EPOXY RESIN COMPOSITION FOR UNDERWATER GROUTING

Abstract

A curable epoxy resin compositions containing at least one epoxy resin having on average more than one epoxide group per molecule, at least one inorganic filler, at least one hydraulic binder, and at least one polycarboxylate ether, wherein the inorganic filler has silica with an amount of between 45 and 65 wt.-%, based on the total curable epoxy resin composition, and the amount of the polycarboxylate ether is between 0.01 and 0.03 wt.-%, based on the total curable epoxy resin composition. Further, a multi-component systems for producing the epoxy resin compositions, cured epoxy resins, and methods for repairing or reinforcing a pile or column.

Claims

1. A curable epoxy resin composition for underwater grouting, containing at least one epoxy resin having on average more than one epoxide group per molecule, at least one inorganic filler, at least one hydraulic binder, and at least one polycarboxylate ether, wherein the inorganic filler comprises silica with an amount of between 45 and 65 wt.-%, based on the total curable epoxy resin composition, and the amount of the polycarboxylate ether is between 0.01 and 0.03 wt.-%, based on the total curable epoxy resin composition.

2. The curable epoxy resin composition according to claim 1, wherein the silica has a particle size of <50 m, determined by sieve analysis according to ASTM E11 using a No. 325 Mesh.

3. The curable epoxy resin composition according to claim 1, wherein the hydraulic binder is cement and comprised in the composition with an amount of between 5 and 10 wt.-%, based on the total curable epoxy resin composition.

4. The curable epoxy resin composition according to at claim 1, additionally containing at least one curing agent and/or at least one reactive diluent.

5. The curable epoxy resin composition according to claim 1, wherein the epoxy resin comprises at least one glycidyl ether, and/or the curing agent contains at least one polyamine, which is selected from the group consisting of aliphatic, cycloaliphatic or arylaliphatic primary diamines, triamines, tetramines, polyamines with more than four amine groups per molecule, secondary amine group-containing polyamines, amine/polyepoxide adducts, poly(ethylene imines), polyamidoamines, Mannich bases and amino-terminated butadiene/acrylonitrile copolymers.

6. The curable epoxy resin composition according to claim 1, wherein the polycarboxylate ether has side chains linked to a main chain via ester, amide and/or ether groups, wherein the main chain has at least one acrylic acid moiety or a salt thereof and/or at least one methacrylic acid moiety or a salt thereof.

7. The curable epoxy resin composition according to claim 1, wherein the polycarboxylate ether is a comb polymer comprising structural units (i) of the formula II and structural units (ii) of the formula III, ##STR00005## wherein R.sup.1, independently of one another, represents COOM, SO.sub.2OM, OPO(OM).sub.2, and/or PO(OM).sub.2, R.sup.2 und R.sup.5, independently of one another, represent H, CH.sub.2COOM, or an alkyl radical with 1 to 5 carbon atoms, R.sup.3 and R.sup.6, independently of one another, represent H or an alkyl radical with 1 to 5 carbon atoms, R.sup.4 und R.sup.7, independently of one another, represent H, COOM, or an alkyl radical with 1 to 5 carbon atoms, or wherein R.sup.1 together with R.sup.4 forms a COOCO ring (anhydride), M, independently of one another, represents H.sup.+, an alkali metal ion, an alkaline earth metal ion, an ammonium cation, an organic ammonium compound, a di- or trivalent metal cation, or mixtures thereof; m=0, 1, or 2, p=0 or 1, X, independently of one another, represents O, NH, or NR.sup.8, R.sup.8, independently of one another, represents a radical of the formula -[AO].sub.nR.sup.a, wherein A=C.sub.2- to C.sub.4-alkylene, R.sup.a represents H, a C.sub.1- to C.sub.20-alkyl group, -cyclohexyl group, or -alkylaryl group, and n=2 to 250, in particular 10 to 200.

8. The curable epoxy resin composition according to claim 7, wherein R.sup.1 represents COOM, R.sup.2, R.sup.4, R.sup.5, R.sup.3, R.sup.6 and R.sup.7 represent H, M, independently of one another, represents H.sup.+, an alkali metal ion, or an alkaline earth metal ion; m=0, p=1, X represents O, R.sup.8 represents a group of formula -[AO].sub.nR.sup.a, wherein A=C.sub.2-alkylene, in particular C.sub.2-alkylene, R.sup.a represents CH.sub.3, and n=22 to 72.

9. A multi-component system for producing a curable epoxy resin composition according to claim 1, comprising a component K1 containing the at least one epoxy resin, and a curing agent component K2 containing at least one curing agent, wherein the inorganic filler, the hydraulic binder, and the polycarboxylate ether are contained in the component K1, the component K2, or in an additional component K3.

10. A multi-component system according to claim 9, wherein the multi-component system is a two-component system, comprising a component K1 containing the at least one epoxy resin, and a curing agent component K2 containing at least one curing agent, wherein the inorganic filler, the hydraulic binder, and the polycarboxylate ether are contained in the component K1.

11. A two-component system according to claim 10, wherein said component K1 comprises between 15 and 35 wt.-%, based on the total component K1, of said epoxy resin; between 0 and 5 wt.-%, based on the total component K1, of an epoxy-functional diluent; between 0 and 0.1 wt.-%, based on the total component K1, of a defoamer; between 5 and 10 wt.-%, based on the total component K1, of said hydraulic binder; between 50 and 70 wt.-%, based on the total component K1, of said inorganic filler; between 0.015 and 0.025 wt.-%, based on the total component K1, of said polycarboxylate ether; and said component K2 comprises between 20 and 60 wt.-%, based on the total component K2, of at least one polyamine; between 0 and 15 wt.-%, based on the total component K2, of an accelerator; between 0 and 50 wt.-%, based on the total component K2, of solvents; wherein all amounts of the individual ingredients in each component K1 and K2 are adjusted such that sum of all individual amounts does not exceed 100% in the respective component K1 or K2.

12. A cured epoxy resin obtainable by curing an epoxy resin composition for underwater grouting, containing at least one epoxy resin having on average more than one epoxide group per molecule, at least one inorganic filler, at least one hydraulic binder, and at least one polycarboxylate ether, wherein the inorganic filler comprises silica with an amount of between 45 and 65 wt.-%, based on the total curable epoxy resin composition, and the amount of the polycarboxylate ether is between 0.01 and 0.03 wt.-%, based on the total curable epoxy resin composition; or by mixing the components and curing a multi- or two-component system according to claim 9.

13. A method for repairing or reinforcing a pile or column, comprising the steps a) optionally pretreating the pile or column by cleaning, sand- or wet blasting, priming, and/or brushing; b) installing a sleeve around the pile or column covering the damaged areas of the pile or column surface such that the sleeve circumvents the pile or column leaving a gap between the surface of the pile or column and the inner surface of the sleeve; c) sealing the sleeve against the pile or column; d) introducing a curable epoxy-resin composition for underwater grouting, containing at least one epoxy resin having on average more than one epoxide group per molecule, at least one inorganic filler, at least one hydraulic binder, and at least one polycarboxylate ether, wherein the inorganic filler comprises silica with an amount of between 45 and 65 wt.-%, based on the total curable epoxy resin composition, and the amount of the polycarboxylate ether is between 0.01 and 0.03 wt.-%, based on the total curable epoxy resin composition; or the epoxy-resin composition obtained by mixing a multi- or two-component system according to claim 9 in the appropriate ratio into the gap between the sleeve and the pile or column; e) curing the epoxy-resin composition.

14. The method according to claim 13, wherein the pile or column is at least partially submerged in water.

15. The method according to claim 12, wherein the pile or column is made of concrete and/or steel.

Description

EXEMPLARY EMBODIMENTS

[0140] The following examples illustrate some embodiments of the invention. The term norm climate refers to a temperature of 23 C. and a relative humidity (r.h.) of 50%.

Test Methods

[0141] Flowability of the epoxy compositions was determined in accordance with Chinese Standard JC/T 986-2005. All the individual components of the composition to be tested were pre-conditioned at norm climate (23 C., 50% r.h.) for at least 8 hours. All the components were mixed together for at least 3 minutes with a mixing spindle attached to a slow speed electric drill (max. 400 rpm) until the material became smooth in consistency and had a uniform color. A bottomless cone (height: 60 mm0.5 mm; top inner diameter: 70 mm0.5 mm; bottom inner diameter: 100 mm0.5 mm) was put vertically on a glass plate and filled to the brim with mixed composition. Using a stopwatch, time recording was started, the test mould was lifted 5-10 cm and held in place for at least 15-20 seconds to let the composition drip off completely. The composition began to spread in all directions on the glass plate. After 30 minutes, the diameters of the flow spread was measured in two directions at right angles to one another. The recorded result (flowability) is the average of those diameters in mm.

[0142] Compressive strength was measured in accordance with EN 196 standard using cured (1 d or 7 d norm climate (air) and 1 d or 7 d underwater (underwater), 23 C.) epoxy-based composition prismatic test specimens (4040160 mm) and a rate of load increase of 2400200 N/s.

[0143] Flexural strength was measured in accordance with EN 196 standard using cured (1 d or 7 d norm climate (air) and 1 d or 7 d underwater (underwater), 23 C.) epoxy-based composition prismatic test specimens (4040160 mm) and a rate of loading of 5010 N/s.

[0144] Density (specific gravity) was determined in accordance with EN ISO 2811-1:2001 standard using a pre-conditioned 100 mL metal pycnometer at a temperature of 20 C.

[0145] Adhesion on concrete (bonding strength by pull-off adhesion test) was determined in accordance with EN 1542 standard by direct pull-off using a steel dolly bonded to the surface of the cured composition. The dimension of the concrete/substrate specimen was 300300100 mm. The surface was sandblasted according to EN 1766. Samples labelled curing in air were cured during 7 days under norm climate using dry concrete substrates. Samples labelled curing underwater were cured during 7 days underwater (23 C.) using wet concrete substrates that had been immersed in water at least 24 h prior to the application of the epoxy-based composition. For the pull-off experiment, a load was continuously and evenly increased at a rate of 0.05MPa/s for each test assembly.

[0146] Underwater behavior of uncured or curing samples of the epoxy-based compositions were assessed by optical inspection. In each experiment, 150 mL of clean water were filled into a 200 mL transparent plastic cup. After this, 100-150 g of the freshly mixed sample composition were poured into the water in the cup. Normally, the composition sank to the ground and remained there. The water phase was checked by eye for floating particles and the formed epoxy-based grout layer was checked for appearance. A good result requires the water to be clear and free of floating particles, coloration, or turbidity (dispersion effects). At the same time, a good result requires the epoxy grout layer to be homogeneous, compact, and free of cracks. Any deviation from this ideal behavior was noted in the results of the assessment.

Example Compositions

Preliminary Study: Influence of Filler and Polycarboxylate Ether

[0147] A series of experimental two-component compositions were prepared in order to study the influence of filler and polycarboxylate ether. In all those experiments, component K2 (hardener component) was identical.

Component K1: Epoxy Resin

[0148]

TABLE-US-00001 TABLE 1 Basic formulation of component K1. wt.-% Ingredient (based on total K1) Bisphenol A-epichlorohydrin resin 24 (Dow D.E.R 331) C12/C14-alkyl glycidyl ether (reactive diluent) 2.5 Portland cement (hydraulic binder) 7.5 Defoamer 0.03 Pigment 4 Filler .sup.1 61 Solvent naphtha .sup.3 0.9-0.97 Polycarboxylate ether (PCE) .sup.2 0-0.07 Total 100 .sup.1 Filler type is specified in each experiment individually and detailed in Table 2. .sup.2 Polycarboxylate ether is a comb polymer comprising structural units (i) of the formula II and structural units (ii) of the formula III, wherein R.sup.1 represents COOM; R.sup.2, R.sup.4, R.sup.5, R.sup.3, R.sup.6 and R.sup.7 represent H; M, independently of one another, represents H.sup.+, an alkali metal ion, or an alkaline earth metal ion; m = 0; p = 1; X represents O; R.sup.8 represents a group of formula -[AO].sub.nR.sup.a, wherein A = C.sub.2-alkylene, R.sup.a represents CH.sub.3, and n = 22 to 72. .sup.3 Amount of solvent naphtha was used to adjust the composition to 100 wt.-%, depending on the amount of PCE used.

TABLE-US-00002 TABLE 2 Type of filler and amount of polycarboxylate ether (PCE) used in the individual components K1. Amount PCE Example Filler (wt.-%) K1-1 BaSO4 (particle size D50 = 10-15 m) 0 K1-2 BaSO4 (particle size D50 = 1.3 m) 0 K1-3 BaSO4 (particle size D50 = 2.3 m) 0 K1-4 Silica (particle size D50 = 20 m) 0 K1-5* Silica (particle size D50 = 20 m) 0.02 K1-6 Silica (particle size D50 = 20 m) 0.05 K1-7 Silica (particle size D50 = 20 m) 0.07 *K1 according to invention. All others are reference examples.

[0149] The epoxy resin was charged first. All other materials were added and homogenized for about 5 minutes.

Component K2: Hardener

[0150]

TABLE-US-00003 TABLE 3 Basic formulation of component K2. wt.-% Ingredient (based on total K2) Benzyl alcohol 34 Cycloaliphatic polyamine 19 Aliphatic polyamine 15.5 Accelerator 7.8 Liquid petroleum resin 18.7 Polyamidoamine 5 Total 100

[0151] In order to obtain curable example compositions, each individual component K1 in Table 2 was mixed with component K2 of Table 3 in a weight ratio K1:K2 of 8:1.

Results of Preliminary Study

[0152]

TABLE-US-00004 TABLE 4 Preliminary test results. Compressive strength [MPa] Flowability (underwater) Underwater Example [mm] 7 d behavior K1-1/K2 n/m 66.82 Serious dispersion in water, filler particles came out K1-2/K2 n/m n/m Severe cracks in composition and turbidity in water K1-3/K2 n/m n/m Severe cracks in composition and turbidity in water K1-4/K2 306 87.4 Good K1-5/K2* 418 90.5 Good K1-6/K2 450 n/m Turbitity and particles in water K1-7/K2 470 n/m Turbidity and particles in water *Experiment according to the invention, n/m means this value was not measured.

[0153] Table 4 shows that only the experiment according to the present invention shows good underwater behavior combined with high flowability and good compressive strength after underwater curing.

Benchmark Test of Selected Epoxy-Based Grouts for Underwater Curing

[0154]

TABLE-US-00005 TABLE 5 Benchmark test results. Simpson K1-5/K2 FX-70-6 (weight Sikadur-53 (Simpson ratio 8:1) (Sika Strong-Tie (see Tables Test method Switzerland) .sup.1 USA) .sup.2 1 to 3) Density [g/cm.sup.3] 2 1.84 1.74 Flowability [mm] 360 374 418 Compressive strength 64.2/88.2 34/59.2 84.1/104.3 [MPa] (1 d/7 d air) Compressive strength 53.6/80.3 29.1/8.2 70.9/90.5 [MPa] (1 d/7 d underwater) Flexural strength n/m/51.6 n/m/42.8 56.6/57 [MPa] (1 d/7 d air) Flexural strength n/m/n/m n/m/n/m 41.3/45.5 [MPa] (1 d/7 d underwater) Adhesion on concrete (air) n/m 2.4 5.17 [MPa] Adhesion on concrete 2.97 n/m 4.89 (underwater) [MPa] n/m means this value was not measured. .sup.1 Commercial two-component epoxy-based grout for underwater curing. Contains approx. 55 wt.-% BaSO.sub.4 based on the total composition. .sup.2 Commercial three-component epoxy-based grout for underwater curing. Contains ca. 50 wt.-% silica, ca. 15 wt.-% fly ash, and ca. 8 wt.-% BaSO.sub.4 based on the total composition. Does not contain polycarboxylate ether.

[0155] The data in Table 5 shows that the composition according to the present invention has improved handling properties (flowability) and, surprisingly, also improved mechanical properties as well as curing behavior in air and underwater.