construction purposes. Especially, the invention relates to a ground solidifying agent, a production method for a ground solidifying agent and an according ground

solidifying method.

In regular road construction, the ground material is removed down to a large depth and replaced by a multi ^¬ layer construction. This construction technique for roads requires a great amount of material, which has to be brought to the construction site, a great amount of labor, and especially requires a long time to finish.

The German Patent DE 199 24 357 CI discloses a ground solidifying agent and ground solidifying method, which allow for a reduced amount of material, labor and time. There, a ground solidifying agent is mixed with ground material. This mixture then hardens and forms the road or is base for a top layer of the road. The solidifying agent and ground solidifying method shown there though are disadvantageous, since due to the composition of the ground solidifying agent, a non-optimal pH value of the resulting solidified ground follows. This leads to

environmental issues. Accordingly, the object of the invention is to provide a ground solidifying agent, a production method for a ground solidifying agent and a ground solidifying method, which allow for a low material use, low labor use and low time consumption, while at the same time being environmentally friendly .

The object is solved by the features of claim 1 for the production method, claim 8 for the ground solidifying agent and claim 15 for the ground solidifying method. The dependent claims contain further developments.

According to a first aspect of the invention, a method for producing a ground solidifying agent is provided. The method comprises providing a paraffin wax, an emulsifier and water, mixing the paraffin wax, the emulsifier and the water, heating the mixture, setting the pH value to a pre- specified pH value by adding a pH value modifying agent, and cooling a resulting compound. By deliberately setting the pH value, it is possible to remove the detrimental environmental effects.

According to a first implementation form of the first aspect, the pH value modifying agent is a base, preferably sodium hydroxide, and/or wherein the pre-specified pH value is between 6.7 and 9, preferably between 7.5 and 8, most preferably about 7.75. It is thereby possible to set the pH value with readily available materials, while at the same time achieving an optimal environmental

friendliness of the resulting compound.

According to a second implementation form of the first aspect, the paraffin wax is an oxidized polyethylene wax, and/or wherein the paraffin wax is provided in liquid form or is provided in solid form as a block or as particles. This allows for a low production cost of the ground solidifying agent. According to a third implementation form of the first aspect, the emulsifier is a product based on fatty alcohol ethoxylates, and/or wherein the emulsifier content is 3%- 15% preferably 5%-ll%, most preferably about 8%, with regard to the weight of the resulting compound. This allows for a low production cost of the ground solidifying agent .

According to a fourth implementation form of the first aspect, ethanol is provided as part of the mixture. This allows for a greater freezing stability and ensures a quicker evaporation of the liquid content within the ground solidifying agent. According to a fifth implementation form of the first aspect, the solids content of the mixture is 25%-45%, preferably 34%-36%, most preferably about 35% with regard to the weight of the resulting compound, wherein the paraffin wax is considered as a solid. This allows for a stable emulsion, while at the same time keeping the volume necessary for performing ground solidifying at a minimum.

According to a sixth implementation form of the first aspect, the mixture is heated to at least 80°C, preferably to at least 90°C, most preferably to about 95°C, and/or wherein the resulting compound is cooled to at most 40°C, preferably at most 30°C, most preferably to about 25°C. This allows for an especially stable emulsion. According to a second aspect of the invention, a ground solidifying agent for solidifying ground is provided. The ground solidifying agent is formed as an emulsion

comprising a paraffin wax, an emulsifier, water and a pH value setting agent. The emulsion is formed by heating the mixture of the paraffin wax, the emulsifier, and the water, adding the pH value setting agent and thereby setting the pH value to a pre-specified pH value, and cooling a resulting compound. By deliberately setting the pH value, it is possible to remove the detrimental

environmental effects.

According to a third aspect of the invention, a ground solidifying method using a ground solidifying agent according to the second aspect is provided. The method comprises mixing the ground solidifying agent into the ground, spreading a binding agent on the ground, mixing the binding agent into the ground and solidifying the ground using a roller. This allows for solidifying the ground using only readily available construction machines and requiring only a low amount of material.

According to an implementation form of the third aspect, after mixing the ground solidifying agent into ground, a preliminary solidifying of the ground is performed, using a roller. This allows for an even better solidification of the resulting solidified ground.

Exemplary embodiments of the invention are now further explained with respect to the drawings by way of example only. In the drawings:

Fig. 1 shows an embodiment of the production method

according to the first aspect of the invention in a flow diagram;

Fig. 2 shows an embodiment of the ground solidifying method according to the third aspect of the invention in a flow diagram; shows an embodiment of a first mixing step in a method according to the third aspect of the invention ; shows an exemplary ground particle; shows an embodiment of an exemplary ground particle coated with a layer of ground

solidifying agent according to the second aspect of the invention; shows an embodiment of a first solidifying step in a ground solidifying method according to the third aspect of the invention; shows an embodiment of spreading a binding agent as a step of a ground solidifying method

according to the third aspect of the invention; shows an embodiment of a second mixing step in a ground solidifying method according to the third aspect of the invention; shows an embodiment of a number of ground particles covered with a layer of ground

solidifying agent according to the second aspect of the invention, bound together by a layer of binding agent, and shows an embodiment of a second solidifying step in a ground solidifying method according to the third aspect of the invention; First we demonstrate the production of a ground

solidifying agent along Fig. 1. Along Fig. 2 - 10 the process of ground solidification is described. Similar entities and reference numbers in different figures have been partially omitted.

In Fig. 1, the production method for producing a ground solidifying agent is shown in a flow diagram. In a first step 100, a paraffin wax, preferably an oxidized

polyethylene wax is provided. The wax can be provided in solid form as a block or as particles, but also can be provided in liquid form.

In a second step 101, an emulsifier is added.

Advantageously, the emulsifier is a product based on fatty alcohol ethoxylates.

In a third step 102, water is added and mixed with the paraffin wax and the emulsifier. Advantageously, the emulsifier content is 3%-15%, preferably 5%-ll%, most preferably 8% of the mixture. Moreover, preferably the solids content of the mixture is 25%-45%, preferably 34- 36%, most preferably 35%. In a fourth step 103, the mixture is heated. The mixture is advantageously heated to at least 80°C, preferably 90°C, most preferably 95°C. This allows for an even distribution of the components and a strong

emulsification .

In an optional fifth step 104, an emulsification

intensifier may be added and mixed in. In a sixth step 105, a pH value modifying agent,

preferably a base, most preferably sodium hydroxide, is added in order to set the pH value of the mixture to between 6.7 and 9, preferably between 7.5 and 8, most preferably to 7.75.

In a final seventh step 106, the mixture is cooled to at most 40°C, preferably at most 30°C, most preferably to 25°C. The resulting compound is the ground solidifying agent .

The pH value modifying agent only makes up a small part of the resulting compound. Therefore, the above-mentioned values regarding the content of solids and emulsifier are also valid with regard to the resulting compound, and not only with regard to the mixture before adding the pH value modifying agent. The same holds true for the

emulsification intensifier. The paraffin wax is advantageously long-chained, has a high melting point and is stable. Due to the oxidation of the oxidized polyethylene wax, a high emulsification activity with water is achieved. The resulting ground solidifying agent can be used between 2.5°C and 50°C. The higher the storage temperature, the lower the time of stability. An average time of stability is six month. In Fig. 2, a ground solidifying method is shown. In a first step 200, a ground solidifying agent is mixed into the ground using a milling machine. In a second step 201, which is an optional step, a

preliminary solidifying of the ground is performed, using a roller. In a third step 202, a binding agent is spread on the ground. The binding agent can for example be cement or chalk. Also other binding agents are possible.

In a fourth step 203, the binding agent is mixed into the ground using a milling machine. The same milling machine as for the first step 200 can be used.

In a final fifth step 204, the ground is solidified using a roller. Also here, the same roller as in the optional step 201 can be used.

In the following, the individual steps shown in Fig. 2 are shown in greater detail. In Fig. 3, the first step of mixing the ground solidifying agent into the ground is shown. Here, a milling machine 10 mixes the ground solidifying agent 30 into the ground 1 resulting in a mixture 2 of ground and ground solidifying agent. The ground solidifying agent 30 is spread onto the mill of the milling machine 10 by a spraying mechanism 11.

It can clearly be seen here that due to loosening the ground 1 and adding the ground solidifying agent 30, the resulting volume of the mixture 2 is larger than that of the previous ground 1.

In Fig. 4, an exemplary ground particle 20 is shown. In Fig. 5, the exemplary ground particle 20, covered in a layer of ground solidifying agent 21, as after step 200 of Fig. 2, is shown. The mixture 2 shown in Fig. 3 consists of particles as shown in Fig. 5.

In Fig. 6, the optional second step 201 of Fig. 3 is shown. A roller 12 solidifies the mixture 2 resulting in a solidified mixture 3. This allows heavy vehicles to move on the solidified mixture 3 more easily.

In Fig. 7, the third step 202 of Fig. 2 is shown. Here, a truck 13 spreads a binding agent 4 on the solidified mixture 3, which rests on a non-modified ground layer 1. If the optional step 202 of Fig. 2 is not performed, the binding agent 4 is spread directly onto the mixture 2.

In Fig. 8, step 203 of Fig. 2 is shown. Here, the binding agent 4 is mixed into the solidified mixture 3 resulting in a bound mixture 5. This again is done by use of a milling machine 10.

In Fig. 9, the composition of the bound mixture 5 is shown. Here a plurality of ground particles 20, each coated with a layer of ground solidifying agent 21, bound together by a layer 22 of binding agent, are shown.

Finally, in Fig. 10, the final step 204 of Fig. 2 is shown in detail. The bound mixture 5 is solidified using a roller, resulting in solidified ground 6.

The invention is not limited to the examples and

especially not to the specific wax material, emulsifier material, binding agent material, etc.. Especially, the ground solidifying agent can be used for solidifying ground for road works, but also for runways, for small midsized airplanes, traffic areas on airports, water repelling surfaces for draining stabilization and dam construction. The characteristics of the exemplary embodiments can be used in any advantageous combination