FIELD OF THE INVENTION

The present invention pertains to a two-component mortar system for chemical fastening of anchoring means in mineral surfaces, comprising a curable aqueous-phase aluminous cement component A and an initiator component B in aqueous-phase for initiating the curing process, component A further comprising at least one blocking agent selected from the group consisting of phosphoric acid, metaphosphoric acid, phosphorous acid and phosphonic acids, at least one plasticizer and water, and component B comprising an initiator, at least one retarder, at least one mineral filler and water. Moreover, the present invention pertains to a two-component system, which is ready-for-use, for chemical fastening of anchoring means, preferably of metal elements, in mineral surfaces, such as structures made of brickwork, concrete, pervious concrete or natural stone as well as its use for chemical fastening of anchoring means.

BACKGROUND OF THE INVENTION

Many two-component mortar systems, which are sometimes also referred to as kit-of-parts, exist, in which each of the components is intended to be mixed prior to use or during application in order to initiate the curing process to provide good chemical fastening of anchoring means in mineral surfaces. For example, organic systems based on free-radically polymerizable resins are used when fast curing is desired. However, such systems are generally known to be polluting, expensive, potentially hazardous and/or toxic for the environment and for the person who handles them and they often need to be specifically labelled. Moreover, organic systems often show a much reduced stability when thermally exposed to strong sunlight or otherwise elevated temperatures thereby decreasing their mechanical performance when it comes to chemically fastening of anchoring means.

In order to overcome these drawbacks, predominantly mineral systems based on aluminous cement have been developed. Aluminous cement has as its major constituent monocalcium aluminate and is widely used in the building and construction industries as the final products evidence a high level of mechanical performance over extended periods of time. Also, aluminous cement is resistant to bases and attains its maximum strength more rapidly than Portland cement and is capable of withstanding solutions of sulfates. Hence, aluminous cement systems are preferably employed in the field of chemical anchoring.

EP 2 162 410 describes a ready-for-use dual-component system including a part A based aqueous-phase aluminous cement, retarded by boric acid or a salt thereof, and a part B for initiating the curing process. The initiator in part B is made of only lithium salts. The system cures in less than 5 minutes after mixing of the two parts. EP 0 081 385 also discloses a dual-component system including a set-inhibited aqueous high alumina cement composition and a reactivator composition. The set inhibitor is boric acid and the reactivator composition includes lithium salts.

However, these aluminous cement aqueous suspensions retarded by boric acid or salts thereof are often not very stable for a sufficient time to be stored prior to use. Moreover, boric acid is quite toxic as well as ecotoxic.

EP 2 794 510 describes a stabilized aqueous suspension comprising aluminous cement and/or calcium sulfoaluminate cement, which is inhibited by a phosphorous-containing compound and can be stored for a sufficient time also at high temperatures. Said stabilized aqueous suspension can serve as a base for surface coatings.

When it comes to chemically fastening anchoring means in mineral surfaces, a rapid curing time, i.e. of less than 5 minutes, is not always desired. Further, most of the known systems lack sufficient fluidity for most practical applications of the resultant compositions. Often such prior art compositions also evidence a tendency to crack in a relatively short time or do not exhibit the required mechanical performance, also under the influence of elevated temperatures.

DE 2 311 239 describes an adjuvant composition for improving the setting and hardening properties of aluminous cement and mortar, comprising Lithia, a water-soluble lithium salt and a hydroxylated organic acid, or a salt or ester thereof. Said fluid is incorporated directly into the aluminous cement or into mortars and concretes during their manufacture or may be added to the mixing water during application. However, a disadvantage of this system lies within the fact that the cement composition as well as the activator composition cannot be stored for a sufficient time in order to be ready-for-use and hence have to be freshly prepared before use depending on desired setting and hardening times implying more procedural steps before application.

Therefore, there is a need for a ready-for-use multiple-component system, preferably a two-component system, which is superior over the prior art systems with regard to environmental aspects, health and safety, handling, storage time and a good balance between setting and hardening of the mortar. Moreover, it is of interest to provide a system that can be used for chemical fastening of anchoring means in mineral surfaces without adversely affecting the handling, characteristics and the mechanical performance of the chemical anchoring system.

In view of the above, it is an object of the present invention to provide a multiple-component system, in particular a two-component mortar system, which overcomes the disadvantages of the prior art systems. In particular, it is an object to provide a two-component mortar system that is ready-for-use, which can be handled easily and is eco-friendly, which can be stably stored for a certain period of time prior to use, which exhibits a good balance between setting and hardening and still has an excellent mechanical performance when it comes to chemically fastening anchoring means, even under the influence of elevated temperatures.

Moreover, it is an object of the present invention to provide a two-component mortar system that can be used for chemical fastening of anchoring means, preferably of metal elements, in mineral surfaces, such as structures made of brickwork, concrete, pervious concrete or natural stone.

These and other objectives as they will become apparent from the ensuring description of the invention are solved by the present invention as described in the independent claims. The dependent claims pertain to preferred embodiments.

SUMMARY OF THE INVENTION

In one aspect, the present invention provides a ready-for-use two-component mortar system comprising a curable aqueous-phase aluminous cement component A and an initiator component B in aqueous-phase for initiating the curing process, component A further comprising at least one blocking agent selected from the group consisting of phosphoric acid, metaphosphoric acid, phosphorous acid and phosphonic acids, at least one plasticizer and water, and component B comprising an initiator, at least one retarder, at least one mineral filler and water. In particular, component B comprises an initiator comprising a mixture of alkali and/or alkaline earth metal salts, at least one retarder selected from the group consisting of citric acid, tartaric acid, lactic acid, salicylic acid, gluconic acid and mixtures thereof, and at least one mineral filler selected from the group consisting of limestone fillers, sand, corundum, dolomite, alkaline-resistant glass, crushed stones, gravels, pebbles and mixtures thereof.

In another aspect, the present invention provides a two-component mortar system that is used for chemical fastening of anchoring means, preferably of metal elements, in mineral surfaces, such as structures made of brickwork, concrete, pervious concrete or natural stone.

