Displaying publications 1 - 20 of 138 in total

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  1. Gan CY, Cheng LH, Azahari B, Easa AM
    Int J Food Sci Nutr, 2009;60 Suppl 7:99-108.
    PMID: 19194813 DOI: 10.1080/09637480802635090
    Cross-linked soy protein isolate (SPI) gels were produced via single-treatment of SPI with microbial transglutaminase (MTG) for 5 h or 24 h, or with ribose for 2 h, or via combined-treatments of SPI with MTG followed by heating with ribose. Assessment of gel strength and solubility concluded that measures which increased protein cross-links resulted in improved gel strength; however, in most cases the digestibility and amino acid content of the gels were reduced. The combined treated gel of SPI/MTG for 24 h/ribose was more easily digested by digestive enzymes and retained higher amounts of amino acids compared with the control Maillard gels of SPI with ribose. MTG consumed lysine and glutamine and reduced the availability of amino acids for the Maillard reaction with ribose. MTG was able to preserve the nutritional value of SPI against the destructive effect of the Maillard reaction and cross-links.
    Matched MeSH terms: Compressive Strength
  2. Mohd Fuad D, Masbah O, Shahril Y, Jamari S, Norhamdan MY, Sahrim SH
    Med J Malaysia, 2006 Feb;61 Suppl A:27-9.
    PMID: 17042225
    Antibiotic-loaded bone cement has been used as prophylaxis against infection in total joint replacement surgery. Its effect on the mechanical strength of cement is a major concern as high dose of antibiotic was associated with a significant reduction in mechanical strength of bone cement. However, the cut-off antibiotic that weakens the mechanical strength of cement remains to be determined. This study was undertaken to observe the changes in the mechanical properties of bone cement with gradual increments of Cefuroxime antibiotic. Cefuroxime at different doses: 0, 1.5, 3.0 and 4.5gm were added to a packet of 40gm bone cement (Simplex P) and study samples were prepared by using third generation cementing technique. Mechanical impact, flexural and tensile strength were tested on each sample. Significant impact and tensile strength reduction were observed after addition of 4.5 gm of Cefuroxime. However, flexural strength was significantly reduced at a lower dose of 3.0 gm. The maximum dose of Cefuroxime to be safely added to 40mg Surgical Simplex P is 1.5gm when third generation cementing technique is used. Further study is needed to determine whether it is an effective dose as regards to microbiological parameters.
    Matched MeSH terms: Compressive Strength
  3. Bakhsheshi-Rad HR, Ismail AF, Aziz M, Akbari M, Hadisi Z, Khoshnava SM, et al.
    Mater Sci Eng C Mater Biol Appl, 2020 Jun;111:110812.
    PMID: 32279830 DOI: 10.1016/j.msec.2020.110812
    Magnesium (Mg) alloys present great potential for the development of orthopedic implants, whereas, their high degradation rate and poor antibacterial performance have restricted orthopedic applications. In this work, PLLA/GO-AgNP (poly-L-lactic acid/graphene oxide- silver nanoparticle) with different concentration of GO-AgNPs were deposited on Mg alloy via electrospinning method for enhancement of corrosion resistance and antibacterial performance. The result revealed that incorporation of GO into PLLA fibrous considerably slowed down the degradation rate of Mg alloy substrate and reduced the H2 release rate from the substrate. Also, co-incorporation of GO and AgNPs into PLLA fibrous resulted in substantial escalate in compressive strength after immersion in simulated body fluid (SBF). Antibacterial activity test exhibited that Mg alloy and neat PLLA fibrous presented minimal inhibition area toward Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). In contrast, using PLLA/GO-AgNPs fibrous improved antibacterial performance against both bacteria. Cytocompatibility results indicated that PLLA/GO-AgNPs fibrous with a low amount of GO-AgNPs enhanced cell proliferation and growth while high co-incorporation of GO-AgNPs showed a negative effect on cell proliferation. Taken together, PLLA/1GO-AgNPs fibrous coating shows suitable corrosion resistance, cytocompatibility, and antibacterial function for use in orthopedic applications.
    Matched MeSH terms: Compressive Strength
  4. Khalajabadi SZ, Abu ABH, Ahmad N, Yajid MAM, Hj Redzuan NB, Nasiri R, et al.
    J Mech Behav Biomed Mater, 2018 Jan;77:360-374.
    PMID: 28985616 DOI: 10.1016/j.jmbbm.2017.09.032
    This study was aimed to improve of the corrosion resistance and mechanical properties of Mg/15TiO2/5HA nanocomposite by silicon and magnesium oxide coatings prepared using a powder metallurgy method. The phase evolution, chemical composition, microstructure and mechanical properties of uncoated and coated samples were characterized. Electrochemical and immersion tests used to investigate the in vitro corrosion behavior of the fabricated samples. The adhesion strength of ~36MPa for MgO and ~32MPa for Si/MgO coatings to substrate was measured by adhesion test. Fabrication a homogenous double layer coating with uniform thicknesses consisting micro-sized particles of Si as outer layer and flake-like particles of MgO as the inner layer on the surface of Mg/15TiO2/5HA nanocomposite caused the corrosion resistance and ductility increased whereas the ultimate compressive stress decreased. However, after immersion in SBF solution, Si/MgO-coated sample indicates the best mechanical properties compared to those of the uncoated and MgO-coated samples. The increase of cell viability percentage of the normal human osteoblast (NHOst) cells indicates the improvement in biocompatibility of Mg/15TiO2/5HA nanocomposite by Si/MgO coating.
    Matched MeSH terms: Compressive Strength
  5. Bharatham BH, Abu Bakar MZ, Perimal EK, Yusof LM, Hamid M
    Biomed Res Int, 2014;2014:146723.
    PMID: 25110655 DOI: 10.1155/2014/146723
    A novel porous three-dimensional bone scaffold was developed using a natural polymer (alginate/Alg) in combination with a naturally obtained biomineral (nano cockle shell powder/nCP) through lyophilization techniques. The scaffold was developed in varying composition mixture of Alg-nCP and characterized using various evaluation techniques as well as preliminary in vitro studies on MG63 human osteoblast cells. Morphological observations using SEM revealed variations in structures with the use of different Alg-nCP composition ratios. All the developed scaffolds showed a porous structure with pore sizes ideal for facilitating new bone growth; however, not all combination mixtures showed subsequent favorable characteristics to be used for biological applications. Scaffolds produced using the combination mixture of 40% Alg and 60% nCP produced significantly promising results in terms of mechanical strength, degradation rate, and increased cell proliferation rates making it potentially the optimum composition mixture of Alg-nCP with future application prospects.
    Matched MeSH terms: Compressive Strength
  6. Askari E, Mehrali M, Metselaar IH, Kadri NA, Rahman MM
    J Mech Behav Biomed Mater, 2012 Aug;12:144-50.
    PMID: 22732480 DOI: 10.1016/j.jmbbm.2012.02.029
    This study describes the synthesis of Al(2)O(3)/SiC/ZrO(2) functionally graded material (FGM) in bio-implants (artificial joints) by electrophoretic deposition (EPD). A suitable suspension that was based on 2-butanone was applied for the EPD of Al(2)O(3)/SiC/ZrO(2), and a pressureless sintering process was applied as a presintering. Hot isostatic pressing (HIP) was used to densify the deposit, with beneficial mechanical properties after 2 h at 1800 °C in Ar atmosphere. The maximum hardness in the outer layer (90 vol.% Al(2)O(3)+10 vol.% SiC) and maximum fracture toughness in the core layer (75 vol.% Al(2)O(3)+10 vol.% SiC + 15 vol.% ZrO(2)) composite were 20.8±0.3 GPa and 8±0.1 MPa m(1/2), respectively. The results, when compared with results from Al(2)O(3)/ZrO(2) FGM, showed that SiC increased the compressive stresses in the outer layers, while the inner layers were under a residual tensile stress.
    Matched MeSH terms: Compressive Strength
  7. Chew KK, Low KL, Sharif Zein SH, McPhail DS, Gerhardt LC, Roether JA, et al.
    J Mech Behav Biomed Mater, 2011 Apr;4(3):331-9.
    PMID: 21316621 DOI: 10.1016/j.jmbbm.2010.10.013
    This paper presents the development of novel alternative injectable calcium phosphate cement (CPC) composites for orthopaedic applications. The new CPC composites comprise β-tri-calcium phosphate (β-TCP) and di-calcium phosphate anhydrous (DCPA) mixed with bovine serum albumin (BSA) and incorporated with multi-walled carbon nanotubes (MWCNTs) or functionalized MWCNTs (MWCNTs-OH and MWCNTs-COOH). Scanning electron microscopy (SEM), compressive strength tests, injectability tests, Fourier transform infrared spectroscopy and X-ray diffraction were used to evaluate the properties of the final products. Compressive strength tests and SEM observations demonstrated particularly that the concomitant admixture of BSA and MWCNT improved the mechanical properties, resulting in stronger CPC composites. The presence of MWCNTs and BSA influenced the morphology of the hydroxyapatite (HA) crystals in the CPC matrix. BSA was found to act as a promoter of HA growth when bounded to the surface of CPC grains. MWCNT-OH-containing composites exhibited the highest compressive strengths (16.3 MPa), being in the range of values for trabecular bone (2-12 MPa).
    Matched MeSH terms: Compressive Strength
  8. Asadi-Eydivand M, Solati-Hashjin M, Shafiei SS, Mohammadi S, Hafezi M, Abu Osman NA
    PLoS One, 2016;11(3):e0151216.
    PMID: 26999789 DOI: 10.1371/journal.pone.0151216
    The ability of inkjet-based 3D printing (3DP) to fabricate biocompatible ceramics has made it one of the most favorable techniques to generate bone tissue engineering (BTE) scaffolds. Calcium sulfates exhibit various beneficial characteristics, and they can be used as a promising biomaterial in BTE. However, low mechanical performance caused by the brittle character of ceramic materials is the main weakness of 3DP calcium sulfate scaffolds. Moreover, the presence of certain organic matters in the starting powder and binder solution causes products to have high toxicity levels. A post-processing treatment is usually employed to improve the physical, chemical, and biological behaviors of the printed scaffolds. In this study, the effects of heat treatment on the structural, mechanical, and physical characteristics of 3DP calcium sulfate prototypes were investigated. Different microscopy and spectroscopy methods were employed to characterize the printed prototypes. The in vitro cytotoxicity of the specimens was also evaluated before and after heat treatment. Results showed that the as-printed scaffolds and specimens heat treated at 300°C exhibited severe toxicity in vitro but had almost adequate strength. By contrast, the specimens heat treated in the 500°C-1000°C temperature range, although non-toxic, had insufficient mechanical strength, which was mainly attributed to the exit of the organic binder before 500°C and the absence of sufficient densification below 1000°C. The sintering process was accelerated at temperatures higher than 1000°C, resulting in higher compressive strength and less cytotoxicity. An anhydrous form of calcium sulfate was the only crystalline phase existing in the samples heated at 500°C-1150°C. The formation of calcium oxide caused by partial decomposition of calcium sulfate was observed in the specimens heat treated at temperatures higher than 1200°C. Although considerable improvements in cell viability of heat-treated scaffolds were observed in this study, the mechanical properties were not significantly improved, requiring further investigations. However, the findings of this study give a better insight into the complex nature of the problem in the fabrication of synthetic bone grafts and scaffolds via post-fabrication treatment of 3DP calcium sulfate prototypes.
    Matched MeSH terms: Compressive Strength
  9. Boukari Y, Scurr DJ, Qutachi O, Morris AP, Doughty SW, Rahman CV, et al.
    J Biomater Sci Polym Ed, 2015;26(12):796-811.
    PMID: 26065672 DOI: 10.1080/09205063.2015.1058696
    An injectable poly(DL-lactic-co-glycolic acid) (PLGA) system comprising both porous and protein-loaded microspheres capable of forming porous scaffolds at body temperature was developed for tissue regeneration purposes. Porous and non-porous (lysozyme loaded) PLGA microspheres were formulated to represent 'low molecular weight' 22-34 kDa, 'intermediate molecular weight' (IMW) 53 kDa and 'high molecular weight' 84-109 kDa PLGA microspheres. The respective average size of the microspheres was directly related to the polymer molecular weight. An initial burst release of lysozyme was observed from both microspheres and scaffolds on day 1. In the case of the lysozyme-loaded microspheres, this burst release was inversely related to the polymer molecular weight. Similarly, scaffolds loaded with 1 mg lysozyme/g of scaffold exhibited an inverse release relationship with polymer molecular weight. The burst release was highest amongst IMW scaffolds loaded with 2 and 3 mg/g. Sustained lysozyme release was observed after day 1 over 50 days (microspheres) and 30 days (scaffolds). The compressive strengths of the scaffolds were found to be inversely proportional to PLGA molecular weight at each lysozyme loading. Surface analysis indicated that some of the loaded lysozyme was distributed on the surfaces of the microspheres and thus responsible for the burst release observed. Overall the data demonstrates the potential of the scaffolds for use in tissue regeneration.
    Matched MeSH terms: Compressive Strength
  10. Mehboob H, Tarlochan F, Mehboob A, Chang SH, Ramesh S, Harun WSW, et al.
    J Mater Sci Mater Med, 2020 Aug 20;31(9):78.
    PMID: 32816091 DOI: 10.1007/s10856-020-06420-7
    The current study is proposing a design envelope for porous Ti-6Al-4V alloy femoral stems to survive under fatigue loads. Numerical computational analysis of these stems with a body-centered-cube (BCC) structure is conducted in ABAQUS. Femoral stems without shell and with various outer dense shell thicknesses (0.5, 1.0, 1.5, and 2 mm) and inner cores (porosities of 90, 77, 63, 47, 30, and 18%) are analyzed. A design space (envelope) is derived by using stem stiffnesses close to that of the femur bone, maximum fatigue stresses of 0.3σys in the porous part, and endurance limits of the dense part of the stems. The Soderberg approach is successfully employed to compute the factor of safety Nf > 1.1. Fully porous stems without dense shells are concluded to fail under fatigue load. It is thus safe to use the porous stems with a shell thickness of 1.5 and 2 mm for all porosities (18-90%), 1 mm shell with 18 and 30% porosities, and 0.5 mm shell with 18% porosity. The reduction in stress shielding was achieved by 28%. Porous stems incorporated BCC structures with dense shells and beads were successfully printed.
    Matched MeSH terms: Compressive Strength
  11. Al-Namnam NM, Kutty MG, Chai WL, Ha KO, Kim KH, Siar CH, et al.
    Mater Sci Eng C Mater Biol Appl, 2017 Mar 01;72:332-340.
    PMID: 28024594 DOI: 10.1016/j.msec.2016.11.086
    Recently, a modified form of a three-dimension (3D) porous poly(caprolactone-trifumarate) (PCLTF) scaffold has been produced using a fabrication technique that involves gelatin microparticles porogen leaching. This poly(caprolactone trifumarate-gelatin microparticles) (PCLTF-GMPs) scaffold has been shown to be biocompatible, more flowable clinically, and has a shorter degradation time as compared to its existing predecessors. In this report, a detailed characterization of this new scaffold was performed by testing its cytocompatibility, analyzing the surface topography, and understanding its thermal, physical and mechanical properties. The result showed that the PCLTF-GMPs has no critical cytotoxic effect. To confirm improvement, the surface properties were compared against the older version of PCLTF fabricated using salt porogen leaching. This PCLTF-GMPs scaffold showed no significant difference (unpaired t-test; p>0.05) in mechanical properties before and after gelatin leaching. However, it is mechanically weaker when compared to its predecessors. It has a high biodegradability rate of 16weeks. The pore size produced ranges from 40 to 300μm, and the RMS roughness is 613.7±236.9nm. These characteristics are condusive for osteoblast in-growth, as observed by the extension of filopodia across the macropores. Overall, this newly produced material has good thermal, physical and mechanical properties that complements its biocompatibility and ease of use.
    Matched MeSH terms: Compressive Strength
  12. Krishnamurithy G, Mohan S, Yahya NA, Mansor A, Murali MR, Raghavendran HRB, et al.
    PLoS One, 2019;14(3):e0214212.
    PMID: 30917166 DOI: 10.1371/journal.pone.0214212
    It has been demonstrated that nanocrystalline forsterite powder synthesised using urea as a fuel in sol-gel combustion method had produced a pure forsterite (FU) and possessed superior bioactive characteristics such as bone apatite formation and antibacterial properties. In the present study, 3D-scaffold was fabricated using nanocrystalline forsterite powder in polymer sponge method. The FU scaffold was used in investigating the physicochemical, biomechanics, cell attachment, in vitro biocompatibility and osteogenic differentiation properties. For physicochemical characterisation, Fourier-transform infrared spectroscopy (FTIR), Energy dispersive X-ray (EDX), X-ray diffraction (XRD), Raman spectroscopy, X-ray photoemission spectrometer (XPS) and Brunauer-Emmett-Teller (BET) were used. FTIR, EDX, XRD peaks and Raman spectroscopy demonstrated correlating to FU. The XPS confirmed the surface chemistry associating to FU. The BET revealed FU scaffold surface area of 12.67 m2/g and total pore size of 0.03 cm3/g. Compressive strength of the FU scaffold was found to be 27.18 ± 13.4 MPa. The human bone marrow derived mesenchymal stromal cells (hBMSCs) characterisation prior to perform seeding on FU scaffold verified the stromal cell phenotypic and lineage commitments. SEM, confocal images and presto blue viability assay suggested good cell attachment and proliferation of hBMSCs on FU scaffold and comparable to a commercial bone substitutes (cBS). Osteogenic proteins and gene expression from day 7 onward indicated FU scaffold had a significant osteogenic potential (p<0.05), when compared with day 1 as well as between FU and cBS. These findings suggest that FU scaffold has a greater potential for use in orthopaedic and/or orthodontic applications.
    Matched MeSH terms: Compressive Strength
  13. Yusoff N, Abu Osman NA, Pingguan-Murphy B
    Med Eng Phys, 2011 Jul;33(6):782-8.
    PMID: 21356602 DOI: 10.1016/j.medengphy.2011.01.013
    A mechanical-conditioning bioreactor has been developed to provide bi-axial loading to three-dimensional (3D) tissue constructs within a highly controlled environment. The computer-controlled bioreactor is capable of applying axial compressive and shear deformations, individually or simultaneously at various regimes of strain and frequency. The reliability and reproducibility of the system were verified through validation of the spatial and temporal accuracy of platen movement, which was maintained over the operating length of the system. In the presence of actual specimens, the system was verified to be able to deliver precise bi-axial load to the specimens, in which the deformation of every specimen was observed to be relatively homogeneous. The primary use of the bioreactor is in the culture of chondrocytes seeded within an agarose hydrogel while subjected to physiological compressive and shear deformation. The system has been designed specifically to permit the repeatable quantification and characterisation of the biosynthetic activity of cells in response to a wide range of short and long term multi-dimensional loading regimes.
    Matched MeSH terms: Compressive Strength
  14. Bajuri MN, Kadir MR, Amin IM, Ochsner A
    Proc Inst Mech Eng H, 2012 Jul;226(7):510-20.
    PMID: 22913098 DOI: 10.1177/0954411912445846
    The wrist is the most complex joint for virtual three-dimensional simulations, and the complexity is even more pronounced when dealing with skeletal disorders of the joint such, as rheumatoid arthritis (RA). In order to analyse the biomechanical difference between healthy and diseased joints, three-dimensional models of these two wrist conditions were developed from computed tomography images. These images consist of eight carpal bones, five metacarpal bones, the distal radius and ulna. The cartilages were developed based on the shape of the available articulations and ligaments were simulated via mechanical links. The RA model was developed accurately by simulating all ten common criteria of the disease related to the wrist. Results from the finite element (FE) analyses showed that the RA model produced three times higher contact pressure at the articulations compared to the healthy model. Normal physiological load transfer also changed from predominantly through the radial side to an increased load transfer approximately 5% towards the ulnar. Based on an extensive literature search, this is the first ever reported work that simulates the pathological conditions of the rheumatoid arthritis of the wrist joint.
    Matched MeSH terms: Compressive Strength
  15. Singh DK, Bailey M, Lee RY
    Clin Biomech (Bristol, Avon), 2011 Jul;26(6):543-7.
    PMID: 21392870 DOI: 10.1016/j.clinbiomech.2011.02.002
    Ageing is associated with geometrical changes in muscle fascicles that may lead to deteriorations in physical functions. The purpose of this study was to study the effects of ageing on fibre orientation and strength of the lumbar extensor muscles.
    Matched MeSH terms: Compressive Strength
  16. Razak HA, Naganathan S, Hamid SN
    J Hazard Mater, 2009 Dec 30;172(2-3):862-7.
    PMID: 19665294 DOI: 10.1016/j.jhazmat.2009.07.070
    Controlled low-strength material (CLSM) is slurry made by mixing sand, cement, ash, and water. It is primarily used as a replacement for soil and structural fillings. This paper presents the findings of a preliminary investigation carried out on the performance of industrial waste incineration bottom ash as CLSM. CLSM mixes were designed using industrial waste incineration bottom ash, and cement. Tests for density, setting time, bleed, and compressive strength on cubes under various curing conditions, corrosivity, and leaching of heavy metals and salts were carried out on the CLSM mixtures, and the results discussed. Compressive strength for the designed CLSM mixtures ranged from 0.1 to 1.7 MPa. It is shown that the variations in curing conditions have less influence on the compressive strength of CLSM at high values of water to cement ratio (w/c), but low values of w/c influences the strength of CLSM. The CLSM produced does not exhibit corrosive characters as evidenced by pH. Leaching of heavy metals and salts is higher in bleed than in leachate collected from hardened CLSM. Cement reduces the leaching of Boron in bleed. It is concluded that there is good potential for the use of industrial waste incineration bottom ash in CLSM.
    Matched MeSH terms: Compressive Strength
  17. Lee SY, Pereira BP, Yusof N, Selvaratnam L, Yu Z, Abbas AA, et al.
    Acta Biomater, 2009 Jul;5(6):1919-25.
    PMID: 19289306 DOI: 10.1016/j.actbio.2009.02.014
    A poly(vinyl alcohol) (PVA) hydrogel composite scaffold containing N,O-carboxymethylated chitosan (NOCC) was tested to assess its potential as a scaffold for cartilage tissue engineering in a weight-bearing environment. The mechanical properties under unconfined compression for different hydration periods were investigated. The effect of supplementing PVA with NOCC (20wt.% PVA:5vol.% NOCC) produced a porosity of 43.3% and this was compared against a non-porous PVA hydrogel (20g PVA: 100ml of water, control). Under non-hydrated conditions, the porous PVA-NOCC hydrogel behaved in a similar way to the control non-porous PVA hydrogel, with similar non-linear stress-strain response under unconfined compression (0-30% strain). After 7days' hydration, the porous hydrogel demonstrated a reduced stiffness (0.002kPa, at 25% strain), resulting in a more linear stiffness relationship over a range of 0-30% strain. Poisson's ratio for the hydrated non-porous and porous hydrogels ranged between 0.73 and 1.18, and 0.76 and 1.33, respectively, suggesting a greater fluid flow when loaded. The stress relaxation function for the porous hydrogel was affected by the hydration period (from 0 to 600s); however the percentage stress relaxation regained by about 95%, after 1200s for all hydration periods assessed. No significant differences were found between the different hydration periods between the porous hydrogels and control. The calculated aggregate modulus, H(A), for the porous hydrogel reduced drastically from 10.99kPa in its non-hydrated state to about 0.001kPa after 7days' hydration, with the calculated shear modulus reducing from 30.92 to 0.14kPa, respectively. The porous PVA-NOCC hydrogel conformed to a biphasic, viscoelastic model, which has the desired properties required for any scaffold in cartilage tissue engineering.
    Matched MeSH terms: Compressive Strength
  18. Al-Makramani BM, Razak AA, Abu-Hassan MI
    J Contemp Dent Pract, 2008;9(2):33-40.
    PMID: 18264523
    The objective of this study is to investigate the effect of different luting agents on the fracture strength of Turkom-Cera all-ceramic copings.
    Matched MeSH terms: Compressive Strength
  19. Sopyan I
    Med J Malaysia, 2008 Jul;63 Suppl A:14-5.
    PMID: 19024961
    Porous calcium phosphate ceramics have found enormous use in biomedical applications including bone tissue regeneration, cell proliferation, and drug delivery. In bone tissue engineering it has been applied as filling material for bone defects and augmentation, artificial bone graft material, and prosthesis revision surgery. Their high surface area leads to excellent osteoconductivity and resorbability providing fast bone ingrowths. Porous calcium phosphate can be produced by a variety of methods. This paper discusses briefly fundamental aspects of porous calcium phosphate for biomedical applications as well as various techniques used to prepare porous calcium phosphate.
    Matched MeSH terms: Compressive Strength
  20. Chandara C, Azizli KA, Ahmad ZA, Sakai E
    Waste Manag, 2009 May;29(5):1675-9.
    PMID: 19131236 DOI: 10.1016/j.wasman.2008.11.014
    The present study is focused on clarifying the influence of waste gypsum (WG) in replacing natural gypsum (NG) in the production of ordinary Portland cement (OPC). WG taken from slip casting moulds in a ceramic factory was formed from the hydration of plaster of paris. Clinker and 3-5wt% of WG was ground in a laboratory ball mill to produce cement waste gypsum (CMWG). The same procedure was repeated with NG to substitute WG to prepare cement natural gypsum (CMNG). The properties of NG and WG were investigated via X-ray Diffraction (XRD), X-ray fluorescence (XRF) and differential scanning calorimetry (DSC)/thermogravimetric (TG) to evaluate the properties of CMNG and CMWG. The mechanical properties of cement were tested in terms of setting time, flexural and compressive strength. The XRD result of NG revealed the presence of dihydrate while WG contained dihydrate and hemihydrate. The content of dihydrate and hemihydrates were obtained via DSC/TG, and the results showed that WG and NG contained 12.45% and 1.61% of hemihydrate, respectively. Furthermore, CMWG was found to set faster than CMNG, an average of 15.29% and 13.67% faster for the initial and final setting times, respectively. This was due to the presence of hemihydrate in WG. However, the values obtained for flexural and compressive strength were relatively the same for CMNG and CMWG. Therefore, this result provides evidence that WG can be used as an alternative material to NG in the production of OPC.
    Matched MeSH terms: Compressive Strength
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