EP0347639A1 - Process for removing mortar residues from a jointed surface - Google Patents

Abstract

In order to prevent the surface of jointing mortar from receding relative to the surrounding stone surface after the action of a cleaning aftertreatment medium, a swelling jointing mortar is used. A cobbled arrangement is achieved, in which the stone edges (11) protrude plastically because the mortar surface (9) adjacent to the stones is slightly recessed (10). <IMAGE>

Description

It is known (DE-A 36 29 738, DE-C 29 44 910) to clean mortar residues from a jointed plaster surface in that the mortar residues are prevented from setting by a setting retarder or cationic surfactants and then sprayed off. The depth of action and wash-off is of the order of a few millimeters, and of course not only above the cobblestones, but also in the joint area. Since the layer to be washed over the stones is generally less than this depth of action, the mortar surface in the joint area is deepened by a few millimeters compared to the surface of the adjacent stones. This is not disadvantageous or even desirable in the case of large plasters (row plasters). In the case of small plasters, on the other hand, a surface that is as smooth and deep as possible is often desirable.

The invention is therefore based on the object of avoiding the formation of a recessed joint surface after using a post-treatment agent.

The solution according to the invention is that a swelling mortar is used for filling the joints, which is allowed to swell beyond the desired joint filling level before it hardens.

Spring mortars are known. They are characterized by the fact that their volume increases due to the formation of fine gas bubbles. The extent of the volume increase and its time course can be influenced in the desired manner by means which are familiar to the person skilled in the art. According to the invention, they are chosen such that after filling and pulling off the joints, the mortar increases in volume such that the mortar grows just above the height difference over the stone surface which is prevented from setting under the action of the aftertreatment agent. The boundary between the non-setting and the setting mortar is then approximately at the level of the stone surface. This limit is also the surface of the mortar after washing off the layer that has not set under the influence of the aftertreatment agent.

Mortar in the sense of the prevailing terminology does not include mortars which, after solidification, are able to absorb liquid and under the influence of which show swelling by which they are pressed tightly against the joint walls (DE-A 20 18 348). Such mortars are of course not suitable for the invention, since the swelling which takes place only after hardening is not capable of the change in height required according to the invention.

The mortar is preferably used in such a consistency that the joints can be flooded with mortar, so that the installation takes place quickly over a large area. The time for filling the joints is then short compared to the swelling time of the mortar, so that the same swelling results are achieved over a large area. The procedure is such that after the preparation and transport of the mortar to the installation site, the joint spaces are flooded with the mortar and the pavement surface is pulled off almost flush. Subsequently, the aftertreatment agent is sprayed on, which is expediently (as known from DE-A 36 29 738) thixotropic in order to ensure the effect for a sufficient time.

The major part of the mortar swelling should take place after the aftertreatment has been removed or applied. Since the expansion can only take place towards the pavement surface, the mortar swells slightly beyond the stone banks. The following day, the paved area is cleaned with water and the undesirable excess mortar in the joint area is removed.

It shows that the remaining mortar surface in the joint area adjacent to the stone is slightly recessed compared to the middle joint area. This is because the increase in the mortar surface during the swelling process in the immediate vicinity of the stones due to the friction on the stone flanks is less than in the middle of the joint, so that the mortar swells in an arc over the stone surface. While its height above the stone surface in the central area corresponds approximately to the depth of action of the post-treatment agent, it is less in the immediate vicinity of the stones, so that the setting prevention is effective down to the level of the stone surface. After cleaning the plaster surface, slight depressions are formed in the mortar adjacent to the stones, whereby the individual stone of the dressing stands out well in terms of its visual effect.

The invention is preferably used when grouting paving surfaces because the joint density is particularly high there. However, it can also be advantageous when grouting panel surfaces or other end surfaces that do not necessarily have to be horizontal.

• Fig. 1 zeigt die Steine 1 des Natursteinpflasters mit den Fugen 2 gesetzt, noch nicht verfugt.
• Fig. 2 zeigt die Fugen mit Fugenmörtel 3 vergossen und abgezogen. Das Nachbehandlungsmittel 4 ist in Form einer Schicht aufgetragen. Die Quel­lung des Mörtels ist noch nicht erkennbar.
• Gemäß Fig. 3 haben sich nach Abschluß der Quellphase über den Fugen erhöhte Wülste 5 gebildet, die im Mittelbereich 6 höher sind als in den an die Steine 1 angrenzenden Bereichen 7.
• Gemäß Fig. 4 sind die auf den Steinen 1 verbliebenen Mörtelreste 8 (Fig. 3) einschließlich einer entsprechend dicken Oberflächenschicht des die Fugen füllenden Mörtels entsprechend der Einwirkungstiefe des Nachbe­handlungsmittels 4 abgewaschen. In den Fugen ist eine Mörteloberfläche verblieben, die lediglich in den Fugenmittelbereichen 9 etwa die Höhe der Steinoberfläche erreicht, während sie in den an die Steine angrenzenden Bereichen 10 vertieft ist, so daß die Steinkanten 11 plastisch hervortre­ten.

The invention is explained below with reference to the drawing, which illustrates successive stages of manufacture in four figures.

• Fig. 1 shows the stones 1 of the natural stone paving set with the joints 2, not yet grouted.
• Fig. 2 shows the joints with grout 3 and removed. The aftertreatment agent 4 is applied in the form of a layer. The swelling of the mortar is not yet apparent.
• 3, after the swelling phase has ended, raised beads 5 have formed which are higher in the central region 6 than in the regions 7 adjacent to the stones 1.
• According to FIG. 4, the mortar residues 8 remaining on the stones 1 (FIG. 3), including a correspondingly thick surface layer of the mortar filling the joints, are washed off in accordance with the depth of action of the aftertreatment agent 4. A mortar surface remains in the joints, which only reaches approximately the height of the stone surface in the joint middle regions 9, while it is recessed in the regions 10 adjacent to the stones, so that the stone edges 11 protrude plastically.

Claims (2)

1. A method for cleaning a grouted surface of mortar residues using an agent that prevents or prevents the setting of a surface layer of the mortar, characterized in that a swelling mortar is used for the filling of the joints, which one before it hardens beyond the desired joint fill level swells. 2. plaster arrangement consisting of stones and mortar-filled joints, characterized in that the mortar surface in the central region of the joints is approximately at the level of the stone surface, while it is recessed adjacent to the stones.

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