Comparison of Mechanical and Microstructural Properties of Fly Ash Geopolymer in Water and Chloride Environment

In cement industry, the emissions of greenhouse gases specifically CO2 from the clinker production led to the need of alternative binders. Geopolymer binder whose precursors are sourced from industrial by-products such as fly ash that are rich is silica and alumina has been studied extensively in the past decades. Chloride attack is one of the threats to concrete structures. Analysis at microstructural level needs to be studied carefully before this binder can be used with confidence. This study attempts to compare the properties of fly ash geopolymer binder when exposed in water and chloride solution. Fly ash geopolymer pastes were prepared using 12M sodium hydroxide (NaOH) as activator. The pastes were tested under two separate curing conditions, i.e in ambient and in distilled water. Compressive strength test along with microstructure properties of samples cured at 7, 14 and 28 days were conducted via Universal testing machine, Fourier Transform Infra-Red (FTIR) spectroscopy and Scanning Electron Microscope with Energy-dispersive X-ray (SEM-EDX). After 28 days of curing, these samples were immersed in 10% sodium chloride (NaCl) solution for another 56 days. Samples cured in ambient condition showed better mechanical performance than those in distilled water. Their differences in compressive strength were also seen consistent with the FTIR results. Samples exposed to NaCl and distilled water showed similar mechanical performance and microstructural properties. Based on SEM-EDX analysis, samples cured in ambient were rich in silica and alumina while the intensity of these compounds were observed to reduce when exposed to distilled water. Samples cured in ambient showed stronger intensity of Si/Al gel as compared to samples exposed to chloride environment and distilled water and these were consistent with the compressive strength results obtained. When immersed in water, concentration gradient changes in the liquid phases, leading to ions diffusion and causing decrement in strength and durability of the solids in fly ash geopolymer

Characterization of Alkali-Activated Palm Oil Fuel Ash Pastes as a Function of Calcination Temperatures of Raw Precursor

This research investigates the influence of calcination temperatures of palm oil fuel ash (POFA) on the properties of the raw precursor and its hardened binder after alkali activation.The raw POFA obtained from palm oil mill is treated at 500°C, 600°C, and 700°C for approximately 6 h. The treated POFA (TPOFA) is characterized for particle size distributions and chemical compositions by X-ray fluorescence (XRF); microstructural properties by observing through scanning electron microscopy (SEM); and Fourier-transform infrared spectroscopy (FTIR) for molecular functional groups. Pastes of alkali-activated POFA (AAPOFA) are synthesized with 12 M sodium hydroxide (NaOH) as alkali activator where the liquid to binder ratio is 0.4. Calcination temperatures are observed to have some influences on the physical properties (such as color, texture, particle size and fineness) and chemical properties (such as composition and reactivity) of the raw precursor. These properties control microstructural evolution of hardened pastes, compressive strength and capillary sorptivity properties of the hardened pastes. Overall results show 500°C is the optimum calcination temperature for POFA that contributes to comparable strength and lowest permeability of AAPOFA binders

Characteristics Analysis of Bio Based Silica Extracted from Sarawak Palm Oil Waste

Due to high production of palm oil, surplus quantities of palm oil wastes such as empty fruit bunches (EFB) and palm kernel shells (PKS) are generated. This study aims to analyze the characteristics of EFB and PKS ashes and their respective bio-silica content when combusted at different temperatures; 400°C, 600°C and 800°C. Several tests like weight loss, colour and Fourier Transform Infrared (FTIR) analysis are conducted. EFB records higher weight loss compared to PKS for all combustion temperatures, thus implying less silica content compared to the later. Both wastes also show the highest weight loss at 99.20% and 98.51% respectively, when they are burnt at 800°C than those combusted at lower temperatures. This happens because more impurities evaporate at 800°C, thus resulting in greater relative amount of silica in the ash. Colour analysis shows that the whiteness of both EFB and PKS ashes are the highest when combustion occurs completely at 800°C, particularly at 71.56 and 42.40 respectively. Besides, FTIR analysis depicts distinct presence of Si-O and Si-O-Si functional groups in both EFB and PKS ashes for all temperatures. It is als

Characterization of Bio-adhesive derived from Sarawak Native Sago Starch

Sago starch has multiple applications in industries such as textile, cosmetics and pharmaceutical, paper and wood. This study focuses on the utilization of sago starch to promote formaldehyde-free adhesives. Formaldehyde-based adhesive commonly used in wood industry emits formaldehyde, which is classified as carcinogen, into the air that has raised concerns over the potential hazards to human health. Sago starch-based adhesive was produced by blending the sago starch with sodium hydroxide (NaOH) and glycerine. Fourier-Transform Infrared Spectroscopy (FT-IR) was used to characterize the chemical changes in the sago starch-based adhesive. The quality of sago starch adhesive was tested according to their viscosity. The mechanical property is analyze based on lap shear (bond) strength of the sago starch adhesives according to ASTM D907 and D143 by using Model D350 Testomeric. Parameters affecting the viscosity of the sago starch-adhesive such as time, temperature, concentration of sodium hydroxide, and the amount of glycerine were studied. The viscosity of the sago starch-based adhesive decreased as the mixing time, temperature, concentration of NaOH and the amount of glycerine increased

Physico-mechanical properties polypropylene/ethylene-propylene diene monomer (PP/EPDM) binary blends

The aim of this study was to develop radiation sterilized polypropylene/ethylene-propylene diene monomer (PP/EPDM) binary blends using melt blending and the mechanical properties of the blends were studied. The PP/EPDM binary blends were prepared in the ratios of 80:20, 60:40, 50:50, 40:60 and 20:80. The binary blends were then compressed for 12 minutes using the hot and cold press machine and were cut into 1mm, 3mm and 6mm thickness for tensile test, impact test, hardness test and Fourier transform infrared spectroscopy analysis. The results showed that higher EPDM content binary blends were more elastic and had better energy absorption compared to lower EPDM ratio binary blends. With the introduction of a 100kGy radiation dose, the binary blends performed better in the Young’s modulus with crosslinking formed within the molecules. Among the PP/EPDM binary blends, 20:80 PP/EPDM blends performed the best in both physical and mechanical properties. This binary blend was suitable for medical devices

PRODUCTION AND PERFORMANCE OF OKARA/SAGO AND OKARA/BANANA PEEL ORGANIC FERTILIZERS IN PLANTATION

The application of chemical fertilizer improved the growth rate in the plantation. However, chemical fertilizer itself was not environmentally friendly. Thus, organic fertilizer with low production cost should be undergoing thorough research. This study investigated the performance of organic fertilizer produced using okara/sago and okara/banana peel on the growth rate of the plants. The organic fertilizers were produced into five samples with different ratios and placed in incubator oven at temperature 100ºC for 4 hours for drying process. Both organic fertilizers were analysed using FTIR, SEM and moisture balance analysis. Both fertilizers were then applied on and Mustard Looseleaf plants. FTIR and SEM analysis proved the well combination of okara with banana peel and sago with smoother surfaces, respectively. Both organic fertilizers were oven-dried to remain as solid stage. The results obtained proved that both organic fertilizers with the highest content of okara was the most effective in enhancing the growth rate of Mustard Looseleaf plants in terms of height and leaf size. Keywords: Banana peel, Okara, Organic fertilizer, Plantation, Sag