Laboratory for Self-healing Construction Materials

Scientific results:

• We have researched the characteristics of self-healing in encapsulated self-healing asphalt concrete containing an encapsulated rejuvenator. Samples of non-aged, short-term-aged and long-term-aged asphalt beams were subjected to three-point bend testing. The rate of emission of the anti-aging agent before and after self-healing was determined quantitatively with the use of IR spectroscopy.
• The Laboratory has researched the development and impact of Bacillus cohnii bacilli on the healing of cracks in concrete, the recovery of compressive strength after preliminary  cracking, the sorption capability, the water absorption and the microstructure of concrete. We used different methods of the treatment of concrete during strength accumulation. It has been demonstrated that bacteria efficiently heal microcracks occurring in concrete during strength accumulation, increasing its characteristics at the age of 28 days.
• It has been demonstrated that introducing Pseudomonas bacteria into concrete mixture leads to a significant increase in compressive strength and tensile strength. In comparison with normal concrete, the results demonstrated a maximum increase of compressive strength by 16%, a maximum increase of tensile strength of 12%. Bacterial concrete had a lower weight loss and a higher tensile strength than ordinary concrete when treated with 5% H₂SO₄ solution or 5% MgSO₄ solution compared with control samples of concrete.
• An analysis using the finite-element method (ANSYS 15.0) has been conducted to study the influence of the concentration of bacteria (the ratio of the mass of bacteria to the mass of concrete was 1%, 2% and 3%), their species (Bacillus subtilis, E. Coli and Pseudomonas sps.) as well as the type of loading (one-point loading, two-point loading and distributed loading across four points) on concrete beams. Two beams were selected from earlier experiments and modeled using ANSYS. The results of the modeling demonstrated that the rational type of bacteria was Bacillus subtilis and that a concentration of 3% for Bacillus subtilis can increase the strength of a beam by 20,2%.

Implementation of research results:

The achieved results in the form of compositions of a bacterial healing agent and compositions of concrete mixtures were transferred for industrial implementation to the leading design companies «PI Georekonstruktsiya» Ltd. and «PSK Venchur» Ltd. The produced results are supposed to be used when designing, constructing and management of buildings and structures made of monolithic reinforced concrete.

Education and retraining of personnel:

• The results of the work of the Laboratory have been used to create a new master’s degree program, «Mechanics of polymer and composite materials» enrollment for which started in 2022.
• In 2021-2022 internships have been organized for employees of the Laboratory at the laboratory of the leading scientist.
• In 2021-2022 two scientific conferences «Self-healing construction materials» were conducted.
• One Doctor of Sciences dissertation has been prepared and defended.

Organizational and infrastructural transformations:

On the grounds of the Laboratory a youth laboratory of protected and module-based buildings has been created.

Other results:

Apart from the leading scientist Georgios Kordas, two renowned Indian researchers work at the Laboratory, Murali Gunasekaran and Saurav Dixit.

Collaboration:

Moscow State University of Civil Engineering, Donbas National Academy of Civil Engineering and Architecture, Kazan State University of Architecture and Engineering (Russia), Tashkent Institute of Irrigation and Agricultural Mechanization Engineers (Uzbekistan), Khalel Dosmukhamedov Atyrau State University (Kazakhstan): joint scientific conferences, student exchanges, internships of professors and postgraduates.

In collaboration with universities of China PR we are taking advantage of the existing branch of Peter the Great St. Petersburg Polytechnic University in China PR.