Sealant Type Research Articles

Patterns and Practices in the Use of Endodontic Materials: Insights from Romanian Dental Practices

The success of endodontic treatment depends on the correct use of materials during the cleaning and filling of the root canal system. The field of endodontics is constantly evolving with the introduction of new procedures and materials. Despite the continuous development of a wide range of chemical solutions and the introduction of new materials in endodontics, driven by the advances in state-of-the-art technologies, there is still a lack of data on how these advances are adapted to the daily practice of Romanian dentists in this field. The aim of this cross-sectional questionnaire-based study was the evaluation of current trends in endodontic practice, focusing on the materials used by dentists throughout Romania, performed by a number of dentists who graduated from universities in the Northern, Southern, Eastern, Western, and Central zones of Romania. The questions were about the irrigants used, the interim medication, the type of sealant, the filling technique, and the number of endodontic treatment sessions. The majority of participants in the research were general practitioners and endodontists, with some dentists of different specialties performing endodontic treatments in their practices. Statistical analyses were performed using DATAtab version 2024 software. The results obtained from this study provide a valuable resource and database for researchers to access a wide range of information and an apparent trend towards high-performance endodontic materials used in Romania.

Prediction of Spalling and Roughness in the Mechanistic-Empirical Pavement Design Guide

This paper documents an assessment of the prediction of joint spalling and International Roughness Index (IRI) for jointed plain concrete pavements (JPCP) in the Mechanistic- Empirical Design Guide (MEPDG) report and software. The role of joint sealant type in the prediction of spalling is examined, as well as the sensitivity of predicted IRI to predicted spalling and other factors. Limitations of the predictive accuracy of the MEDG spalling and IRI models are detailed. Users of the MEPDG and its accompanying software should be aware of the inference space of the data from which these spalling and IRI models were developed, and the practical implications of using the MEPDG models to predict the effect of joint sealant type, joint spalling, climate, and other factors on roughness in jointed plain concrete pavements. The MEPDG software predicts essentially no spalling for joints with preformed sealant, but substantially more spalling – and exactly the same amount of spalling – for unsealed joints, hotpour- sealed joints, and silicone-sealed joints.

Integrating deep learning in public health: a novel approach to PICC-RVT risk assessment.

Machine learning is pivotal for predicting Peripherally Inserted Central Catheter-related venous thrombosis (PICC-RVT) risk, facilitating early diagnosis and proactive treatment. Existing models often assess PICC-RVT risk as static and discrete outcomes, which may limit their practical application. This study aims to evaluate the effectiveness of seven diverse machine learning algorithms, including three deep learning and four traditional machine learning models, that incorporate time-series data to assess PICC-RVT risk. It also seeks to identify key predictive factors for PICC-RVT using these models. We conducted a retrospective multi-center cohort study involving 5,272 patients who underwent PICC placement. After preprocessing patient data, the models were trained. Demographic, clinical pathology, and treatment data were analyzed to identify predictive factors. A variable analysis was then conducted to determine the most significant predictors of PICC-RVT. Model performance was evaluated using the Concordance Index (c-index) and the composite Brier score, and the Intraclass Correlation Coefficient (ICC) from cross-validation folds assessed model stability. Deep learning models generally outperformed traditional machine learning models in terms of predictive accuracy (mean c-index: 0.949 vs. 0.732; mean integrated Brier score: 0.046 vs. 0.093). Specifically, the DeepSurv model demonstrated exceptional precision in risk assessment (c-index: 0.95). Stability varied with the number of predictive factors, with Cox-Time showing the highest ICC (0.974) with 16 predictive factors, and DeepSurv the most stable with 26 predictive factors (ICC: 0.983). Key predictors across models included albumin levels, prefill sealant type, and activated partial thromboplastin time. Machine learning models that incorporate time-to-event data can effectively predict PICC-RVT risk. The DeepSurv model, in particular, shows excellent discriminative and calibration capabilities. Albumin levels, type of prefill sealant, and activated partial thromboplastin time are critical indicators for identifying and managing high-risk PICC-RVT patients.

Comparative evaluation of pit & fissure sealant retention using cotton roll & rubber dam isolation techniques-a systematic review & meta-analysis.

Isolation with cotton rolls does not always provide as complete isolation as rubber dam, especially in procedures where absolute moisture control is critical. Therefore, this review aims to summarize and analyze previous studies evaluating the retention and marginal integrity of pit & fissure sealant using rubber dam and cotton roll isolation techniques during dental treatment in children. In accordance with PRISMA guidelines, search yielded 1361 articles, with seven RCTs and one non-RCT design meeting the inclusion criteria. Data were extracted on study design, sample size, sealant type, follow-up duration, retention rates, and caries incidence. The comparison of retention rate between rubber dam and cotton roll at six months difference was non-significant (OR:1.15; p = 0.64) while there was significant difference at 12 month (OR:2.23; p < 0.001). The difference for the marginal integrity was statistically significant at six months (OR:2.00; p = 0.03) while non-significant difference observed (OR:1.74; p = 0.10) at 12 months. The sealant placed using a rubber dam as an isolation technique showed higher retention than the cotton roll after 12 months. In terms of marginal integrity, the performance of the rubber dam and cotton roll was equivalent at the end of 12 months.

Influence of worn on flow characteristics of aircraft engine labyrinth seals

Labyrinth seals are currently the most common type of sealant in aircraft engines. The article proposes an approach to take into account the value of their cutting into the stator part when determining the air flow rate. The comparison of the results of calculation of characteristics of labyrinth seals taking into account cutting of seal combs into the stator part with the use of semi-empirical and numerical models is carried out. The nature of the change in air flow through the seal is revealed when the geometric parameters of the grooves in the stator part change as a result of wear of the actuated coating when the ridge of the labyrinth seal is inserted. The most effective semi-empirical models for calculating the characteristics of such seals for various wear patterns and gap sizes are proposed, as well as recommendations for their modernization to improve the accuracy of calculations.

Evaluation of dimensional changes in EndoSeal mineral trioxide aggregate and AH Plus sealers using micro-computed tomography imaging

Background: Optimal dimensional stability is required for successful root canal treatment. A sealant called EndoSeal mineral trioxide aggregate (MTA) was recently introduced to the market due to its favorable physical and chemical properties. On the other hand, AH Plus (AHP) is considered the gold-standard seal. Materials and Methods: In this ex vivo quasi-experimental study, 24 single-canal premolars extracted from humans were cleaned and shaped with a motorized and rotary file, then that is divided into two groups. The teeth of each group were filled with gutta F3 and each type of sealant. The teeth were scanned by a micro-computed tomography device after 24 h. After 7 days of storage in phosphate-buffered saline solution, the samples were re-scanned. Data were analyzed using SPSS software (version 21). Descriptive data were presented as frequency, percentage, mean, and standard deviation. The Shapiro–Wilk and Kolmogorov–Smirnov tests were used to investigate the normality of the data. The Mann–Whitney test was used to compare the two groups, and the differences were ultimately not significant. The level of significance was set at 0.05 (P &lt; 0.05). Results: The mean differences between sealer volumes before and after the intervention were not significantly different between the two groups indicating that the EndoSeal MTA sealer is not inferior to the gold-standard root canal sealer, AHP. Conclusion: EndoSeal MTA can be considered a reliable sealer in endodontic treatments and be subjected to further investigation.

Optimizing the Use of Sealant Material Type 5977 for Car Engine Production at PT X Using the PDCA (Plan, Do, Check, Action) Method

Business development in the world causes companies to be able to compete, especially in the field of automotive manufacturing so that companies must have a strategy. This study aims to identify, analyze, and evaluate the use of sealant type 5977 in automotive manufacturing companies to optimize the use of sealant material type 5977 at PT X to remain competitive in local and global markets. This research uses the Deming Cycle Method or PDCA Cycle and the tools used in this research are Checksheets obtained from data for the last 3 months. From the results of this study it can be seen that by optimizing the use of sealant type 5977 for engine production, the results are very good, for 3 months no defects were found or defects that could affect the quality of the engines produced and with the application of cost reduction it is good for the company to reduce its production costs. Based on these results the company can still compete competitively in local and global markets with more efficient costs, the costs incurred before the improvement of Rp 199,000 or 100 engine units to Rp 39,000 or 20 engine units in one month, which saves Rp 160,000 every month or Rp 1,920,000 per year.

Evaluation of the effectiveness of prophylactic sealing of pits and fissures of permanent teeth with fissure sealants - umbrella review

BackgroundTooth decay is an infectious disease which, in its initial phase, leads to the formation of cavities in the teeth through decalcification of the enamel and local tissue destruction. In addition to proper oral hygiene, prophylactic sealing of fissures and cavities with a sealant is a method of preventing the development of caries. The aim of this study is to summarise the effectiveness of fissure sealing of permanent teeth with fissure sealants compared to other preventive methods or no intervention.MethodAn umbrella review was carried out to achieve the purpose of our study. Searches were performed in Medline (via PubMed), Embase (via OVID), and Cochrane Library databases. Quality assessment of the included studies was performed using the AMSTAR2 tool. In addition, a manual search for recommendations/clinical practice guidelines on dental prophylaxis was performed.Results204 publications were identified, of which 15 met the inclusion criteria. Based on the results of 3 systematic reviews, there was a statistically significant reduced odds of caries occurrence or development with prophylactic sealing of permanent teeth compared with no intervention – depending on the review and follow-up period odds ratio (OR) ranged from 0.06 [95%CI: (0.01–0.32)] to 0.28 [95%CI: (0.20–0.38)]. In the eight systematic reviews that analysed different sealants, there were no statistically significant differences between the types of materials used for prophylactic tooth sealing. For systematic reviews comparing the efficacy of fissure sealants with fluoride varnish, three reported no statistically significant difference in the efficacy of caries incidence, with only one systematic review based on 1 RCT finding a statistically significant difference in favour of fissure sealants.ConclusionCompared to the no intervention, dental sealing is an effective method for the prevention of dental caries. However, it is not possible to conclude conclusively which type of sealant and which of the available prophylactic methods is more effective in preventing caries.

Mechanical Evaluation of Commercially Available Fibrin Sealants for Cartilage Repair.

Fibrin sealants are routinely used for intra-articular surgical fixation of cartilage fragments and implants. However, the mechanical properties of fibrin sealants in the context of cartilage repair are unknown. The purpose of this study was to characterize the adhesive and frictional properties of fibrin sealants using an ex vivo model. Native bovine cartilage-bone composites were assembled with a single application of Tisseel or Vistaseal. Composites were tested in tension and lap shear. In addition, the coefficient of friction (COF) was measured in a native cartilage annulus model alone and with minced cartilage. Finally, the effect of a double application of fibrin sealant was evaluated. There were no significant differences in tensile modulus, ultimate tensile strength (UTS), shear modulus, or ultimate shear strength (USS) between the 2 fibrin sealants. Both fibrin sealants demonstrated a UTS and USS of <8 and <30 kPa, respectively. There were no differences in COF between the sealants when tested alone or with minced cartilage. A double application of fibrin sealant did not alter the mechanical properties compared with a single application of fibrin sealant. Fibrin sealant adhesive properties are not affected by the sealant type studied or the number of applications in a bovine cartilage-bone model. Fibrin sealant tribological properties are not affected by sealant type or the addition of minced cartilage. The adhesive properties of Tisseel and Vistaseal were less than those desired for the in vivo fixation of cartilage repair implants. These findings motivate the development of an improved cartilage-specific adhesive for cartilage repair applications.

Experimental Study on Waterproofing Performance of Segments Based on Sealant Installation Methods

When constructing a tunnel using a shield Tunnel Boring Machine, segments are mainly used. Sealants are then installed at segments for waterproofing. Two types of sealants, a hydrophilic rubber waterstop and a rubber gasket, are mainly used. Sealants can be arranged in single or double layers in consideration of construction site conditions. In this study, waterproofing performance was experimentally evaluated based on the type of sealant and the number of layers. A total of five types of sealant installation methods were tested. Waterproofing performance tests were used to determine their relative waterproofing performances under the same experimental conditions. Results showed that the hydrophilic waterstop was relatively vulnerable to a gap and the gasket was relatively vulnerable to an offset. If double layers of sealants are to be arranged at the construction site, it is recommended to arrange double layers of different types of sealants rather than double layers of the same type of sealants. This study could be helpful for selecting the type of sealant and/or the number of arrays at a construction site.

Evaluation of In situ Adaptability of Two Types of Fissure Sealants Placed with or Without Enameloplasty

Context: Literature has no consensus over the utility of enameloplasty before fissure sealant placement. Aim: The objective of the study was to explore the effect of enameloplasty using a scanned electron microscope on the adaptability of resin-modified glass ionomer versus flowable resin-based sealants. Settings and Design: An in vitro, experimental study was done from July to November 2017 at the NED University and Dow University of Health Sciences, Karachi, Pakistan. Materials and Methods: An in vitro experimental study was done, for which twenty extracted human molars and premolars were selected. They were divided into two groups on the basis of sealant type (resin-modified glass ionomer versus flowable resin-based sealant). The groups were further subdivided on the basis whether these were subjected to enameloplasty or not. All specimens were thermocycled, sectioned, dried, and gold sputtered before inspection under a scanning electron microscope (×50). Statistical Analysis Used: The adaptability of the sealant material in the tooth fissures was assessed on an ordinal scale. SPSS version 23.0 was used for data analysis. Mann–Whitney U-test and ordinal regression were applied at 0.05 level of significance. Results: There were no statistically significant differences between adaptability scores achieved with resin-modified glass ionomer-based sealant and flowable resin-based sealant (P = 0.96). Moreover, enameloplasty resulted in inferior adaptability of the two sealant materials (P = 0.02). Conclusions: Enameloplasty has shown to exert a negative influence over adaptation of the sealant material into the tooth fissure irrespective of the sealant chemistry.

Progression of Enamel Demineralisation Around Fissure Sealants: Optical Coherence Tomography Study.

To evaluate the progression of enamel demineralisation around fissure sealants using cross-polarisation optical coherence tomography (CP-OCT). Three fissure sealants; Fuji Triage (FJ, GC), Beautisealant (BT, Shofu) and Helioseal resin sealant (HL, Ivoclar Vivadent) were placed in cavities (3 × 0.5 × 1 mm) prepared in bovine enamel blocks (n = 5). After 7-day artificial saliva incubation, specimens were subjected to demineralisation for 4 weeks (pH 4.5). CP-OCT scans (Santec) were acquired for each specimen after 1, 2 and 4 weeks of demineralisation and lesions were quantitatively measured to analyse lesion progression. Repeated-measures ANOVA demonstrated that lesion size was statistically significantly affected by demineralisation period, fissure sealant type, and their interaction (P < 0.001). At 4 weeks, the highest mean value of lesion size was observed in HL group while FJ group showed the lowest. The rate of lesion progression was slower in FJ and statistically significantly different from BT (P < 0.05), which in turn was statistically significantly different than HL (P < 0.001). Fissure sealants that actively release ions are capable of improving the acid resistance of adjacent enamel. Beautisealant showed increased demineralisation inhibition compared to conventional resin sealant, but less than that provided by glass-ionomer sealant.

An In Vitro Microleakage Study for Comparative Analysis of Two Types of Resin-based Sealants Placed by Using Three Different Types of Techniques of Enamel Preparation.

BackgroundClinicians always experience dilemmas while choosing the type of pit and fissure sealant and the method of enamel preparation before the application of sealant. This study was accomplished using the unfilled and filled types of resin sealant deploying three different techniques of enamel preparation.Aim and objectiveTo do a comparative analysis of unfilled and filled sealants by deploying three techniques of enamel preparation.Materials and methodsThe total number of 60 extracted teeth were divided into 3 groups, each containing 20 samples. Conventional acid etching of enamel was labeled as (group I), laser application as (group II), and fissurotomy bur (group III). The samples of group I were prepared by conventional acid etching, the group II was subjected to Er:YAG lasing, while in group III fissurotomy followed by acid etching was done. The sealant placement was done using split tooth design in all the samples. Dye penetration using 5% methylene blue was used for microleakage assessment.ResultsThe highest microleakage was found with Gr. II whereas Gr. I exhibited the least microleakage. No statistical difference was observed between the unfilled and filled sealant (p = 0.652).ConclusionConventional acid etching alone or with fissurotomy weighed up appropriate option regardless of the type of sealant material used.Clinical significanceIn regard to the selection of material and proper technique of enamel preparation, this study will be useful to clinicians.How to cite this articleShingare P, Chaugule V. An In Vitro Microleakage Study for Comparative Analysis of Two Types of Resin-based Sealants Placed by Using Three Different Types of Techniques of Enamel Preparation. Int J Clin Pediatr Dent 2021;14(4):475–481.

Surface Modification of Nanofibers by Physical Adsorption of Fiber-Homologous Amphiphilic Copolymers and Nanofiber-Reinforced Hydrogels with Excellent Tissue Adhesion.

Herein, we report a simple approach to modify hydrophobic PCL nanofibers by adsorption of a fiber-homologous amphiphilic triblock copolymer (PCL-b-PEG-b-PCL, PCEC). The modified PCL nanofibers were then utilized to reinforce a physical hydrogel, which was formed by micellar crosslinking of the same PCEC triblock copolymer. Therefore, the copolymer played a dual role in not only dispersing and stabilizing nanofibers but also additionally providing a framework for the hydrogel matrix. The mechanical strength of the hydrogel was significantly enhanced by addition of the modified PCL nanofibers, and the gel modulus can be tuned by varying the concentration of the copolymer and nanofibers. The effect of nanofiber size and content on the mechanical properties of the hydrogel matrices was studied. Different from hydrogel composites that were reinforced by 2D fiber meshes or 3D woven fiber networks, this free fiber-reinforced hydrogel can be readily injected to adapt to the environmental shape and self-heal. The hydrogel composites showed superior tissue adhesion properties compared to the commercially available fibrin glue, especially in muscle adhesion. Due to its injectable and self-healing properties, this nanofiber-reinforced hydrogel may have great potential as a new type of tissue sealant.

Effectiveness of fissure sealants on initial caries lesions (ICDAS 1-3) of permanent molars: A 4-year follow-up.

The aim of the present prospective study was to evaluate the retention and effectiveness of two types of sealants (clear vs. opaque) on early pit and fissure occlusal non-cavitated ICDAS II #1-3, caries lesions of permanent posterior teeth of children. Study Design: 6986 pit and fissure occlusal surfaces were randomly sealed with clear or opaque sealants out of which, 5828 sealants were placed on sound and 1158 on questionable surfaces, while 3508 were clear and 3478 opaque sealants. The mean age of the sample at initial sealant placement was 9.5 (±2.9) years and the follow-up time was 12-48 months. The median (IQR, range) follow-up time was 17.9 (8.7-28.6) months. Study inclusion and exclusion criteria applied to the combined database in order to select the study sample. Teethmate™ F-1 natural and opaque sealants (Kuraray, Hattersheim am Main, Germany) were applied following the standard procedure of preparation with moisture control kept by cotton rolls handled Dri-Angles" and a 30 seconds acid-etch with 37% ortho-phosphoric acid gel was used followed by 10 sec air-water spraying washing and polymerization for 20x2 sec. Sealants were applied on sound tooth surfaces (ICDAS #0) with no visible defects or on surfaces with early caries lesions (ICDAS #1-3), randomly and interchangeably on the upper or lower Jaw. Total retention was considered when all pits and fissures were completely sealed, while partial or complete loss was scored as one code, although was registered separately. Separate analyses were performed for each type of failure (loss of sealant or restoration). Cumulative probabilities of failure over time after sealant placement, overall or by specific characteristics, were calculated using the Kaplan-Meier method. Association between these characteristics and the hazard of failure were investigated using appropriate Cox proportional hazard models. Sealed surfaces with ICDAS II # 1-3, showed 100% higher probability of having a restoration and 60% higher probability of sealant loss, with both differences being statistically significant (aHR=2.03, p=0.046), adjusted for age, sex, type of sealant and location of surface. Opaque sealants presented statistically significant (p 0.009) higher re-application rate, while fissures had 70% statistically significant (p<0.001) higher probability for resealing with time compared to pits, with gender not affecting sealant retention while the earlier a sealant was placed on children's teeth, the more probable it was to need resealing or restoration (p <0.012). The therapeutic use of sealants on occlusal surfaces of posterior permanent molars with early carious lesions (ICDAS II 1-3) is inferior compared to sound surfaces, showing higher sealant failures and restorations.

A novel Ag–CuAlO2 sealant for reactive air brazing of 3YSZ and AISI 310S

Based on reactive air brazing (RAB), we designed a new type of sealant (Ag–xCuAlO2) for joining 3 mol.% yttria-stabilized zirconia (YSZ) ceramics and AISI 310S stainless steel. The CuAlO2 content affected the wettability of the sealant on the YSZ surface, and the joints had a high shear strength when Ag–2 wt.%CuAlO2, which had a small contact angle on the YSZ substrate, was used as the sealant. In addition, the thickness of the oxide layer was reduced compared to that for the Ag–CuO sealant. The effects of the processing parameters on the microstructure and shear strength of the joints were investigated, and the as-brazed joints reached their highest shear strength (93.7 MPa) when brazed at 1040 °C for 30 min. After high-temperature oxidation at 800 °C for 200 h, the shear strength of the joints remained at 50 MPa, and no apparent change in the microstructure was observed, proving that the joints possessed excellent oxidation resistance.

Comparison of Two Types of Pit and Fissure Sealants in Reducing the Incidence of Dental Caries Using a Split-Mouth Design.

ObjectivesTo evaluate the effectiveness of two pit and fissure sealants (PFS) in reducing the incidence of dental caries in schoolchildren.Material and MethodsA randomized split-mouth experimental design was used in a sample of 140 subjects assigned to two groups. The sealants used were Clinpro©3M and BeautiSealant©Shofu placed in first permanent molars (FPMs). Each sealant was compared to molars in the controls to determine effectiveness over a period of 6 months. The study had a 12.9% loss to follow-up. No statistically significant differences (p>0.05) were observed for sex, age, baseline dmft, or type of sealants. Nonparametric tests were used for statistical analysis.ResultsAverage dmft index at baseline was 4.10±3.16. Lower incidence of caries was observed in FPMs with pit and fissure sealants (p<0.01), regardless of the type used. When sealants remained intact there was a lower caries incidence compared to sealants partially or completely missing – but differences were only significant for FPM 16. Caries incidence was higher for BeautiSealant sealed teeth than for Clinpro’s, but only statistically significant in FPMs 16, 36 and 46 (p< 0.05). Caries incidence was higher in those cases with a higher baseline dmft but it only reached statistical significance in FPMs 26 and 36. Relative risks for dental caries were lower in sealed teeth (p<0.01).ConclusionsPit and fissures sealants are an effective preventive treatment to reduce caries during a 6-month follow-up in schoolchildren 6 to 8 years of age, regardless of the type of sealant used. The sealant brand that showed greater effectiveness in terms of prevention and retention was Clinpro©3M.

Machine-Learning Modeling of Asphalt Crack Treatment Effectiveness

Although many research projects have been completed to investigate asphalt crack treatment/repair effectiveness, all of them reported local investigation results with small sample sizes, incomplete time durations, and restricted types of sealants and/or treatment methods. Most importantly, machine-learning techniques have not been used to compare treatment methods and predict treatment effectiveness. In this study, all reported data regarding asphalt crack treatments were collected, and the large sample size data were comprehensively analyzed by statistical measures and machine-learning techniques to find the optimal crack treatment method. The variables including service time, environment temperature, type of sealant, treatment method, and traffic conditions were used as inputs, and the effectiveness of the asphalt crack treatment was selected as output information to compare the contribution of different variables for the treatment effectiveness and to provide prediction models. Chi-square test indicated that except for the variable “Traffic condition,” all other variables (Type of sealants, Treatment method, Service time, and Environmental temperature) had a significant relationship with the target variable (crack treatment effectiveness). The decision tree analysis results showed that the relative significance of the input variables to the target variable was ordered as Service time > Environmental temperature > Type of sealants > Treatment method > Traffic condition. The asphalt crack treatment effectiveness (%) can be predicted according to known variable values using the developed linear regression and artificial neural network (ANN) models. ANN model prediction has better performance than that of the linear regression model.

Feldspar-based CaO–K2O–Na2O–BaO silicate glass sealant for solid oxide fuel cells

Sealants have been widely used in solid oxide fuel cells (SOFCs), and glass sealants have shown considerable potentials due to their low leakage rate. We report a type of feldspar-based glass sealant, mainly composed of CaO–K2O–Na2O–BaO, with a coefficient of thermal expansion (CTE) of 10.11 × 10−6 k−1, a glass transition temperature at 528 °C, and a softening temperature at 573 °C. Using this sealant to seal anode-supported SOFCs, the open-circuit voltage (OCV) remains at 1.08 V after five thermal cycles and 50-h aging at 750 °C, close to the theoretical OCV value. The SEM and EDS reveal stable interface between the glass sealant and the anode, indicating excellent performance of the CaO–K2O–Na2O–BaO glass sealant for SOFC sealing applications.

ВИКОРИСТАННЯ ГОТОВИХ УЩІЛЬНЮВАЧІВ ШВІВ В ЦЕМЕНТОБЕТОННИХ ПОКРИТТЯХ АВТОМОБІЛЬНИХ ДОРІГ І АЕРОДРОМІВ

Increased requirements for reliability, performance and durability of pavement caused by the increase in vehicle carrying capacity and traffic on the roads. As the domestic and world experience shows, the increasing requirements of the movement are best matched by cement concrete pavements. Stable transport transport performance, high durability give them advantages over pavements built using organic binders. During construction and reconstruction, longitudinal and transverse joints for various purposes are arranged in cement concrete pavements of roads and airfields to prevent deformation and destruction of coating pavements (cracking, chipping of corners and edges of slabs, peeling of the concrete surface layer, the appearance of potholes and sinks, vertical displacement of slabs and their warpage destruction of butt joints and joint fillers). The destruction of pavements, as a rule, takes place in cases where the stresses and deformations arising in the plates exceed the permissible values, as well as in case of failure of the sealing of joints and cracks. Restoring the sealing of expansion joints and cracks are important stages of work to extend the operational life of pavements. A large role on the efficiency of the sealant in the joints and its service life is provided by the deformability of the sealing materials. When choosing a type of sealant, the possible maximum negative and positive air temperatures of the region where the pavements are used are taken into account. Currently, unique sealing materials using polymer compositions have been created. These materials have high technical and operational characteristics and a guaranteed service life of at least 5 years. The sealing or filling of transverse and longitudinal joints in cement concrete pavements is an important factor in ensuring long-term performance of the coating. The experience of using different types of joint sealing materials shows that their proper installation can provide important protective equipment that improves the performance of joints and pavements. In recent years, in foreign practice, the technology of pressing elastic whole or porous rubber profiles into the seam is very often used for sealing joints. In this case, it is possible to carry out work even in wet weather and at low temperatures. Special machines have been developed for the installation of profiles. The article discusses the sealing of transverse and longitudinal seams of cement concrete pavements of roads and airfields with sealing materials, including ready-made seals, the need to use them and study the effect of sealing materials on the design of joints and operational performance of cement concrete coatings in general.