Afizah Ayob
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Preferred name
Afizah Ayob
Official Name
Afizah, Ayob
Alternative Name
Ayob, Afizah
Ayob, A.
Afizah, A.
Main Affiliation
Scopus Author ID
23767077500
Researcher ID
D-3484-2018

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Applications of waste material in the pervious concrete pavement: A review

2017-09-26 , Shahrul Azwan Shakrani , Afizah Ayob , Mohd Asri Ab Rahim

Pervious concrete pavement is one of the innovative structures designed in order to manage the quantity and quality of urban stormwater for a sustainable development. In general, pervious concrete pavement enables water to permeate through its structure and have a capability to cater dynamic loads at the same time. However, the conventional pervious concrete pavement lacks a superior strength while performing as pavement structure. Thus, an extensive research has been carried out in order to explore the possible materials to be incorporated into the pervious concrete pavement for better physical, structural and mechanical properties. The objectives of this paper are to review the waste materials used in the pervious concrete pavement along with their mechanical, durability and permeability performance.

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Stability of kaolin particles subjected to elevated temperatures using various dispersing agents

2020-06-17 , Shahrul Azwan Shakrani , Afizah Ayob , Mohd Asri Ab Rahim , Alias S.

The stability of kaolin particles is largely influenced by nature and the behaviour of dispersing agents introduced to the system. This study analysed the size of kaolin particles subjected to elevated temperatures by using various dispersing agents such as ultrapure water (UPW), acetone (Ace) and sodium hydroxide (NaOH). It was found that kaolin particles in UPW formed a stable dispersion compared to particles in Ace and NaOH without further aggregation. Interestingly, kaolin particles under UPW, Ace, and NaOH dispersants had a strong affinity for water and can be classified as possessing hydrophilic behaviour. The mean size of kaolin particles was reduced under UPW and Ace dispersion but increased under NaOH suspension. Under UPW dispersion, kaolin particles ranged from 141.8nm to 5560nm, creating a mid-range monodisperse size distribution (0.08 < PDI < 0.7) without any presence of agglomeration due to high potential energy barrier and electrostatic repulsion. Kaolin particles subjected to NaOH dispersant produced a narrow distribution of particle sizes ranging from 295.3nm to 1106nm but appeared to agglomerate because of Van der Waals interactions. In contrast, the Ace dispersant produced a very broad polydisperse particle size distribution (PDI > 0.7) of greater than 10μm in kaolin with a little aggregation but lacking consistency in terms of stability. However, all dispersants contributed to the kaolin particles dispersion but UPW shown more stability dispersion due to increase in number of hydroxyl groups in dispersant molecule. In conclusion, this simple and low cost methodology can be useful in characterising kaolin particle sizes with limited resources.

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The Behavior of Non-Destructive Test for Different Grade of Concrete

2020-12-28 , Mustaqqim Abdul Rahim , Mohd Shahidan Shaari , Onn L.C. , Saiful Bahari N.A.A. , Rahman N.A. , Afizah Ayob

Rebound hammer tests are generally preferred as a non-destructive testing method as compared to destructive testing methods such as compression tests. In this study, a general series of rebound hammer tests and destructive tests were carried on in a heavy concrete laboratory. A set of concrete cubes measuring 100 x 100 x 100 mm were cast and subjected to water curing for 7, 14 and 28 days to obtain the cube strength and rebound number. Three grades of concrete, namely M20, M25 and M30 were used in this experiment. At 28 days, the minimum target strength should be 30 MPa. The rebound hammer tests were conducted before the compression tests. The data obtained for each test was evaluated and tabulated in the findings of this study. It was found that the variation between predicted strength and experimental strength for the rebound hammer test was 0.18%. This indicates that the rebound hammer test is able to predict strength with acceptable accuracy.

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Properties of pulverized kaolin particles via ball-to-powder weight ratios milling process: XRF and Zetasizer particle size analysis

2020-06-10 , Shahrul Azwan Shakrani , Afizah Ayob , Mohd Asri Ab Rahim , Alias, S.

Kaolin particles were pulverized in order to reduce the size by using high-energy ball milling under various ball-to-powder weight ratios. The elemental composition and particle size analysis of milled kaolin particles were carried out using X-ray fluorescence and Zetasizer particle size analyzer. The increased in ball-to-powder weight ratios have raised the amounts of oxide minerals such as K2O, MgO, Fe2O3, TiO2, CaO, SO3 and LOI in the kaolin particles while reducing the concentration of SiO2, Al2O3, P2O5, and MnO as compared to the control sample. Kaolin particles reached an average of 944nm in size after milling for 4hr under ball-to-powder weight ratio of 4, which is much smaller than unpulverized kaolin particles at the average mean size of 9.985Chai T and Draxler R R 2014 Root Mean Square Error (RSME) or Mean Absolute Error (MAE)-Arguments against avoiding RSME in the literature Retrieved February 10 from World Wide Web www.geosci-model-dev.netm. The energy dissipation has produced a very strong energy impacts and fractures in order to produce the number of collisions between balls and container wall in the high-energy ball milling process to allow the reduction of particles size of kaolin. This enables kaolin particles to be reduced in size and produced in the practically simple, effective, and low-cost process using high-energy ball milling. However, the continuous milling has caused the particles to agglomerate as a way to release the excessive specific surface energy and micro strains produced by high-energy ball milling.

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A review of nanoclay applications in the pervious concrete pavement

2017-09-26 , Shahrul Azwan Shakrani , Afizah Ayob , Mohd Asri Ab Rahim

In recent years, the use of nanoclay has received various interests in order to enhance the properties of construction materials which can also be eligible for pavement technology and engineering application. This review paper summarizes the effect of nanoclay as cement replacement and additive to the performance of pervious concrete pavement. The addition of nanoclay to pervious concrete has demonstrated improvements in strength properties such as compressive and flexural strength, durability such as freeze-thaw and chloride penetration resistance, shrinkage, and denser microstructure but at the same time reduced the porosity, permeability and water absorption properties. This enhancement is due to the roles of nanoclay as nanoreinforcements, nanofillers, nucleation site, and reactive pozzolans in order to promote hydration and improve material properties.

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