FLEXIBLE MORTAR COMPOSITIONS

Abstract

Methods are disclosed in which an additive is used for controlling the flexibility of a hydraulic binder composition, where the additive includes a silane-functional polymer, the silane-functional polymer being a silane-functional polyurethane polymer and/or a silane-functional polyether.

Claims

1. A method comprising adding an additive to a hydraulic binder composition, the additive being added in an amount effective to increase the flexibility of the hydraulic binder composition, wherein the additive comprises a silane-functional polymer, and the silane-functional polymer is a silane-functional polyurethane polymer and/or a silane-functional polyether.

2. The method according to claim 1, wherein the hydraulic binder composition comprises an aluminate cement and/or a sulphoaluminate cement.

3. The method according to claim 1, wherein the hydraulic binder composition comprises aggregates selected from sand, quartz, calcium carbonate and/or gravel.

4. The method according to claim 1, wherein the silane-functional polymer has at least one functional group of the formula (I): ##STR00005## where the radical R.sup.1 is an alkyl group having 1 to 8 C atoms; the radical R.sup.2 is an acyl or alkyl group having 1 to 5 C atoms; the radical R.sup.3 is a linear or branched, optionally cyclic, alkylene group having 1 to 12 C atoms, optionally with aromatic moieties, and optionally with 1 or more heteroatoms; and the index a has a value of 0 or 1 or 2.

5. The method according to claim 1, wherein the silane-functional polymer has an average molecular weight Mn, determined by GPC against polystyrene standard, of between 4000 and 30 000 g/mol.

6. The method according to claim 1, wherein the silane-functional polymer is a polymer with a polypropylene glycol backbone or a polyethylene glycol and polypropylene glycol mixed backbone, optionally comprising urethane linkages.

7. The method according to claim 1, wherein the silane-functional polymer is a polymer with dialkoxy(alkyl)silylalkylcarbamate end groups and/or trialkoxysilylalkylcarbamate end groups.

8. The method according to claim 1, wherein the additive further comprises one or more of the following substances: a catalyst for the hydrolysis and/or condensation of the silane-functional polymer; an adhesion promoter; a surfactant; fibers; and/or hard aggregates.

9. The method according to claim 1, wherein said additive comprises an adhesion promoter, said adhesion promoter being a silane having a primary amino group.

10. The method according to claim 1, wherein the additive comprises or consist of: 70-90 wt. % of the silane-functional polymer; 10-20 wt. % of the surfactant; optionally, 1-5 wt. % of a catalyst for the hydrolysis and/or condensation of the silane-functional polymer; optionally, 1-5 wt. % of an adhesion promoter; the weight percentages being with respect to the total weight of the additive.

11. The method according to claim 1, wherein the additive is used in combination with no water.

12. An additive for increasing the flexibility of a hydraulic binder composition, the additive comprising: 70-90 wt. % of a silane-functional polymer, the silane-functional polymer being selected from silane-functional polyurethane polymers; 10-20 wt. % of a surfactant, the surfactant being selected from a homopolymer or a copolymer of alkylene oxides; optionally, 1-5 wt. % of a catalyst for the hydrolysis and/or condensation of the silane-functional polymer; and optionally, 1-5 wt. % of an adhesion promoter; the weight percentages being with respect to the total weight of the additive.

13. The additive according to claim 12, wherein 1-5 wt. % of the catalyst is present in the additive, the catalyst being a metal complex; and 1-5 wt. % of the adhesion promoter is present in the additive, the adhesion promoter being a silane having a primary amino group; the weight percentages being with respect to the total weight of the additive.

14. A method for increasing the flexibility of a hydraulic binder composition, the method comprising: (i) providing the additive of claim 12 and (ii) mixing the additive into a hydraulic binder composition.

15. A hydraulic binder composition comprising the additive of claim 12.

16. The method according to claim 2, wherein the aluminate cement is comprised in the hydraulic binder composition, and the aluminate cement is a calcium aluminate cement.

17. The method according to claim 2, wherein the sulphoaluminate cement is comprised in the hydraulic binder composition, and the sulphoaluminate cement is a calcium sulphoaluminate cement.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0184] The drawings used to explain the embodiments show:

[0185] FIG. 1 the strength versus elongation diagram of the three samples recorded in the bending flexibility tests;

[0186] FIG. 2 strength versus elongation diagram of the three samples recorded in the compression tests;

[0187] FIG. 3 a detailed view of the data recorded in the compressive tests.

EXEMPLARY EMBODIMENTS

[0188] 1. Additive Compositions

[0189] Table 1 shows three inventive additive compositions A1-A3. The additive compositions have been prepared by intermixing all of the components for 10 minutes under vacuum conditions in a glass bottle. Then the bottles were flushed with nitrogen and closed.

TABLE-US-00001 TABLE 1 Additive compositions Component A1 A2 A3 Silane-functional polymer.sup.1) [wt. %] 79.6 81.7 93.8 Adhesion promotor.sup.2) [wt. %] 2.6 2.7 3.1 Catalyst.sup.3) [wt. %] 2.6 0 3.1 Surfactant.sup.4) [wt. %] 15.2 15.6 0 .sup.1)Geniosil STP-E15, polyether polyol endcapped with isocyanate-functional alkoxysilane, Wacker Chemie AG, Germany .sup.2)Silquest A1110, primary amino silane, Momentive Performance Materials, USA .sup.3)Tin catalyst comprising 10 wt.% dibutyltin dilaurate in diisodecyl phthalate .sup.4)Dowfax DF-143, Polypropylene glycol monobutyl ether, Dow Chemical Company

[0190] The bottles with the additive compositions have been stored at 22° at 60% relative humidity for 6 months. At 0, 3 and 6 months, samples of the additive compositions have been taken in order to measure the evolution of the viscosities of the samples. Thereby, no significant changes in viscosities could be observed. Thus, all of the additive compositions A1-A3 turned out to be storage stable under the given conditions for at least 6 months.

[0191] 2. Grout Compositions

[0192] Table 2 shows a grout composition HBC (=hydraulic binder composition) used in the working examples. The grout composition has been prepared by intermixing all of the components in dry state. Thus, the grout composition HBC is present in dry form.

TABLE-US-00002 TABLE 2 Grout compositions in dry state (before adding additives and water) Component HBC Hydraulic binder [wt. %] Portland cement (CEM I, 52.5R) 16.0 Calcium sulfoaluminate cement.sup.1) 19.6 Calcium sulfate dihydrate 0.6 Aggregates [wt. %] Filler (calcium carbonate) 4.5 Sand (grain size 0.06-3.2 mm) 42.2 Calcium carbonate (0.7-1.2 mm) 14.3 Additives [wt. %] Plasticizer.sup.2) 0.4 Processing additives.sup.3) 2.25 .sup.1)AliCem, calcium sulfoaluminate cement, HeidelbergCement, Germany .sup.2)Sika Viscocrete 425 P, polycarboxylate ether, Sika Germany GmbH, Germany .sup.3)Defoamer, rheology modifiers, thixotropic agents, retarder, etc.

[0193] 3. Use of the Additives in Grout Compositions

[0194] Additives A1-A3 have been used for controlling the flexibility of the grout composition HBC. Table 3 gives an overview of the proportions used.

TABLE-US-00003 TABLE 3 Processable grout compositions Component P1 P2 P3 Grout composition HBC [wt. %] 66.7 67.5 97.2 Additive A1 [wt. %] 33.3 — — Additive A2 [wt. %] — 32.5 — Additive A3 [wt. %] — — 2.8 Sum 100.0 100.0 100.0 Water [wt. % with respect to — 13 15 hydraulic binder in grout composition HBC]

[0195] With processable grout compositions P2 and P3, in a first step the water has been mixed with the dry grout composition HBC for 3 minutes in order to obtain homogeneous mixtures. Then, in a second step, additive A2 or A3, respectively, were added and the so obtained mixtures have been mixed again for 5 minutes in order to obtain processable grout compositions.

[0196] For processable grout composition P1, additive A1 has been mixed directly with the dry grout composition HBC for 5 minutes in order to obtain a grout processable compositions.

[0197] 4. Tests and Results

[0198] 4.1 Workability

[0199] Flow table spread values were assessed according standard EN 12350-5:2009. 10 minutes after preparation, grout composition P3 showed a very good consistency and workability. Specifically, a flow table spread value of about 240 mm could be achieved.

[0200] The flow table spread values of grout compositions P1 and P2 were somewhat lower. Specifically, flow table spread values 10 minutes after preparation were about 160 mm for composition P2. Composition P1 featured a rather sticky consistence. Nevertheless, workability was still suitable for practical grouting applications.

[0201] 4.2 Flexibility

[0202] For testing mechanical properties of the grout compositions P1-P3 after hardening, samples in the form of square prisms of the grout compositions with a size of 4 cm×4 cm×16 cm have been produced.

[0203] In order to check the bending flexibility, a bending moment was exerted on the prisms by load transmission through one upper and two lower rollers, similar to the procedure described in EN 12390-5 or ASTM C78 (simple beam with third-point loading). Thereby, a 1-point load application setup was used with the load transfer above through one roller in the center of the prisms and the lower rollers are at a distance of about 12 cm, i.e. about 3 times the height of the sample. Thereby, the load (or strength) acting through the load-transferring roller onto the sample was recorded as a function of the displacement or elongation, respectively, of the load transferring roller.

[0204] For checking the compressive flexibility, the prisms in upright position have been compressed along their longitudinal axes between two movable jaws. Thereby, the load (or strength) acting through the jaws onto the sample was recorded as a function of the displacement or elongation, respectively, of the jaws.

[0205] FIG. 1 shows a strength versus elongation diagram of the three samples P1-P3 recorded in the bending flexibility tests. FIG. 2 shows a strength versus elongation diagram of the three samples P1-P3 recorded in the compression tests. FIG. 3 is a detailed view of the data recorded in the compressive tests showing the differences between samples P2 and P3.

[0206] In general, the flatter the gradient of the function of strength versus elongation, the higher the flexibility of the sample.

[0207] As can be seen from the data shown in FIG. 1-3, sample P3 comprising additive A3 in rather low proportions is quite stiff or less flexible when compared to the other samples P1 and P2 comprising additives A1 or A2, respectively. When comparing samples P1 and P2, it turns out that sample P1 with additive A1 and without water is more flexible than sample P2 with additive P2 but with water.

[0208] 4.3 Waterproofness

[0209] The liquid-water transmission rates (permeability) of the hardened samples have been tested according to EN 1062-3:2008-04. Thereby, the samples fulfilled the criteria to be classified as waterproof.

[0210] In summary, the use of the inventive additives allow for controlling and significantly increasing the flexibility of hydraulic binder compositions and at the same time achieving excellent waterproofness. Nevertheless, the grout compositions feature a practically suitable workability and mechanical properties.

[0211] 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.