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

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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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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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Properties and morphology of fly ash based Alkali Activated Material (AAM) paste under steam curing condition

2022 , Rafiza Abd Razak , Sh. Nur Syamimi Sy. Izman , Mohd. Mustafa Al Bakri Abdullah , Zarina Yahya , Alida Abdullah , Rosnita Mohamed

This paper details the properties, microstructures, and morphologies of the fly ash-based alkali-activated material (AAM), also known as geopolymers, under various steam curing temperatures. The steam curing temperature result in subsequent high strengths relative to average curing temperatures. However, detailed studies involving the use of steam curing for AAM remain scarce. The AAM paste was prepared by mixing fly ash with an alkali activator consisting of sodium silicate (Na2SiO3) and sodium hydroxide (NaOH). The sample was steam cured at 50°C, 60°C, 70°C, and 80°C, and the fresh paste was tested for its setting time. The sample also prepared for compressive strength, density, and water absorption testings. It was observed that the fastest time for the fly ash geopolymer to start hardening was at 80°C at only 10 minutes due to the elevated temperature quickening the hydration of the paste. The compressive strength of the AAM increased with increasing curing time from 3 days to 28 days. The AAM’s highest compressive strength was 61 MPa when the sample was steam cured at 50°C for 28 days. The density of AAM was determined to be ~2122 2187 kg/m3 , while its water absorption was ~6.72-8.82%. The phase analyses showed the presence of quartz, srebrodolskite, fayalite, and hematite, which indirectly confirms Fe and Ca’s role in the hydration of AAM. The morphology of AAM steam-cured at 50°C showed small amounts of unreacted fly ash and a denser matrix, which resulted in high compressive strength.

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Potential Applications of Geopolymer Cement-Based Composite as Self-Cleaning Coating: A Review

2022-02-01 , Siti Norsaffirah Zailan , Norsuria Mahmed , Mohd. Mustafa Al Bakri Abdullah , Shayfull Zamree Abd. Rahim , Dewi Suriyani Che Halin , Sandu A.V. , Vizureanu P. , Zarina Yahya

Nowadays, concepts of self-cleaning have received great attention in construction building materials. Self-cleaning with the presence of photocatalyst has been applied in building materials to overcome the problem of building surfaces becoming dirty after exposure for a long time in highly polluted areas. To date, the concept of green blending materials has led to the development of a new binding material for green materials, which is geopolymer with an addition of photocatalyst. This review focused on the development of conventional self-cleaning paste, including the method of preparation and the impact of adding photocatalyst on physical and mechanical properties. However, although self-cleaning has been widely applied in conventional cement paste, its applications in geopolymers are still in the early stages of development and require more research. Therefore, this paper also intended to review the current knowledge on properties of geopolymer cement-based composite and its potential to be applied as a self-cleaning coating.

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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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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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Asas Geopolimer Teori & Amali

2013 , Mohd. Mustafa Al Bakri Abdullah , Rafiza Abd Razak , Zarina Yahya , Kamarudin Hussin , Liew Yun Ming , Heah Cheng Yong , Mohd Izzat, Ahmad

Buku Asas Geopolimer: Teori dan Amali ialah sebuah buku yang membincangkan beberapa perkara asas yang penting mengenai geopolimer. Ia meliputi aspek-aspek seperti; Sejarah geopolimer Pengenalan kepada geopolimer Perbandingan konkrit geopolimer dengan konkrit biasa Bahan mentah dalam geopolimer Tindak balas kimia Kaedah pemprosesan Kualiti konkrit geopolimer Penyelidikan geopolimer masa kini Penulisan buku ini menumpukan kepada teori asas, proses dan pencirian geopolimer yang memberi pengetahuan kepada pembaca mengenai teori dan praktikal berasaskan hasil penyelidikan yang dibuat penyelidik. Tiga perkara utama yang dibincangkan di dalam buku ini ialah bahan mentah (larutan pengaktif alkali), tindak balas kimia yang memainkan peranan dalam proses pengeopolimeran dan pemprosesan geopolimer. Buku Asas Geopolimer: Teori dan Amali ini juga adalah buku pertama yang dihasilkan dalam Bahasa Melayu.

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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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Durability of geopolymer lightweight concrete infilled LECA in seawater exposure

2017-11-23 , Rafiza Abd Razak , Mohd. Mustafa Al Bakri Abdullah , Zarina Yahya , Hamid M.

This paper describes a development of lightweight concrete using lightweight expanded clay aggregate (LECA) in fly ash (FA) based geopolymer immersed in seawater. The objective of this research is to compare the performance of geopolymer concrete (GPC) with ordinary Portland cement (OPC) concrete infilled lightweight expanded clay aggregate (LECA) in seawater exposure. Geopolymer concrete is produced by using alkaline activator to activate the raw material, FA. The highest compressive strength of this study is 42.0 MPa at 28 days and 49.8 MPa at 60 days. The density for this concrete is in the range of 1580 kg/m3 to 1660 kg/m3. The result for water absorption is in the range of 6.82% to 14.72%. However, the test results of weight loss is in the range between 0.30% to 0.43%.

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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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