Effect of Type and Dosage of Activators on Strength of Repair Concretes

2013 ◽  
Vol 454 ◽  
pp. 213-217
Author(s):  
Long Fei Xue ◽  
Jian Le Xu ◽  
Jue Fei Yi
Keyword(s):  
Mechanical Properties ◽  
Pozzolanic Reaction ◽  
Strength Measurement ◽  
Repair Materials ◽  
Early Strength ◽  
Optimum Chemical ◽  
Scan Electronic Microscope ◽  
Chemical Activator ◽  
Electronic Microscope ◽  
Sem Test

The different effect of chemical activators on mechanical properties and microstructure of cement-base repair materials were investigated. The microstructure of repair concrete was also analyzed by using scan electronic microscope (SEM). Test of mechanical properties indicate that the optimum chemical activator suitable to repair concrete with nearly 30% mineral materials replacement of cement is the type J-B, and the optimum addition is 5% dosage by weight of binders. The presence of chemical activator J-B increase the early strength and exert significantly advantageous affect on the later strength. Measurement of microstructure indicates that the surface of fly ash particle can be seen obvious pozzolanic reaction, and this is due to the presence of chemical activator which accelerate the pozzolanic reaction and densify the mortar pore structure.

Effect of Activator on Mechanical Properties and Porosity of Cement-Base Repair Mortar

2013 ◽  
Vol 830 ◽  
pp. 86-89
Author(s):  
Jian Le Xu ◽  
Long Fei Xue ◽  
Jue Fei Yi
Keyword(s):  
Mechanical Properties ◽  
Pore Structure ◽  
Total Porosity ◽  
Pozzolanic Reaction ◽  
Mineral Admixture ◽  
Strength Measurement ◽  
Repair Mortar ◽  
Early Strength ◽  
Chemical Activator

This study investigated the different effect of three chemical activators on mechanical properties and porosity of cement-base repair mortar, whose binder consists of 80% cement and 20% mineral admixture. Test of mechanical properties indicate that the addition of 5% chemical activator A increase both the early and later strengths of repair mortar. The presence of 3% chemical activator C increase the early strength but has no significantly affect on the later strength. Measurement of pore structure indicate that repair mortar with chemical activator has lower total porosity and finer pore structure due to the presence of chemical activator which accelerate the pozzolanic reaction and densify the mortar pore structure.

Study of Microstructure and Dynamic Mechanical Analysis of Biodegradable Tableware Produced with Corn Straw

2011 ◽  
Vol 380 ◽  
pp. 160-163 ◽  
Author(s):  
Alun ◽  
Zhi Hui Sun ◽  
Quan Rong Jing ◽  
Ri Dun Hu ◽  
Chun Li Yang
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Storage Modulus ◽  
Dynamic Mechanical Properties ◽  
Mechanical Analysis ◽  
Dynamic Mechanical Property ◽  
Corn Straw ◽  
Dynamic Mechanical ◽  
Scan Electronic Microscope ◽  
Electronic Microscope

This paper focused on biodegradable tableware processed with plant fiber, which were obtained by mechanical processing corn straw, abundant in Heilongjiang Province of China. Firstly, the microstructure characteristics of tableware were described by Scan Electronic Microscope (SEM). Secondly, the dynamic mechanical property of biodegradable tableware was analyzed by DMA, which will provide a reference to optimize the biodegradable tableware design in future. And the dynamic mechanical property of biodegradable tableware also was compared with the dynamic mechanical properties of the plastic snack box. The results showed that biodegradable tableware had a highly storage modulus (E′) originally, it was 3216MPa,while the maximum storage modulus (E′) of plastic snack box was 852MPa. And the results also indicated that the treat temperature has a significant effect on the dynamic mechanical properties of biodegradable tableware, as the treat temperature increased closely to 95°C, the biodegradable tableware appeared glassy transition, but the storage modulus (1650MPa) was still much higher than that of the plastic snack box.

Microstructure and Mechanical Properties of Shale Ceramsite Concrete

2006 ◽  
Vol 302-303 ◽  
pp. 371-375 ◽  
Author(s):  
Xiu Hua Zheng ◽  
Bao Sheng Zhang ◽  
Yuan Jie ◽  
Xu Chi ◽  
Yong Zhi Guo ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Growth Rate ◽  
Concrete Strength ◽  
Point Of View ◽  
Interfacial Zone ◽  
Pore Characteristics ◽  
Different Ages ◽  
Early Strength ◽  
Change Tendency ◽  
Electronic Microscope

The influence of pre-wetted time on strength of shale ceramsite concrete is studied.Microstructures of both cement paste and interfacial zone between aggregate and paste of concrete are observed by scanning electronic microscope (SEM). The results show that, if the pre-wetted time of the shale ceramsite increased, the decline degree of early strength of concrete will be greater than strength at a longer age, and the growth rate of concrete strength may obviously increase. The pore characteristics of concrete at different ages is examined. The change tendency of concrete strength at different ages is revealed from the point of view of microstructure.

Microstructure and Mechanical Properties of (CrTiNb)N Films

2014 ◽  
Vol 915-916 ◽  
pp. 808-811
Author(s):  
Yu Feng ◽  
Jun Zhang
Keyword(s):  
Mechanical Properties ◽  
Bias Voltage ◽  
High Speed ◽  
High Speed Steel ◽  
Fracture Morphology ◽  
Micro Hardness ◽  
X Ray Diffraction ◽  
Friction Resistance ◽  
Scan Electronic Microscope ◽  
Electronic Microscope

(CrTiNb)N hard reactive films are prepared by multi-arc ion plating technology using the combination of Ti-Nb alloy target and Cr target. The high speed steel (HSS) is adopted as substrate. The surface and cross-fracture morphology, the surface compositions and the phase structures of the as-deposited (CrTiNb)N films are observed and measured by scan electronic microscope (SEM) and X-ray diffraction (XRD). The mechanical properties including the micro-hardness, the adhesion between film and substrate, the friction and wear resistance of the as-deposited (CrTiNb)N films are systemically investigated. The effects of deposition bias voltage and the addition of Nb element on the as-deposited (CrTiNb)N films are discussed. It is revealed that the optimally comprehensive performances including the micro-hardness, the adhesion and also the friction resistance can be achieved by the (CrTiNb)N hard reactive films with bias voltage of 200V.

Microstructure and Mechanical Properties of TiAlON/TiAlN/TiAl Films

2014 ◽  
Vol 628 ◽  
pp. 93-97 ◽  
Author(s):  
Jun Zhang ◽  
Jia Jing Cai ◽  
Wei Zhao ◽  
Zheng Gui Zhang
Keyword(s):  
Mechanical Properties ◽  
Adhesive Strength ◽  
High Speed ◽  
High Speed Steel ◽  
Fracture Morphology ◽  
Liquid Droplets ◽  
X Ray Diffraction ◽  
Good Adhesive ◽  
Scan Electronic Microscope ◽  
Electronic Microscope

TiAlON/TiAlN/TiAl hard films are prepared by multi-arc ion plating technology using the Ti-50Al (at%) alloy target. The high speed steel (HSS) is adopted as substrate. The surface and cross-fracture morphology, the surface and cross-fracture compositions and the phase structures of the as-deposited TiAlON/TiAlN/TiAl hard films are observed and measured by scan electronic microscope (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD). The mechanical properties, including micro-hardness and adhesive strength between film and substrate, of the as-deposited TiAlON/TiAlN/TiAl hard films are investigated. The effects of oxygen partial pressure on the as-deposited films are discussed. It is revealed that the increase of oxygen decreased liquid droplets distribution density to some extent, caused complicated phase structure. Nevertheless, the good adhesive strength and the improved hardness with a maximum of 3900HV are achieved.

scholarly journals Utilization of Solid Waste from Brick Industry and Hydrated Lime in Self-Compacting Cement Pastes

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1109
Author(s):  
Mati Ullah Shah ◽  
Muhammad Usman ◽  
Muhammad Usman Hanif ◽  
Iqra Naseem ◽  
Sara Farooq
Keyword(s):  
Mechanical Properties ◽  
Solid Waste ◽  
Manufacturing Industry ◽  
Setting Time ◽  
Hydrated Lime ◽  
Pozzolanic Reaction ◽  
Early Age ◽  
Cement Pastes ◽  
Brick Powder ◽  
High Degree

The huge amount of solid waste from the brick manufacturing industry can be used as a cement replacement. However, replacement exceeding 10% causes a reduction in strength due to the slowing of the pozzolanic reaction. Therefore, in this study, the pozzolanic potential of brick waste is enhanced using ultrafine brick powder with hydrated lime (HL). A total of six self-compacting paste mixes were studied. HL 2.5% by weight of binder was added in two formulations: 10% and 20% of waste burnt brick powder (WBBP), to activate the pozzolanic reaction. An increase in the water demand and setting time was observed by increasing the replacement percentage of WBBP. It was found that the mechanical properties of mixes containing 5% and 10% WBBP performed better than the control mix, while the mechanical properties of the mixes containing 20% WBBP were found to be almost equal to the control mix at 90 days. The addition of HL enhanced the early-age strength. Furthermore, WBBP formulations endorsed improvements in both durability and rheological properties, complemented by reduced early-age shrinkage. Overall, it was found that brick waste in ultrafine size has a very high degree of pozzolanic potential and can be effectively utilized as a supplementary cementitious material.

Effect of Metakaolin on Geopolymer Industry

2019 ◽  
pp. 49-70
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Reaction Mechanisms ◽  
Ordinary Portland Cement ◽  
Setting Time ◽  
Experimental Studies ◽  
Acid Attack ◽  
Repair Materials ◽  
Hardened State

This chapter discusses the effects of metakaolin (MK) on geopolymer mortar and concrete industries. The research topics of MK-based geopolymer cover reaction mechanisms and kinetics. This chapter aims at augmenting knowledge about enhancing mechanical properties of geopolymer mortars/concrete using MK. Specifically, this chapter presents literature studies as well as current experimental studies which delineate the effect of MK on fresh and hardened-state properties of geopolymer mortars (GPMs). Properties and characteristics of metakaolin are explained followed by properties of fresh MK mortars. Properties of hardened MK concrete and durability aspects of MK mortars are explained. Applications of MK-based geopolymers and metakaolin-based geopolymers as repair materials are also included in this chapter. The results of using MK-based GPMs revealed improved workability, enhanced setting time, increased density, higher compressive strength, flexural strength, and resistance against acid attack than conventional ordinary portland cement mortar/concrete.

scholarly journals Mechanical properties of kenaf fibrous pulverized fuel ash concrete

2018 ◽  
Vol 250 ◽  
pp. 05007
Author(s):  
Norazura Mizal Azzmi ◽  
Jamaludin Mohamad Yatim ◽  
Hazlan Abdul Hamid ◽  
Azmahani Abdul Aziz ◽  
Adole Michael Adole
Keyword(s):  
Mechanical Properties ◽  
Natural Fiber ◽  
Coal Ash ◽  
Physical And Mechanical Properties ◽  
Short Fiber ◽  
Pozzolanic Reaction ◽  
Strength Development ◽  
Kenaf Fiber ◽  
Fuel Ash ◽  
Pulverized Fuel

The main objective of the experimental work is to identify the mechanical properties of Kenaf Fiber incorporate with Ordinary Portland Cement (OPC) and Pulverised Fuel Ash (PFA) in the mix proportions of concrete. Kenaf Fibrous Concrete (KFC) and Kenaf Fibrous Pulverised Fuel Ash Concrete (KFPC) will be measured on physical and mechanical properties in order to investigate the suitability of this natural fiber as a composite material. A comparison of properties between these two composites will determine the density, workability, compressive, tensile, and flexural strength of the concrete. Eight different mixes with varying percentage of Kenaf fiber were prepared with 30N/mm2 strength at 28days ,56 days and 90 days. Short fiber with 25mm and 50mm length were randomly distribute in composite to enhance the tensile and durability. PFA was obtained by the process of burning in the Power Station Coal Ash at Tanjung Bin, Johor. The unburning powder from the process is called as a PFA generally suitable for cement replacement in the concrete mix. The pozzolanic reaction will improve the adhesion of cement gel, hence increased the properties of concrete in a long-term strength development. The result shows that the inclusion of Kenaf fiber improve tensile strength of composite, furthermore the 25% PFA mix increase the durability of concrete.

The Research on the Microstructure and Property of Gear with Sinter Powder Material

2010 ◽  
Vol 37-38 ◽  
pp. 1558-1560 ◽  
Author(s):  
Bai Yang Lou ◽  
Fang Liang Dong ◽  
Bin Xu
Keyword(s):  
Powder Material ◽  
Base Material ◽  
Residual Austenite ◽  
Optical Microscope ◽  
Micro Hardness ◽  
Tempered Martensite ◽  
Common Part ◽  
Energy Spectrometer ◽  
Scan Electronic Microscope ◽  
Electronic Microscope

Gear is a widely used common part of machinery, which is of good lubricate property and low materials consumption when it is made of sinter powder material. In this paper, the chemical composition, microstructure and property of sintered gear were investigated with optical microscope, scan electronic microscope, micro hardness meter and X-diffraction energy spectrometer. The results show that the microstructure of the gear includes of tempered martensite, carbide, residual austenite and a small quantity of cavity. The distribution of iron element is even. The copper and nickel distribute unevenly and cover around the surface of carbide in gear material which makes different property of covered layer itself between carbide and base material. The existing of covered layer and weak grain-boundary strength are main reason for gear brittle fracture. The gear’s toughness can be increased by optimizing sintering technology and heat treatment.

Research on Mechanical Properties of C100 High-Strength Concrete Used for Frozen Shaft

2012 ◽  
Vol 598 ◽  
pp. 388-392
Author(s):  
Hong Qiang Chu ◽  
Lin Hua Jiang ◽  
Ning Xu ◽  
Chuan Sheng Xiong
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Fly Ash ◽  
High Strength Concrete ◽  
High Strength ◽  
Cementitious Materials ◽  
Poisson's Ratio ◽  
Strength Concrete ◽  
Tensile Elastic Modulus ◽  
Early Strength

The mechanical properties of C100 high-strength concrete used for frozen shaft were studied in this research. The results demonstrate that: The cementitious materials 570kg/m3 concrete 28 strength is only 104.5MPa, which is lower than the C100 requirements; the early strength (3d) of the concrete doped with 30% admixture is less than 20% admixture concrete, but with the age increase, its strength gradually reaches close to concrete doped with 20% admixture, and eventually exceeds the concrete doped with 20% admixture.The tension-compression of high strength concrete doped with 15% fly ash and 15% slag is the smallest, while the tension-compression of the concrete doped 10% fly ash and 10% slag reaches the maximum.The Poisson's ratio of C100 concrete is between 0.20 and 0.24; the compressive elastic modulus is about 50GPa; and the tensile elastic modulus is about 110GPa.

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