Papers by Khairul Nizar Ismail
In this paper, we report the results of our investigation on the possibility of
producing foam co... more In this paper, we report the results of our investigation on the possibility of
producing foam concrete by using a geopolymer system. Class C fly ash was mixed with an alkaline activator solution (a mixture of sodium silicate and NaOH), and foam was added to the geopolymeric mixture to produce lightweight concrete. The NaOH solution was prepared by dilute NaOH pellets with distilled water. The reactives were mixed to produce a homogeneous mixture, which was placed into a 50 mm mold and cured at two different
curing temperatures (60 °C and room temperature), for 24 hours. After the curing process, the strengths of the samples were tested on days 1, 7, and 28. The water absorption, porosity, chemical composition, microstructure, XRD and FTIR analyses were studied. The results showed that the sample which was cured at 60 °C (LW2) produced the maximum compressive strength for all tests, (11.03 MPa, 17.59 MPa, and 18.19 MPa) for days 1, 7, and 28, respectively. Also, the water absorption and porosity of LW2 were reduced by 6.78% and 1.22% after 28 days, respectively. The SEM showed that the LW2 sample had a denser matrix than LW1. This was because LW2 was heat cured, which caused the geopolymerization rate to increase, producing a denser matrix. However for LW1 microcracks were present on the surface, which reduced the compressive strength and increased water absorption and porosity.
American Journal of …, Jan 1, 2007
Temperature is an important parameter for transformation of minerals in clinker during cement pro... more Temperature is an important parameter for transformation of minerals in clinker during cement productions. It influences the formation of alite from belite during calcinations and clinkering processes. The result of microstructure shows that the formation of belite minerals started at temperature nearly 1200 o C which is at calcinations zone temperature, followed by formation of αbelite at higher temperature (around 1300 o C), then formation of β-belite and finally, with the suitable conditions it will form alite minerals. The differences between minerals are identified physically using scanning electron microscope (SEM).
nuklearmalaysia.org
Fly ash is the finely divided mineral residue resulting from the combustion of coal in electric g... more Fly ash is the finely divided mineral residue resulting from the combustion of coal in electric generating plants. Fly ash consists of inorganic, incombustible matter present in the coal that has been fused during combustion into a glassy, amorphous structure. Fly ash particles are generally spherical in shape and range in size from 2 μm to 10 μm. They consist mostly of silicon dioxide (SiO 2 ), aluminium oxide (Al 2 O 3 ) and iron oxide (Fe 2 O 3 ). Fly ash like soil contains trace concentrations of the following heavy metals : nickel, vanadium, cadmium, barium, chromium, copper, molybdenum, zinc and lead. The chemical compositions of the sample have been examined and the fly ash are of ASTM C618 Class F.
Pulverised fuel ash is the finely divided mineral residue resulting from the combustion of coal i... more Pulverised fuel ash is the finely divided mineral residue resulting from the combustion of coal in electric generating plants. Pulverised fuel ash consists of inorganic, incombustible matter present in the coal that has been fused during combustion into a glassy, amorphous structure. Pulverised fuel ash particles are generally spherical in shape and range in size from 2 µm to 10 µm. They consist mostly of silicon dioxide (SiO 2 ), aluminium oxide (Al 2 O 3 ) and iron oxide (Fe 2 O 3 ). Pulverised fuel ash like soil contains trace concentrations of the following heavy metals: nickel, vanadium, cadmium, barium, chromium, copper, molybdenum, zinc and lead. The chemical compositions of the sample have been examined and the fly ash are of ASTM C618 Class F.
academicjournals.org
Every 1 ton of concrete leads to CO 2 emissions which vary between 0.05 to 0.13 tons. About 95% o... more Every 1 ton of concrete leads to CO 2 emissions which vary between 0.05 to 0.13 tons. About 95% of all CO 2 emissions from a cubic yard of concrete are from cement manufacturing. It is important to reduce CO 2 emissions through the greater use of substitute to ordinary Portland cement (OPC) such as fly ash, clay and others geo-based material. This paper, report on the study of the processing of geopolymer using fly ash and alkaline activator with geopolymerization process. The factors that influence the early age compressive strength such as molarity of sodium hydroxide (NaOH) have been studied. Sodium hydroxide and sodium silicate solution were used as an alkaline activator. The geopolymer paste samples were cured at 70°C for 1 day and keep in room temperature until the testing days. The compressive strength was done at 1, 2, 3 and 7 days. The result showed that the geopolymer paste with NaOH concentration of 12 M produced maximum compressive strength.
iefpedia.com
The major areas covered and presented in this volume are very wide and related with the economic ... more The major areas covered and presented in this volume are very wide and related with the economic clusters of ECER development which include manufacturing, environment, transportation, tourism, agriculture, human capital, education, socio-economic, infrastructure, business and financial. The main media for the proceedings of this conference is the CD-ROM which was distributed to all participants and ONLINE proceeding which can be accessed through ABSTRACT Malaysian capital market offers an array of investment products in a form of shares, loan stocks, bonds, warrants, and unit trusts. The type of products chosen by an investor to commit his capital depends largely on his financial goals, time frame, and amount of capital available. Different people invest with different strategies or even no-strategies. However, previous studies found that most individual investors who play the stock market often ask for 'hot tips' that will enrich them overnight. Too often investors buy stocks on a whim or on the recommendation of a stranger when they should buy stocks that are showing fundamental strength and consistence with their investment objectives. Therefore, the main objective of this research is to study factors that influence investors' investment decision making. Do they rational or irrational in their decision making behavior. The population for the study consists of individual investor who trade share at Bursa Malaysia. 147 questionnaires were distributed and usable. The results from correlation analysis indicate positive and significant correlations among the independent and the dependent variables. However, multiple regression analysis shows significant relationships only exist for economy and frame of references indicating that Malaysian investors rely both on fundamental analysis as well as following others opinion (herding). In other words, they are partially rational in their decision making.
… Journal of Applied …, Jan 1, 2007
Chemical composition analysis using x-ray fluorescence is one of the important quality analysis f... more Chemical composition analysis using x-ray fluorescence is one of the important quality analysis for examining of cement and widely used in cement industries for a long time as a tool to estimate phase composition. X-ray diffraction is one of the established techniques as a qualitative tool to identify phase existing in the sample. This study will discuss about the correlation between quantitative and qualitative analyses in order to understand phase transformation in production of cement. Qualitative analysis had revealed a lot of information which could not be identified by using x-ray fluorescence especially polymorphisms existed in the clinker samples.
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Papers by Khairul Nizar Ismail
producing foam concrete by using a geopolymer system. Class C fly ash was mixed with an alkaline activator solution (a mixture of sodium silicate and NaOH), and foam was added to the geopolymeric mixture to produce lightweight concrete. The NaOH solution was prepared by dilute NaOH pellets with distilled water. The reactives were mixed to produce a homogeneous mixture, which was placed into a 50 mm mold and cured at two different
curing temperatures (60 °C and room temperature), for 24 hours. After the curing process, the strengths of the samples were tested on days 1, 7, and 28. The water absorption, porosity, chemical composition, microstructure, XRD and FTIR analyses were studied. The results showed that the sample which was cured at 60 °C (LW2) produced the maximum compressive strength for all tests, (11.03 MPa, 17.59 MPa, and 18.19 MPa) for days 1, 7, and 28, respectively. Also, the water absorption and porosity of LW2 were reduced by 6.78% and 1.22% after 28 days, respectively. The SEM showed that the LW2 sample had a denser matrix than LW1. This was because LW2 was heat cured, which caused the geopolymerization rate to increase, producing a denser matrix. However for LW1 microcracks were present on the surface, which reduced the compressive strength and increased water absorption and porosity.
producing foam concrete by using a geopolymer system. Class C fly ash was mixed with an alkaline activator solution (a mixture of sodium silicate and NaOH), and foam was added to the geopolymeric mixture to produce lightweight concrete. The NaOH solution was prepared by dilute NaOH pellets with distilled water. The reactives were mixed to produce a homogeneous mixture, which was placed into a 50 mm mold and cured at two different
curing temperatures (60 °C and room temperature), for 24 hours. After the curing process, the strengths of the samples were tested on days 1, 7, and 28. The water absorption, porosity, chemical composition, microstructure, XRD and FTIR analyses were studied. The results showed that the sample which was cured at 60 °C (LW2) produced the maximum compressive strength for all tests, (11.03 MPa, 17.59 MPa, and 18.19 MPa) for days 1, 7, and 28, respectively. Also, the water absorption and porosity of LW2 were reduced by 6.78% and 1.22% after 28 days, respectively. The SEM showed that the LW2 sample had a denser matrix than LW1. This was because LW2 was heat cured, which caused the geopolymerization rate to increase, producing a denser matrix. However for LW1 microcracks were present on the surface, which reduced the compressive strength and increased water absorption and porosity.