scholarly journals Experimental Research on Key Factors Influencing the Expansion Performance of New Type Sealing Materials

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Yaobin Li ◽  
Xin Guo ◽  
Sheng Xue ◽  
Chun-Shan Zheng ◽  
Maoliang Shen ◽  
...  
Keyword(s):  
Hydration Product ◽  
Expansion Rate ◽  
Quadratic Model ◽  
Utilization Rate ◽  
Hardened Cement ◽  
Cement Slurry ◽  
Optimal Ratio ◽  
Sealing Material ◽  
Sealing Materials ◽  
Scanning Electron

To improve the borehole sealing effect, especially that of coal seam with low permeability and micro fissures, this paper takes the expansion rate of the sealing material as the response value and establishes the quadratic model embracing the expansion rate and various experimental factors by designing orthogonal experiments. The response surface is used to further determine the significance order of each key factor according to the expansion rate and adjust the admixture content to obtain the optimal ratio of the sealing material. For the research investigating a sealing material, the optimal ratio of the sealing material is obtained: the content of water reducing agent of 0.5%, the content of retarder of 0.04%, water-cement ratio of 0.8, and the content of expansion agent of 10%. At this time, the expansion rate reaches 3.136%. Besides, a scanning electron microscope is used to observe the microscopic morphology of the material. According to the scanning electron microscopy analysis of new borehole sealing materials, the surface of the new borehole sealing material shows no holes and possesses compactness; and a large amount of ettringite is formed on the surface of the hydration product of hardened cement slurry. The ettringite improves the expansibility of the material. The new sealing material provides a new idea for gas sealing, which is of great significance to improve the efficiency of borehole extraction, improve the utilization rate of resources, and prevent gas accidents.

scholarly journals Fluidity Influencing Factors Analysis and Ratio Optimization of New Sealing Materials Based on Response Surface Method

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Xin Guo ◽  
Sheng Xue ◽  
Yaobin Li ◽  
Chunshan Zheng ◽  
Gege Yang
Keyword(s):  
Compressive Strength ◽  
Setting Time ◽  
Expansion Rate ◽  
Key Factors ◽  
Gas Drainage ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Sealing Material ◽  
The Impact ◽  
Sealing Materials

The borehole sealing material is one of the key factors affecting the gas drainage effect of a borehole. This paper takes the compressive strength, fluidity, expansion rate, and setting time of the sealing material as the main research indicators and explores the influence of each key influencing factor on the performance of the high-fluid sealing material through the single factor experiment method. Using the Design-Expert 8.0.5 Trial software designed orthogonal experiments and establishing a quadratic model between liquidity and each test factor, which showed the impact of each key factor on the fluidity. Finally, by adjusting the amount of admixtures, the optimal ratio of high-fluidity borehole sealing materials was obtained. The results showed that the key factors had the following order of significance: water – cement   reducing   agent > water – cement   ratio > retarder > expansion   agent . With the water-cement ratio and the amount of water reducing agent increase, the fluidity of the material will increase; and with the increase of the retarder and expansion agent, the fluidity will decrease. In actual use, the fluidity is the main factor, but the expansion rate, compressive strength, and setting time are also considered. The optimal percentages were found for the high-fluidity borehole sealing material: a water-cement ratio of 1, along with 0.03% retarder, 0.5% water reducer, and 8% expansion agent. These research results could provide a reference for improving the performance of gas drainage borehole sealing materials and enhancing the effect of gas drainage.

Comparative Study of Acid Etching on Dental Enamel

2018 ◽  
Vol 69 (10) ◽  
pp. 2913-2915
Author(s):  
Daniela Jumanca ◽  
Anamaria Matichescu ◽  
Atena Galuscan ◽  
Laura Cristina Rusu ◽  
Cornelia Muntean
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Experimental Study ◽  
Orthophosphoric Acid ◽  
Dental Enamel ◽  
Acid Etching ◽  
Sealing Material ◽  
Mechanical Bond ◽  
Materials Used ◽  
Scanning Electron

This experimental study aims to analyse the effectiveness of various materials used in demineralisation of dental enamel. This work aims to create a mechanical bond by filling the pegs with sealing material. In order to achieve this goal, five teeth were compared using different concentrations of orthophosphoric acid and exposure times. In this regard, five different tests were performed and the results were analysed using the SEM technique (scanning electron microscopy). These comparative analyses revealed that etching using 35% orthophosphoric acid for one minute and etching using Icon Etch for two minutes were the most effective.

scholarly journals Strength Tests of Hardened Cement Slurries for Energy Piles, with the Addition of Graphite and Graphene, in Terms of Increasing the Heat Transfer Efficiency

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1190
Author(s):  
Tomasz Sliwa ◽  
Aneta Sapińska-Śliwa ◽  
Tomasz Wysogląd ◽  
Tomasz Kowalski ◽  
Izabela Konopka
Keyword(s):  
Hardened Cement ◽  
Environmental Aspects ◽  
Cement Slurry ◽  
Subsequent Increase ◽  
Load Bearing ◽  
Heat Transfer Efficiency ◽  
Strength Tests ◽  
Energy Piles ◽  
New Buildings ◽  
New Facility

The development of civilization, and subsequent increase in the number of new buildings, poses engineering problems which are progressively more difficult to solve, especially in the field of geotechnics and geoengineering. When designing new facilities, particular attention should be paid to environmental aspects, and thus any new facility should be a passive building, fully self-sufficient in energy. The use of load-bearing energy piles could be a solution. This article presents research on the cement slurry formulas with the addition of graphite and graphene, that can be used as a material for load-bearing piles. The proposed solution is to introduce U-tubes into the pile to exchange heat with the rock mass (the so-called energy piles). A comparison of four slurry formulas is presented: the first one consisting mainly of cement (CEM I), graphite, and water, and the remaining three with different percentages of graphene relative to the weight of dry cement. The results could contribute to the industrial application of those formulas in the future.

scholarly journals Evaluation of Antimicrobial Efficacy and Permeability of Various Sealing Materials at the Implant–Abutment Interface—A Pilot In Vitro Study

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 385
Author(s):  
Igor Smojver ◽  
Marko Vuletić ◽  
Dražena Gerbl ◽  
Ana Budimir ◽  
Mato Sušić ◽  
...  
Keyword(s):  
Fungal Infections ◽  
Aerobic Condition ◽  
In Vitro Study ◽  
Vitro Study ◽  
Antimicrobial Efficacy ◽  
Sealing Material ◽  
Implant Abutment ◽  
Static Conditions ◽  
Sealing Materials

The microenvironment of the oral cavity is altered when an implant, a biocompatible foreign body, is inserted into the mouth. Bacteria settle in the tissues in and around the implant due to the passage of microorganisms through the microgap at the connection of the implant and prosthetic abutment. To prevent colonization of the implant by microorganisms, one idea is to use sealing and antimicrobial materials to decontaminate the implant–abutment interface and close the microgap. The purpose of this study is to evaluate the antimicrobial efficacy and permeability of different types of sealing materials at the implant–abutment interface, under static conditions. Three different sealing material (GapSeal gel, Oxysafe gel and Flow.sil) were used for sealing the implant–abutment interfaces in 60 titanium dental implants, which were first contaminated with a solution containing Staphylococcus aureus and Candida albicans for 14 days under an aerobic condition. Results showed that a complete seal against bacterial infection was not formed at the implant–abutment interface, while for fungal infections, only GapSeal material helped to prevent microleakage. Findings of this in vitro study reported that application of sealing material before abutment connection may reduce peri-implant bacterial and fungal population compared with the interface without sealing material.

scholarly journals Influence of Organic Esters on Portland Cement Hydration and Hardening

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Duan-le Li ◽  
Da-peng Zheng ◽  
Dong-min Wang ◽  
Ji-hui Zhao ◽  
Cheng Du ◽  
...  
Keyword(s):  
Organic Compounds ◽  
Cement Hydration ◽  
Setting Time ◽  
Exothermic Peak ◽  
Hardened Cement ◽  
Test Results ◽  
Trimethyl Phosphate ◽  
Cement Slurry ◽  
Hydration Degree ◽  
Dimethyl Oxalate

This paper investigated the effect of organic compounds with ester groups on the hydration and hardening of cement. The effects of five kinds of organic compounds with ester groups (ethyl acetate, dimethyl oxalate, glyceryl triacetate, trimethyl phosphate, and triethanolamine borate) on hydration heat, hydration degree, setting time, mechanical properties, microstructure, and pore structure of hardened cement slurry were studied. The test results showed that esters can make the end time of cement hydration induction longer and delay the occurrence of the second exothermic peak. Also, the effect of five kinds of esters on the hydration and hardening of cement was basically followed by TG> TB> DMO> EAC> TMP. In terms of molecular structure, for organic compounds containing only ester groups, the higher the number of ester groups, the greater the effect on the hydration of cement. The introduction of other functional groups (such as phosphate or borate) will influence the effect of the esters.

scholarly journals Moisture-Resistant Sealing Materials for Downhole HPHT Electrical Feedthrough Package

2019 ◽  
Vol 16 (3) ◽  
pp. 141-148
Author(s):  
Hua Xia ◽  
Nelson Settles ◽  
David DeWire
Keyword(s):  
High Temperature ◽  
Water Immersion ◽  
Electrical Power ◽  
Covalent Bond ◽  
Phase Structures ◽  
Sealing Material ◽  
Drilling Tools ◽  
Measurement While Drilling ◽  
Sealing Materials ◽  
Moisture Resistant

Abstract A bismuth oxide–based multicomponent glass system, xH3BO3-yBi2O3-(1-x-y-δ)MO-δ· rare earth oxides (REOs) with MO = TiO2, BaO, ZnO, Fe2O3, etc., and lanthanum series–based REOs, for making downhole high-pressure and high-temperature electrical feedthrough package has been developed using high-temperature melt-quenching and sintering technologies. By properly controlling phase structures in material-manufacturing processes, the obtained sealing materials have shown moisture-resistant properties in their monoclinic and tetragonal mixed phase structures but strongly hydrophobic properties in their covalent bond tetragonal phase. Sealed electrical feedthrough packages have been evaluated under boiling water immersion and 200°C/30,000 PSI water-fluid–simulated downhole harsh environments. The post electrical insulation measurement has demonstrated to be greater than 1.0 × 1014 Ω electrical resistance. This article will show that such a high–bonding strength and high–insulation strength sealing material could be used to seal electrical feed-throughs and connectors for 300°C/30,000 PSI downhole and subsea wireline, logging while drilling, and measurement while drilling tools' signal, data, and electrical power transmissions.

The Evolution of a Range of Service Experience Rationalised Sealing Materials

2004 ◽  
Author(s):  
John R. Hoyes
Keyword(s):  
Material Testing ◽  
End User ◽  
Cost Performance ◽  
Service Failures ◽  
Testing Tools ◽  
Sealing Material ◽  
The Relationship ◽  
Survival Of The Fittest ◽  
Sealing Materials ◽  
Structure Test

With the benefit of hindsight some of the initial non-asbestos offerings were doomed to be commercial failures and since then evolution, in the true Darwinian “survival of the fittest” sense, has resulted in the demise of those offerings. In parallel with this process of evolution, the sealing material testing tools that are available have improved. Consequently, the relationship between a material’s contents, its structure, test data and its service potential is far better understood than in previous times. This improved understanding has brought, and will continue to bring, enhanced performance benefits to the end user and increased security against unplanned shut down due to service failures. This paper reviews the evolution process, highlights the classes of materials that have proven to be successful and tries to indicate why, in terms of the properties of the material, they have been successful. The salient features of the content and structure of these materials are also discussed. The paper also speculates about the way in which further consolidation of the range of sealing materials may come about as the process of evolution, driven by cost, performance and environment pressures, continues.

Influence of Cementitious Capillary Crystalline Waterproofing Material on the Water Impermeability and Microstructure of Concrete

2019 ◽  
Vol 953 ◽  
pp. 209-214
Author(s):  
Yi Teng Zhang ◽  
Lian Zuo ◽  
Jin Chao Yang ◽  
Wei Xia Zhao ◽  
Xiang Xiong Zeng
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Differential Scanning Calorimetry ◽  
Cement Matrix ◽  
Hardened Cement ◽  
Hydration Products ◽  
Hardened Cement Paste ◽  
Scanning Calorimetry ◽  
Chinese Standard ◽  
Scanning Electron

The main objective of this study is to investigate the effect of cementitious capillary crystalline waterproofing (CCCW) material on the water impermeability and microstructure of concrete. The water impermeability of concrete covered with or without CCCW material was tested according to the Chinese standard GB 18445-2012. The results indicate that concretes coated with CCCW material showed much higher water impermeability than blank ones, and the ratio of water impermeability pressure between them reached 275. The samples obtained in various depths of hardened cement paste specimens with or without CCCW coating were analyzed through scanning electron microscopy (SEM) and thermogravimetry-differential scanning calorimetry (TG-DSC), to study the differences in microstructure and hydration products. The results present that after a 28-day standard curing, there were lots of ettringite crystals and CaCO3 formed in the paste in 1 cm from the coating, but the action depth of the CCCW coating could not reach 3 cm. The ettringite and CaCO3 is precipitated in the pore structure of cement matrix and filling the voids, which leads to the significant enhancement in water impermeability.

Fabrication and Properties of Panicum repens Reinforced Cement

2018 ◽  
Vol 879 ◽  
pp. 161-165
Author(s):  
Varinthorn Boonyaroj ◽  
Sirichai Saramanus
Keyword(s):  
Compressive Strength ◽  
Raw Materials ◽  
Chemical Characteristics ◽  
Sodium Hydroxide Concentration ◽  
X Ray ◽  
Optimal Ratio ◽  
Panicum Repens ◽  
Reinforced Cement ◽  
Materials Used ◽  
Scanning Electron

This research aims to fabrication and evaluation the properties of cement reinforcement made from Panicumrepens. The research is divided into two parts are as follows; to determined the optimal ratio selection, and to compare the properties of Panicumrepens reinforced cement, and without grasses by using the optimal ratio. The raw materials used in this research were cut in length of 2.0-2.5 cm. In this research was determined the properties of Panicumrepens reinforced cement in terms of bulk density, water absorption, and compressive strength. The influence of fibers soaked with 5% of sodium hydroxide concentration was also conducted in this research. The surface structure and chemical characteristics of fibers used to produce reinforced cement were observed by using scanning electron microscope (SEM), and energy dispersive x-ray spectrometer (EDS), respectively. Moreover, relationships of information collected from this research were concerned. Furthermore, the addition of Panicumrepens fibers could improve the flexural strength of composite materials.

Study on Microstructure of Long-Age Concrete with HCSA Expansive Agent

2017 ◽  
Vol 744 ◽  
pp. 40-44 ◽  
Author(s):  
Fang Fang Hou
Keyword(s):  
Fly Ash ◽  
High Volume ◽  
Hydration Product ◽  
Curing Time ◽  
Average Ratio ◽  
Expansive Agent ◽  
Binding Material ◽  
High Volume Fly Ash ◽  
Energy Dispersion Spectrum ◽  
Scanning Electron

The microstructure of high-volume fly ash and long-age concrete with HCSA expansive agent at different curing time is studied by means of scanning electron microscope and energy dispersion spectrum analysis. The result shows that wet curing is benefit to the generation of ettringite which is the hydration product of HCSA expansive agent, and also is benefit to the hydration of cement and fly ash, which can fundamentally improve compactness of concrete. For the concrete which mix 6% amount of HCSA expansive agent a 60% amount of fly ash, when it is not cured, the average ratio of Ca to Si is 1.8, and the value is 0.36 after 28d curing. Since the ration of Ca to Si is lower, the hydration rate of binding material is faster.

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