Zarina Yahya
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Preferred name
Zarina Yahya
Official Name
Zarina, Yahya
Alternative Name
Yahya, Zarina
Zarina, Y.
Zarina, Yahya
Main Affiliation
Scopus Author ID
51162069600
Researcher ID
DXZ-6436-2022

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Comparative study on early strength of sodium hydroxide (NaOH) activated fly ash based geopolymer

2017-09-29 , Zarina Yahya , Mohd. Mustafa Al Bakri Abdullah , Siti Zulaikha Abd Talib , Rafiza Abd Razak

The urge to reduce carbon dioxide (CO2) emission has encourage researchers to introduce environmental friendly binder or known as geopolymer. This new binder was produced by mixing source materials rich in silica and alumina with alkaline liquids. For this study, class F fly ash was used as source material with two different types of alkaline activator; sodium hydroxide (NaOH) only and a combination of water glass with NaOH. The different concentration of the NaOH solutions (8M, 10M, 12M and 14M) is used in the production of geopolymer. The parameters such as curing regime, solid/liquid ratio, and water glass/NaOH ratio are controlled in the study. The samples with combination of NaOH and water glass as alkaline activator were prepared by mixing these two solution and stirred for 2 minutes. Then this solution were mixed together with fly ash for 3 minutes and casted in the mould. The performance of the fly ash based geopolymer are evaluated by the compressive strength, water absorption and density at the early age of 1th, 3th and 7th days. Based on the study, at a concentration of 14M on 7th days had achieved the maximum compressive strength of 7.1 MPa for samples activated with NaOH only. Meanwhile, for geopolymer samples activated with a combination of the water glass and NaOH, the maximum strength of 33.33 MPa was recorded on 7th days of testing with NaOH concentration of 12 M. The water absorption for all geopolymer samples were ranging from 2.04 % to 2.78%, which are below the limit (3%). While the density of the geopolymer paste were in the range of 1552 kg/m3 to 1680 kg/m3, which are below the limit (2400 kg/m3). From the standpoint of strength of hardened geopolymer samples, the most effective alkaline activator in geopolymer is the combination of NaOH and water glass.

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A Review on the Concrete Durability Exposed to Different Wet-Dry Cycles Conditions

2024-04-19 , Zarina Yahya , Rafiza Abd Razak , Khairunnisa Muhamad

Concrete structure is prone to corrosion and weathering when built near marine environment. The greater damage on the concrete can be observed when it involves wet-dry action such as tidal waves combine with the existence of aggressive ions such as sulphate and chloride in seawater. The objective of this study is to review on the mechanism of sulphate, chloride attack toward concrete, parameters that influence the wet-dry action and identify the overview of research trends. The mechanism of sulphate and chloride attack during wet-dry action had reciprocal inhibiting effect on concrete and the penetration level for each ion also vary. The physical and mechanical damage of concrete exposed to wet-dry action also influence by wet-dry ratio, number of cycles and temperature during drying process. The main compound detected during exposure period are Friedel salt, ettringite, mirabilite and thenardite which can cause concrete delamination and spalling.

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Development of High Strength Alluvial Brick by Incorporative of Coconut Fibre

2024-04-19 , Rafiza Abd Razak , Sagaran R. , Mohd. Mustafa Al Bakri Abdullah , Zarina Yahya , Junaidi S. , Alida Abdullah

The new properties of alluvial brick can be created by addition to the coconut fibre. An analysis on compressive strength and water absorption percentage of alluvial brick and coconut fibre alluvial brick are presented in this research. There are four main different operations are involved in the process of manufacturing of alluvial bricks such as preparation of alluvial clay and coconut fibre, moulding of bricks, pre-drying of bricks and burning of bricks at 500°C, 600°C and 700°C. The results showed that the alluvial soil brick (without coconut fibre) burnt at 600°C exhibits the highest compressive strength of 17.33MPa and water absorption rate is 5.56% after soaked 24 hours in water. By using 600°C as the optimum temperature, alluvial bricks incorporating of coconut fibre are burnt. The highest value of compressive strength of coconut fibre alluvial brick is 16.57MPa and the water absorption is 11.11%. The outcomes of this research proved that the pure alluvial soil brick which not mixed with any add mixtures can be used in the construction project and it can be considered as a new type of brick in construction material. The coconut fibre alluvial brick also has fulfil the requirements to contribute to sustainable development as coconut fibre alluvial brick is made use of waste coconut fibre that environmental friendly and at the same time, it could decreases the waste material disposal.

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Rice husk (RH) as additive in fly ash based geopolymer mortar

2017-09-26 , Zarina Yahya , Rafiza Abd Razak , Mohd. Mustafa Al Bakri Abdullah , Mohd Azrin Adzhar Rahim , Armia Nasri

In recent year, the Ordinary Portland Cement (OPC) concrete is vastly used as main binder in construction industry which lead to depletion of natural resources in order to manufacture large amount of OPC. Nevertheless, with the introduction of geopolymer as an alternative binder which is more environmental friendly due to less emission of carbon dioxide (CO2) and utilized waste materials can overcome the problems. Rice husk (RH) is an agricultural residue which can be found easily in large quantity due to production of paddy in Malaysia and it's usually disposed in landfill. This paper investigated the effect of rice husk (RH) content on the strength development of fly ash based geopolymer mortar. The fly ash is replaced with RH by 0%, 5%, 10%, 15% and 20% where the sodium silicate and sodium hydroxide was used as alkaline activator. A total of 45 cubes were casted and their compressive strength, density and water absorption were evaluated at 1, 3, and 7 days. The result showed compressive strength decreased when the percentage of RH increased. At 5% replacement of RH, the maximum strength of 17.1MPa was recorded at day 7. The geopolymer has lowest rate of water absorption (1.69%) at 20% replacement of RH. The density of the sample can be classified as lightweight geopolymer concrete.

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The Influence of Cement Content to Properties of High Strength Anti Washout Concrete (HSAWC)

2024-04-19 , Khairunnisa Muhamad , Muhammad Haikal Farizad , Zarina Yahya , Liyana Ahmad Sofri

The high strength of concrete required a lot of cement content to increase its strength but not for the anti washout concrete (AWC) or underwater concrete (UWC). AWC will face another problem which is higher cement content could make the segregation to occur. This segregation process will give bad impact to the strength of the AWC. This research studied on four different cement content to examine: 450 kg/m3, 500 kg/m3, 550 kg/m3 and 600 kg/m3 towards its fresh and hardened properties of concrete. Superplasticizer is used as water reducing agent in the mix proportions to achieve high strength and self-consolidated concrete. Apart from that, there are two types of concrete samples produced, the air sampling concrete and underwater sampling concrete which have the same mix proportion. The overall results show a good correlation between the cement content in the mix and the strength of the air sampling concrete achieved. However, anti washout concrete having issues which is segregation. This segregation had affected the strength of the concrete. In conclusion, Anti washout concrete shows that optimal cement content without any viscocity modifying agent (VMA) is at 550 kg/m3

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Utilization of palm oil boiler ash (POBA) as geopolymer material for Industrialized Building System (IBS) application

2015 , Zarina Yahya

The increment of palm oil waste from palm oil extraction increased every year in Malaysia. Palm oil boiler ash (POBA) or bottom ash is one of the waste material from the palm oil industry where it was obtained from the burning process of solid waste such as empty fruit bunch, shell and fiber. The production of POBA was estimated about 4 million tonnes/year where it was usually used as fertilizer. Geopolymer or alkali-activated binder is produced by synthesizing aluminosilicate source materials with an alkaline activator solution. This study has been conducted to produce POBA geopolymer paste and brick and IBS brick by using geopolimerization process. The parameters for the geopolymer paste production included the NaOH concentration, ratios of S/L as well as Na2SiO3/NaOH and curing temperature. Then, the effect of each parameter towards production of geopolymer paste was evaluated using compressive strength, XRD, FTIR, and SEM. Meanwhile, for mix design of geopolymer brick and IBS brick, the optimum ratio (NaOH concentration, ratio of S/L and Na2SiO3/NaOH and curing temperature) from the geopolymer paste production has been used to produce the bricks. The ratio of POBA-to-sand for geopolymer brick and IBS brick for this study was 1:3. The performance of geopolymer brick and IBS brick were analyzed in term of compressive strength, water absorption and density at different aging period, which is 1st, 3rd, 7th, 28th and 60th days.

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Properties of Blended Alkaline System Geopolymer-A Review

2020-03-18 , Ahmad Zaidi F.H. , Romisuhani Ahmad , Zarina Yahya , Muhammad Faheem Mohd. Tahir , Wan Mastura Wan Ibrahim , Saufi A.S.

Geopolymers are inorganic material that comprise of silicon(Si) and aluminium(Al) bonded by oxygen atom to form a polymer network. The binder material used for geopolymer such as fly ash and blast furnace are mostly the industrial waste or by-products containing high content of silica and aluminium which acted as precursor for geopolymerization. The raw material plays an important role in the formation of geopolymer for each material may result in different properties of geopolymer. To improve the performance of these binders, numerous studies have been focused on the production of mixes based on blends of reactive precursors. The blends usually involve a Ca-rich precursor such as granulated blast furnace slag (GGBS), and an aluminosilicate source such as metakaolin or low calcium fly ash, to promote the stable coexistence of calcium silicate hydrate (C-S-H) gels formed from the activation of the GGBS and the geopolymer gel (N-A-S-H) produced from the activation of the aluminosilicate. Thus, this paper is intended to review the properties of different type of mixes of blended alkaline system.

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Effect of Rice Straw Ash (RSA) as partially replacement of cement toward fire resistance of self-compacting concrete

2022 , Yi Qin Chin , Rafiza Abd Razak , Mohd. Mustafa Al Bakri Abdullah , Zarina Yahya , Mokhzani Khair Ishak , Sebastian Garus , Marcin Nabiałek , Warid Wazien Ahmad Zailani , Khairil Azman Masri , Andrei Victor Sandu , Agata Śliwa

Malaysia’s construction industry is experiencing rapid growth, translating into increased demand for cement. However, cement production pollutes the air to the detriment of the climate via CO2 emission, making research into a cementitious replacement in concrete a necessity. This paper details an experimental study of self-compacting concrete (SCC) with partial replacement of cement by rice straw ash (RSA), which is expected to result in environmental preservation due to the green materials being used in cement production. The physicomechanical properties of the SCC with RSA replacement were determined via its compressive strength, water absorption, self-workability, and fire resistance (residual strength after exposure to high temperatures). The proportion of RSA replacement used were 0%, 5%, 10%, 15%, 20%, and 25%, and all passed the slump flow test, except the 20% and 25% samples. The SCC samples with 15% of RSA replacement reported the highest compressive strength at 7 and 28 curing days and the highest residual strength post-exposure to high temperatures. The lowest percentage of water absorption was reported by the 15% of RSA replacement, with a density of 2370 kg/m3

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Artificial lightweight aggregates made from pozzolanic material: A review on the method, physical and mechanical properties, thermal and microstructure

2022 , Dickson Ling Chuan Hao , Rafiza Abd Razak , Marwan Kheimi , Zarina Yahya , Mohd. Mustafa Al Bakri Abdullah , Dumitru Doru Burduhos Nergis , Hamzah Fansuri , Ratna Ediati , Rosnita Mohamed , Alida Abdullah

As the demand for nonrenewable natural resources, such as aggregate, is increasing worldwide, new production of artificial aggregate should be developed. Artificial lightweight aggregate can bring advantages to the construction field due to its lower density, thus reducing the dead load applied to the structural elements. In addition, application of artificial lightweight aggregate in lightweight concrete will produce lower thermal conductivity. However, the production of artificial lightweight aggregate is still limited. Production of artificial lightweight aggregate incorporating waste materials or pozzolanic materials is advantageous and beneficial in terms of being environmentally friendly, as well as lowering carbon dioxide emissions. Moreover, additives, such as geopolymer, have been introduced as one of the alternative construction materials that have been proven to have excellent properties. Thus, this paper will review the production of artificial lightweight aggregate through various methods, including sintering, cold bonding, and autoclaving. The significant properties of artificial lightweight aggregate, including physical and mechanical properties, such as water absorption, crushing strength, and impact value, are reviewed. The properties of concrete, including thermal properties, that utilized artificial lightweight aggregate were also briefly reviewed to highlight the advantages of artificial lightweight aggregate.

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Mechanical performance, microstructure, and porosity evolution of fly ash geopolymer after ten years of curing age

2023 , Ikmal Hakem A. Aziz , Mohd. Mustafa Al Bakri Abdullah , Rafiza Abd Razak , Zarina Yahya , Mohd Arif Anuar Mohd Salleh , Jitrin Chaiprapa , Catleya Rojviriya , Petrica Vizureanu , Andrei Victor Sandu , Muhammad Faheem Mohd. Tahir , Alida Abdullah , Liyana Jamaludin

This paper elucidates the mechanical performance, microstructure, and porosity evolution of fly ash geopolymer after 10 years of curing age. Given their wide range of applications, understanding the microstructure of geopolymers is critical for their long-term use. The outcome of fly ash geopolymer on mechanical performance and microstructural characteristics was compared between 28 days of curing (FA28D) and after 10 years of curing age (FA10Y) at similar mixing designs. The results of this work reveal that the FA10Y has a beneficial effect on strength development and denser microstructure compared to FA28D. The total porosity of FA10Y was also lower than FA28D due to the anorthite formation resulting in the compacted matrix. After 10 years of curing age, the 3D pore distribution showed a considerable decrease in the range of 5–30 µm with the formation of isolated and intergranular holes.

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