Photo: Dimitar Kyosemarliev
Large-panel blocks are reliable reinforced concrete buildings that could function for centuries. They do not have a specific service life – 20, 50 or 100 years. Apartment owners should have peace of mind if the professionals in the construction process have done their job well and if care is taken during operation. This became clear from the conversation of Prof. Arch. Borislav Borisov, vice-chairman of the Chamber of Architects in Bulgaria (CAB) and engineer Georgi Cordov, expert in surveying building structures and former research assistant at the Scientific Research Construction Institute – NISI, in the program “Properties” with host Hristo Nikolov.
Panel buildings are not risky in terms of an earthquake, explained Borisov. And he added that there are concrete buildings in Rome that were built many centuries ago and currently do not pose a risk.
“In the past, entire Bulgarian institutes with hundreds of specialists worked purposefully to create completely reliable buildings. During the large-scale panel construction in Bulgaria, control was at a very high level. If a wonderful project is 100% earthquake-rated, but during in the execution, the builder made mistakes (with the quality of the concrete or with the connections between the panels) that went unnoticed, then there is some risk, although very small,” said the guest.
For three years, I worked in a home-building plant for the production of large-panel elements, and I can say that the quality was uncompromising. Large-panel buildings are perhaps the most certified in terms of concrete strength, embedded reinforcement and compliance with regulations, said Engineer Georgi Cordov.
We have investigated panel connections in many buildings and have not come across a single case where we have found a problem with these dowels. There are no papers and styrofoam inserted in these places, the kind of information that appears in the public space, the guest added.
“A risk could arise from poor maintenance during operation. Leaks are very dangerous for buildings. They can occur on the roof, on the facades and reach the foundations.”
The operational period is related to the care provided. No matter how long-lasting a building is, if the owners do not take care of it, sooner or later there will be problems, added Borisov.
With regard to building structures, the term “exemplary design service life” appears in the Eurocodes applied in Bulgaria. There is a table that states that the design life expectancy for building structures is 50 years. However, below the table there is a note that the term design service life of a structure is not covered by the term “service life” of a building.
The two interlocutors drew attention to the reconstructions of the ground floors in shops, which were made after the beginning of democracy, mainly in the central parts of the cities. “I have come across unregulated reconstructions that were carried out without project documentation. This is dangerous, because when the building structure is affected, it usually leads to a reduction in its load-bearing capacity and earthquake resistance,” said Engineer Georgi Cordov.
“My observations are that these conversions continue. This is a very heavy element for a building construction, especially if it is not done professionally. The problem can be solved if technical passports are made for buildings with conversions, accompanied by a structural study, for to assess the condition of the whole building.’
Remodeling is no joke and the structure should not be affected. If necessary, this should be done with a professional who can prove the preservation or improvement of the building in terms of construction, added Borislav Borisov.
See the entire conversation at the video of Bloomberg TV Bulgaria
