**7.7. Lock at the Danube River (Gabcikovo, Slovakia)**

#### **Task:**

330 Polyurethane

**Solution:** 

The proposed technology was based on grouting of overlaying rocks ahead of the workingface by PU grouting system Geopur® to the distance of 3 m. In the given geological conditions the technology proved to be a safe and economic solution. The use of PU grouting resin system Geopur® enabled to perform the whole cycle of grouting works in 4 hours. Proposed technology did not require equipment of great size. Borings for grouting were drilled using a light hand drilling equipment; grouting works were performed using transportable pumps. 9-12 grouting tubes were used per one section (3 m), in accordance with local geological conditions. Distance between the grouting tubes was 0,3 m at the face and 0,4 m at the sides of the tunnel. Minimal compressive strength of the formed geocomposite reached in the upper part of the profile 4-6 MPa and 2-4 MPa on the sides. The

**7.6. Repair of cracks in the concrete of highway bridge (Belotin, Czech Republic)** 

During the construction of the highway near Belotin, bridge beams were damaged probably due to the frosty weather. Cracks of up to 11 m length formed at the construction. It was

Boreholes of 14 mm diameter were drilled into the concrete beam along the cracks, diagonally across the crack. Steel bars of 10 mm diameter were inserted into the drillings

necessary to reconnect the cracks using a reinforced grouting technology.

and subsequently the drillings were grouted with Geopur® PU resin (Figs 27,28)

strength of the rock was reached in 20 min after grouting works.

**Figure 26.** Grouted gravel in the face of the tunnel

**Task:** 

**Solution:** 

During operation of the lock on the Danube River cavities had been formed on the outer side of the lock in the soil, caused by insufficiently sealed dilatation joints (Fig. 29). Water flowed through the soil embankment, washed out the fine grained particles and cavities were formed. Additional sealing of the dilatation joints was therefore proposed.

#### **Solution:**

In 2005 additional sealing of dilatation joints and sealing of cracks in the concrete was performed using PU grouting system Geopur®. In total an area of 42 m2 of concrete was repaired, 210 m of dilatation joints was resealed and 207 m of cracks in the concrete was sealed. Total of 7 dilatation joints was successfully repaired using total of 700 kg of Geopur® (Fig. 30).

Polyurethane Grouting Technologies 333

with axis pressure of 7,9 tons. Despite everyday maintenance, signs of damage occurred and

A new method of repair of the concrete sleepers was proposed based on anchoring and use of PU resin. The performance of the works concurrently led also to stopping of water inflows from the subsoil of the railway. Concrete sleepers were stabilized and anchored

Grouting works were performed between 2005 and 2006, mainly during night time and without necessity of putting the metro out of operation. Total of 2842 anchors were made of the following parameters: length of the anchor 500 mm, diameter of the anchor 18 mm, diameter of borehole 25 mm, grouting material Supermin® with reaction start of 2 minutes. Further, total of 2430 grouting boreholes were drilled of the following parameters: borehole diameter 14 mm, length up to 1 m, length of inserted steel bars up to 600 mm, diameter of

In addition, water infiltration from below of the railway was stopped in a total length of 58

the bars 8 mm, grouting material Geopur® 082/1000 with reaction time 2 minutes.

repair works were launched.

**Figure 31.** Detail of the grouting works

**Figure 32.** View of the railway after repair works

m of the metro tunnel using material Geopur® 082/350.

without the necessity to replace them (Figs 31,32).

**Solution:** 

**Figure 29.** Dilatation joint before the grouting

**Figure 30.** Dilatation joint after the grouting
