Preparation of Porous HA Bioceramics by Gelcasting and Pressureless Sintering

2011 ◽  
Vol 335-336 ◽  
pp. 1454-1458
Author(s):  
Jing Xian Zhang ◽  
Bi Qin Chen ◽  
Dong Liang Jiang ◽  
Qing Ling Lin ◽  
Zhong Ming Chen ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Pore Size ◽  
Pressureless Sintering ◽  
High Compressive Strength ◽  
Microstructure And Properties ◽  
Pmma Beads ◽  
Average Compressive Strength

In the present work, porous HA scaffolds with well controlled pore size, porosity and high compressive strength were prepared by aqueous gelcasting. PMMA beads with different size were used as the pore forming agent. The compositions, microstructure and properties of porous HA bioceramics were analyzed by XRD, SEM, Hg porosimetry etc. The mechanical properties were also tested. For scaffolds with the porosity as 70%, the average compressive strength was 11.9±1.7 MPa. Results showed that glecasting process can be used for the preparation of porous HA biomaterials with well controlled pore size and improved mechanical properties.

scholarly journals Enhancing Density-Based Mining Waste Alkali-Activated Foamed Materials Incorporating Expanded Cork

CivilEng ◽  
2021 ◽  
Vol 2 (2) ◽  
pp. 523-540
Author(s):  
Imed Beghoura ◽  
Joao Castro-Gomes
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Pore Size ◽  
Physical And Mechanical Properties ◽  
Critical Parameters ◽  
Porous Structures ◽  
Foaming Agent ◽  
Al Powder ◽  
Highly Porous ◽  
Alkali Activated

This study focuses on the development of an alkali-activated lightweight foamed material (AA-LFM) with enhanced density. Several mixes of tungsten waste mud (TWM), grounded waste glass (WG), and metakaolin (MK) were produced. Al powder as a foaming agent was added, varying from 0.009 w.% to 0.05 w.% of precursor weight. Expanded granulated cork (EGC) particles were incorporated (10% to 40% of the total volume of precursors). The physical and mechanical properties of the foamed materials obtained, the effects of the amount of the foaming agent and the percentage of cork particles added varying from 10 vol.% to 40% are presented and discussed. Highly porous structures were obtained, Pore size and cork particles distribution are critical parameters in determining the density and strength of the foams. The compressive strength results with different densities of AA-LFM obtained by modifying the foaming agent and cork particles are also presented and discussed. Mechanical properties of the cured structure are adequate for lightweight prefabricated building elements and components.

scholarly journals PENELITIAN UJI KUAT TEKAN BETON DENGAN MEMANFAATKAN LIMBAH AMPAS TEBU DAN ZAT ADDITIF SIKACIM BONDING ADHESIVE

2019 ◽  
Vol 2 (1) ◽  
pp. 1
Author(s):  
Agil Dwi Krisna ◽  
Sigit Winarto ◽  
Ahmad Ridwan
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Concrete Mixture ◽  
High Compressive Strength ◽  
Compressive Loads ◽  
Average Compressive Strength

Concrete has the disadvantage of having a low tensile strength and convincing brittle beams with steel inscriptions to anticipate. In this study, the concrete mixture was given additional bagasse and additives of cycacim bonding. This addition was carried out to study and study the effect of bagasse on the compressive strength of normal k300 concrete by replacing bagasse by 0%, 5%, 10% and 15% in compressive loads. Compressive strength specimens in the form of cubes with a size of 15 cm x 15 cm x 15 cm. Testing is done after 28 days. Concrete with increased bagasse of 5% is better able to produce high compressive strength values than others. The addition of bagasse resulted in an average compressive strength of 5%, 229.64 kg / cm2, 10%, 190.35 kg / cm2, 15%, 160.87 kg / cm2.Beton mempunyai kelemahan yaitu mempunyai kuat tarik yang rendah dan bersifat getas sehingga beton diberi tulangan baja untuk mengantisipasinya. Pada penelitian ini, campuran beton diberi bahan tambahan ampas tebu dan zat additif sikacim bonding adhesive. Penambahan ini dilakukan untuk mempelajari dan mengetahui pengaruh ampas tebu terhadap kuat tekan pada beton mutu normal k300 dengan penambahan ampas tebu sebesar 0%, 5%, 10% dan 15% pada beban tekan. Benda uji kuat tekan berbentuk kubus dengan ukuran 15 cm x 15 cm x 15 cm. Pengujian dilakukan setelah 28 hari. Beton dengan penambahan ampas tebu 5% lebih mampu menghasilkan nilai kuat tekan tinggi dari pada yang lainya. Penambahan ampas tebu menghasilakan kuat tekan rata-rata yaitu 5%,229,64 kg/cm2, 10%,190,35 kg/cm2, 15%,160,87kg/cm2.

scholarly journals Effect of Filler Type on the Thermo-Mechanical Properties of Metakaolinite-Based Geopolymer Composites

Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2395 ◽  
Author(s):  
Jan Kohout ◽  
Petr Koutník
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Pore Size ◽  
Average Pore Size ◽  
Diffraction Method ◽  
Thermal Exposure ◽  
Total Shrinkage ◽  
Pore Size Distributions ◽  
Geopolymer Composites

Metakaolinite-based geopolymer binder was prepared at room temperature by mixing calcined claystone and potassium alkaline activator. Various granular inorganic fillers were added, amounting to 65 vol % to form geopolymer composites. The effect of four types of fillers (sand quartz, chamotte, cordierite, and corundum) on the thermo-mechanical properties of metakaolinite-based geopolymer composites were investigated. The samples were also examined by an X-ray diffraction method to determine their phase composition. The pore size distributions were determined by a mercury intrusion porosimeter. The XRD revealed the crystallization of new phase (leucite) after thermal exposure at 1000 °C and higher. Geopolymer binders had low mechanical properties (flexural strength 2.5 MPa and compressive strength 45 MPa) and poor thermo-mechanical properties (especially high shrinkage—total shrinkage 9%) compared to geopolymer composites (flexural strength up to 13.8 MPa, compressive strength up to 95 MPa and total shrinkage up to 1%). The addition of fillers reduced the shrinkage of geopolymers and improved their mechanical properties. The results have shown that the compressive strength tested in situ and after exposure to high temperature are in conflict. Geopolymer composites with the addition of chamotte had the best mechanical properties before and after thermal exposure (compressive strength up to 95 MPa). The average pore size diameters increased with the increasing temperature (from 10 nm to approx. 700 nm). The fillers addition decreased the pore volume (from 250 mm3/g to approx. 100 mm3/g).

scholarly journals Effect of Pore Structure on Thermal Conductivity and Mechanical Properties of Autoclaved Aerated Concrete

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 339
Author(s):  
Gonglian Chen ◽  
Fenglan Li ◽  
Pengfei Jing ◽  
Jingya Geng ◽  
Zhengkai Si
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Compressive Strength ◽  
Pore Structure ◽  
Pore Size ◽  
Base Material ◽  
Test Results ◽  
Foam Stabilizer ◽  
Base Materials ◽  
Aerated Concrete

With the premise of investigating mechanical properties, the thermal conductivity of autoclaved aerated concrete (AAC) is a key index of self-insulation block walls for building energy conservation. This study focused on the effect of pore structures on the mechanical performance and thermal conductivity of AAC with the comparison of AAC base materials. Different kinds of AAC and their base materials were prepared and experimentally investigated. While maintaining a consistent mix proportion of the AAC base material, the pore structure of AAC was changed by the dosage of aluminum power/paste, foam stabilizer, and varying the stirring time of aluminum paste. The steam curing systems of AAC and the base material were determined based on SEM (Scanning Electronic Microscopy) and XRD (X-Ray Diffraction) tests. With almost the same apparent density, the pore size decreased with the increasing content of foam stabilizer, and the mixing time of aluminum paste and foam stabilizer has a great influence on pore size. The thermal conductivity test and compressive test results indicated that that pore size had an effect on the thermal conductivity, but it had little effect on the compressive strength, and the thermal conductivity of sand aeration AAC was 8.3% higher than that of fly ash aeration AAC; the compressive strength was 10.4% higher, too. With almost the same apparent density, the regression mathematical model indicates that the thermal conductivity of AAC increased gradually with the increase of pore size, but it had little effect on the compressive strength. From the test results of basic mechanical properties, the mechanical model of cubic compressive strength, elastic modulus, axial compressive strength, and splitting tensile strength was obtained. The proposed stress–strain relationship model could well describe the relationship of AAC and the base material at the rising section of the curve.

VANADIS 23

Alloy Digest ◽  
1997 ◽  
Vol 46 (3) ◽  
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Tool Steel ◽  
Molten Steel ◽  
High Performance ◽  
Heat Treating ◽  
Bend Strength ◽  
High Compressive Strength ◽  
Carbide Particles

Abstract Vanadis 23 is a high-performance tool steel produced from superclean molten steel, which is then atomized to powder. The alloy is characterized by uniformly distributed carbide particles that help in its good mechanical properties, toughness, and bend strength. Vanadis 23 is recommended for mixed-wear (abrasive and adhesive) resistance and high compressive strength. This datasheet provides information on composition, and microstructure. It also includes information on heat treating, machining, and joining. Filing Code: TS-552. Producer or source: Uddeholm Corporation. See also Alloy Digest TS-561, October 1998.

Effect of Freezing Temperature on the Microstructure of Negative Temperature Concrete

2013 ◽  
Vol 663 ◽  
pp. 343-348 ◽  
Author(s):  
Shu Hui Dong ◽  
De Cheng Feng ◽  
Shou Heng Jiang ◽  
Wei Zhong Zhu
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Pore Size ◽  
Standard Condition ◽  
Negative Temperature ◽  
Freezing Temperature ◽  
Curing Temperature ◽  
Original Structure ◽  
Testing Methods ◽  
The Relationship

The pore size distribution and the microstructure of negative temperature concrete was studied with different temperature, combining with some testing methods, such as MIP and SEM. Moreover, the change of the compressive strength was also studied with different ages. In addition, the relationship between the microstructure and the macro-mechanical properties on negative temperature concrete was explored further with different freezing temperature. It indicated that the lower the early curing temperature, the looser the original structure of cement paste; the total volume of gel pore whose pore size was less than 20nm was decreasing apparently, and the compressive strength declined. When changing to standard curing, the pore size trended to be thinner, the compressive strength was increasing sharply. The concrete was cured from -5°C to standard curing, the volume of pore that was less than 200nm was equal to that of the concrete with the standard curing in the age of 28d, so was the compressive strength. However, the volume of the macro pore of the concrete curing under -10°C and -15°C was greater than the concrete curing the standard condition, the compressive strength was less.

scholarly journals The Development of Coir- Concrete Blocks Aslightweight Construction Material

2020 ◽  
Vol 9 (3) ◽  
pp. 924-927
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Construction Material ◽  
Mechanical Tests ◽  
Absorption Characteristic ◽  
Coir Fiber ◽  
Lightweight Construction ◽  
Coir Fibers ◽  
Concrete Blocks ◽  
Average Compressive Strength

This paper presents the research into the incorporation of coir fiber in concrete blocks for construction purposes. Mechanical tests were performed on concrete samples containing different percentages of chopped coir fibers (0.25, 0.50, 0.75 and 1 by weight of aggregates). Density and water absorption characteristic of the samples were also measured and evaluated in relation to the mechanical properties. It was found that the average compressive strength of the blocks is in the range of 5–6 MPa and the average flexural strength is in the range of 1.04–1.47 MPa, which are lower compared to the results of samples without coir. Nevertheless, the compressive strength range of coir- concrete blocks in this study satisfies the requirements of relevant standards (SNI, AS and ASTM), specifically for non-structural or non-load-bearing concrete blocks. Furthermore, the density of the coir-concrete blocks is between 1230–1536 kg/m3 which fit into the category of lightweight blocks. Based on the results, it can therefore be suggested that the development of coir-concrete blocks is feasible for non-structural, non-loadbearing, lightweight construction material.

Effect of Manganese Dioxide on Structure and Compressive Strength of Foam Glass

2014 ◽  
Vol 488-489 ◽  
pp. 94-97
Author(s):  
Long Wu ◽  
Yi Hong Zhao ◽  
Rong Fa Chen ◽  
Hua Yang ◽  
Qing Qing Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Physical Properties ◽  
Pore Size ◽  
Foam Glass ◽  
Xrd Analysis ◽  
Foaming Agent ◽  
Metallurgical Structure ◽  
Xrd Method ◽  
Uniform Pore Size

The MnO2 was used as foaming agent to produce the glass foams in this paper. The macro morphology, physical properties and the metallurgical structure were discussed in detail by the modern means of DTA, SEM and XRD analysis. The results indicated that the less dense and more uniform pore size of foam glass was prepared, and the good mechanical properties were obtained. And the main crystal was quartz, nepheline and albite by the XRD method.

scholarly journals Effects of Reactive MgO on the Reaction Process of Geopolymer

Materials ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 526 ◽  
Author(s):  
Zhaoheng Li ◽  
Wei Zhang ◽  
Ruilan Wang ◽  
Fangzhu Chen ◽  
Xichun Jia ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Pore Size ◽  
Autogenous Shrinkage ◽  
Drying Shrinkage ◽  
Reaction Process ◽  
Chemical Shrinkage ◽  
Uniform Expansion ◽  
Geopolymer Paste

In order to compensate for the shrinkage of geopolymer pastes uniformly, reactive MgO powders are evenly dispersed in the geopolymer. The deformation performance, mechanical properties, microstructure and components of geopolymer pastes with reactive MgO are characterized. The effects of the content and the activity of MgO are discussed. The results indicate that the chemical shrinkage, autogenous shrinkage and drying shrinkage decrease with the addition of reactive MgO. MgO reacted with water, and fine Mg(OH)2 crystals forms as a geopolymer paste. Mg(OH)2 produces uniform expansion, which refines the pore size of pastes and the compressive strength increases. The shrinkage of the geopolymer pastes is thus effectively compensated.

scholarly journals Investigation of the Effect of Freeze-thaw Cycles on the Mechanical Properties of Hardened Self-compacting Concrete

2020 ◽  
Author(s):  
Tuncay Kap
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Statistical Analysis ◽  
Fresh Concrete ◽  
The Other ◽  
Unit Weight ◽  
Self Compacting Concrete ◽  
Freeze Thaw ◽  
The Core ◽  
Average Compressive Strength

This study investigated the effects of freeze-thaw cycles on the mechanical properties of hardened self-compacting concrete for varying column heights. A column (100×20×300 cm) was fabricated by C30 self-compacting concrete in the laboratory and 10 cube samples (10x10x10 cm) were taken from fresh concrete as the references. After a period of 28 days, 160 core specimens (Ø67 mm in diameter) were taken from different column heights. Unit weight, water absorption, compressive strength, and freeze-thaw tests were performed on these 170 (10 reference cubic and 160 core) samples. The mechanical properties of the core specimens before freeze-thaw and after 8-56 freeze-thaw cycles were reported for varying column heights. The average compressive strength value of the reference cubic samples was determined as 40.28 MPa, while the compressive strengths of the core specimens before freeze-thaw were ranged from 40.25 MPa to 49.62 MPa, impying an increase in compressive strength values up to 23.18% compared to the reference cubic samples. Compressive strengths of the specimens subjected to 8 and 56 freeze-thaw cycles varied between 38.71‒48.07 MPa and 31.72‒39.11 MPa, respectively. Statistical analysis revealed that the compressive strength of the concrete exposed to 56 freeze-thaw cycles was significantly different from that of the other specimens.

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