**4. Reconstruction of the historic bridge**

Starting summer 2019, a vast reconstruction of the bridge structure had carried out. During the fieldwork after lowering the terrain around the bridge, a problem of much a worse state of the pillars in their lower part, as well as a higher level of groundwater, arose. Some of the pillars had to be statically supported.

The reconstructing the historic bridge is described briefly in the following processes: Digging up the terrain around the bridge.

Vegetation surrounding the bridge was removed. Subsequently, all historical bricks from the area around the bridge were collected, cleared up and stored. The bricks were cleaned from moss and other vegetation.

Diversion of the stream and remediation of pillars in the original stream bed, damaged bricks replacement.

In order to enable repairs and remediation of the middle pillars of the stream bed, it was crucial to temporarily divert the stream bed. The terrain around the pillars was manually dug away while the vaults were gradually supported (**Figure 14**). Within deeper layers, it had to be needed to drain the leaking groundwater.

Damaged and irregularly shaped bricks had to be taken away carefully and replaced by new replicas produced of at least the same quality compared to the original ones, meaning the quality of "klinker brick these bricks were inserted into cleaned holes after missing or removed ones in order to be statically integrated (activated) at the place of contact with the original brickwork by a special and appropriate expandable mortar mixture—a filler substance intended for caulking of load-bearing joints, the substance is freeze and weather conditions resistant as well." After returning the stream into its original position, gradual remediation of other bridge piers followed.

Repair of fillings above the vaults, remediation of the parapet walls and drainage pipelines (**Figures 13** and **14**).

When dismantling the masonry it was necessary to preserve or avoid breaking the original backfill especially in the area below the level of the drain pipes, meaning under the clay waterproofing. Historical backfill above this level had to be cleared of roots and contaminating soil and preserved for reuse, i.e. to replenish the lower part

**Figure 13.** *An overall view of the top of the bridge during reconstruction.* *A Deep Review on a Historical Brick Bridge in South Moravia; Reconstruction and Assessment DOI: http://dx.doi.org/10.5772/intechopen.102602*

**Figure 14.** *Dismantling and support of arches, summer 2019.*

of the backfill. Replicas of hand-fired bricks were made after laboratory analysis. A lime mortar was used for masonry. Replicas of the drainpipes were installed in the original places just above the clay waterproofing on the same slope. These replicas were made of fired ceramic precisely according to the preserved remains of the original historical pipes, the exact length was determined on-site so that the face of the parapet walls is exceeded at least 40 mm (**Figure 15**). The pipes were hydrophobized from inside before mounting.

Based on the probes for ascertaining the structure condition below the terrain, it was decided that the soil was removed only to the level of limestone blocks, not to the base of stone packing, in order to avoid possible movements of the stone foundations.

Discovered original bricks were used to complete the lower faces of the vaults. Leaning-out retaining walls at the beginning and the end of the bridge were dismantled and straightened up. The described situation was repeated in other sections—it was essential to perform manual demounting of existing bricks from damaged parts including their cleaning and reusing in particular sections (**Figure 15**). Based on the experimental analysis the original bricks were compared with brick production in a nearby brickyard. Laboratory analysis revealed that the newly produced bricks

**Figure 15.** *View over the bridge during reconstruction, summer 2019 and detail drainpipes replicas.*

**Figure 16.** *The bridge after completion, 2020.*

were not suitable for use due to poor frost resistance and it was necessary to find an adequate replacement of another supplier.

Completion of the original fillings and construction of the road threshing surface.

Threshing became the chosen technology for the final surface treatment of the bridge deck, under which is the original threshing layer, stone packing and the backfill [7–9].

The bridge construction that connected the Portz Island to land was not far from sinking into oblivion until recently. Thanks only to the inimitable quality of the bricks made by Mikulov's skilful brick makers of the 17th century, the bridge construction has survived until today (**Figure 16**).
