POLYURETHANE BASED POLYMER CONCRETES AND GROUTING MORTARS OF CONTROLLED DENSITY

Abstract

The use of a desiccant for influencing the density of a curable binder composition including a) at least one organic binder including a polyisocyanate and a polyol, and b) at least 50% by weight of an inorganic filler F, more particularly in the form of quartz aggregates and/or slag, the proportions by weight being based on 100% by weight of the binder composition.

Claims

1. A curable binder composition comprising a) at least one organic binder comprising a polyisocyanate and a polyol, and b) at least 50% by weight of an inorganic filler F, and c) a desiccant, the proportions by weight being based on 100% by weight of the curable binder composition.

2. The curable binder composition of claim 1, wherein the desiccant is selected from a molecular sieve, calcium oxide, calcium chloride, sodium carbonate, potassium carbonate, calcium sulfate and/or magnesium sulfate.

3. The curable binder composition of claim 1, wherein the desiccant is present in a proportion of not more than 1% by weight, based on 100% by weight of the curable binder composition.

4. The curable binder composition of claim 1, wherein the desiccant is present in a proportion of not more than 15% by weight, based on the total weight of the polyols and of the desiccant together.

5. The curable binder composition of claim 1, wherein the water content in the curable binder composition is not more than 0.5% by weight, based on the total weight of the curable binder composition.

6. The curable binder composition of claim 1, wherein the water content in the curable binder composition is 0.01-0.45% by weight.

7. The curable binder composition of claim 1, wherein the filler F has a particle size of at least 0.1 mm, and wherein at least three different grain fractions are further present, a first grain fraction having a grain size within a range of 0.125-0.25 mm, a second grain fraction having a grain size within a range of 0.5-0.8 mm, and a third grain fraction having a grain size within a range of 2.0-3.15 mm.

8. The curable binder composition of claim 1, wherein the filler F is present in the form of quartz aggregates, slag or a mixture of slag and quartz aggregates, the slag, if present, being selected from the group consisting of blast furnace slags.

9. The curable binder composition of claim 1, wherein an additional filler material different from the filler F is present, the additional filler material having a particle size of not more than 0.1 mm.

10. The curable binder composition of claim 1, wherein the polyisocyanate and the polyol together have a proportion of at least 5% by weight, based on 100% by weight of the curable binder composition.

11. The curable binder composition of claim 1, wherein the organic binder includes at least a mixture of polyols having different OH functionality.

12. The curable binder composition of claim 1, wherein the curable binder composition is curable to afford a cured mineral binder composition having a foam structure.

13. (canceled)

14. The curable binder composition of claim 1, comprising: 3% to 40% by weight of polyisocyanates, 3% to 40% by weight of polyols, 50% to 93.999% by weight of filler F, 0.001-1% by weight of desiccant, optionally 10% to 40% by weight of additional filler material. 0% to 0.5% by weight of water, and 0% to 15% by weight of further additives, based on 100% by weight of the curable binder composition.

15. (canceled)

16. The curable binder composition of claim 1, wherein a desiccant content and/or the water content are such that, after curing, a cured binder composition has a foam structure with a density within a range of 1.7-3.9 g/cm.sup.3.

17. A multicomponent system for producing the curable binder composition of claim 1, comprising at least one polyisocyanate component comprising at least one polyisocyanate, and at least one polyol component comprising at least one polyol, wherein the filler F, the desiccant, and optionally further ingredients are present in the polyisocyanate components, in the polyol components and/or in any further component optionally present.

18. A cured binder composition obtained by curing of the curable binder composition of claim 1 or by mixing of the components and curing of the multicomponent system comprising at least one polyisocyanate component comprising at least one polyisocyanate, and at least one polyol component comprising at least one polyol, wherein the filler F, the desiccant, and optionally further ingredients are present in the polyisocyanate components, in the polyol components and/or in any further component optionally present.

19. The cured binder composition as claimed in claim 18, which is present in the form of a foamed body.

20. The binder composition as claimed in claim 18, wherein pores having a pore diameter in the range of <4 mm are present in the cured binder composition.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0249] FIG. 1 shows: a schematic representation of exemplary cross sections of irregularly shaped slag particles,

[0250] FIG. 2 shows: the compressive strengths of inventive test specimens having a polyurethane matrix and different fillers after storage in different media (H.sub.2O, AcOH or NaOH);

[0251] FIG. 3 shows: the compressive strengths of further inventive test specimens having a polyurethane matrix and different fillers after storage in different media;

[0252] FIG. 4 shows: the compressive strengths of epoxy resin-based test specimens having different fillers after storage in different media;

[0253] FIG. 5 shows: cured test specimens of polyurethane-based grouting mortar that had been foamed in a controlled manner using varying amounts of desiccant;

[0254] FIG. 6 shows: on the left-hand side a cross section through a strongly foamed polyurethane-based grouting mortar sample and on the right-hand side a cross section through an unfoamed sample containing air bubbles;

[0255] FIGS. 7a-e show: scanning electron micrographs of cured samples of polyurethane matrix E having varying porosity;

[0256] FIGS. 8a-e show: scanning electron micrographs of cured samples of polyurethane matrix E and 89% by weight of quartz sand containing varying proportions of molecular sieve.

EXAMPLES

[0257] Working examples are presented hereinbelow, the purpose of which is to further elucidate the described invention. The invention is of course not limited to these described working examples.

[0258] “Ex.” stands for “example”.

[0259] “Ref.” stands for “reference example”.

[0260] Materials Used

[0261] Setathane® 1150 is a polyol based on a reaction product of castor oil with ketone resins (Alinex Resins Germany GmbH, Germany).

[0262] Desmophen® T4011 is a polyether polyol based on 1,1,1-trimethylolpropane (Covestro AG, Germany).

[0263] Sylosiv® is a zeolite-based molecular sieve powder having a pore diameter of 3-5 Å and a surface area of approx. 800 m.sup.2/g (W.R. Grace & Co., USA)

[0264] Desmodur® VL is an aromatic polyisocyanate based on diphenylmethane diisocyanate (Covestro AG, Germany)

[0265] Desmodur® CD-L is an aromatic polyisocyanate based on 4,4′-diphenylmethane diisocyanate (Covestro AG, Germany)

[0266] Neukapol® 1119 is a reaction product of epoxidized vegetable oils (rapeseed oil) having a proportion of unsaturated C18 fatty acids of 91% by weight, based on the total amount of fatty acids, with monofunctional C.sub.1 to C.sub.8 alcohols; OH functionality 2.0, average molecular weight approx. 390 g/mol, OH value of 290 mg KOH/g (Altropol Kunststoff GmbH, Germany).

[0267] Neukapol® 1582 is a reaction product of epoxidized fatty acid methyl esters with glycerol, where the epoxidized fatty acid methyl esters, as fatty acid component, are based on fatty acid mixtures of rapeseed oil or sunflower oil, in a mixture with N,N,N′,N′-tetrakis(2-hydroxypropyl)ethylenediamine (Altropol Kunststoff GmbH, Germany).

[0268] The quartz sand and slags were dried before use and divided into grain fractions by sieving. The grain fractions were then mixed such that the grain size distribution of the sands used corresponded to a specified grain size distribution (grading curve).

[0269] EFS is an electric furnace slag from Stahl Gerlafingen AG, Switzerland. The material used had a bulk density of around 3.3 kg/l and an iron content, calculated as FeO, of about 19% by weight.

[0270] BFS is a blast furnace slag from Hüttenwerke Krupp Mannesmann, Germany, available from Hermann Rauen GmbH & Co., Germany. The material used had a bulk density of 2.9 kg/l and an iron content, calculated as FeO, of about 3% by weight.

[0271] Raulit® is a blast furnace slag from DK-Recycling und Roheisen GmbH, Germany, available under the brand name Raulit®-Mineralbaustoffgemisch from Hermann Rauen GmbH & Co., Germany. The material used had a bulk density of around 2.9 kg/l and an iron content, calculated as FeO, of about 1% by weight.

[0272] FS is a foundry sand from voestalpine AG, Austria. The material used had a bulk density of around 2.9 kg/l and an iron content, calculated as FeO, of less than 1% by weight.

[0273] CS is NAstra® iron silicate granules, a glassy copper slag available from Sibelco Deutschland GmbH, having a bulk density of about 3.7 kg/l and an iron content, calculated as FeO, of about 51% by weight.

[0274] Sikadur®-42 HE is a three-component epoxy-resin-based grouting mortar available from Sika Schweiz AG.

[0275] The polycarboxylate ether is a comb polymer with carboxylic acid groups and polyethylene glycol side chains, Sika Viscocrete® 430P available from Sika Schweiz AG.

[0276] Measurement Methods

[0277] Compressive strength and flexural strength were determined on 40×40×160 mm test specimens using testing machines in accordance with DIN EN 196-1 and EN 12190.

[0278] For determination of the specific electrical volume resistance, the opposite 40×40 mm surfaces of the 40×40×160 mm test specimens were coated with electrically conductive gel and a steel electrode covering the entire surface was laid flush on both surfaces. The electrical volume resistance of the test specimens was determined by applying a voltage of 100 mV AC at a frequency of 1 kHz and 10 kHz to the two electrodes.

[0279] Thermal conductivity was determined in accordance with ASTM D5470-06 using the ZFW TIM tester from ZFW (Center for Thermal Management) Stuttgart, Germany, on test specimens 30 mm in diameter and 2 mm in height.

[0280] Polyurethane Matrix

[0281] For the examples, the polyol components (component A) and polyisocyanate components (component B) described in Tables 1 and 2 were used as the polyurethane matrix.

[0282] For each composition, the ingredients specified in Tables 1 and 2 were processed in the specified amounts (in parts by weight) of the polyol component A, by means of a vacuum dissolver with exclusion of moisture, to give a homogeneous paste and stored. The ingredients of the polyisocyanate component B specified in Tables 1 and 2 were likewise stored.

TABLE-US-00001 TABLE 1 Compositions of the polyurethane matrices (all figures except ratios in % by weight) A B C D E F Component A Setathane ® 1150 65.6 65.6 59.7 59.7 55.3 55.3 Desmophen ® T4011 4.3 4.3 3.7 3.7 3.5 3.5 Hydroxy-terminated 19.0 19.0 18.7 18.7 17.3 17.3 polybutadiene polyol Chain extender Butane-1,4-diol 4.3 4.3 — — — — Pentane-1,5-diol — — 11.2 11.2 — — Ethylhexane-1,3-diol — — — — 13.8 13.8 Sylosiv ® 6.9 6.9 6.6 6.6 10.0 10.0 Process chemicals.sup.1) 0.1 0.1 0.1 0.1 0.1 0.1 Component B Desmodur ® VL.sup.6) 100 — 100 — 100 — Desmodur ® CD-L.sup.7) — 100 — 100 — 100 Mixing ratio A:B 100:49.4 100:52.9 100:65.1 100:69.7 100:57.5 100:61.6 [wt %/wt %] NCO:OH 1.11 1.11 1.11 1.11 1.10 1.10 .sup.1)Defoamer and catalyst

TABLE-US-00002 TABLE 2 Compositions of the polyurethane matrices (all figures except ratios in % by weight) G H I J Component A Neukapol ® 1119 43.9 43.9 58.0 58.0 Neukapol ® 1582 22.0 22.0 29.0 29.0 Hydroxy-terminated 22.0 22.0 — — polybutadiene polyol Sylosiv ® 12.0 12.0 12.8 12.8 Process chemicals.sup.1) 0.1 0.1 0.1 0.1 Component B Desmodur ® VL 100 — 100 — Desmodur ® CD-L — 100 — 100 Mixing ratio A:B 100:64.6 100:69.2 100:81.9 100:87.8 [wt %/wt %] NCO:OH 1.07 1.07 1.07 1.07 .sup.1)Defoamer and catalyst

[0283] Solid Component

[0284] For production of the solid component, the solid constituents listed in Table 3 were mixed dry, during which a polycarboxylate ether solution was applied by spraying.

TABLE-US-00003 TABLE 3 Composition of the solid component Proportion Constituent [wt %] Mixture of limestone powder and baryte 25.2 powder, <0.1 mm Sand (slag sand or quartz sand)*, 0.12-3.2 mm 74.3 Polycarboxylate ether solution (20% by weight of 0.5 polycarboxylate ether dissolved in 80% by weight of benzyl alcohol) *Sand type: See examples.

[0285] Production of Curable Grouting Mortars and Test Specimens

[0286] The polyol components A and polyisocyanate components B from Tables 1 and 2 were processed into a homogeneous paste for 30 seconds using a SpeedMixer® (DAC 150 FV, Hauschild; for mixing ratios see Tables 1 and 2). A solid component as per Table 3 was then added and mixed in thoroughly. Unless otherwise stated, the solid component had a constant proportion of 89.5% by weight, while the mixed polyol components A and polyisocyanate components B together had a proportion of 10.5% by weight.

[0287] For comparison purposes, curable compositions and test specimens based on an epoxy resin matrix (hereinafter referred to as SD) were produced as follows: Sikadur®-42 HE component A (comprising the epoxy resin) was mixed thoroughly with the associated component B (comprising the curing agent) in a weight ratio of 3:1 and then a self-produced solid component as per Table 3 was added and mixed in thoroughly. Unless otherwise stated, the solid component had a constant proportion of 89.5% by weight, while the mixed epoxy resin and curable components together had a proportion of 10.5% by weight.

[0288] To produce the test specimens, the mixed curable compositions were poured into steel molds and stored in the formwork for 24 hours at 20° C. The test specimens were then removed from the formwork and stored further at 20° C. After 7 days of storage, the specific electrical resistance, strength, and thermal conductivity were determined.

[0289] Strength and Electrical Volume Resistance of Grouting Mortars

[0290] The strengths and electrical volume resistance of various grouting mortars are reported in the tables below.

[0291] The “Binder matrix” row indicates the polyurethane matrix/epoxy resin matrix used (see Tables 1 and 2), while the “Sand” row indicates the type of sand or slag used in the solid component (see Table 3).

TABLE-US-00004 TABLE 4 Results when using quartz sand and Desmodur ® VL as polyisocyanate component in the polyurethane matrix Ref. 1 B1 B2 B3 B4 B5 Binder matrix SD I G E C A Sand Quartz Quartz Quartz Quartz Quartz Quartz sand sand sand sand sand sand Compressive 104 99 71 74 82 64 strength [MPa] Flexural 26 26 22 24 25 24 strength [MPa] Specific electrical 243.0 21.4 23.3 24.0 24.5 24.6 volume resistance [MΩ .Math. cm] at 1 kHz Factor.sup.1) 1 kHz 0.09 0.10 0.10 0.10 0.10 Specific electrical 24.9 2.2 2.4 2.5 2.5 2.5 volume resistance [MΩ .Math. cm] at 10 kHz Factor 10 kHz 0.09 0.10 0.10 0.10 0.10 .sup.1)Factor by which the specific electrical volume resistance of a mortar as per 5 examples B1 to B5 is reduced compared to the specific electrical volume resistance of reference mortar Ref. 1, e.g. resistance B1/resistance Ref. 1

TABLE-US-00005 TABLE 5 Results when using quartz sand and Desmodur ® CD-L as polyisocyanate component in the polyurethane matrix Ref. 1 B6 B7 B8 B9 B10 Binder matrix SD J H F D B Sand Quartz Quartz Quartz Quartz Quartz Quartz sand sand sand sand sand sand Compressive 104 102 75 75 82 73 strength [MPa] Flexural 26 27 23 24 26 27 strength [MPa] Specific electrical 243.0 26.0 23.3 24.5 25.9 23.6 volume resistance [MΩ .Math. cm] at 1 kHz Factor.sup.1) 1 kHz 0.11 0.10 0.10 0.11 0.11 Specific electrical 24.9 2.7 2.4 2.5 2.7 2.4 volume resistance [MΩ .Math. cm] at 10 kHz Factor 10 kHz 0.11 0.10 0.10 0.11 0.10 .sup.1)see Table 4 above

TABLE-US-00006 TABLE 6 Results when using copper slag (CS) and Desmodur ® VL as polyisocyanate component in the polyurethane matrix Ref. 2 B11 B12 B13 B14 B15 Binder matrix SD I G E C A Sand CS CS CS CS CS CS Compressive 116 93 66 65 82 51 strength [MPa] Flexural 31 26 20 23 29 21 strength [MPa] Specific electrical 24.9 15.5 15.3 16.7 15.5 15.8 volume resistance [MΩ .Math. cm] at 1 kHz Factor.sup.1) 1 kHz 0.62 0.61 0.67 0.62 0.63 Specific electrical 3.3 1.6 1.6 1.8 1.6 1.7 volume resistance [MΩ .Math. cm] at 10 kHz Factor 10 kHz 0.48 0.48 0.55 0.48 0.52 .sup.1)see Table 4 above

TABLE-US-00007 TABLE 7 Results when using copper slag (CS) and Desmodur ® CD-L as polyisocyanate component in the polyurethane matrix Ref. 2 B16 B17 B18 B19 B20 Binder matrix SD J H F D B Sand CS CS CS CS CS CS Compressive 116 95 68 67 69 63 strength [MPa] Flexural 31 27 20 20 25 25 strength [MPa] Specific electrical 24.9 15.8 16.1 16.3 15.5 16.1 volume resistance [MΩ .Math. cm] at 1 kHz Factor.sup.1) 1 kHz 0.63 0.65 0.65 0.62 0.65 Specific electrical 3.3 1.7 1.7 1.7 1.7 1.7 volume resistance [MΩ .Math. cm] at 10 kHz Factor 10 kHz 0.52 0.52 0.52 0.52 0.52 .sup.1)see Table 4 above

[0292] Thermal Conductivity

[0293] The thermal conductivities of various grouting mortars were also measured. This was done by producing test specimens having a diameter of 30 mm and a height of 2 mm by pouring into appropriate molds and allowing them to cure at 20° C. for 7 days.

TABLE-US-00008 TABLE 8 Results for thermal conductivities Ref. 3 B21 B22 B23 B24 B25 B26 Binder matrix SD I I I I I I Sand Quartz sand BFS Raulit FS EFS CS Thermal 2.8 2.9 1.1 1.1 0.9 1.0 0.9 conductivity [W/mK]]

[0294] By using slag instead of quartz sand, the thermal conductivity can be reduced.

[0295] Corrosion Resistance

[0296] To test the corrosion resistance of the binder compositions and of test specimens produced therefrom, various test specimens were produced as described above and allowed to cure for 7 days at 20° C. Compressive strength was then determined in accordance with ASTM D695.

[0297] Thereafter, the test specimens were stored for 21 days (21 d) respectively in pure water (H.sub.2O), in 10% by volume acetic acid (AcOH) or in 50% by weight sodium hydroxide solution (NaOH) and then dried to constant weight. Compressive strength was then determined again in accordance with ASTM D695.

[0298] FIG. 2 shows the compressive strengths of test specimens based on polyurethane matrix E and a solid component as described above, with quartz sand, FS, CS, Raulit, BFS, and EFS alternately used as sand.

[0299] It can be seen here that the compressive strengths, irrespective of which medium is used (H.sub.2O, AcOH or NaOH), are not only unimpaired but increase during storage.

[0300] FIG. 3 shows the compressive strengths of test specimens based on polyurethane matrix G and a solid component as described above, with quartz sand, FS, CS, Raulit, BFS, and EFS alternately used as sand.

[0301] In this case too, the compressive strengths increase in H.sub.2O and NaOH, whereas in AcOH a slight decrease is discernible for certain solid components.

[0302] FIG. 4 shows for comparison the results for test specimens based on epoxy resin matrix SD and a solid component as described above, with quartz sand, FS, CS, Raulit, BFS, and EFS again alternately used as sand.

[0303] This shows clearly the sharp decrease in compressive strength on storage in H.sub.2O and AcOH. Only in NaOH is the compressive strength maintained, or where this increases slightly during storage.

[0304] Grouting Mortars Having Different Amounts of Polyurethane Matrix

[0305] Table 9 shows the compositions and compressive strengths of further grouting mortars in which the amounts of the binder matrix and the solid components were modified.

TABLE-US-00009 TABLE 9 Grouting mortars having different amounts of sand and polyurethane matrix B27 B28 B29 B30 B31 B32 Binder matrix/ E E E E E E Proportion [wt %] 6.0 6.0 20.0 20.0 12.5 12.5 Slag/ CS EFS CS EFS CS EFS Proportion [wt %] 79.9 79.9 66.9 66.9 75.4 75.4 Mixture of limestone 14.0 14.0 13.0 13.0 12.0 12.0 powder and baryte powder [wt %] Polycarboxylate ether 0.1 0.1 0.1 0.1 0.1 0.1 solution [wt %] Compressive strength 36.6 18.3 40.7 31.9 55.0 33.8 [MPa]

[0306] The results in Table 9 show that a proportion of binder matrix in the region of more than 6.0% by weight is advantageous in respect of compressive strength. In the case of copper slag (CS) and electric furnace slag (EFS), the test with 12.5% by weight of binder matrix shows the highest compressive strength.

[0307] Controlled Foaming with Molecular Sieve

[0308] To analyze the influence of the proportion of molecular sieve on foaming, the proportion of molecular sieve was in several experiments reduced starting from binder composition B3 (see Table 4; binder matrix E and quartz sand as a sand type). Table 10 gives an overview of the results.

[0309] The samples of component A with and without fillers and desiccant were weighed into headspace GC sample vials and a defined amount of dichloromethane added as extractant. After an extraction time of at least one hour at room temperature, the water content of the pure dichloromethane and of the filtered solutions of component A in dichloromethane was determined by coulometric Karl Fischer titration.

TABLE-US-00010 TABLE 10 Influence of the proportion of molecular sieve in the polyurethane matrix E on the foaming, density, and strength of grouting mortars. Proportion of molecular sieve 4/4 3/4 2/4 1/4 0 Concentration of 10 7.5 5.0 2.5 0 molecular sieve powder in matrix [wt %] Water content [wt %] 0.13 0.11 0.14 0.10 0.10 Density [g/cm.sup.3] 2.48 2.43 2.38 2.25 1.84 Foaming [vol %] 0 2 4 10 35 Compressive strength 74 73 69 55 29 [MPa] Flexural strength [MPa] 24 25 24 18 12

[0310] A molecular sieve proportion of “4/4” corresponds to the original proportion of 10% by weight in component A/in the polyurethane matrix (cf. Table 4). In the experiment with “¾”, the proportion was reduced to 7.5% by weight (compensated by increasing the other constituents), in “ 2/4” to 5% by weight, and in “¼” to 2.5% by weight. “0” corresponds to a formulation containing no molecular sieve at all.

[0311] FIG. 5 shows the corresponding, cured grouting mortar. The increase in volume as the proportion of molecular sieve decreases from left to right can be clearly seen.

[0312] The left-hand side of FIG. 6 shows a cross section through the reactively foamed sample produced without molecular sieve (sample “0” in Table 10 or the test specimen on the far left in FIG. 5). Shown on the right-hand side in FIG. 6 is a cross section through the non-reactively foamed sample produced with the original amount of 10% by weight of molecular sieve in component A (sample “4/4” in Table 10 and the test specimen on the far right in FIG. 5). The pores that can be seen are the result of outgassing of air dissolved in the binder and dispersed in the binder composition during curing.

[0313] Whereas the sample without molecular sieve has fewer pores with larger diameters, the sample with molecular sieve has a greater abundance of smaller pores having a diameter <1 mm.

[0314] In addition, microsections of cured grouting mortars were produced and examined by scanning electron microscopy (SEM) with energy-dispersive X-ray analysis (EDX); SEM: Zeiss Sigma 300 VP, electron source: Schottky field emission; detectors: in-lens and secondary electron detector (SE2), variable-pressure (VP) cascade current detector (C2D), high-resolution backscattered electron detector (HDBSD), multimode transmission REM detector (STEM); energy dispersive X-ray spectroscopy: Ametek EDAX, detector: Apollo X-SDD, resolution 127.7 eV).

[0315] FIGS. 7a-7e show scanning electron microscopy images obtained at a magnification of 200× of the cured polyurethane matrix E containing varying proportions of molecular sieve. The sample without molecular sieve (FIG. 7a) shows irregularly shaped, large air pores having diameters of 200-400 μm. The sample with a ¼ proportion of molecular sieve (FIG. 7b) already has markedly fewer air pores than the sample without molecular sieve and the pores all have a rounder shape. The diameter of the pores varies here within a range of approx. 100-200 μm. The samples with a proportion of 2/4 (FIG. 7c), a proportion of ¾ (FIG. 7d), and a proportion of 4/4 (FIG. 7e) are very similar and have a lower pore density compared to the sample with a molecular sieve proportion of ¼, with pore diameters of mostly around 100 μm.

[0316] FIGS. 8a-8e show scanning electron microscopy images recorded at a magnification of 200× of samples of the cured binder matrix E and 89% by weight of quartz sand as sand type containing varying proportions of molecular sieve. The sample without molecular sieve (FIG. 8a) shows a high proportion of pores. These are mostly irregular in shape, typically having a diameter of between 50-250 μm. There are also a few pores in the sample that have diameters of 300-700 μm. Many pores appear to connect to adjoining pores. The sample with a molecular sieve proportion of ¼ (FIG. 8b) likewise has a high proportion of pores, although lower than the sample without molecular sieve. The pores are irregular in shape, with diameters of 50-200 μm, in rare instances up to 400 μm. In the sample with a molecular sieve proportion of 2/4 (FIG. 8c), the pore content is further reduced. The shape of the pores is now mostly round, although there are still pores with an irregular shape. The diameter of the pores is between 40 and 150 μm, although pores of up to 250 μm are also found in rare instances. In the sample with a molecular sieve proportion of ¾ (FIG. 8d), the pore content is again greatly reduced and the pore shape is mostly round. The pore sizes vary within a range of 30-120 μm, with pores having a diameter of up to 200 μm also present. The sample with a molecular sieve proportion of 4/4 (FIG. 8e) shows a tendency to slightly fewer pores than the sample with a proportion of ¾. The typical diameter is again slightly reduced, at 30-100 μm (in rare instances up to 200 μm). The shape of the pores is still mostly round.

[0317] This shows that the pore structure, the pore density, and the density of the foamed grouting mortar, thus all of the parameters subsumed under the term “foaming”, can be selectively influenced by the molecular sieve.

[0318] Controlled Foaming with Calcium Oxide

[0319] To analyze the influence of the proportion of calcium oxide on foaming and density, a binder matrix E′ based on matrix E (see Table 1) was provided in which the molecular sieve (Sylosiv®) was replaced by varying amounts of pulverulent calcium oxide. The binder matrix E′ thus produced was then processed together with quartz sand (in analogous manner to experiment B3; Table 4) into grouting mortars, which were investigated in respect of density and foaming. Table 11 gives an overview of the results.

[0320] The water content of the samples after mixing was also determined. The samples of component A with and without fillers and desiccant were weighed into headspace GC sample vials and a defined amount of dichloromethane added as extractant. After an extraction time of at least one hour at room temperature, the water content of the pure dichloromethane and of the filtered solutions of component A in dichloromethane was determined by coulometric Karl Fischer titration.

TABLE-US-00011 TABLE 11 Influence of the proportion of calcium oxide in the polyurethane matrix E′ on the foaming and density of grouting mortars. Proportion of calcium oxide 4/4 3/4 2/4 1/4 1/7 1/10 Concentration of calcium 10 7.5 5.0 2.5 1.5 1.0 oxide in matrix [wt %] Water content [wt %] — 0.02 — 0.05 0.05 0.04 Density [g/cm.sup.3] 3.70 3.52 3.45 3.30 2.94 2.75 Foaming [vol %] 0 5 7 11 21 26

[0321] The results show that the foaming and density can be selectively adjusted via the proportion of calcium oxide in a manner comparable to that with molecular sieve.