A crumbling concrete base, broken out areas and loose granite slabs: After around 40 years of frost and thaw cycles and repeated waterlogging, the foundation of the 13-metre-high Karl Marx monument in the former Karl Marx City of Chemnitz had lost its load-bearing strength. The restoration of the base of one of the largest portrait busts in the world in line with monument conservation requirements placed high demands on both the surfacing work and the urgently required drainage of the surfacing structure.
The approximately 18.5 x 10.5 meter wide, 40 to 80 centimetre high base of the monument, which was erected in 1971, consists of concrete and bricks at its core. The original brick surround of this foundation, which was built as a lost formwork, has now been replaced by a concrete apron about 25 centimetres wide. The one-piece granite corner elements were excluded from the dismantling of the previous surround and left in their original position. In this way, the installers ensured that both the heights and the alignments remained unchanged.
The employees of the specialist company Natur- und Kunststeinbau Martin Herberholz in Chemnitz carefully removed the approximately 250 slabs from the existing building. As many granite slabs as possible were to be reused in line with the concept of monument preservation. In the end, the stone workers checked a good three quarters of the slabs for damage, cleaned them and laid them again. The new slabs required were supplied by the same quarry in the Ukraine from which the Soviet sculptor Lew Kerbel, who was commissioned to build the Karl Marx monument at the time, had obtained the original granite slabs.
Read more about “Surface drainage” in STEIN in March 2014.