scholarly journals Interface Bonding Properties between Nonwater Reaction Polyurethane Polymer Materials and Concrete

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Xijun Zhang ◽  
Chaojie Wang ◽  
Han Tian ◽  
Mingsheng Shi
Keyword(s):  
Moisture Content ◽  
Bond Strength ◽  
Environmental Temperature ◽  
Polymer Materials ◽  
Polymer Concrete ◽  
Bond Failure ◽  
Construction Design ◽  
Bonding Properties ◽  
Increasing Temperature ◽  
Polymer Density

The concentric pushing method was used to study the bonding properties between polymer and concrete. This paper studied the influence of polymer density, environmental temperature, and moisture content of concrete between polymer and concrete on the bond strength. The results indicated that the bond failure of specimens occurred mainly when the polymer was pushed out. Furthermore, increasing the polymer density increases the bond strength at the polymer-concrete interface but decreases as the moisture content of the concrete increases. The environmental temperature affects the curing time, and the bond strength increases with increasing temperature. Under the same condition, the bond strength was influenced by the roughness of the interface. This study provides references for the construction design and enhances polymer materials and matrix application for repairing cracks in concrete dams.

scholarly journals The Effects of Prophylactic Ozone Pretreatment of Enamel on Shear Bond Strength of Orthodontic Brackets Bonded with Total or Self-Etch Adhesive Systems

2010 ◽  
Vol 04 (04) ◽  
pp. 367-373 ◽  
Author(s):  
Sevi Burcak Cehreli ◽  
Asli Guzey ◽  
Neslihan Arhun ◽  
Alev Cetinsahin ◽  
Bahtiyar Unver
Keyword(s):  
Bond Strength ◽  
Shear Bond Strength ◽  
Orthophosphoric Acid ◽  
Ozone Treatment ◽  
Bond Failure ◽  
Group 4 ◽  
Group 3 ◽  
Group 2 ◽  
Self Etch ◽  
Group 1

Objectives: The aim of this in vitro study is to determine (1) shear bond strength (SBS) of brackets bonded with self-etch and total-etch adhesive after ozone treatment (2) bond failure interface using a modified Adhesive Remnant Index (ARI).Methods: 52 premolars were randomly assigned into four groups (n=13) and received the following treatments: Group 1: 30 s Ozone (Biozonix, Ozonytron, Vehos Medikal, Ankara, Turkey) application + Transbond Plus Self-Etching Primer (SEP) (3M) + Transbond XT (3M), Group 2: Transbond Plus SEP + Transbond XT, Group 3: 30 s Ozone application + 37% orthophosphoric acid + Transbond XT Primer (3M) + Transbond XT, Group 4: 37% orthophosphoric acid + Transbond XT Primer + Transbond XT. All samples were stored in deionised water at 37oC for 24 hours. Shear debonding test was performed by applying a vertical force to the base of the bracket at a cross-head speed of 1 mm/min.Results: The mean SBS results were Group 1: 10.48 MPa; Group 2: 8.89 MPa; Group 3: 9.41 MPa; Group 4: 9.82 MPa. One-Way Variance Test revealed that the difference between the groups was not statistically significant (P=0.267). Debonded brackets were examined by an optical microscope at X16 magnification to determine the bond failure interface using a modified ARI. The results were (mean) Group 1: 2.38; Group 2: 1.31; Group 3: 3.00; Group 4: 1.92. Multiple comparisons showed that Groups 1 and 2, 2 and 3, 3 and 4 were statistically different (P=0.014, P<.001 and P=0.025).Conclusions: Ozone treatment prior to bracket bonding does not affect the shear bond strength. (Eur J Dent 2010;4:367-373)

scholarly journals Influence of surface treatment on bond strength of resin cements to a nickel alloy

2014 ◽  
Vol 62 (4) ◽  
pp. 377-382
Author(s):  
Camilla Bottino da SILVA ◽  
Daniel de Mattos SALIM ◽  
Gabriel Maia KAMMER ◽  
Waldimir CARVALHO ◽  
Cresus Vinicius Depes de GOUVÊA
Keyword(s):  
Bond Strength ◽  
Surface Treatment ◽  
Nickel Alloy ◽  
Visual Analysis ◽  
Fracture Pattern ◽  
Resin Cements ◽  
Bond Failure ◽  
Oxide Particles ◽  
Mixed Fracture ◽  
Microscopy Images

OBJECTIVE: To compare the bond strength of two dual-cure resin cements to Ni-Cr alloy test specimens (TS), with and without surface treatment. METHODS: RelyX ARC and Panavia Fluoro Cements were tested. Eighty nickel alloy TS were cast, measuring 10mmx7mmx2.5mm, forming a total of 40 pairs. Four groups of TS were obtained.Twenty pairs were treated by airborne abrasion with 50µm aluminum oxide particles and 20did not undergo treatment.The TS were cleaned usingultrasound. The parts were cemented according to manufacturers' instructions. A shear bond strength test was performed until bond failure occurred. RESULTS: Analysis of variance (ANOVA) showed there was a statistical difference (p>0.05) between thegroups. Visual analysis of optical microscopy images showed a mixed fracture pattern with adhesive predominance for RelyX ARC, and mixed with cohesive predominance for Panavia F. The sandblasted groups obtained better bonding, with Panavia F attaining higher bond-strength values than RelyX ARC. CONCLUSION: The Ni-Cr alloy/Panavia F on a treated surface behaved better in terms of bonding.

scholarly journals Improvement of the Bonding Properties of Mineral Trioxide Aggregate by Elastin-Like Polypeptide Supplementation

Scanning ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Hyun-Jung Kim ◽  
Donghyun Lee ◽  
Seungryong Cho ◽  
Ji-Hyun Jang ◽  
Sahng Gyoon Kim ◽  
...  
Keyword(s):  
Contact Angle ◽  
Bond Strength ◽  
Flow Rate ◽  
Mineral Trioxide Aggregate ◽  
Strength Test ◽  
Research Data ◽  
Intimate Contact ◽  
Tooth Structure ◽  
Bonding Properties ◽  
Push Out

Introduction. Elastin-like polypeptide (ELP) supplementation was previously reported to enhance the physical properties of mineral trioxide aggregate (MTA). The aim of this study was to investigate the effect of ELP supplementation on the bonding properties of MTA to dentin. Methods. Two types of ELPs were synthesized and mixed with MTA in a 0.3 liquid/powder ratio. The push-out bond strength test and interfacial observation with scanning electron microscopy were performed for ELP-supplemented MTA. The porosity of MTA fillings in the cavity was observed with microcomputed tomography. The stickiness, flow rate, and contact angle were additionally measured for potential increased bonding properties. Results. ELP supplementation improved the bond strength of MTA to dentin. MTA supplemented by a specific ELP exhibited a less porous structure, higher stickiness, and higher flow rate. ELPs also decreased the contact angle to dentin. Conclusions. This research data verifies that ELP improves the bonding properties of MTA to a tooth structure. The sticky and highly flowable characteristics of ELP-supplemented MTA may provide intimate contact with dentin and supply a less porous cement structure, which might improve the bonding properties of MTA.

scholarly journals Evaluation of the effect of different surface treatments on the bond strength of non-precious alloy‒ceramic interface: An SEM study

2019 ◽  
Vol 13 (3) ◽  
pp. 200-207
Author(s):  
Vikram M. Belkhode ◽  
Sharayu V. Nimonkar ◽  
S. R. Godbole ◽  
Pranali Nimonkar ◽  
Seema Sathe ◽  
...  
Keyword(s):  
Bond Strength ◽  
Surface Treatments ◽  
Surface Grinding ◽  
Tensile Bond Strength ◽  
Bond Failure ◽  
Dental Porcelain ◽  
Surface Irregularities ◽  
Group A ◽  
Group B ◽  
Group D

Background. Dental porcelain has excellent esthetics in combination with biocompatibility and is one of the most commonly used restorative materials. Its low tensile strength remains a major drawback. The porcelain-fused-to-metal restorations have been introduced to increase the fracture resistance of dental porcelain. The aim of this study was to evaluate the effect of different surface treatments on the bond strength of a non-precious alloy to ceramic. Methods. The present cross-sectional observational study was conducted with forty samples of cobalt‒chromium that were fabricated with porcelain interposed between the two metal test pieces. The metal was subjected to combinations of different surface treatments. The samples group A (n=10) were not subjected to any surface treatments. Group B samples underwent sandblasting and surface grinding. Group C samples were subjected to sandblasting, surface grinding and degassing; and group D samples underwent sandblasting, surface grinding, ultrasonic cleaning and degassing. The tensile bond strength was measured in a universal testing machine, and a scanning electron microscope (SEM) was used to obtain images of the samples after surface treatment to determine the surface irregularities and after the debonding of the samples for the type of the bond failure. ANOVA was used for the statistical analysis. Results. The results showed significant variations in the tensile bond strength between the four groups (F=251.05, P=0.000). The SEM images of group A showed no surface irregularities; group C samples exhibited surface irregularities more than those in group B. Group D had the highest surface irregularities. SEM evaluations showed a statistically significant difference in the type of bond failure (P<0.001). Conclusion. Based on the results of this study, it can be concluded that the surface treatments on the metal increased the bond strength of the metal‒ceramic interface significantly. A combination of sandblasting, surface grinding and ultrasonic cleaning, followed by degassing, resulted in the highest tensile bond strength.

Physicochemical and Morphological Properties of Extruded Adlay (Coix lachryma-jobi L) Flour

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Gaopeng Zhang ◽  
Yangyue Ding ◽  
Chunlei Ni ◽  
Qingfeng Ban ◽  
Li Xu ◽  
...  
Keyword(s):  
Moisture Content ◽  
Water Solubility ◽  
Basic Structure ◽  
Morphological Properties ◽  
X Ray Diffraction ◽  
Relative Crystallinity ◽  
Job’S Tears ◽  
Twin Screw ◽  
And Function ◽  
Increasing Temperature

The effects of extrusion treatment on the structure and properties of adlay (Job’s tears) were investigated. Adlay flour was extruded through a twin-screw extruder with different parameters, including barrel temperature (80–160°C), moisture content (19–27%), and screw speed (170–330 rpm). The results showed that although the expansion index increased with increasing temperature, an increase in moisture content significantly decreased the EI (p<0.05). Extrusion improved the water solubility index and water absorption index of adlay flour (p<0.05). Furthermore, analysis of the gelating properties revealed that the structure and function of adlay flour had radically changed. After extrusion, the viscosity of the adlay flour decreased (peak viscosity decreased by more than 1000 cP), and its fluidity increased. The rheological data were modeled by the Herschel–Bulkley model. X-ray diffraction experiments showed that extrusion contributed to a decrease in relative crystallinity. Scanning electron microscopy revealed that extrusion damaged the basic structure of adlay flour, causing holes and pits on the extrudate surface. Compared to the native adlay flour, the extrusion resulted in significantly changing the pasting, gelating, thermal, rheological, and morphological properties of adlay flour. In conclusion, the extrusion can alter adlay characteristics, but it is necessary to choose appropriate conditions to attain the desired properties.

scholarly journals Effect of Elevated Temperature on the Bond Strength of Prestressing Reinforcement in UHPC

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4990
Author(s):  
Petr Pokorný ◽  
Jiří Kolísko ◽  
David Čítek ◽  
Michaela Kostelecká
Keyword(s):  
Bond Strength ◽  
High Performance ◽  
Elevated Temperatures ◽  
High Performance Concrete ◽  
Future Research ◽  
Ultra High Performance Concrete ◽  
Negative Effect ◽  
Laboratory Investigations ◽  
Increasing Temperature ◽  
Positive Effect

The study explores the effect of elevated temperatures on the bond strength between prestressing reinforcement and ultra-high performance concrete (UHPC). Laboratory investigations reveal that the changes in bond strength correspond well with the changes in compressive strength of UHPC and their correlation can be mathematically described. Exposition of specimens to temperatures up to 200 °C does not reduce bond strength as a negative effect of increasing temperature is outweighed by the positive effect of thermal increase on the reactivity of silica fume in UHPC mixture. Above 200 °C, bond strength significantly reduces; for instance, a decrease by about 70% is observed at 800 °C. The decreases in compressive and bond strengths for temperatures above 400 °C are related to the changes of phase composition of UHPC matrix (as revealed by X-ray powder diffraction) and the changes in microstructure including the increase of porosity (verified by mercury intrusion porosimetry and observation of confocal microscopy) and development cracks detected by scanning electron microscopy. Future research should investigate the effect of relaxation of prestressing reinforcement with increasing temperature on bond strength reduction by numerical modelling.

scholarly journals The Toxicological Testing and Thermal Decomposition of Drive and Transport Belts Made of Thermoplastic Multilayer Polymer Materials

Polymers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2232 ◽  
Author(s):  
Piotr Krawiec ◽  
Łukasz Warguła ◽  
Daniel Małozięć ◽  
Piotr Kaczmarzyk ◽  
Anna Dziechciarz ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Degradation Kinetics ◽  
Combustion Products ◽  
Polymer Materials ◽  
Toxic Substances ◽  
Butadiene Rubber ◽  
Different Temperatures ◽  
Increasing Temperature ◽  
In Fire ◽  
Kinetics Of

The article presents the potential impact of flat drive and transport belts on people’s safety during a fire. The analysis distinguished belts made of classically used fabric–rubber composite materials reinforced with cord and currently used multilayer polymer composites. Moreover, the products’ multilayers during the thermal decomposition and combustion can be a source of emissions for unpredictable and toxic substances with different concentrations and compositions. In the evaluation of the compared belts, a testing methodology was used to determine the toxicometric indicators (WLC50SM) on the basis of which it was possible to determine the toxicity of thermal decomposition and combustion products in agreement with the standards in force in several countries of the EU and Russia. The analysis was carried out on the basis of the registration of emissions of chemical compounds during the thermal decomposition and combustion of polymer materials at three different temperatures. Moreover, the degradation kinetics of the polymeric belts by using the thermogravimetric (TGA) technique was evaluated. Test results have shown that products of thermal decomposition resulting from the neoprene (NE22), leder leder (LL2), thermoplastic connection (TC), and extra high top cower (XH) belts can be characterized as moderately toxic or toxic. Their toxicity significantly increases with the increasing temperature of thermal decomposition or combustion, especially above 450 °C. The results showed that the belts made of several layers of polyamide can be considered the least toxic in fire conditions. The TGA results showed that NBR/PA/PA/NBR belt made with two layers of polyamide and the acrylonitrile–butadiene rubber has the highest thermal stability in comparison to other belts.

scholarly journals Apparent vs. True Bond Strength of Steel and PC with Nanoalumina

2015 ◽  
Vol 1129 ◽  
pp. 307-314
Author(s):  
Ala Eddin Douba ◽  
Moneeb Genedy ◽  
Edward Matteo ◽  
John Stormont ◽  
Mahmoud Reda Taha
Keyword(s):  
Bond Strength ◽  
Steel Surface ◽  
Maximum Shear Stress ◽  
Polymer Concrete ◽  
Fe Model ◽  
Shear Tests ◽  
Steel Pipes ◽  
Wellbore Integrity ◽  
Interface Surface ◽  
Slant Shear

The bond of polymer concrete (PC) to a steel surface is a critical aspect in many infrastructure applications. Bond strength can be evaluated through several means including pull-off, flexural, twist-off, and slant shear tests. While pull-off strength tests are the most common method for evaluating bond for PC overlays in bridge and parking structures, slant shear tests are more suitable when vertical rather than horizontal bond lines are used. In this paper, we discuss the use of slant shear tests to examine bond of polymer concrete repair material to steel pipes used to ensure wellbore integrity of abandoned oil wells used for CO2sequestration.Bond strength of Novolac PC incorporating nanoalumina particles to a steel surface was measured using slant shear tests. Different amounts of nanoalumina were used in the PC to improve bond strength without significantly reducing PC flowability. Slant shear testing confirmed the ability of nanoalumina to improve the steel-PC bond strength. A finite element (FE) model using the ABAQUS simulation environment was developed to compare the apparent versus the true bond strength. A cohesive contact element surface was used to simulate bond along the interface line. The FE model showed that the stiffness mismatch between the PC and steel controls the maximum shear stress developed at the interface surface. The true bond strength extracted from the FE model appears to be about twice that of the apparent bond strength.

scholarly journals Sensitivity of Idealized Moist Baroclinic Waves to Environmental Temperature and Moisture Content

2018 ◽  
Vol 75 (1) ◽  
pp. 337-360 ◽  
Author(s):  
D. J. Kirshbaum ◽  
T. M. Merlis ◽  
J. R. Gyakum ◽  
R. McTaggart-Cowan
Keyword(s):  
Kinetic Energy ◽  
Moisture Content ◽  
Potential Energy ◽  
Diabatic Heating ◽  
Environmental Temperature ◽  
Mechanical Energy ◽  
Negative Relationship ◽  
Vertical Motion ◽  
Periodic Wave ◽  
Cloud Band

Idealized simulations are used to examine the sensitivity of moist baroclinic wave growth to environmental temperature and moisture content. With relative humidity held fixed, the surface temperature at 45°N, denoted T0, is varied from 275 to 290 K. As T0 increases, the atmospheric moisture content, moist instability, and moist available potential energy also increase. For the chosen initial configuration, moist waves develop larger eddy kinetic energy K e than corresponding dry waves, but enhanced diabatic heating at larger T0 does not further increase K e. This finding is linked to a warm-frontal cyclonic potential vorticity (PV) anomaly that strengthens and shifts downstream at larger T0 owing to increased diabatic heating along the frontal cloud band. This eastward shift feeds back negatively on the parent cyclone by increasing the downstream export of mechanical energy aloft and degrading the phasing between dry baroclinic vertical motion and buoyancy within the warm sector. The latter suppresses the conversion from eddy potential energy to K e [ C( P e, K e)], offsetting a direct enhancement of C( P e, K e) by diabatic heating. Compared to their dry counterparts, isolated moist waves (initiated by a single finite-amplitude PV anomaly) display a similar sensitivity to T0, while periodic wave trains (initiated by multiple such anomalies) exhibit a stronger negative relationship. The latter stems from anticyclonic diabatic PV anomalies aloft that originate along the warm front and recirculate through the system to interact with the upper-level trough. This interaction leads to a horizontal forward wave tilt that enhances the conversion of wave K e into zonal-mean kinetic energy.

Sign in / Sign up

Export Citation Format

Share Document