Improvement of adhesion performance of mortar-repair interface with inducing crack path into repair

2015 ◽  
Author(s):  
A. Satoh ◽  
K. Yamada ◽  
M. Satoh
Keyword(s):  
Crack Path ◽  
Fem Analysis ◽  
Repair Material ◽  
High Modulus ◽  
Fine Aggregates ◽  
Repair Materials ◽  
Adhesion Performance ◽  
Fractographic Observation ◽  
Strength And Ductility

The most important performance for repair materials is adhesion to the substrate. The authors experimentally find out that high modulus fine aggregates in repair material enhance strength of it as well as the strength of the interface repaired with it, compared to the ordinary repair without fine aggregates. This paper elaborates the mechanisms for that with fractographic observation and FEM analysis based on the results of experiment. Also the authors discuss the ways for enhancing the strength and ductility of the repaired mortar.

FEM Analysis on Concrete Column Confined by Straps of BFRP Sheets

2013 ◽  
Vol 639-640 ◽  
pp. 1083-1086
Author(s):  
Xiao Kun Wang ◽  
Hua Xin Liu ◽  
Xue Zhi Wang ◽  
Cheng Zhai
Keyword(s):  
Compressive Strength ◽  
Axial Loading ◽  
Fem Analysis ◽  
High Strength ◽  
Confined Concrete ◽  
Concrete Column ◽  
Good Resistance ◽  
Axial Compressive Strength ◽  
Loading Tests ◽  
Strength And Ductility

More attention has been paid on the technology of BFRP in civil engineering due to it’s unique properties, such as high strength-to-weight radio, good resistance to corrosion and convenient to construction. In order to study the properties of BFRP sheets confined concrete column ,we did it through three groups of columns subjected to axial loading tests and FEM analyses, mainly considering the effect of spacing of straps of BFRP sheets confining concrete column.The results shows that the axial compressive strength and ductility of concrete column winded by BFRP straps have all increased and the process of destruction of concrete column wrapped by BFRP is longer than that of the unconfined concrete column.

Properties of Phosphate Cement Mortar Used as Rapid-Repair Material

2011 ◽  
Vol 250-253 ◽  
pp. 1752-1756 ◽  
Author(s):  
Hong Wei Deng ◽  
Ying Zi Yang ◽  
Xiao Jian Gao
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
No Reduction ◽  
Cement Mortar ◽  
Magnesium Phosphate ◽  
Strength Development ◽  
Repair Material ◽  
Rapid Repair ◽  
Repair Materials ◽  
Early Strength

In order to determine the optimal proportion of magnesium phosphate cement mortar, the influences of ratio of magnesium phosphate cement-based binder (MPB) to sand (MPB/S), effects of fly ash on fluidity and strength development of MPB mortar, and the compatibility between MPB and traditional concrete and shrinkage of MPB mortar were investigated in this paper. The optimal proportion in this test was: setting adjusting agent of 12%, P/M ratio of 1:2(in weight), MPB/S ratio of 1:1 and FA/S ratio of 15%. The results showed that the MPB mortar met the higher early strength requirement of rapid-repair materials, with compressive strength beyond 50MPa and flexural strength more than 9.1MPa at 3 hours, and at later ages no reduction of strength happened. There was a good compatibility between MPB and traditional concrete. The shrinkage of MPB mortar at 28 days was less than 2.89 × 10-4. Therefore MPB is very suitable for rapid repairing of concrete structures.

scholarly journals Comparative Evaluation of Sealing Ability and Marginal Adaptation of Furcation Repair Materials: An in vitro Study

2020 ◽  
pp. 35-43
Author(s):  
Sonam Yangchen Bhutia ◽  
Munish Goel ◽  
Vijay Kumar ◽  
Shweta Verma
Keyword(s):  
High Vacuum ◽  
In Vitro Study ◽  
Tooth Surface ◽  
Repair Material ◽  
Gap Formation ◽  
Iatrogenic Perforation ◽  
Sealing Ability ◽  
Repair Materials ◽  
Repair Procedure

The present study was undertaken for evaluating the sealing ability of furcation repair materials GC Fuji VII, MTA Plus and Biodentine. Diagnosis of iatrogenic perforation requires a combination of symptomatic findings in clinical observations. Perforations can be defined as mechanical or pathological communications between the root canal system and the external tooth surface. Study was conducted in the Department of Conservative Dentistry and Endodontics, Himachal Dental College, Sundernagar, Himachal Pradesh, India. Fifty five sound mandibular molars with non fused and well developed roots were used for the study. The specimens were examined using SEM which is maintained approximately 15Kv and 10-6 Torr under high vacuum condition. Specimen imaging were done by secondary electrons using a secondary electron detector. Scanning Electron Microscope (SEM) pictures, MTA plus shows the minimum marginal gap of 2.17 micrometers, followed by Biodentine 5.55 micrometers and GC FUJI VII 8.00 micrometers. The most important factors determining the success of a perforation repair procedure are the location of the perforation; time elapsed between the occurrence of the perforation and repair, the ability of the material to seal the perforation and the biocompatibility of the repair material. In our study, MTA Plus showed minimum leakage compared to GC FUJI VII and Biodentine. The minimum microleakage as observed in MTA Plus group might be attributed to its superior marginal sealing ability resulting from its hydrophilic properties and formations of an inter facial layer. Biodentine also provides a good seal almost similar to that of MTA Plus when used as a furcation repair material. GC Fuji VII showed significantly more leakage and gap formation than Biodentine and MTA Plus.

High Strength Polymer-Modified Repair Cementitious Composite for Fire Protection

2007 ◽  
Vol 15 (5) ◽  
pp. 379-388 ◽  
Author(s):  
Jong-Pil Won ◽  
Seok-Won Choi ◽  
Chan-Gi Park ◽  
Chang-Il Jang
Keyword(s):  
Fire Resistance ◽  
Mechanical Performance ◽  
High Strength ◽  
Repair Material ◽  
Cementitious Composite ◽  
Internal Temperature ◽  
Existing Structures ◽  
Repair Materials ◽  
Cover Thickness ◽  
Water Tightness

The purpose of this study was to evaluate the mechanical performance and fire resistance of a high strength polymer-modified cementitious composite, to test its ability to repair concrete tunnel structures that are in danger of collapse due to cracks or deterioration. In particular, because existing repair materials are not fire-resistant and commercial fire-resistant materials have low strength, this study was aimed at increasing the water tightness and strength of a repair material and also making it resistant to fire. In addition, this study evaluated changes in internal temperature depending on the cover thickness of repair materials to determine the optimal cover thickness at which a high strength polymer-modified cementitious composite could protect existing concrete tunnel structures from fire. Results indicated that the high strength polymer-modified cementitious composite had superior strength and water tightness than commercial fire-resistant materials and it also provided good fire resistance. The high strength polymer-modified cementitious composite required to be applied in an optimal layer thickness of at least 40 mm to protect existing structures from fire.

scholarly journals Skull Repair Materials Applied in Cranioplasty: History and Progress

2017 ◽  
Vol 3 (1) ◽  
pp. 48-57 ◽  
Author(s):  
Qingsheng Yu ◽  
Lin Chen ◽  
Zhiye Qiu ◽  
Yuqi Zhang ◽  
Tianxi Song ◽  
...  
Keyword(s):  
Mechanical Characteristics ◽  
Human Life ◽  
Polymeric Materials ◽  
Repair Material ◽  
The Past ◽  
Artificial Materials ◽  
Repair Materials ◽  
Biological Performance ◽  
The Brain ◽  
Mineralized Collagen

The skull provides protection and mechanical support, and acts as a container for the brain and its accessory organs. Some defects in the skull can fatally threaten human life. Many efforts have been taken to repair defects in the skull, among which cranioplasty is the most prominent technique. To repair the injury, numerous natural and artificial materials have been adopted by neurosurgeons. Many cranioprostheses have been tried in the past decades, from autoplast to bioceramics. Neurosurgeons have been evaluating their advantages and shortages through clinical practice. Among those prostheses, surgeons gradually prefer bionic ones due to their marvelous osteoconductivity, osteoinductivity, biocompatibility, and biodegradability. Autogeneic bone has been widely recognized as the “gold standard” for renovating large-sized bone defects. However, the access to this technique is restricted by limited availability and complications associated with its use. Many metal and polymeric materials with mechanical characteristics analogous to natural bones were consequently applied to cranioplasty. But most of them were unsatisfactory concerning osteoconductiion and biodegradability owe to their intrinsic properties. With the microstructures almost identical to natural bones, mineralized collagen has biological performance nearly identical to autogeneic bone, such as osteoconduction. Implants made of mineralized collagen can integrate themselves into the newly formed bones through a process called “creeping substitution”. In this review, the authors retrospect the evolution of skull repair material applied in cranioplasty. The ultimate skull repair material should have microstructure and bioactive qualities that enable osteogenesis induction and intramembranous ossification.

scholarly journals The Preparation andIn VitroEvaluations of a Nanoscaled Injectable Bone Repair Material

2015 ◽  
Vol 2015 ◽  
pp. 1-8
Author(s):  
Xinhui Liu ◽  
Chao Zhu ◽  
Yijiong Li ◽  
Yueling Yan ◽  
Chuanyong Hou ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Bone Repair ◽  
Cell Attachment ◽  
Repair Material ◽  
Cellular Functions ◽  
Repair Materials ◽  
Proliferation And Differentiation ◽  
Negative Effect ◽  
Bone Repair Material

There are usually two forms of bone repair materials, block and granular, for common clinical use. This paper describes a novel injectable material, nano-HA/collagen/alginate (nHAC/Alg) composite biomaterial, including its preparation and evaluationsin vitro. Based on the idea of bionics and the study of collagen/calcium phosphate salt composite materials, the injectable bone repair material was developed. Then, human bone marrow stem cells (hBMSCs) were cultured on the nHAC/Alg material. The cell attachment, proliferation, and differentiation were evaluated with inverted microscope, scanning electron microscope, laser scanning confocal microscope, 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) analysis, and alkaline phosphatase (ALP) test. The results showed that nHAC/Alg not only had no negative effect on cellular functions but also promotes cell proliferation and differentiation into osteogenic cells, which suggests that the nanoscaled injectable bone repair material has good clinical application prospects for bone repair.

scholarly journals Effect of PCE on Properties of MMA-Based Repair Material for Concrete

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 859
Author(s):  
Jian Han ◽  
Lingling Xu ◽  
Tao Feng ◽  
Xin Shi ◽  
Pan Zhang
Keyword(s):  
Mechanical Properties ◽  
Ultraviolet Radiation ◽  
Methyl Methacrylate ◽  
Mass Fraction ◽  
Bending Strength ◽  
Polymerization Reaction ◽  
Repair Material ◽  
Ionic Solutions ◽  
Low Viscosity ◽  
Repair Materials

Methyl methacrylate (MMA)-based repair material for concrete has the characteristics of low viscosity, excellent mechanical properties, and good durability. However, its application is limited due to its large shrinkage. Existing studies have shown that adding perchloroethylene can reduce the shrinkage. On this basis, other properties of modified MMA-based repair materials were tested and analyzed in the present study. The results revealed that the addition of perchloroethylene (PCE) can hinder the polymerization reaction of the system. When CaCO3 with a mass fraction of 30% was added, the viscosity of the material was within the range of 450–500 mPa·s, and the shrinkage decreased to approximately 10%. The bending strength of MMA, and MMA modified by PCE, repair materials at 28 days could reach up to 28.38 MPa and 29.15 MPa, respectively. After the addition of HS-770 light stabilizer with a mass fraction of 0.4%, the retention ratios of the bending strength of materials with ratios of P0 and P3 could reach 91.11% and 89.94%, respectively, after 1440 h of ultraviolet radiation. The retention ratio of the bending strength of the material could reach more than 95% after immersion in different ionic solutions for 90 days.

Simulation of Adhesion Performance of Mortar-Mortar Interface with Varied Fractographic Features

2013 ◽  
Vol 577-578 ◽  
pp. 357-360
Author(s):  
Ayumi Satoh ◽  
Kanji Yamada ◽  
Yasuji Shinohara
Keyword(s):  
Mechanical Properties ◽  
Material Properties ◽  
Crack Path ◽  
Fem Simulation ◽  
Interface Model ◽  
Projected Length ◽  
Adhesion Performance ◽  
Fractographic Features ◽  
The Relationship ◽  
Combination Of Material

This paper aims at revealing the relationship between fractographic parameters of the mortar-mortar interface and the mechanical properties of such interface in terms of flexural strength and fracture energy. The FEM simulation was conducted where 8 cases of the combination of material properties were applied for all 7 interface models. The fractographic parameters evaluated on each interface model were six. Among them, both Sd (standard deviation of the height) and RL (ratio of the real length of the crack path to the projected length) are closely related to the mechanical properties.

scholarly journals Characterisation at the Bonding Zone between Fly Ash Based Geopolymer Repair Materials (GRM) and Ordinary Portland Cement Concrete (OPCC)

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 56
Author(s):  
Warid Wazien Ahmad Zailani ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
Mohd Fadzil Arshad ◽  
Rafiza Abd Razak ◽  
Muhammad Faheem Mohd Tahir ◽  
...  
Keyword(s):  
Fly Ash ◽  
Portland Cement ◽  
Ordinary Portland Cement ◽  
Repair Material ◽  
Portland Cement Concrete ◽  
Cement Concrete ◽  
Repair Materials ◽  
High Calcium ◽  
Bonding Zone ◽  
Ordinary Portland Cement Concrete

In recent years, research and development of geopolymers has gained significant interest in the fields of repairs and restoration. This paper investigates the application of a geopolymer as a repair material by implementation of high-calcium fly ash (FA) as a main precursor, activated by a sodium hydroxide and sodium silicate solution. Three methods of concrete substrate surface preparation were cast and patched: as-cast against ordinary Portland cement concrete (OPCC), with drilled holes, wire-brushed, and left as-cast against the OPCC grade 30. This study indicated that FA-based geopolymer repair materials (GRMs) possessed very high bonding strength at early stages and that the behavior was not affected significantly by high surface treatment roughness. In addition, the investigations using scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX) spectroscopy have revealed that the geopolymer repair material became chemically bonded to the OPC concrete substrate, due to the formation of a C–A–S–H gel. Fundamentally, the geopolymer network is composed of tetrahedral anions (SiO4)4− and (AlO4)5− sharing the oxygen, which requires positive ions such as Na+, K+, Li+, Ca2+, Na+, Ba2+, NH4+, and H3O+. The availability of calcium hydroxide (Ca(OH)2) at the surface of the OPCC substrate, which was rich in calcium ions (Ca2+), reacted with the geopolymer; this compensated the electron vacancies of the framework cavities at the bonding zone between the GRM and the OPCC substrate.

scholarly journals Effectiveness of Silorane-based Composite as a Repair Filling for Dimethacrylate- or Silorane-based Composite Restorations

2012 ◽  
Vol 3 (2) ◽  
pp. 161-165
Author(s):  
Daphne Câmara Barcellos ◽  
Cesar Rogério Pucci ◽  
Carlos Rocha Gomes Torres ◽  
Sergio Eduardo de Paiva Gonçalves ◽  
Patricia Rondon Pleffken ◽  
...  
Keyword(s):  
Bond Strength ◽  
Distilled Water ◽  
Repair Material ◽  
Single Bond ◽  
Composite Restorations ◽  
Truncated Cone ◽  
Repair Materials ◽  
High Bond ◽  
High Bond Strength ◽  
One Way Anova

ABSTRACT Objective This study aimed to evaluate the suitability of one specific silorane-based composite for the application as a repair material for different substrates. Materials and methods Truncated cones of composites fabricated and thermocycled for 6000 cycles to serve as a substrate were made of two commercially available dimethacrylate-based composites (DBC) (Filtek Supreme and Clearfil APX) and one silorane-based composite (SBC) (Filtek P90). The surface of the specimens was treated with air-abraded using Al2O3-particles of 50 µm size. A Teflon device was used to fabricate inverted truncated cones of repair composite over the surface-treated top of each original truncated cone. DBC and SBC were used as repair materials and bonded to the specimens using either a dimethacrylate-based (single bond 2) or a phosphate-methacrylate-based (adhesive belongs to the silorane) adhesives. The specimens were stored in distilled water at 37°C for 7 days and stressed to failure under tension. The data were analyzed with one-way ANOVA and Tukey tests at 5%. Results Bonding DBC as a repair material to a DBC substrate using the dimethacrylate-based adhesive produced the highest bond strength. Bonding DBC as repair material using the phosphate-methacrylate-based adhesive or SBC as repair material using the dimethacrylate-based adhesive produced lower bond strength, regardless the brand and of the chemical formulation of the aged substrate. Conclusion In order to obtain high bond strength, there is need to match adhesive and repair material, regardless the brand and of the chemical formulation of the substrate. How to cite this article Barcellos DC, Pleffken PR, Pucci CR, Pagani C, Gonçalves SEP, Torres CRG. Effectiveness of Silorane-based Composite as a Repair Filling for Dimethacrylate- or Silorane-based Composite Restorations. World J Dent 2012;3(2):161-65.

Sign in / Sign up

Export Citation Format

Share Document