Researchershttp://dspace.unimap.edu.my:80/xmlui/handle/123456789/116792024-03-29T06:00:10Z2024-03-29T06:00:10ZSynthesis of sodium silicate from rice husk ash as an activator to produce epoxy-geopolymer cementL. HandayaniS. ApriliaAbdullahC. RahmawatiMohd Mustafa Al Bakri, AbdullahIkmal Hakem, AzizEmy Aizat, Azimihttp://dspace.unimap.edu.my:80/xmlui/handle/123456789/748702022-03-30T07:49:05Z2021-03-01T00:00:00ZSynthesis of sodium silicate from rice husk ash as an activator to produce epoxy-geopolymer cement
L. Handayani; S. Aprilia; Abdullah; C. Rahmawati; Mohd Mustafa Al Bakri, Abdullah; Ikmal Hakem, Aziz; Emy Aizat, Azimi
Rice husk ash (RHA), a byproduct of the rice industry, is the primary source of amorphous silica for producing sodium silicate solutions to replace standard commercial sodium silicate in geopolymer mixture design. The effect of various concentrations of NaOH used as an activator to produce epoxy-geopolymer cement was studied. Three initial concentrations of NaOH were used (8, 10, and 12M) to examine the optimum dissolution and formation of silica oligomers that can function as the activator during the geopolymerization. The result indicated the increase of NaOH concentration raises the silica yield strength. The silica yield found was 65.84%, 70.53% and 72.06% on NaOH use of 8, 10, 12 M, respectively. IR-spectra results showed silica functional groups and the sodium silicate were successfully synthesized. The IR spectra indicated the appearance of hydroxyl bonds, which strengthen the geopolymer matrix. SEM results showed the C-S-H and N-A-S-H bonds in the geopolymer. With 10M NaOH, the compressive strength of the geopolymer cement paste was optimal at 27.53 MPa. Thus, Rice husk ash (RHA) is feasible to be used as an activator in high calcium fly ash-based epoxy geopolymer cement
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2021-03-01T00:00:00ZThe effects of various concentrations of NaOH on the inter-particle gelation of a fly ash geopolymer aggregateAlida, AbdullahKamarudin, HussinMohd Mustafa Al Bakri, AbdullahZarina, YahyaSochacki, WojciechRafiza, Abd RazakBłoch, KatarzynaHamzah, Fansurihttp://dspace.unimap.edu.my:80/xmlui/handle/123456789/747602022-03-23T01:46:49Z2021-02-01T00:00:00ZThe effects of various concentrations of NaOH on the inter-particle gelation of a fly ash geopolymer aggregate
Alida, Abdullah; Kamarudin, Hussin; Mohd Mustafa Al Bakri, Abdullah; Zarina, Yahya; Sochacki, Wojciech; Rafiza, Abd Razak; Błoch, Katarzyna; Hamzah, Fansuri
Aggregates can be categorized into natural and artificial aggregates. Preserving natural resources is crucial to ensuring the constant supply of natural aggregates. In order to preserve these natural resources, the production of artificial aggregates is beginning to gain the attention of researchers worldwide. One of the methods involves using geopolymer technology. On this basis, this current research focuses on the inter-particle effect on the properties of fly ash geopolymer aggregates with different molarities of sodium hydroxide (NaOH). The effects of synthesis parameters (6, 8, 10, 12, and 14 M) on the mechanical and microstructural properties of the fly ash geopolymer aggregate were studied. The fly ash geopolymer aggregate was palletized manually by using a hand to form a sphere-shaped aggregate where the ratio of NaOH/Na2SiO3 used was constant at 2.5. The results indicated that the NaOH molarity has a significant effect on the impact strength of a fly ash geopolymer aggregate. The highest aggregate impact value (AIV) was obtained for samples with 6 M NaOH molarity (26.95%), indicating the lowest strength among other molarities studied and the lowest density of 2150 kg/m3. The low concentration of sodium hydroxide in the alkali activator solution resulted in the dissolution of fly ash being limited; thus, the inter-particle volume cannot be fully filled by the precipitated gels.
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2021-02-01T00:00:00ZOptimizing of the cementitious composite matrix by addition of steel wool fibers (chopped) based on physical and mechanical analysisAkrm A Rmdan, AmerMohd Mustafa Al Bakri, AbdullahLiew, Yun-MingIkmal Hakem, AzizWysłocki, Jerzy J.Muhammad Faheem, Mohd TahirSochacki, WojciechGarus, SebastianGondro, JoannaHetham A, . R. Amerhttp://dspace.unimap.edu.my:80/xmlui/handle/123456789/747592022-03-23T01:42:04Z2021-02-01T00:00:00ZOptimizing of the cementitious composite matrix by addition of steel wool fibers (chopped) based on physical and mechanical analysis
Akrm A Rmdan, Amer; Mohd Mustafa Al Bakri, Abdullah; Liew, Yun-Ming; Ikmal Hakem, Aziz; Wysłocki, Jerzy J.; Muhammad Faheem, Mohd Tahir; Sochacki, Wojciech; Garus, Sebastian; Gondro, Joanna; Hetham A, . R. Amer
The demand for durable, resistant, and high-strength structural material has led to the use of fibers as reinforcing elements. This paper presents an investigation into the inclusion of chopped steel wool fibers (CSWFs) in cement to form a high-flexural strength cementitious composite matrix (CCM). CSWFs were used as the primary reinforcement in CCM at increments of 0.5 wt%, from 0.5–6 wt%, with ratios of cement to sand of 1:1.5 and water to cement of 0.45. The inclusion of CSWFs resulted in an excellent optimization of the physicomechanical properties of the CCM, such as its density (2.302 g/cm3), compressive strength (61.452 MPa), and maximum flexural strength (10.64 MPa), all of which exceeded the performances of other reinforcement elements reported in the literature.
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2021-02-01T00:00:00ZThe effect of thermal annealing on the microstructure and mechanical properties of Sn-0.7Cu-xZn solder jointMohd Izrul Izwan, RamliMohd Arif Anuar, Mohd SallehRita, Mohd SaidMohd Mustafa Al Bakri, AbdullahDewi Suriyani, Che HalinNorainiza, SaudNabiałek, Marcinhttp://dspace.unimap.edu.my:80/xmlui/handle/123456789/747582022-03-23T01:38:19Z2021-02-01T00:00:00ZThe effect of thermal annealing on the microstructure and mechanical properties of Sn-0.7Cu-xZn solder joint
Mohd Izrul Izwan, Ramli; Mohd Arif Anuar, Mohd Salleh; Rita, Mohd Said; Mohd Mustafa Al Bakri, Abdullah; Dewi Suriyani, Che Halin; Norainiza, Saud; Nabiałek, Marcin
The microstructural properties of a Pb-free solder joint significantly affect its mechanical behaviours. This paper details a systematic study of the effect of the annealing process on the microstructure and shear strength of a Zn-added Sn-0.7Cu solder joint. The results indicated that the IMC layer’s thickness at the solder/Cu interface increases with annealing time. The interfacial IMC layer of the Sn-0.7Cu solder joint gradually thickened with increasing annealing time and annealing temperature, while the interfacial IMC layer’s morphology changed from scallop-type to layer-type after the annealing process. However, the addition of 1.0 wt.% and 1.5 wt.% Zn in the Sn-0.7Cu effectively altered the interfacial IMC phase to Cu-Zn and suppressed the growth of Cu3Sn during the annealing process. The single-lap shear tests results confirmed that the addition of Zn decreased the shear strength of Sn-0.7Cu. The interfacial IMC of the Cu6Sn5 phase in Sn-0.7Cu changed to Cu-Zn due to the addition of Zn. The shear fractures in the annealed solder joint were ductile within the bulk solder instead of the interfacial IMC layer. Increased annealing time resulted in the increased presence of the Cu-Zn phase, which decreased the hardness and shear strength of the Sn-0.7Cu solder joint
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2021-02-01T00:00:00Z