A series of catechol-modified epoxy resin biomimetic coatings (CE-X, X represents the weight fraction of catechol-modified epoxy resin, X , = , 0, 5%, 10%, 15%, 20%, 25%) with high ADHESIVE strength on saturated CONCRETE substrate were designed and synthesized. The chemical structures of the CE-X were confirmed by proton nuclear magnetic resonance (1H NMR), carbon-13 nuclear magnetic resonance spectroscopy (13C NMR), and Fourier transform infrared spectroscopy (FTIR). The thermal property of CE-X was characterized by thermogravimetric analysis (TGA). The ADHESIVE properties were characterized by pull-off tests. Results showed that when the content of catechol–, epoxy resin was under 20% by weight, the ADHESIVE strength could be further increased by forming hydrogen bonds and coordination complexes in the interface of coating and saturated CONCRETE of the substrate. When the content of catechol–, epoxy resin was above 20% by weight, the pull-off tests showed cohesive failure, and the ADHESIVE strength on saturated CONCRETE substrate reached the maximum value of 4. 61 , ±,  , 0. 8 MPa, which was improved by , ~ , 3 MPa compared to that of the control sample. The ADHESIVE properties of epoxy coatings on saturated CONCRETE substrate could be improved by adding a proper amount of catechol groups. In addition, when it was immersed in water for 30 and 120 days, its ADHESIVE strength was reduced by about 7. 8% and 22%, respectively. This work provides a new method for designing and synthesizing protective coatings with high ADHESIVE strength on the saturated CONCRETE substrate.

One of the most widely used techniques in the rehabilitation of CONCRETE structures is the application of post-installed ADHESIVE anchors in CONCRETE. The main purpose of this study is to evaluate the efficiency and safety of this technique under domestic Iranian workshop conditions. This study focuses on the effects of parameters such as ADHESIVEs used in Iran, embedment depth, edge distance, and the use of either single or group of anchors in both reinforced and plain CONCRETE members. The design procedure is in accordance with ACI 318-19 guidelines. For this study, eight tension and eight shear tests are carried out and the type of failure and the factors affecting their behavior are examined. The results show that by increasing embedment depth and distance from the edge of the CONCRETE member, both tensile and shear capacities increase. In group installation, by reducing the rebar spacing, the nominal bond strength between ADHESIVE and CONCRETE decreases due to the initiation of cracks in adjacent rebars. Finally, the comparison of experimental results with ACI 318-19 equations shows that the code predicts the tensile and shear failure capacities with safety factors of at least 1.5 and 2, respectively.

Statement of Problem: A few studies have been conducted about bioglass posts.Aim: The aim of this study was to compare bioglass posts with prefabricated metallic posts in clinical performance of extensive composite restorations for anterior endodontically treated teeth.Materials and Methods: Sixty endodontocally maxillary anterior teeth, with horizontally or vertically destruction were selected. Teeth were divided into two groups based on the kind of post: Metallic prefabricated parapost and bioglass post. Each group was divided into three subgroups based on anterior bite: normal, deep bite and edge to edge. Gutta-percha was removed from 2/3 of canal length for parapost and 1/3 for bioglass post. After etching with phosphoric-acid (37%) and applying dentine bonding Syntac, Duo cement was used for the adhesion of bioglass post and a self cured composite (Degufil) for parapost. Restoration was done with a hybrid composite (Heliomolar). Follow up studies, radiographically and clinically, were done every three months for a 1.5-year period. Exact Fisher and Pearson tests were used for data analysis.Results: Apical lesion was not observed in any of the radiographs. Post seal was increased by resin cement and dentin bonding agent. Post type did not significantly affect on the clinical success rate of the restorations. The retention of restoration, for both posts, was the same. Crown destruction had no significant effect on success rate. The type of anterior bite had a significant effect on success rate, as the total 6.6% failure rate was related to the patients with anterior deep bite.Conclusion: It is suggested to use metallic paraposts and bioglass posts, in extensive composite restorations for patients with deep-bite, more conservatively.

One of the important issues in the production of CONCRETE is environmental variability that affects the CONCRETE and elements constructed from this material. Due to the importance of different characteristics of CONCRETE in short- and long-term conditions, this article aims to investigate the influence of initial temperature conditions of self-compacting CONCRETE on its long-term characteristics and determine the initial optimal temperature of CONCRETE. For these purposes, several experiments under three temperature conditions of 5, 20, and 40 degree-of-Celsius were conducted to evaluate the rheology and mechanical properties of fresh CONCRETE in the range of 7 and 28 days. In these experiments, alternative mineral admixtures of cement such as micro-silica, fly ash, and zeolite were used to build the CONCRETE specimens. Results demonstrate that the mechanical properties of the specimens increase with increasing initial temperature in the short term, while such properties significantly decrease in the long term compared to the specimens constructed under lower initial temperature. Moreover, the fluidity of self-compacting CONCRETE increases with increasing initial temperature.

Hypothesis: ADHESIVEs and sealants based on modified silane polymer (MS polymer) are increasingly gaining market share in ADHESIVE and sealant market place due to their desirable performance in various applications. Methods: In order to find the most optimal ADHESIVE processing parameters, different stages of aluminum surface treatment in three stages were investigated, including the surface degreasing, sanding and priming. In this manner, the performance of four different types of degreasing agents and two kinds of silane-based primers were investigated individually. The optimum bond line thickness was also determined through ADHESIVE joint shear strength. The effect of different degreasing agents and silane-based primers were evaluated through lap-shear strength. The effect of ADHESIVE layer thickness was studied through lap-shear strength and cleavage strength tests. Findings: Optimum bond line thickness was determined at 0. 5 mm based on the results of the ADHESIVE shear strength, whereas the results of the fracture toughness indicated 1. 25 mm as the optimum ADHESIVE layer thickness. The lower ADHESIVE strength in thicker bond lines may well be due to the possible formation of air traps and lower constrained effect of the substrate. Therefore, the least requirements for aluminum surface treatment was surface degreasing followed by sanding which results in a transition from ADHESIVE fracture mode to cohesive fracture. The use of two kinds of silane-based primers containing the amine group, triethoxy silylpropylamine (APS) and the other with epoxy group, glycidoxypropyl trimethoxysilane (GPS) was more efficient in improving joint durability even after 2500 h cyclic aging with the more pronounced results for the APS.

This study aims to investigate the effects of key parameters on the interfacial bond strength between two CONCRETE members. Different types of overlay in terms of strength (normal-strength CONCRETE, high-strength CONCRETE), surface roughness, and ADHESIVE type are considered as variable factors influencing the bond behavior. First, the surface roughness of the old CONCRETE and the compressive strength of the CONCRETE overlay are evaluated separately. Then among the specimens, the composite with the highest bond strength is chosen as the optimum CONCRETE composite. After finding the optimum composite, epoxy ADHESIVE and cellulose mortar are applied to the optimum sample, and its corresponding interfacial strength is evaluated by bi-surface shear and splitting tensile strength tests. The results showed that, as the compressive strength of new CONCRETE and CONCRETE roughness increases, the bond strength increases. The highest bond strength achieved in composites containing high-strength CONCRETE is 23.37% higher than that of samples with normal-strength CONCRETE. Moreover, the interfacial bond strength of composite with the wire-brushed surface is the highest among other treatment methods, due to the interlocking action it provides. The bond strength of CONCRETE composites containing epoxy ADHESIVE is ∼100-200% higher than that of samples without epoxy resin. However, the addition of cellulose mortar slightly reduces the adhesion resistance of the optimum sample. Therefore, it is anticipated that the use of high-strength CONCRETE concomitant with wire-brushed surface treatment and epoxy resin ADHESIVE shows substantial potential as an excellent method for repair of CONCRETE structure.

Objective: The aim of this study was to evaluate the bond strength of self- etch ADHESIVE system (AdheSE) with three dentin conditioning methods.Materials and Method: Sixty six human intact premolar was divided into 3 group (n=22), a flat dentin surface was made. In group 1: The tooth was etched by phosphoric acid (%35), then bonding material of AdheSE was used. In group 2: only bonding material was used. In group 3: The procedure was as the first group, but after etching, the tooth surface was deproteinized by Naocl (%5). Then with a cylindrical composite model were made. Thermolcycling was performed using 500 cycles, and subjected to a blade (cross head) with the speed of 0.5 mm/min .Collected data was analyzed using 1 way ANOVA test in addition to a Duncan test.Results: Results revealed that hypochlorite sodium (Naocl) decreased the bond strength. When acid phosphoric and then dentin bonding agent were used, mean bond strength (25.72 MPa) was the most. Excess etching increases the bond strength.Conclusion: When the self etching ADHESIVEs are used for repair of teeth, excess etching increases the bond strength.