Evaluation of rheological properties of mortar with TiO2 addition

Adding TiO2 tocoating mortars is carried out to promote self-cleaning through photocatalytic activity. However, this addition influences the workability of the mortar and, consequently, the application stage as the TiO2 used can present a large number of fine particles and a high surface area, increasing the demand for mixing water, requiring consistency adjustments before coating. In this work, three mortars (two with the addition of different types of TiO2 and one reference) were developed on a laboratory scale to maintain similar workability, using the flow table test. The amount of kneading water was changed to maintain a spread of 220 ± 10 mm and the content of air-entrained was kept constant, around 25%. The mortars were evaluated using the squeeze flow method. Then, a blind test was performed to assess the mason sensitivity during handling and application of the coating, and all mortars were considered similar. However, the yield of the compositions with TiO2 addition was lower compared to the reference composition, making it possible to explain the results based on the physical parameters of the formulations and with a more in-depth analysis of the rheological indices obtained by the squeeze flow test.

Effect of Whole-Body Cryotherapy on Morphological, Rheological and Biochemical Indices of Blood in People with Multiple Sclerosis

The aim of this study was to examine and assess the impact of a series of 20 whole-body cryotherapy (WBC) treatments on the biochemical and rheological indices of blood in people with multiple sclerosis. In this prospective controlled study, the experimental group consisted of 15 women aged 34–55 (mean age, 41.53 ± 6.98 years) with diagnosed multiple sclerosis who underwent a series of whole-body cryotherapy treatments. The first control group consisted of 20 women with diagnosed multiple sclerosis. This group had no intervention in the form of whole-body cryotherapy. The second control group consisted of 15 women aged 30–49 years (mean age, 38.47 ± 6.0 years) without neurological diseases and other chronic diseases who also underwent the whole-body cryotherapy treatment. For the analysis of the blood indices, venous blood was taken twice (first, on the day of initiation of whole-body cryotherapy treatments and, second, after a series of 20 cryotherapy treatments). The blood counts were determined using an ABX MICROS 60 hematological analyzer (USA). The LORCA analyzer (Laser–Optical Rotational Cell Analyzer, RR Mechatronics, the Netherlands) was used to study the aggregation and deformability of erythrocytes. The total protein serum measurement was performed using a Cobas 6000 analyzer, Roche and a Proteinogram-Minicap Sebia analyzer. Fibrinogen determinations were made using a Bio-Ksel, Chrom-7 camera. Statistically significant differences and changes after WBC in the levels of red blood cells (RBC), hemoglobin (HGB), hematocrit (HCT), elongation index, total extend of aggregation (AMP), and proteins (including fibrinogen) were observed. However, there was no significant effect of a series of 20 WBC treatments on changes in blood counts, rheology, and biochemistry in women with multiple sclerosis. Our results show that the use of WBC has a positive effect on the rheological properties of the blood of healthy women.

Relationship between Rheological Indices and Cracking Performance of Virgin, Recycled, and Rejuvenated Asphalt Binders and Mixtures

Long-term cracking performance of asphalt mixtures is heavily influenced by asphalt binder rheology, and changes in binder stiffness, ductility, and aging condition significantly affect the cracking resistance of the corresponding asphalt mixture. This study evaluated the effectiveness of several common and recently developed binder rheological indices in capturing the effects of binder performance grade (PG) and source, recycled binder content, recycling agent (rejuvenator) dose, and long-term aging. These binder rheological indices included the Superpave intermediate-temperature PG (PGI), the Glover-Rowe (G-R) parameter, the crossover temperature (Tδ = 45°), the rheological index (R-value), and ΔTc. This study also directly compared the binder rheological indices with the cracking performance of corresponding asphalt mixtures to explore possible correlations and their robustness. Asphalt mixture cracking performance was evaluated using the Illinois Flexibility Index Test (I-FIT) for intermediate-temperature cracking, and the disk-shaped compact tension (DCT) test and the uniaxial thermal stress and strain test (UTSST) for low-temperature cracking. Results indicated that all the binder rheological indices (except PGI) consistently captured the effects of binder blend composition and proportions and aging condition, with a few exceptions. Results also showed that the G-R parameter, the crossover temperature (Tδ = 45°), and ΔTc had the best correlation to asphalt mixture and field core cracking performance as compared with other rheological indices (PGI and R-value), with ΔTc demonstrating the overall best correlation to mixture cracking performance.

Increasing Efficiency of Waste Water Treatment of Wine-Making Enterprises with Simultaneous Production of Bio Surface for Oil Industry

A method for pre-treatment of wastewater with the simultaneous production of biological surface-active substances (bio-surfactants) by deep cultivation of the microscopic fungus Hypomyces odoratus in the wastewater of a winery has been developed. In wastewater after cultivation of the fungus under aerobic conditions for 12 hours, a steady decrease in BOD was observed by 2.5 times, COD by 3 times, the content of suspended solids, sulfates, phosphates, ammonium ions, nitrates, nitrites, anionic surfactants decreased significantly substances (ACAS), cationic surfactants (CAS), wastewater in chemical composition began to approach the indicators of municipal sewage. The complexity of the composition obtained during the cultivation of the biomass fungus and the isolated exopolysaccharide contributed to a decrease in the surface tension of the oil and indicated that the fungus synthesizes the bio-surfactant complex. After contact with a 12-hour mass of fungus or exopolysaccharide obtained from biomass in highly viscous, water-flooded bituminized oil, an improvement in rheological indices was noted, and the water cut and content of paraffin deposits decreased.

CONCRETE COMPOSITES USING GRAND-SANDY MIXTURES OF DEPOSITS OF THE CHECHEN REPUBLIC

Objectives Development of optimal recipes of concrete mixtures using local natural raw materials in the form of gravel-sand mixtures from deposits of the Chechen Republic.Method The research methods adopted in the work are based on the theoretical principles and laws of designing and optimizing polydisperse multicomponent systems, the phase and structure formation of clinker minerals, the logic of mathematical calculations, the technological features of the structure formation of composite masses, the theoretical principles of controlling the rheological processes of mixes. All experimental data presented in the work were obtained according to the methods of current regulatory documents (GOST, recommendations, etc.).Result The paper presents the results of a study of the composition and properties of sand and gravel mixtures of deposits of the Chechen Republic and concretes based on them. In particular, the granulometric and chemical compositions and the physicomechanical properties of sand and gravel mixtures have been studied. An analysis of the scientific literature and experience in the use of sand and gravel in construction. The leading scientific schools of the country and abroad in the field of concrete science are presented. The rheological indices of concrete mixes were studied and the dynamics of the curing of concrete of different classes were obtained on the basis of unfortified sand and gravel mixtures in the presence of a chemical additive, the superplasticizer Polyplast SP-1.Conclusion It is proposed to use sand-gravel in its natural form in concrete for non-critical structures in its natural form without additional costs for enriching its composition. The feasibility of obtaining low-grade concrete with the use of sand and gravel mixtures without its enrichment and fractionation is established.