Alida Abdullah

Study on Physical and Chemical Properties of Fly Ash from Different Area in Malaysia

Fly ash is residue from the combustion of coal which widely available in worldwide and lead to waste management proposal. Moreover, the use of fly ash is more environmental friendly and save cost compared to OPC. Fly ash mostly consists of silicon dioxide (SiO2), aluminium oxide (Al2O3) and iron oxide (Fe2O3). The chemical compositions of the sample have been examined according to ASTM C618. Different sources of fly ash may result in different chemical composition. The fly ash is mainly an amorphous material with the presents of crystalline phase of quartz and mullite. Fly ash consists of mostly glassy, hollow and spherical particles.

New Processing Method of Kaolin-Based Geopolymer Brick by Using Geopolymer Brick Machine

With increased activity in construction, deficiency of building materials and construction waste improvements have encouraged the development of new building materials. Conventional construction bricks are usually made from clay and sand, which are mixed and molded in various method and need to be dried and burned. Geopolymer bricks making process consume less energy and low cost in term of production compared to conventional bricks. The development of geopolymer brick is an important step towards produce bricks with better performance and environmental friendly material This research focusing on the processing process of the clay-based geopolymer brick from the mixing until the curing by using a geopolymer brick making machine.

Study on the Properties of Oil Palm Trunk Fiber (OPTF) in Cement Composite

Properties of oil palm trunk fiber reinforced cement composite were investigated in this study. Oil palm trunk fiber was used to improve the properties of cement composite. It was found that increasing in oil palm trunk fiber content up to certain percentage increase the compressive strength and decrease the density of cement composite. Besides, the study also found that additional of excessive of oil palm trunk fiber in cement composite decrease the compressive strength and continues to increase the water absorption and moisture content hence decrease the density. From this study, it was found that 2 wt. % of fiber content was the optimum fiber content to give the highest compressive strength of 38.61 MPa.

On the Fatigue of Shape Memory Alloys

When we use effectively shape memory alloys require knowledge of operational behavior at the thermal stresses and mechanical variables. Measurements performed on a CuZnAl alloy, revealed fatigue properties by considering the size of the maximum load deformation corresponding recovered memory. It requires knowledge in design fatigue behavior of shape memory alloy components after education, fatigue strength by performing partial memory loss or physical destruction. The properties of memory shape alloys recommend their use for complex mechanical applications in domains as follows medicine, robotics, aeronautics, electric contacts, actuators. Shape memory metal alloys in the construction of such installations are subject to mechanical stress, and the thermal stresses, so their inclusion in a computing system fatigue involves consideration of the function performed.

Compressive Strength and Morphology of Fly Ash Based Geopolymer as Artificial Aggregate with Different Curing Temperature

This paper presented the compressive strength of geopolymer paste with different NaOH concentration and morphology analysis for sintered artificial aggregate. This artificial aggregate was produce based on mix design with highest compressive strength which is 12 M. The sample was cured at 70 °C for 24 hours and then it was exposed to different temperature at range 500 °C to 700 °C. Scanning Electron Microscopy (SEM) has been used to identify the formation of microstructure. The geopolymer artificial aggregate was an alternative ways to produce a greener environmental. In this study, the compressive strength for different Na2SiO3/NaOH ratio has been analyzed. The morphology for best mix design then were analyze for different curing temperature. The result shows fly ash based geopolymer paste with 12 M of NaOH concentration shows excellent result with 7.30 MPa at 2.5 ratio of Na2SiO3/NaOH and for geopolymer artificial aggregate, when temperature of heat treatment increased, the open porosity of porous geopolymer surface decreased.

On the Structure of Shape Memory Alloys

The paper presents the obtaining of shape memory alloys, base copper and a diffractometer and microscopic study on some samples. The study was made on CuZnAl samples, obtained by classic casting and educated. The shape memory alloys properties recommend their use for applications in domains as follows electric contacts, robotics, and aeronautics. When choosing the type of alloy used for the manufacture of the component parts of different industrial applications, it must be taken into account fatigue resistance, resistance to shocks and resistance to corrosion. Shape memory alloys are a unique group of alloys with the ability to remember a form even after quite severe plastic deformations. At low temperatures, shape memory alloys can be deformed apparently like other metallic alloys, but this deformation can recover with a relatively modest increase in temperature.

Compressive strength of fly ash based geopolymer / glass fiber composite via filament winding

In general, filament winding technique is used to fabricate the composite pipes using continuous fiber and matrix resin. In this study, fly ash based geopolymer resin composites reinforced by continuous glass fiber were used for fabrication and synthesized by different curing and sintering temperature, different pattern and different viscosity of geopolymer. The effects of that parameter on the product were investigated. The compressive properties of the resulting composite were determined on an Instron Universal Testing under compression mode and the results show that the helical pattern with low viscosity cured at 75°C give the highest strength.

Effect of Space Holder and Compaction Pressure on the Porosity of Sintered Copper

The effect of space-holder content on the porosity of sintered copper that was fabricated by powder metallurgy technique has been investigated. Carbamide was used as space-holder and the content selected was 10 wt. %, 20 wt. % and 30 wt. %. A roll mill was used to mix the copper powder and the carbamide particles with rotation speed of 160 rpm for 2 hours. The mixture was compacted by hand press at 200-350MPa and sintered under argon atmosphere at 800°C. True density of the sample was determined by a gas pycnometer. Bulk density was determined using mass and volume of the sample. Result shows that the sintered porous copper with 30 wt. % of space-holder produced the highest porosity and the lowest density. Microstructure of pores was analyzed by a scanning electron microscope (SEM) which reveals the elongated pores interconnected to each other.

Characterization of Porous Aluminum Fabricated via Sintering-Dissolution Process (SDP)

Porous metals that have open pores structure with low density and light weight properties are suitable to be used in many engineering applications. In this work, the porous aluminum was fabricated via sintering dissolution process (SDP). Aluminum and sodium chloride (20, 40, 50 wt. %) powders were mixed together to produce a homogeneous mixture. The mixture was compressed at 200 MPa followed by sintering at 500 °C, 550 °C and 600 °C for 2 hours. The sintered samples were placed under a warm running water stream for 45 min to dissolve the sodium chloride that embedded in the aluminum. From the result, the sodium chloride content controlled the total porosity between 20% and 40% of the sintered aluminum. Porosity increased and compressive strength decreased as the content of NaCl increased. It was also observed, the porosity increased with increasing sintering temperature for the sample with 40 wt. % of NaCl.

Effect of different sintering temperature on fly ash based geopolymer artificial aggregate

This research was conducted to study the mechanical and morphology of fly ash based geopolymer as artificial aggregate at different sintering temperature. The raw material that are used is fly ash, sodium hydroxide, sodium silicate, geopolymer artificial aggregate, Ordinary Portland Cement (OPC), coarse aggregate and fine aggregate. The research starts with the preparation of geopolymer artificial aggregate. Then, geopolymer artificial aggregate will be sintered at six difference temperature that is 400°C, 500°C, 600°C, 700°C, 800°C and 900°C to known at which temperature the geopolymer artificial aggregate will become a lightweight aggregate. In order to characterize the geopolymer artificial aggregate the X-ray Diffraction (XRD) and X-Ray Fluorescence (XRF) was done. The testing and analyses involve for the artificial aggregate is aggregate impact test, specific gravity test and Scanning Electron Microscopy (SEM). After that the process will proceed to produce concrete with two type of different aggrega...