Papers by Ahmad Farhan Hamzah
1ST INTERNATIONAL POSTGRADUATE CONFERENCE ON OCEAN ENGINEERING TECHNOLOGY AND INFORMATICS 2021 (IPCOETI 2021)
Sand mining is a worldwide environmental threat that is gaining media's attention. Sand and grave... more Sand mining is a worldwide environmental threat that is gaining media's attention. Sand and gravel are the most important materials for building construction. However, excessive withdrawal from the river system may cause irreversible damages to the ecological and socio-economics in the long run. As demands for stronger regulation of mining develop, the scientific evidence needs to be understood in order to justify the effectiveness of the management. The mining process not only induced channel incision, but also disrupted sediment balance in the area whereas, the sediment loads responsible for the changes of the banks that lead to exposure of underlying grain, deteriorating the water quality and encroaching the abundance of species habitats. By using Quick Scoping Review (QSR), the aim for this paper is to provide a summary of various studies on the impacts practice of sand mining either positively or negatively on the environment, aquatic habitat, biodiversity and hydraulic regime of the river system. It was found that negative impacts and significant alteration were dominant opposed to the positive impacts. Channel incision, loss of habitat and sedimentation at downstream areas were identified as direct impact due to sand mining activities. QSR results show that response river ecosystem to sand mining is complex. The documented collected response showed that channel incision contributes the most impact due to sand mining activity at the river, followed by sediment fluctuation on river bed. However, self-sustaining of river to dynamic equilibrium will give little help to reduce the negative impact of sand mining activities but self-adjustment process acquires longer time than the former. These findings may help authorities on planning the best management practice for sustainable mining activities in the and nurture the importance of preserving river ecosystem and providing mitigation plan in future.
International Journal of Integrated Engineering
Overthe years, Sungai Bunus has undergone hydrological changes and has become lower and narrower.... more Overthe years, Sungai Bunus has undergone hydrological changes and has become lower and narrower. Under a flood mitigation project, a flood diversion channel is proposed to reduce the volume of water in Sungai Bunusfurthermore avoid the spill over into Sungai Klang and reduce flooding events in Kuala Lumpur city. This research describes the physical modelling of the flow state of the Sungai Bunus stilling basin. Physical model was constructed to verify the design criteria of the stilling basin that will be adopted for construction. Experimental work has been carried out both with and without piers under three specified discharges (52 L/s, 86 L/s and 121 L/s) and subsequently the measurement of the water surface height profiles and point velocities through the proposed system. Consequently, there are no significant differences of outcomes between the two circumstances. The results show that there is no overflow of water at discharges of 52 L/s and 86 L/s. The water level at the Sunga...
ARPN journal of engineering and applied sciences, 2015
Nowadays, practicing ‘industrial ecology’ for sustainable industrial development is a common prac... more Nowadays, practicing ‘industrial ecology’ for sustainable industrial development is a common practice in the engineering field. This practice promotes recycling by-product waste of one industry by substituting/replacing them for the virgin raw material of another industry, thereby reducing the environmental impact of both. One of those by-product wastes is bottom ash, which produced from coal-fired power plant that faces an increasing production up to hundred and thousand tones over the continents. Previously, a significant amount of research has been conducted in order to explore the potential use of bottom ash in the production of concrete and mortar. Most of the research focused on its potential use as fine aggregate replacing natural sand, and exploring its beneficial properties in enhancing the properties of concrete and mortar. This present paper reviews the literature related to the properties of fresh and hardened concrete incorporating bottom ash as a partial or total repla...
Concrete is a major building material use for numerous purposes in construction including the con... more Concrete is a major building material use for numerous purposes in construction including the concrete structures that exposed to aggressive environment or seawater such as coastal berthing facilities, breakwaters, retaining walls, tidal barriers, dry docks, container terminals, off-shore floating docks and drilling platforms. As these concrete structures that usually exposed to an aggressive environment, it is expected to require a minimum level of repair or maintenance during their service life. The ingress of aggressive agents, in particular chloride and sulphate ions, can lead to corrosion of reinforcing steel bars and thus cause a reduction in strength and subsequent decrease in the service life of concrete structures. In context to resist this type of premature deterioration, concrete must be proportioned to achieve high durability in aggressive environments. The incorporation of coal bottom ash as sand replacement material was possible to help self-compacting concrete in desi...
International Journal of Engineering and Technology, 2018
MATEC Web of Conferences, 2016
This paper presents the effect of using coal bottom ash as a partial replacement of fine aggregat... more This paper presents the effect of using coal bottom ash as a partial replacement of fine aggregates in self-compacting concrete (SCC) on its fresh properties and flexural strength. A comparison between SCC with various replacements of fine aggregates with coal bottom ash showed that SCC obtained flexural strength decrease on increase of water cement ratio from 0.35 to 0.45. The natural sand was replaced with coal bottom ash up to 30% volumetrically. The fresh properties were investigated by slump flow, T500 spread time, L-box test and sieve segregation resistance in order to evaluate its self-compatibility by compared to control samples embed with natural sand. The results revealed that the flowability and passing ability of SCC mixtures are decreased with higher content of coal bottom ash replacement. The results also showed that the flexural strength is affected by the presence of coal bottom ash in the concrete. In addition, the water cement ratios are influence significantly with higher binder content in concrete.
Procedia - Social and Behavioral Sciences, 2015
Self-Compacting Concrete (SCC) is a flowing mixture that consolidates under its own weight and a ... more Self-Compacting Concrete (SCC) is a flowing mixture that consolidates under its own weight and a highly workable concrete that can flow through densely reinforced and complex structural elements. The source material like a granular aggregate is often used in construction but difficult to find and the price is expensive. In developing country like Malaysia, the demand of natural sand is quite high to the rapid infrastructural growth. The aims for this paper is to study the effect of coal bottom ash on the replacement level of coal bottom ash as partial replacement of fine aggregate in SCC and to investigate the effect of coal bottom ash on the split tensile strength. The test involved designation of 0%, 10%, 20% and 30% of coal bottom ash (CBA) as a partial replacement of fine aggregate with variation of water cement ratio of 0.35, 0.40 and 0.45. The results shows that slump flow, Lbox ratio and sieve segregation resistance of SCC mixtures with CBA are decreased, while T 500 slump flow time increased with the increase of CBA replacement level. The highest tensile strength of SCC is 4.25 MPa achieved by control sample with the water cement ratio of 0.35 at the age 28 days. The increment of CBA replacement levels resulted in the reduction of split tensile strength and density of SCC. Meanwhile, the increment of water cement ratio was reduced the split tensile strength of SCC.
Applied Mechanics and Materials, 2015
Self-compacting concrete which commonly abbrevited as SCC is a special concrete that have the abi... more Self-compacting concrete which commonly abbrevited as SCC is a special concrete that have the ability to consilodate fully under its own self-weight without any internal or external vibration. This paper presents the experimental investigation carried out to study the strength of self-compacting concrete incorporating bottom ash at different replacement level of natural sand. The composite cement was used and the replacement level of bottom ash to natural sand is set up to 30% by volume. The strength properties such as compressive strength, split tensile strength and flexural strength of the concrete at the age of 7 and 28 days of curing day were conducted. Results shows that the strength of the concrete with bottom ash increased up to replacement level 15% higher than control specimens. This show that bottom ash can be used as supplimentary cementitious materials, having the pozzolanic reactivty.
Applied Mechanics and Materials, 2014
Bottom ash is a solid residue produced through combustion process in a coal-fired power plant. It... more Bottom ash is a solid residue produced through combustion process in a coal-fired power plant. It has been catogarized as a waste and usually disposed in the utility disposed site. With higher demand on the power energy, more coal-power plant are constructed and abundance of bottom ash are produced. Recently, the utilization of bottom ash in the construction industry has gained the interest of researches. Since it has similiar particle size distribution as normal sand, many attempt has been made in studying it potential use in mortar and concrete. In complementary to that, this paper presents the effect of bottom ash on fresh and hardened properties of self-compacting concrete (SCC). Bottom ash is used as fine aggregate replacing sand with replacement ratio range from 0% to 30% by volume. The effects of bottom ash on the SCC were investigated by comparing the test result of SCC mixed bottom ash with control specimens (0% of bottom ash). The test result on fresh properties of the con...
Civil Engineering and Architecture, 2021
Kerian and other villages further downstream are vulnerable to dam failure as Bukit Merah Dam is ... more Kerian and other villages further downstream are vulnerable to dam failure as Bukit Merah Dam is an aging Malaysian dam, having been used since 1906. The aim of this article is to evaluate how the demographic characteristics of downstream communities affect their perceptions of the existing dam. The article will also analyze the effect these demographic characteristics have on the awareness levels of dam failure risk and the implementation of the Emergency Action Plan (EAP) by Department of Irrigation and Drainage Kerian (DID). The vulnerability of the downstream communities to a dam failure disaster can be minimized by their own preparedness for actions that should be taken during a dam failure event. This study opted for a quantitative approach, which included a questionnaire survey. The data discussion revealed that the demographic characteristics influenced the community perceptions of the dam, their awareness of a dam failure disaster and the implementation of the EAP by DID Kerian. From the result, it can be concluded that the dam has positive impacts on the livelihoods of downstream communities as mean outputs for this analysis are above 3.0. For the standard deviation, the value was 0.595, 0.747 and 0.533, meaning that demographic characteristics influenced the communities' perceptions. They know the potential future risk (66.7% to 100% said 'yes' in the statement of risk awareness) but lack knowledge about the implementation of the EAP (42.9% to 75.0% responded 'no' in the statement of EAP knowledge). Most respondents accepted the EAP positively and are trying to understand the importance of the EAP.
The Journal of The Institution of Engineers, Malaysia, 2020
Changes in rainfall pattern, rapid urbanization, infrastructure development and uncontrolled agri... more Changes in rainfall pattern, rapid urbanization, infrastructure development and uncontrolled agricultural activities have been found as major sources to contribute to excessive reservoir sedimentation problem in Malaysia, thus significantly shorten the design life of a reservoir. Hence, reservoir functions have deteriorated, such as reduction in power generation capacity, additional lateral load affected to dam stability and decrease in storage capacity for flood control. The objective of this study is to model, simulate and propose alternative method for sediment removal control in Ringlet Reservoir. The construction of physical model of Ringlet Reservoir took place in the Hydraulic and Instrumentation Laboratory, National Hydraulic Research Institute of Malaysia (NAHRIM), with geometric similitude of 1:30. Three different average recurrent intervals (ARI) of 1, 5 and 100 were tested at Sungai Habu and Ringlet. Groyne was identified as a control mitigation structure for sediment co...
Concrete durability remains a concern in the construction industry due to salt attacks that accel... more Concrete durability remains a concern in the construction industry due to salt attacks that accelerate concrete deterioration. The salt attack has a significant impact on concrete durability and thus reduces the concrete lifespan. Detailed background information on concrete deterioration is presented in this chapter. This chapter also covers the concepts and mechanisms of salt attack in concrete. The influential factors affecting salt attack such as cement type, water binder ratio, and curing condition are discussed in detail. Moreover, aggressive exposure conditions such as wetting and drying and freeze and thawing are also briefed in this chapter. 1.1 Historical Background of Concrete Deterioration Concrete is themost commonmaterial used in construction for various purposes such as dams, highways, buildings, foundations, etc. Besides, concrete is fundamentally brittle and thus is susceptible to form cracks, which then affects the durability of concrete structures. In other words, ...
Properties of Self-Compacting Concrete with Coal Bottom Ash Under Aggressive Environments, 2021
The penetration of harmful chemical ions such as sulphate and chloride ions into the concrete mat... more The penetration of harmful chemical ions such as sulphate and chloride ions into the concrete matrix is one of the leading causes of steel reinforcement corrosion. This has considerably affected both the compressive strength and service life of the concrete structure. As a result, cement-based concrete structures exposed to harsh conditions should be appropriately designed to achieve high strength and meet durability requirements. One of the sustainable strategies for prolonging a concrete lifespan is the use of coal bottom ash in self-compacting concrete. A brief background of both the sulphate attack and the chloride attack mechanism is highlighted in this chapter. The effects of different CBA replacement levels as fine aggregates in SCC exposed to sodium sulphate (Na2SO4) and sodium chloride (NaCl) solution are discussed in detail.
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Papers by Ahmad Farhan Hamzah