz and 80 Hz are not required according to ISO 10140:2010. However, based on experience from previous measurements on ships, it seems reasonable to include these frequency ranges.

[0204] All relevant instruments in the test setup are calibrated before and during the testing period for every construction.

[0205] 4.3 Measurements According to ASTM E2963-16

[0206] The reference deck must not be removed from the test opening during the measuring series. This is necessary in order not to introduce differences due to the mounting in the test facilities.

[0207] Measurements of transmission loss and acceptance will be performed simultaneously with airborne noise excitation in the source room. Measurements of sound absorption are done in connection with the transmission loss measurements. Measurements of transmission loss are performed in accordance with ASTM E90-09.

[0208] Primarily, the damping properties for the constrained damped test constructions was determined of the loss factor using the test beam method e.g. as described in ASTM E756-5(2010).

[0209] All calculations are performed for each one-third octave band frequency.

[0210] 4.4 Tests Decks [0211] Example 1: The floor is a constrained damped construction on a steel deck 4 as shown in FIG. 3. The constrained damped construction is consisting of 1 mm viscoelastic damping layer 5 of mortar composition M2. The density of compound is 1,300 kg/m.sup.3. On top of the damping layer 1.5 mm steel plates 6 with coverage of 90% are applied. The total surface mass is approximately 11.9 kg/m.sup.2 for the total construction. The total building height is 2.5-3 mm. [0212] Example 2: In example 2, a constrained damped construction consisting of 3 mm viscoelastic damping layer of mortar composition M2 was used. Otherwise, the setup was identical to example 1. [0213] Example 3: The floor is a combined constrained damped and floating floor construction on a steel deck 7 as shown in FIG. 4. The constrained damped construction is consisting of an approximately 1.5 mm viscoelastic damping layer 8 of mortar composition M2. The density of compound is 1,300 kg/m.sup.3. On top of the damping layer 1.5 mm steel plates 9 with coverage of 90% are applied. [0214] On top, a floating floor is applied which consists of 50 mm mineral wool 10 (type SeaRox SL 436), with a density of 140 kg/m.sup.3. The top layer 11 consists of 25 mm Litosilo X. The total surface mass is approximately 45.9 kg/m.sup.2 for the total construction. The total building height is 78 mm. [0215] Example 4: For reasons of comparison, in example 4, a constrained damped construction consisting of 1 mm SikaFloor® Marine PU-Red (polyurethane based layer) instead of the mortar composition M2 was used. Otherwise, the setup was essentially identical to example 1.

[0216] 4.5 Results

[0217] For illustration, FIG. 6 shows the measured sound reduction index R for the mortar composition M2 of example 1 expressed in dB per one-third octave frequency bands (closed circles). For comparison the results of the measurements on the bare steel deck are also shown (open circles). The difference between the curves for the test deck and the curves for the reference steel deck thus indicates the improvement in the sound reduction and the impact sound insulation caused by the applied floor construction.

[0218] Table 2 gives an overview of measured characteristic properties for the three examples.

TABLE-US-00002 TABLE 2 Characteristic properties Example 1 Example 2 Example 3 Example 4 (cf. FIG. 3) (cf. FIG. 3) (cf. FIG. 4) (cf. FIG. 3) R'w (weighted sound 43 dB 43 dB 58 dB 45 dB reduction index according to EN ISO 717-1:2013) L.sub.n,w (weighted normalized 92 dB 92 dB 56 dB — impact sound pressure level according to EN ISO 717-2: 2013) Calculated Impact 18 dB 18 dB 53 dB — Insulation Class IIC according to E989 ASTM STC (weighted Sound 43 dB 43 dB 59 dB — Transmission Class according to ASTM E413- 10 Classification for Rating Sound Insulation)

[0219] Thus, all of the tested examples 1-3, clearly show a significant noise and vibration suppression, which is at least comparable with standard PU-based systems (example 4). Thus, mortar compositions according to the present invention can be used as replacements for known polyurethane systems.

[0220] 5. Fire Resistance

[0221] Fire tests have been performed in a furnace 12 covered with a steel deck 13 with a thickness of 8 mm and an area of 10 m.sup.2, as depicted in FIG. 5. The steel deck 12 was covered with a layer 14 of about 1 mm of mortar composition M2. On top of layer 14, steel plates 15 with coverage of about 90% as well as an insulation 16 and a deck covering 17 were applied.

[0222] Fire tests have been performed in line with the international code for application of fire test procedures, 2010 (International Maritime Organization, resolution msc.307(88), adopted on 3 Dec. 2010.

[0223] The tests have shown that the setup prevents the passage of flame and smoke for 60 minutes. An average temperature rise on the unexposed deck side was less than 140° C. above the temperature before starting the standard fire test. Overall, with the inventive mortar composition it is possible to produce class A-60 type decks.

[0224] In summary, the inventive mortar compositions can be used for producing effective fire barriers.

[0225] Therefore, mortar compositions according to the present invention can indeed be used as improved replacements for known polyurethane systems.

[0226] Thus, it will be appreciated by those skilled in the art that the present invention can be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The presently disclosed embodiments are therefore considered in all respects to be illustrative and not restricted.