Jamal Khatib - Academia.edu (original) (raw)
Papers by Jamal Khatib
International Journal of Technology, 2022
This paper reports a study on producing admixtures from chitosan (Ch) obtained from shrimp shell ... more This paper reports a study on producing admixtures from chitosan (Ch) obtained from shrimp shell treatment. The admixtures (Ch-g-AA) were based on chitosan (Ch) and acrylic acid (AA) in the following composition ratios: 65/35, 50/50, and 35/65. The grafted copolymers were synthesized using grafting polymerization and potassium persulphate as the initiator. This study investigated the properties of mortars in the presence of grafted copolymers, including setting time, workability, water absorption, and compressive strength. The results showed that grafted copolymers premixed with mortar mixes improved the properties of the mortar. However, increasing the AA ratio in the grafted copolymer decreased the W/C ratio, setting time, and water absorption, whereas the fluidity and compressive strength increased.
International Journal of Basic and Applied Sciences, 2014
Copolymer solution latexes based on 2-hydroxy ethyl acrylate (2-HEA) with butylacrylate (BuA) P[2... more Copolymer solution latexes based on 2-hydroxy ethyl acrylate (2-HEA) with butylacrylate (BuA) P[2-HEA-co-BuA], were synthesized with different composition ratios [(99: 01), (97: 03), (95: 05)] using azo-bisisobutyro-nitrile (ABIN) as free radical initiation system. The obtained latexes were characterized by H NMR, 1 FT-IR, DSC and GPC. The results showed that the molecular weight of latexes increase with increasing ratio of BuA in the copolymer. The effect of copolymer latexes in presence of NaOH on properties of Portland cement (PC) was studied. Various formulations were designed to investigate the effects ofprocess variables such as composition ratio of monomers and pH on the physico-mechanicalproperties of PC. The water of consistency decreased with latexes addition, whereas the setting times (initialand final) increased. The compressive strength slightly increased during the early stages of hydration and sharply increased during the later stages. Adding latexes improved the workability, densityand combined water content of PC. Moreover, increasing BuA content in the composition ratio improves the properties of PC. However the increasing pH of copolymer latexes improved the properties of PC more than without pH.
Engineering Sciences, 2011
The potential uses and the high cost of land-filling of used foundry sands have prompted research... more The potential uses and the high cost of land-filling of used foundry sands have prompted research into their beneficial reuse. This paper presents the results of experimental research into concrete produced by replacing the natural aggregates with recycled aggregates coming from foundry industries. Little work has been done so far on the effect of used foundry sand on the durability of concrete especially water absorption. The main aim of this work was to determine capillary water absorption and methods of improvement. Capillary water absorption, compressive strength and ultrasonic pulse velocity at 28 days of curing were reported in this investigation. The natural was replaced with 0%, 30%, 60% and 100% with foundry sand. Coarse natural aggregate was used in all cases and the amount of cement and W/C ratio of 0.5 remained constant in the all mixes. There was an increase in capillary water absorption (C.W.A), a decrease in compressive strength and ultrasonic pulse velocity (U.P.V) w...
Sustainability
The construction industry is known as one of the biggest generators of solid waste. Considering t... more The construction industry is known as one of the biggest generators of solid waste. Considering this, attention needs to be paid to construction and demolition (C&D) waste. Lebanon has experienced many situations that have increased the generation of C&D waste. Therefore, it is essential to manage C&D waste. This research aims to assess and analyse the importance of waste management plans and their impact on the generation of construction and demolition waste in Lebanon. For this purpose, an extensive literature review has been carried out, and a questionnaire survey consisting of five sections has been developed. Factors were ranked by using 5-point Likert scales. Additionally, four optional open-ended questions were also included in the survey for qualitative data collection. A survey questionnaire was sent to 80 Lebanese experts, and 50 questionnaires were returned. Most of the responses (i.e., consultants and academics) were from the private sector; results showed that responden...
Sustainability
Among many alternatives to replace sand in cement-based materials, cathode-ray tube (CRT) glass e... more Among many alternatives to replace sand in cement-based materials, cathode-ray tube (CRT) glass emerges as a suitable replacement for many reasons. This paper provides a state-of-the-art review on the use of cathode-ray tube (CRT) glass waste in cement-based concrete and mortar in accordance with PRISMA guidelines. The new aspects of the research are the literature coverage up to 2021 which would make it distinct from other articles. This review would act as a catalyst to use CRT glass waste in concrete mixtures. A total of 61 papers from literature were analyzed with emphasis on the fresh, mechanical, and durability performance of cement-based materials containing CRT glass waste as fine aggregates. The analysis revealed that the majority of the studies agreed that replacing sand with CRT glass waste increased the consistency where the low permeability of the CRT glass caused this effect. Strength of cement-based materials, on the other hand, decreased due to the weaker bond betwee...
Buildings
The improper curing of concrete can seriously affect its hardened properties. However, a large qu... more The improper curing of concrete can seriously affect its hardened properties. However, a large quantity of water is required to cure concrete after casting. Water is a valuable resource and its availability is posing a particular challenge in the Middle East including the Kurdistan region of Iraq. Self-curing concrete may be considered a novel curing method in that the water inside the concrete mix is retained so that hydration can continue without the supply of additional water after casting. Therefore, the aim of this study was to include a self-curing agent, named Polyethylene glycol-400 (PEG-400), as one of the concrete mix constituents in order to save water that is normally required after casting. Six concrete mixes were cast with a constant W/C ratio of 0.5; two of them were ordinary concrete mixes whereas the other mixes contained 0.5%, 1%, 1.5%, and 2% of PEG-400 by weight of cement. All concrete ingredients, except the PEG-400, were provided locally. Three different curing...
Buildings
Newer technologies such as warm mix asphalt (WMA) and reclaimed asphalt pavement (RAP) have gaine... more Newer technologies such as warm mix asphalt (WMA) and reclaimed asphalt pavement (RAP) have gained international approval and have been considered as appropriate solutions that support the sustainability goals of the highway sector. However, both technologies present some shortcomings. The lower mixing and compaction temperatures of WMA reduce the binder aging and the bond between the aggregates and the coating binder, thus resulting in less rutting resistance and higher moisture susceptibility. On the other hand, RAP mixes tend to be stiffer and more brittle than conventional hot mix asphalt (HMA) due to the effect of aged binder. This tends to increase the crack propagation distresses. In an attempt to overcome their individual shortcomings, this study investigated the new concept of a combined WMA-RAP technology. The chemical WMA additive Rediset LQ1102CE was utilized with mixtures incorporating low (15%), medium (25%), and high (45%) RAP contents. Dynamic modulus (DM) and flow n...
Buildings
Nowadays, the increasing demand for concrete is causing serious environmental impact including po... more Nowadays, the increasing demand for concrete is causing serious environmental impact including pollution and waste generation, rapid depletion of natural resources, and increased CO2 emission. Incorporating natural fibers in concrete can contribute toward environmental sustainability. This paper is concerned with the use of natural fibers obtained from the plant species Phragmites australis (PA). The plant is invasive, and rapidly grows abundantly along rivers and waterways, causing major ecological problems. This research is part of a wide range investigation on the use of natural fibers produced from the stem of PA plants in concrete. Using a machine, plant stems were crushed into fibers measuring 40 mm in length and 2 mm in width, and treated with 4% NaOH solution for 24 h. A total of four concrete mixes were prepared with varying additions of treated fibers, ranging from 0% to 1.5% (by volume) with water to cement ratio of 0.5% (by volume). Concrete specimens were tested at 3, 7...
BAU Journal - Science and Technology, 2021
The rapid growth in the construction industry at the global level has made concrete the most wide... more The rapid growth in the construction industry at the global level has made concrete the most widely used construction material throughout the world. Accordingly, the consumption of natural sand which is one the main raw material constituent of concrete is continuously growing. The demand for river sand is highly increasing due to its scarcity in the market. Manufactured sand produced by crushed rock is being considered as an appropriate alternative to replace river sand in concrete. In recent years, there is a growing interest in the use of crushed sand obtained from limestone quarries in some countries where river sand is not widely available". The objective of this study is to investigate the effect of total replacement of the natural sand by fine aggregates obtained from crushed limestone. However, it needs more research on the crushed stone fine aggregates to reveal its engineering properties prior to utilization in concrete. Another objective of this study is to study the effect of using the waste engine oil as partial replacement of water reducing admixture. The use of waste engine oil in concrete is beneficial for the environment. It is to be noted that some countries are recycling this used oil but others are throwing it in the sea and harming the marine life. In this paper, different combinations and grading of fine lime stone and coarse aggregates were tried in order to attain the optimal proportion that provide an acceptable concrete performance in terms of workability and compressive strength. Also, different percentages of admixture replacement ranging from zero to one hundred percent of the used engine oil were tried in the selected optimal mixture proportion. The final selected proportion using engine oil and crushed limestone could be considered as an economical solution and friendly environmental concrete product.
BAU Journal - Science and Technology, 2019
The generation of waste materials is causing an impact on the environment due to many reasons inc... more The generation of waste materials is causing an impact on the environment due to many reasons including the effect on human health and decrease in landfill space. Of these waste materials is the waste cooking oil. There are large amounts of waste vegetable oil generated in the world and most of it is disposed of in the sewer system which can cause problems when treating wastewater. This paper is a review of literature on the use of vegetable oil (VO) and waste vegetable oil (WVO) as chemical admixtures in construction materials. The construction materials include mainly concrete and pavement. The properties examined were fresh, mechanical and durability properties. Fresh properties included slump test while the mechanical properties comprised compressive and flexural strength as well as shrinkage. The durability and durability related properties consisted of water absorption both by total immersion and capillary action, carbonation and efflorescence. This review suggests that virgin vegetable oil and its waste has the potential to be used as chemical admixtures in construction materials to improve their workability water resistance.
Environments, 2022
Numerous studies investigated the possibility of incorporating plastic wastes in concrete mixture... more Numerous studies investigated the possibility of incorporating plastic wastes in concrete mixtures, thus contributing to efficient management and sustainable development of the construction industry. This paper investigates the possibility of reducing the water-to-cement ratio and/or incorporating steel fibers or polymeric latexes to mitigate the drop in structural properties of reinforced concrete (RC) beams containing polyethylene terephthalate (PET) additions. The PET was derived from waste plastic bottles that were shredded into small pieces and added during concrete batching at 1.5% to 4.5%, by total volume. Test results showed that the concrete plain and structural properties degrade with PET additions, given their lightweight nature and poor characteristic strength compared to aggregate particles. The reduction of w/c from 0.55 to 0.46 proved efficient to refine the matrix porosity and reinstate the shear and flexural strengths of RC beams. Moreso, the incorporation of 0.8% s...
Using fibers in concrete applications has become a common practice. This is partly due to improve... more Using fibers in concrete applications has become a common practice. This is partly due to improvement in ductility and crack control of concrete. There will be an added advantage if these fibers come from a waste source as it would lead to reduction in environmental pollution and the need for landfill spaces. This paper forms the initial part of a wide range investigation on the use of waste plastic fibers in concrete applications. This study attempts to apply the concept of sustainability and reduces the environmental pollution by producing fibers from waste plastic straws and adding them to plain concrete to improve the tensile strength and ductility. The experimental work was carried to examine the effect of including waste plastic fibers on the properties of concrete. The fiber percentages used were 0%, 0.5%, 1.5% and 3%. Testing included workability, density, compressive and tensile strength, ultrasonic pulse velocity and length change. Generally, the addition of waste plastic fibers increased the tensile strength, whereas there was a slight reduction in compressive strength when more plastic fibers were added. The ultrasonic pulse velocity and density show a slight decrease in the presence of fibers.
The behaviour of concrete, whether fresh or hardened, depends basically on the behaviour of its c... more The behaviour of concrete, whether fresh or hardened, depends basically on the behaviour of its components and the relationship between them, therefore, obtaining a concrete with certain properties depends fundamentally on the concrete mix design. Concrete mix design generally includes two main steps: 1-Selection of the main components suitable for the concrete (cement, aggregate, water, and additives); 2-Determination of more economical mix ratios to fulfil the workability, strength and efficiency requirements. Currently, there are many international methods locally approved for mix designs. They are all related to each other, they give relatively the same quantities of the mix components and they are all capable of providing a good concrete mix. It is important to consider that these methods give approximate quantities which should be checked by experimental mixes in order to obtain results suitable for the requirements of the local environment and local materials. The ACI and BS methods are the most commonly used. Both of these methods depend on graphs and standard tables derived from previous research experience and actual concrete production as well as studies of the properties of the materials used. This paper illustrates a new approach for concrete mix design named as: "Double Coating Method", which is currently used in some research centers in the republic of Poland and was recently applied in the laboratories of the Civil Engineering Departments in the Universities of Tripoli and Benghazi in Libya. This paper describes experiment in which 24 mixtures were used to assess the usefulness of this technique for problem of proportioning concrete mixtures in general.
Cathode-ray tube (CRT) glass is a hazardous material that should be responsibly managed when disp... more Cathode-ray tube (CRT) glass is a hazardous material that should be responsibly managed when disposed. One of the possible options for recycling CRT waste glass is using it as fine aggregates in concrete for its richness in silica. For the aim of evaluating concrete with this material, four mixes with replacement levels of 0%, 10%, 20% and 30% are prepared. Workability, hardened density, ultra-pulse velocity, compressive strength, tensile strength, and static modulus of elasticity were examined. Experimental results showed that the use of CRT improved properties of concrete at certain replacement levels. CRT glass improved the workability of concrete where mixes with CRT required less water reducer to reach the same slump. Hardened density increased with the increase of the CRT glass. The mechanical properties of the concrete were enhanced at 10% replacement level only. In general, CRT glass proved to be adequate as a replacement for sand in concrete
BAU Journal - Science and Technology, 2020
Corrosion of reinforcing steel is the one of the main causes of deterioration in reinforced concr... more Corrosion of reinforcing steel is the one of the main causes of deterioration in reinforced concrete structure. During the initial stage of corrosion, the steel volume increases. This creates tensile stresses in the concrete, which can eventually lead to cracking, delamination, and spalling. This potential risk of corrosion in a structure is quite unpredictable. Therefore, this paper examines the influence of accelerated corrosion on the bond between concrete and the coated and uncoated steel bars. The bar coating consisted of epoxy rich in zinc. Six concrete mixes were prepared. Three mixes had cement contents of 300, 400 and 500 Kg/m3 and a water cement ratio of 0.4. In the rest of the mixes, cement was replaced with 10% silica fume and the water to binder ratio was 0.5. The reinforcing bars were placed inside concrete cylinders. After curing for 3 days, the specimens were immersed in a 5% NaCl solution for 7 days while a DC current of 5V flowed through them using a portable power...
![Research paper thumbnail of Implementing the last planner TM system in a road construction project in Nigeria / Ograbe Ahiakwo … [et al.]](https://attachments.academia-assets.com/96296289/thumbnails/1.jpg)
](This paper describes a research investigation into the implementation of the Last Planner System ... more This paper describes a research investigation into the implementation of the Last Planner System (LPS) in a road construction project. LPS is known to be the most developed practical use of Lean Construction. It focuses on minimising the negative impacts of variability, uncertainties, buffers, making projects more predictable, creating reliable work plans and convalescing collaborative planning. LPS is unpopular in highway and road construction projects, as a lot of case studies have been recorded of its application on infrastructure and building projects as against highway and road projects. However in the road project. In order to achieve this aim, an Action Research strategy is adopted using different data collection methods such as interviews, observation and survey questionnaire. The initial state of production plan reliability within this case project was observed to be highly unreliable with a high degree of variability. However as the implementation commenced, production pla...
Journal of Environmental Engineering and Landscape Management, 2011
Wastewater from infected leprosy patients is expected to contain considerably higher concentratio... more Wastewater from infected leprosy patients is expected to contain considerably higher concentrations of pathogens than standard domestic wastewater and, therefore, is more infectious. Isolation of lepers' is thought to prevent the spread of a wide range of infectious diseases that could potentially be contacted through direct or indirect exposure from an infected person's wastewater in the surrounding environment. However, inappropriate management of wastewater and sewage from these camps has led to contamination of the surrounding environment, typical in Nigeria. This study aims to recommend safe, efficient and sustainable management of wastewater and sewage in a lepers' colony in Ogbomosho, south west Nigeria. The case study is privately owned, with three camps and a leprosarium. Information and data (primary and secondary) were collected from medical personnel (doctors, matrons and nurses), management staff and lepers in each camp, through handdelivered and orally expl...
Construction and Building Materials, 2005
The influence of incorporating ground granulated blastfurnace slag (GGBS) and metakaolin (MK) on ... more The influence of incorporating ground granulated blastfurnace slag (GGBS) and metakaolin (MK) on concrete strength is investigated. Portland cement was partially replaced with 0–80% GGBS and 0–20% MK. The water to cementitious materials ratio was maintained at 0.5 for all mixes. The incorporation of MK causes an increase in strength, especially during the early ages of curing. However, the use
Cement and Concrete Research, 2005
The properties of concrete containing fine recycled aggregate are investigated. Recycled aggregat... more The properties of concrete containing fine recycled aggregate are investigated. Recycled aggregate consisted of crushed concrete (CC) or crushed brick (CB) with particles less than 5 mm in diameter. The free water/cement ratio was kept constant for all mixes. The fine aggregate in concrete was replaced with 0%, 25%, 50% and 100% CC or CB. Generally, there is strength reduction of 15-30% for concrete containing CC. However, concrete incorporating up to 50% CB exhibits similar long-term strength to that of the control. Even at 100% replacement of fine aggregate with CB, the reduction in strength is only 10%. Beyond 28 days of curing, the rate of strength development in concrete containing either CC or CB is higher than that of the control indicating further cementing action in the presence of fine recycled aggregate. More shrinkage and expansion occur in concrete containing CC or CB.
Cement and Concrete Research, 1996
The role of metakaolin (MK) in enhancing the strength of concrete is reviewed and the principal m... more The role of metakaolin (MK) in enhancing the strength of concrete is reviewed and the principal mechanisms identified. Metakaolin concretes with a range of MK contents (030%) have been cured for periods of 1 to 90 days. The change in relative strength with both curing time ...
International Journal of Technology, 2022
This paper reports a study on producing admixtures from chitosan (Ch) obtained from shrimp shell ... more This paper reports a study on producing admixtures from chitosan (Ch) obtained from shrimp shell treatment. The admixtures (Ch-g-AA) were based on chitosan (Ch) and acrylic acid (AA) in the following composition ratios: 65/35, 50/50, and 35/65. The grafted copolymers were synthesized using grafting polymerization and potassium persulphate as the initiator. This study investigated the properties of mortars in the presence of grafted copolymers, including setting time, workability, water absorption, and compressive strength. The results showed that grafted copolymers premixed with mortar mixes improved the properties of the mortar. However, increasing the AA ratio in the grafted copolymer decreased the W/C ratio, setting time, and water absorption, whereas the fluidity and compressive strength increased.
International Journal of Basic and Applied Sciences, 2014
Copolymer solution latexes based on 2-hydroxy ethyl acrylate (2-HEA) with butylacrylate (BuA) P[2... more Copolymer solution latexes based on 2-hydroxy ethyl acrylate (2-HEA) with butylacrylate (BuA) P[2-HEA-co-BuA], were synthesized with different composition ratios [(99: 01), (97: 03), (95: 05)] using azo-bisisobutyro-nitrile (ABIN) as free radical initiation system. The obtained latexes were characterized by H NMR, 1 FT-IR, DSC and GPC. The results showed that the molecular weight of latexes increase with increasing ratio of BuA in the copolymer. The effect of copolymer latexes in presence of NaOH on properties of Portland cement (PC) was studied. Various formulations were designed to investigate the effects ofprocess variables such as composition ratio of monomers and pH on the physico-mechanicalproperties of PC. The water of consistency decreased with latexes addition, whereas the setting times (initialand final) increased. The compressive strength slightly increased during the early stages of hydration and sharply increased during the later stages. Adding latexes improved the workability, densityand combined water content of PC. Moreover, increasing BuA content in the composition ratio improves the properties of PC. However the increasing pH of copolymer latexes improved the properties of PC more than without pH.
Engineering Sciences, 2011
The potential uses and the high cost of land-filling of used foundry sands have prompted research... more The potential uses and the high cost of land-filling of used foundry sands have prompted research into their beneficial reuse. This paper presents the results of experimental research into concrete produced by replacing the natural aggregates with recycled aggregates coming from foundry industries. Little work has been done so far on the effect of used foundry sand on the durability of concrete especially water absorption. The main aim of this work was to determine capillary water absorption and methods of improvement. Capillary water absorption, compressive strength and ultrasonic pulse velocity at 28 days of curing were reported in this investigation. The natural was replaced with 0%, 30%, 60% and 100% with foundry sand. Coarse natural aggregate was used in all cases and the amount of cement and W/C ratio of 0.5 remained constant in the all mixes. There was an increase in capillary water absorption (C.W.A), a decrease in compressive strength and ultrasonic pulse velocity (U.P.V) w...
Sustainability
The construction industry is known as one of the biggest generators of solid waste. Considering t... more The construction industry is known as one of the biggest generators of solid waste. Considering this, attention needs to be paid to construction and demolition (C&D) waste. Lebanon has experienced many situations that have increased the generation of C&D waste. Therefore, it is essential to manage C&D waste. This research aims to assess and analyse the importance of waste management plans and their impact on the generation of construction and demolition waste in Lebanon. For this purpose, an extensive literature review has been carried out, and a questionnaire survey consisting of five sections has been developed. Factors were ranked by using 5-point Likert scales. Additionally, four optional open-ended questions were also included in the survey for qualitative data collection. A survey questionnaire was sent to 80 Lebanese experts, and 50 questionnaires were returned. Most of the responses (i.e., consultants and academics) were from the private sector; results showed that responden...
Sustainability
Among many alternatives to replace sand in cement-based materials, cathode-ray tube (CRT) glass e... more Among many alternatives to replace sand in cement-based materials, cathode-ray tube (CRT) glass emerges as a suitable replacement for many reasons. This paper provides a state-of-the-art review on the use of cathode-ray tube (CRT) glass waste in cement-based concrete and mortar in accordance with PRISMA guidelines. The new aspects of the research are the literature coverage up to 2021 which would make it distinct from other articles. This review would act as a catalyst to use CRT glass waste in concrete mixtures. A total of 61 papers from literature were analyzed with emphasis on the fresh, mechanical, and durability performance of cement-based materials containing CRT glass waste as fine aggregates. The analysis revealed that the majority of the studies agreed that replacing sand with CRT glass waste increased the consistency where the low permeability of the CRT glass caused this effect. Strength of cement-based materials, on the other hand, decreased due to the weaker bond betwee...
Buildings
The improper curing of concrete can seriously affect its hardened properties. However, a large qu... more The improper curing of concrete can seriously affect its hardened properties. However, a large quantity of water is required to cure concrete after casting. Water is a valuable resource and its availability is posing a particular challenge in the Middle East including the Kurdistan region of Iraq. Self-curing concrete may be considered a novel curing method in that the water inside the concrete mix is retained so that hydration can continue without the supply of additional water after casting. Therefore, the aim of this study was to include a self-curing agent, named Polyethylene glycol-400 (PEG-400), as one of the concrete mix constituents in order to save water that is normally required after casting. Six concrete mixes were cast with a constant W/C ratio of 0.5; two of them were ordinary concrete mixes whereas the other mixes contained 0.5%, 1%, 1.5%, and 2% of PEG-400 by weight of cement. All concrete ingredients, except the PEG-400, were provided locally. Three different curing...
Buildings
Newer technologies such as warm mix asphalt (WMA) and reclaimed asphalt pavement (RAP) have gaine... more Newer technologies such as warm mix asphalt (WMA) and reclaimed asphalt pavement (RAP) have gained international approval and have been considered as appropriate solutions that support the sustainability goals of the highway sector. However, both technologies present some shortcomings. The lower mixing and compaction temperatures of WMA reduce the binder aging and the bond between the aggregates and the coating binder, thus resulting in less rutting resistance and higher moisture susceptibility. On the other hand, RAP mixes tend to be stiffer and more brittle than conventional hot mix asphalt (HMA) due to the effect of aged binder. This tends to increase the crack propagation distresses. In an attempt to overcome their individual shortcomings, this study investigated the new concept of a combined WMA-RAP technology. The chemical WMA additive Rediset LQ1102CE was utilized with mixtures incorporating low (15%), medium (25%), and high (45%) RAP contents. Dynamic modulus (DM) and flow n...
Buildings
Nowadays, the increasing demand for concrete is causing serious environmental impact including po... more Nowadays, the increasing demand for concrete is causing serious environmental impact including pollution and waste generation, rapid depletion of natural resources, and increased CO2 emission. Incorporating natural fibers in concrete can contribute toward environmental sustainability. This paper is concerned with the use of natural fibers obtained from the plant species Phragmites australis (PA). The plant is invasive, and rapidly grows abundantly along rivers and waterways, causing major ecological problems. This research is part of a wide range investigation on the use of natural fibers produced from the stem of PA plants in concrete. Using a machine, plant stems were crushed into fibers measuring 40 mm in length and 2 mm in width, and treated with 4% NaOH solution for 24 h. A total of four concrete mixes were prepared with varying additions of treated fibers, ranging from 0% to 1.5% (by volume) with water to cement ratio of 0.5% (by volume). Concrete specimens were tested at 3, 7...
BAU Journal - Science and Technology, 2021
The rapid growth in the construction industry at the global level has made concrete the most wide... more The rapid growth in the construction industry at the global level has made concrete the most widely used construction material throughout the world. Accordingly, the consumption of natural sand which is one the main raw material constituent of concrete is continuously growing. The demand for river sand is highly increasing due to its scarcity in the market. Manufactured sand produced by crushed rock is being considered as an appropriate alternative to replace river sand in concrete. In recent years, there is a growing interest in the use of crushed sand obtained from limestone quarries in some countries where river sand is not widely available". The objective of this study is to investigate the effect of total replacement of the natural sand by fine aggregates obtained from crushed limestone. However, it needs more research on the crushed stone fine aggregates to reveal its engineering properties prior to utilization in concrete. Another objective of this study is to study the effect of using the waste engine oil as partial replacement of water reducing admixture. The use of waste engine oil in concrete is beneficial for the environment. It is to be noted that some countries are recycling this used oil but others are throwing it in the sea and harming the marine life. In this paper, different combinations and grading of fine lime stone and coarse aggregates were tried in order to attain the optimal proportion that provide an acceptable concrete performance in terms of workability and compressive strength. Also, different percentages of admixture replacement ranging from zero to one hundred percent of the used engine oil were tried in the selected optimal mixture proportion. The final selected proportion using engine oil and crushed limestone could be considered as an economical solution and friendly environmental concrete product.
BAU Journal - Science and Technology, 2019
The generation of waste materials is causing an impact on the environment due to many reasons inc... more The generation of waste materials is causing an impact on the environment due to many reasons including the effect on human health and decrease in landfill space. Of these waste materials is the waste cooking oil. There are large amounts of waste vegetable oil generated in the world and most of it is disposed of in the sewer system which can cause problems when treating wastewater. This paper is a review of literature on the use of vegetable oil (VO) and waste vegetable oil (WVO) as chemical admixtures in construction materials. The construction materials include mainly concrete and pavement. The properties examined were fresh, mechanical and durability properties. Fresh properties included slump test while the mechanical properties comprised compressive and flexural strength as well as shrinkage. The durability and durability related properties consisted of water absorption both by total immersion and capillary action, carbonation and efflorescence. This review suggests that virgin vegetable oil and its waste has the potential to be used as chemical admixtures in construction materials to improve their workability water resistance.
Environments, 2022
Numerous studies investigated the possibility of incorporating plastic wastes in concrete mixture... more Numerous studies investigated the possibility of incorporating plastic wastes in concrete mixtures, thus contributing to efficient management and sustainable development of the construction industry. This paper investigates the possibility of reducing the water-to-cement ratio and/or incorporating steel fibers or polymeric latexes to mitigate the drop in structural properties of reinforced concrete (RC) beams containing polyethylene terephthalate (PET) additions. The PET was derived from waste plastic bottles that were shredded into small pieces and added during concrete batching at 1.5% to 4.5%, by total volume. Test results showed that the concrete plain and structural properties degrade with PET additions, given their lightweight nature and poor characteristic strength compared to aggregate particles. The reduction of w/c from 0.55 to 0.46 proved efficient to refine the matrix porosity and reinstate the shear and flexural strengths of RC beams. Moreso, the incorporation of 0.8% s...
Using fibers in concrete applications has become a common practice. This is partly due to improve... more Using fibers in concrete applications has become a common practice. This is partly due to improvement in ductility and crack control of concrete. There will be an added advantage if these fibers come from a waste source as it would lead to reduction in environmental pollution and the need for landfill spaces. This paper forms the initial part of a wide range investigation on the use of waste plastic fibers in concrete applications. This study attempts to apply the concept of sustainability and reduces the environmental pollution by producing fibers from waste plastic straws and adding them to plain concrete to improve the tensile strength and ductility. The experimental work was carried to examine the effect of including waste plastic fibers on the properties of concrete. The fiber percentages used were 0%, 0.5%, 1.5% and 3%. Testing included workability, density, compressive and tensile strength, ultrasonic pulse velocity and length change. Generally, the addition of waste plastic fibers increased the tensile strength, whereas there was a slight reduction in compressive strength when more plastic fibers were added. The ultrasonic pulse velocity and density show a slight decrease in the presence of fibers.
The behaviour of concrete, whether fresh or hardened, depends basically on the behaviour of its c... more The behaviour of concrete, whether fresh or hardened, depends basically on the behaviour of its components and the relationship between them, therefore, obtaining a concrete with certain properties depends fundamentally on the concrete mix design. Concrete mix design generally includes two main steps: 1-Selection of the main components suitable for the concrete (cement, aggregate, water, and additives); 2-Determination of more economical mix ratios to fulfil the workability, strength and efficiency requirements. Currently, there are many international methods locally approved for mix designs. They are all related to each other, they give relatively the same quantities of the mix components and they are all capable of providing a good concrete mix. It is important to consider that these methods give approximate quantities which should be checked by experimental mixes in order to obtain results suitable for the requirements of the local environment and local materials. The ACI and BS methods are the most commonly used. Both of these methods depend on graphs and standard tables derived from previous research experience and actual concrete production as well as studies of the properties of the materials used. This paper illustrates a new approach for concrete mix design named as: "Double Coating Method", which is currently used in some research centers in the republic of Poland and was recently applied in the laboratories of the Civil Engineering Departments in the Universities of Tripoli and Benghazi in Libya. This paper describes experiment in which 24 mixtures were used to assess the usefulness of this technique for problem of proportioning concrete mixtures in general.
Cathode-ray tube (CRT) glass is a hazardous material that should be responsibly managed when disp... more Cathode-ray tube (CRT) glass is a hazardous material that should be responsibly managed when disposed. One of the possible options for recycling CRT waste glass is using it as fine aggregates in concrete for its richness in silica. For the aim of evaluating concrete with this material, four mixes with replacement levels of 0%, 10%, 20% and 30% are prepared. Workability, hardened density, ultra-pulse velocity, compressive strength, tensile strength, and static modulus of elasticity were examined. Experimental results showed that the use of CRT improved properties of concrete at certain replacement levels. CRT glass improved the workability of concrete where mixes with CRT required less water reducer to reach the same slump. Hardened density increased with the increase of the CRT glass. The mechanical properties of the concrete were enhanced at 10% replacement level only. In general, CRT glass proved to be adequate as a replacement for sand in concrete
BAU Journal - Science and Technology, 2020
Corrosion of reinforcing steel is the one of the main causes of deterioration in reinforced concr... more Corrosion of reinforcing steel is the one of the main causes of deterioration in reinforced concrete structure. During the initial stage of corrosion, the steel volume increases. This creates tensile stresses in the concrete, which can eventually lead to cracking, delamination, and spalling. This potential risk of corrosion in a structure is quite unpredictable. Therefore, this paper examines the influence of accelerated corrosion on the bond between concrete and the coated and uncoated steel bars. The bar coating consisted of epoxy rich in zinc. Six concrete mixes were prepared. Three mixes had cement contents of 300, 400 and 500 Kg/m3 and a water cement ratio of 0.4. In the rest of the mixes, cement was replaced with 10% silica fume and the water to binder ratio was 0.5. The reinforcing bars were placed inside concrete cylinders. After curing for 3 days, the specimens were immersed in a 5% NaCl solution for 7 days while a DC current of 5V flowed through them using a portable power...
This paper describes a research investigation into the implementation of the Last Planner System ... more This paper describes a research investigation into the implementation of the Last Planner System (LPS) in a road construction project. LPS is known to be the most developed practical use of Lean Construction. It focuses on minimising the negative impacts of variability, uncertainties, buffers, making projects more predictable, creating reliable work plans and convalescing collaborative planning. LPS is unpopular in highway and road construction projects, as a lot of case studies have been recorded of its application on infrastructure and building projects as against highway and road projects. However in the road project. In order to achieve this aim, an Action Research strategy is adopted using different data collection methods such as interviews, observation and survey questionnaire. The initial state of production plan reliability within this case project was observed to be highly unreliable with a high degree of variability. However as the implementation commenced, production pla...
Journal of Environmental Engineering and Landscape Management, 2011
Wastewater from infected leprosy patients is expected to contain considerably higher concentratio... more Wastewater from infected leprosy patients is expected to contain considerably higher concentrations of pathogens than standard domestic wastewater and, therefore, is more infectious. Isolation of lepers' is thought to prevent the spread of a wide range of infectious diseases that could potentially be contacted through direct or indirect exposure from an infected person's wastewater in the surrounding environment. However, inappropriate management of wastewater and sewage from these camps has led to contamination of the surrounding environment, typical in Nigeria. This study aims to recommend safe, efficient and sustainable management of wastewater and sewage in a lepers' colony in Ogbomosho, south west Nigeria. The case study is privately owned, with three camps and a leprosarium. Information and data (primary and secondary) were collected from medical personnel (doctors, matrons and nurses), management staff and lepers in each camp, through handdelivered and orally expl...
Construction and Building Materials, 2005
The influence of incorporating ground granulated blastfurnace slag (GGBS) and metakaolin (MK) on ... more The influence of incorporating ground granulated blastfurnace slag (GGBS) and metakaolin (MK) on concrete strength is investigated. Portland cement was partially replaced with 0–80% GGBS and 0–20% MK. The water to cementitious materials ratio was maintained at 0.5 for all mixes. The incorporation of MK causes an increase in strength, especially during the early ages of curing. However, the use
Cement and Concrete Research, 2005
The properties of concrete containing fine recycled aggregate are investigated. Recycled aggregat... more The properties of concrete containing fine recycled aggregate are investigated. Recycled aggregate consisted of crushed concrete (CC) or crushed brick (CB) with particles less than 5 mm in diameter. The free water/cement ratio was kept constant for all mixes. The fine aggregate in concrete was replaced with 0%, 25%, 50% and 100% CC or CB. Generally, there is strength reduction of 15-30% for concrete containing CC. However, concrete incorporating up to 50% CB exhibits similar long-term strength to that of the control. Even at 100% replacement of fine aggregate with CB, the reduction in strength is only 10%. Beyond 28 days of curing, the rate of strength development in concrete containing either CC or CB is higher than that of the control indicating further cementing action in the presence of fine recycled aggregate. More shrinkage and expansion occur in concrete containing CC or CB.
Cement and Concrete Research, 1996
The role of metakaolin (MK) in enhancing the strength of concrete is reviewed and the principal m... more The role of metakaolin (MK) in enhancing the strength of concrete is reviewed and the principal mechanisms identified. Metakaolin concretes with a range of MK contents (030%) have been cured for periods of 1 to 90 days. The change in relative strength with both curing time ...