The Vaults of the Subotica Synagogue after 114 Years: Condition Assessment and Repair Recommendations

Abstract

This paper presents an original contribution with assessment of the current state in exploitation safety and usability of thin concrete domes of the beauteous Subotica Synagogue, built in 1902. The authors are analyzing the condition of the materials used in the Subotica Synagogue, on extracted samples of concrete and steel reinforcement with a binder which was used instead of cement, a gypsum -CaSO4×0,5H2O. The source of the problem, according to the author, is the lack of limeCa(OH)2 from the mixture of gypsum and pozzolanic aggregates made of baked clay. This is the main reason for poor concrete strength of only 7.6 MPa and the present significant corrosion processes in the steel reinforcement of that concrete, which far from the recommended values of pH ≥ 12, have a measured value of only pH = 7.55. These results advise a need for repair of the part of the building that has not been analyzed or investigated yet, partially due to difficult access and also apparently good condition, since cracks, larger deformation or collapse have not appeared yet. The condensation on the domes is damaging the painted decorations with gilding which is falling and reduces the exploitation safety and the mood of the visitors and believers, who came to the synagogue. The authors are proposing a method for rehabilitation of the vaults and ribs of the beautiful Subotica Synagogue domes by simultaneously satisfying the exploitation safety and avoiding the occurrence of condensation and damaging of the painted and gilded ceilings. We believe that the article will inspire and have a positive effect in the professional and scientific society so in other synagogues in Europe and around the world the exploitation usability of vaults will be inspected and if necessary, possible repairs can be made in the same or any similar way as proposed in this scientific work.

Tradicinalni Materijali Kao Rešenje Za Građenje U Novom Vremenu Klimatskih Poremećaja

“…U uvodnom delu ovoga rada smo već naglasili razloge da u podnebljima sa tropskom klimom gde su vrlo visoke temperature koje idu čak i do +50 0 C a relativna spoljašnja vlažnost može biti preko 90%, najbolje rešenje za klimatizaciju prostorija zgrada predstavljaju debeli zidovi od nepečene gline. Debeli zidovi od nepečene gline su u stanju uspešno izvršiti klimatizaciju prostorija jer je spoljašnja strana zidova zagrejana i isušena, kako je to prikazano na Slici 11 [1]. Na spoljašnjoj strani zida vlažnost H1 je najmanja i ona teži vrednosti H1 = H = 0%.…”

“…Slika 11. Fizikalno objašnjenje razmene vodene pare između unutrašnjeg i spoljašnjeg prostoraprirodan efekat hlađenja prostorija i zidova [1] Prema zakonu fizike pritisak vodene se kreću uvek sa mesta višeg pritiska prema mestu nižeg pritiska. To znači da će se vodena para kretati sa unutrašnje strane zida prema spoljašnjoj strani zida.…”