Incorporating waste stone powders into the production of reactive powder concretes (RPCs) can be eco-friendly. Since high cementitious material content is used in producing RPCs, CO2, as a harmful greenhouse gas, was used for carbonation curing in this study. For this purpose, waste limestone powder was substituted by 0%, 18%, 36% and 54% of silica sand and the specimens were cured in water for up to 90 days in a CO2 chamber for up to 48 hours. The physical and mechanical properties of the concrete and the specimens' CO2 uptake were measured at different ages. Results showed that the 28-day compressive strength of the moist cured RPCs was higher than 100 MPa and the properties of the RPCs were improved by increasing limestone substitution. CO2 curing of the RPCs significantly increased the samples' compressive strength and limestone-powder substitution as silica sand significantly decreased the carbonation and autogenous shrinkages of the RPCs. Moreover, carbonation curing can make eco-friendly limestone-modified RPCs, where their properties are improved. KEYWORDS: CO2 curing, Reactive powder concrete, Waste limestone powder, Shrinkage.
{"title":"CO2 Curing of Reactive Powder Concretes Modified by Waste Limestone Powder","authors":"H. Rahmani, Nooshin Mohammadzade","doi":"10.14525/jjce.v17i3.08","DOIUrl":"https://doi.org/10.14525/jjce.v17i3.08","url":null,"abstract":"Incorporating waste stone powders into the production of reactive powder concretes (RPCs) can be eco-friendly. Since high cementitious material content is used in producing RPCs, CO2, as a harmful greenhouse gas, was used for carbonation curing in this study. For this purpose, waste limestone powder was substituted by 0%, 18%, 36% and 54% of silica sand and the specimens were cured in water for up to 90 days in a CO2 chamber for up to 48 hours. The physical and mechanical properties of the concrete and the specimens' CO2 uptake were measured at different ages. Results showed that the 28-day compressive strength of the moist cured RPCs was higher than 100 MPa and the properties of the RPCs were improved by increasing limestone substitution. CO2 curing of the RPCs significantly increased the samples' compressive strength and limestone-powder substitution as silica sand significantly decreased the carbonation and autogenous shrinkages of the RPCs. Moreover, carbonation curing can make eco-friendly limestone-modified RPCs, where their properties are improved. KEYWORDS: CO2 curing, Reactive powder concrete, Waste limestone powder, Shrinkage.","PeriodicalId":51814,"journal":{"name":"Jordan Journal of Civil Engineering","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2023-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42042503","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Shadman Rahman Sabab, H. Md. Shahin, Muftashin Muhim Bondhon, Md. Ehsan Kabir
This study focuses on establishing a robust relationship between Standard Penetration Test-N values (SPT-N), geotechnical parameters and unconfined compressive strength (qu) using regression analysis. The proposed relationship offers a reliable method for estimating qu based on SPT-N values. A comprehensive dataset comprising approximately 200 soil samples collected from various boreholes across Dhaka city was utilized. Multiple Linear Regression (MLR), Rando-forest Regression (RFR) and AdaBoost Regression techniques were employed to develop a unified correlation model. Evaluation metrics including R-squared (R2), Mean Absolute Error (MAE) and Root Mean Squared Error (RMSE), along with Trend-behavior Analysis were employed to assess and compare the performances of the models. Additionally, sensitivity analysis was carried out on the selected model in order to assess the importance of each parameter used to predict qu. Finally, the selected model was compared against the existing empirical models that were published in previous studies. In terms of evaluation metrics and Trend-behavior Analysis, the results showed that the RFR model performed better than the others. Additionally, the selected model outperformed the others, demonstrating the highest R2 score, the smallest RMSE and MAE values and lower residuals compared to the previous models. Hence, the proposed model provides accurate predictions of qu for clayey soil in Bangladesh. Its implementation could ensure more efficient geotechnical designs, specifically adjusted to the geological conditions of the Dhaka region. While previous studies have established regional equations for various parts of the world, our model uniquely has incorporated the Plasticity Index (PI) as a predictor for qu and is specifically calibrated for the geological characteristics of Dhaka city. The findings of this study highlight the effectiveness and applicability of regression analysis in predicting qu for Dhaka's soil properties, thus introducing a valuable tool for enhancing the accuracy and effectiveness of geotechnical assessments and design in the region. KEYWORDS: Unconfined compressive strength, Standard penetration test-N values, Plasticity index, Multiple linear regression, Random-forest regression, AdaBoost regression, Evaluation metrics, Trend-behavior analysis, Sensitivity analysis
{"title":"Regression Analysis for Predicting Soil Strength in Bangladesh","authors":"Shadman Rahman Sabab, H. Md. Shahin, Muftashin Muhim Bondhon, Md. Ehsan Kabir","doi":"10.14525/jjce.v17i3.14","DOIUrl":"https://doi.org/10.14525/jjce.v17i3.14","url":null,"abstract":"This study focuses on establishing a robust relationship between Standard Penetration Test-N values (SPT-N), geotechnical parameters and unconfined compressive strength (qu) using regression analysis. The proposed relationship offers a reliable method for estimating qu based on SPT-N values. A comprehensive dataset comprising approximately 200 soil samples collected from various boreholes across Dhaka city was utilized. Multiple Linear Regression (MLR), Rando-forest Regression (RFR) and AdaBoost Regression techniques were employed to develop a unified correlation model. Evaluation metrics including R-squared (R2), Mean Absolute Error (MAE) and Root Mean Squared Error (RMSE), along with Trend-behavior Analysis were employed to assess and compare the performances of the models. Additionally, sensitivity analysis was carried out on the selected model in order to assess the importance of each parameter used to predict qu. Finally, the selected model was compared against the existing empirical models that were published in previous studies. In terms of evaluation metrics and Trend-behavior Analysis, the results showed that the RFR model performed better than the others. Additionally, the selected model outperformed the others, demonstrating the highest R2 score, the smallest RMSE and MAE values and lower residuals compared to the previous models. Hence, the proposed model provides accurate predictions of qu for clayey soil in Bangladesh. Its implementation could ensure more efficient geotechnical designs, specifically adjusted to the geological conditions of the Dhaka region. While previous studies have established regional equations for various parts of the world, our model uniquely has incorporated the Plasticity Index (PI) as a predictor for qu and is specifically calibrated for the geological characteristics of Dhaka city. The findings of this study highlight the effectiveness and applicability of regression analysis in predicting qu for Dhaka's soil properties, thus introducing a valuable tool for enhancing the accuracy and effectiveness of geotechnical assessments and design in the region. KEYWORDS: Unconfined compressive strength, Standard penetration test-N values, Plasticity index, Multiple linear regression, Random-forest regression, AdaBoost regression, Evaluation metrics, Trend-behavior analysis, Sensitivity analysis","PeriodicalId":51814,"journal":{"name":"Jordan Journal of Civil Engineering","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2023-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46120840","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The Syrian construction industry is plagued with risks that can be challenging to the overall success of any construction project. To minimize a project’s damage in terms of cost, time and quality, an authentic data-driven and expert-approved risk plan must be developed. This paper proposes a methodology to identify and assess major risks based on the personal evaluation of experienced civil engineers as a step in a comprehensive risk-management process. By combining a ranked risk magnitude index and an assigned risk zone, fifteen major risks were identified and assessed. Companies are advised to use the list to develop a resourceful general risk plan. Combining the two methods together makes the risk plan more representative and thus more reliable, as the two proposed methods can result in different rankings. The top fifteen risks in the Syrian construction industry were mainly management, financial and design risks. Locating in the zone of maximum risk came “an unprecedented increase in raw-material prices” and “the loss due to an increase in fuel prices” as number one and number two, respectively”. “Unavailability of resources” was next in the zone of high risk. “Improper cost estimation” and “losing critical work forces at a critical time” scored high in the final ranking. KEYWORDS: Risk identification, Risk assessment, Syria, Construction industry.
{"title":"Identification and Assessment of Major Risks in Syrian Construction Projects: Lattakia-Syria Case","authors":"Reem Ghanem Kattoub, J. Omran","doi":"10.14525/jjce.v17i3.13","DOIUrl":"https://doi.org/10.14525/jjce.v17i3.13","url":null,"abstract":"The Syrian construction industry is plagued with risks that can be challenging to the overall success of any construction project. To minimize a project’s damage in terms of cost, time and quality, an authentic data-driven and expert-approved risk plan must be developed. This paper proposes a methodology to identify and assess major risks based on the personal evaluation of experienced civil engineers as a step in a comprehensive risk-management process. By combining a ranked risk magnitude index and an assigned risk zone, fifteen major risks were identified and assessed. Companies are advised to use the list to develop a resourceful general risk plan. Combining the two methods together makes the risk plan more representative and thus more reliable, as the two proposed methods can result in different rankings. The top fifteen risks in the Syrian construction industry were mainly management, financial and design risks. Locating in the zone of maximum risk came “an unprecedented increase in raw-material prices” and “the loss due to an increase in fuel prices” as number one and number two, respectively”. “Unavailability of resources” was next in the zone of high risk. “Improper cost estimation” and “losing critical work forces at a critical time” scored high in the final ranking. KEYWORDS: Risk identification, Risk assessment, Syria, Construction industry.","PeriodicalId":51814,"journal":{"name":"Jordan Journal of Civil Engineering","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2023-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47430651","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Excavation of tunnels or chambers causes crack initiation, propagation and coalescence, resulting in the instability and destruction of underground projects. Understanding the damage mechanism of joint rock-like materials is important for maintaining the stability of concrete construction. Based on the Mohr–Coulomb criterion and Lemaitre strain equivalence hypothesis, the coupling-damage constitutive model of rock masses was improved for application to plain concrete. Parameters including the mesoscopic and macro-meso coupling damage variables, as well as the fractal dimension, were calculated to realize the non-linear mechanical behaviour during damage evolution. The rationality of the model was verified by comparing experimental and theoretical parameters. Results revealed that the coupled-damage constitutive model of rock masses has a good applicability to plain concrete. Furthermore, two main factors affected the damage deformation: the number of joints and the inclination angle. As the number of joints increased, the early damage accumulation increased and the inflection point of the damage rate occurred in advance. The damage deformation varied significantly when the inclination angle was changed. The cumulative damage curve of the plain-concrete specimens is shown as the evolution law of an S-type curve. Both peak strength and elastic modulus were positively correlated with the damage variable. Moreover, a smaller peak strength resulted in a larger fractal dimension and coupling-damage variable. KEYWORDS: Rock mass, Joint inclination angle, Mesoscopic, Macroscopic, Fractal dimension, Coupling-damage constitutive model.
{"title":"Damage Mechanism on Different Joint Types of Plain Concrete under Uniaxial Compression","authors":"Shanshan Guo, D. Cui, Liang Lv","doi":"10.14525/jjce.v17i2.14","DOIUrl":"https://doi.org/10.14525/jjce.v17i2.14","url":null,"abstract":"Excavation of tunnels or chambers causes crack initiation, propagation and coalescence, resulting in the instability and destruction of underground projects. Understanding the damage mechanism of joint rock-like materials is important for maintaining the stability of concrete construction. Based on the Mohr–Coulomb criterion and Lemaitre strain equivalence hypothesis, the coupling-damage constitutive model of rock masses was improved for application to plain concrete. Parameters including the mesoscopic and macro-meso coupling damage variables, as well as the fractal dimension, were calculated to realize the non-linear mechanical behaviour during damage evolution. The rationality of the model was verified by comparing experimental and theoretical parameters. Results revealed that the coupled-damage constitutive model of rock masses has a good applicability to plain concrete. Furthermore, two main factors affected the damage deformation: the number of joints and the inclination angle. As the number of joints increased, the early damage accumulation increased and the inflection point of the damage rate occurred in advance. The damage deformation varied significantly when the inclination angle was changed. The cumulative damage curve of the plain-concrete specimens is shown as the evolution law of an S-type curve. Both peak strength and elastic modulus were positively correlated with the damage variable. Moreover, a smaller peak strength resulted in a larger fractal dimension and coupling-damage variable. KEYWORDS: Rock mass, Joint inclination angle, Mesoscopic, Macroscopic, Fractal dimension, Coupling-damage constitutive model.","PeriodicalId":51814,"journal":{"name":"Jordan Journal of Civil Engineering","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2023-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47986686","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This research aims to investigate the use of magnetic iron nano-particles (FeN) for the removal of heavy metals under single and ternary scenarios. The methodology includes synthesis of FeN using chemical precipitation approach, batch experiments for single and ternary metals removal, isotherm and kinetic studies, thermos-dynamic study and assessing the effect of different parameters on the adsorption process. The results showed that the maximum removal for As and Hg was achieved at a pH of 7, while a pH of 6 provided a slightly higher removal of Cd than a pH of 7 at an optimum mixing time of 120 minutes. The optimum adsorption capacities of As, Cd and Hg at the initial concentration of 200 ppm were 260, 280 and 75.0 mg/g in the case of single metal removal against 91.5, 237.8 and 341.5 mg/g in the case of ternary combination, respectively. The removal of all metals increased with increasing the FeN dose and the mixing time, while it decreased with the increase of the initial concentration. The removal efficiency was affected strongly by the presence of multiple metals, while As removal decreased sharply and Hg removal increased significantly. Adsorption selectivity is affected negatively by the increase in atomic weight and atomic radius. In the case of single-metal removal, fitting of isotherm models can be ranked as Langmuir>Freundlich>Temkin>D-R for As and Cd and Temkin>Freundlich>D-R>Langmuir for Hg, while contradictory results were obtained in the case of ternary combination. Kinetic studies found that the adsorption follows the pseudo-second-order model with R2=0.99. For all metals, the adsorption process is highly favourable at higher temperatures and is endothermic in nature with (ΔHo) of 10.91, 23.86 and 0.163 for As, Cd and Hg, respectively. Coating of FeN with silica resulted in lower removal efficiency for all metals up to 50%. It can be concluded that FeN can be successfully used for the removal of heavy metals either through the single or ternary approach, but the single approach provides a higher performance. KEYWORDS: Nano-materials, Magnetite iron, Adsorption, Arsenic, Cadmium, Mercury, Lead.
{"title":"Single and Ternary Removal of Heavy Metals from Aqueous Solution Using Fe3O4 Magnetic Nano-particles","authors":"K. Al-Zboon","doi":"10.14525/jjce.v17i2.13","DOIUrl":"https://doi.org/10.14525/jjce.v17i2.13","url":null,"abstract":"This research aims to investigate the use of magnetic iron nano-particles (FeN) for the removal of heavy metals under single and ternary scenarios. The methodology includes synthesis of FeN using chemical precipitation approach, batch experiments for single and ternary metals removal, isotherm and kinetic studies, thermos-dynamic study and assessing the effect of different parameters on the adsorption process. The results showed that the maximum removal for As and Hg was achieved at a pH of 7, while a pH of 6 provided a slightly higher removal of Cd than a pH of 7 at an optimum mixing time of 120 minutes. The optimum adsorption capacities of As, Cd and Hg at the initial concentration of 200 ppm were 260, 280 and 75.0 mg/g in the case of single metal removal against 91.5, 237.8 and 341.5 mg/g in the case of ternary combination, respectively. The removal of all metals increased with increasing the FeN dose and the mixing time, while it decreased with the increase of the initial concentration. The removal efficiency was affected strongly by the presence of multiple metals, while As removal decreased sharply and Hg removal increased significantly. Adsorption selectivity is affected negatively by the increase in atomic weight and atomic radius. In the case of single-metal removal, fitting of isotherm models can be ranked as Langmuir>Freundlich>Temkin>D-R for As and Cd and Temkin>Freundlich>D-R>Langmuir for Hg, while contradictory results were obtained in the case of ternary combination. Kinetic studies found that the adsorption follows the pseudo-second-order model with R2=0.99. For all metals, the adsorption process is highly favourable at higher temperatures and is endothermic in nature with (ΔHo) of 10.91, 23.86 and 0.163 for As, Cd and Hg, respectively. Coating of FeN with silica resulted in lower removal efficiency for all metals up to 50%. It can be concluded that FeN can be successfully used for the removal of heavy metals either through the single or ternary approach, but the single approach provides a higher performance. KEYWORDS: Nano-materials, Magnetite iron, Adsorption, Arsenic, Cadmium, Mercury, Lead.","PeriodicalId":51814,"journal":{"name":"Jordan Journal of Civil Engineering","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2023-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46463622","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Concrete, being the most widely used construction material in the world, lacks strength in direct tension and flexure. Attempts to reinforce concrete in tension include the use of steel rebars to strengthen the tensile side of concrete as well as the use of discrete fibers as a reinforcing medium. The study conducted in this manuscript details the effects of including alkali-resistant glass fibers in concrete. Mechanical strength, such as strength in compression and flexure, chord modulus of elasticity and bond pull-out strength, have been measured along with porosity and resistance to accelerated carbonation. Five different water to binder ratios in a range of 0.4 to 0.6 had been used to prepare the design mix proportions. The optimum fiber dosage was found to be 1.5% by weight of cement used. The same had been adopted in the design mix proportions. The average increase in compressive strength and flexural strength was 13% and 28%, respectively. Alkali-resistant glass fiber concrete showed less resistance to carbonation when compared to control mix. Results indicate that glass fibers play a predominant role in providing flexural strength to concrete. The pull-out strength of fiber was added to extra post-cracking flexural strength. The inclusion of alkali-resistant glass fibers imparted a maximum addition of 44% increase in the flexural strength compared to control concrete. The inclusion of alkali-resistant glass fibers in concrete paves the way for a leaner mix and eradicates the possibility of congestion of steel reinforcement for certain structures. KEYWORDS: Alkali-resistant glass fibers, Accelerated carbonation, Bond strength, Compressive strength, Flexural strength.
{"title":"Mechanical and Durability Performances of Alkali-resistant Glass Fiber-reinforced Concrete","authors":"Shaik Hussain, J. Yadav","doi":"10.14525/jjce.v17i2.06","DOIUrl":"https://doi.org/10.14525/jjce.v17i2.06","url":null,"abstract":"Concrete, being the most widely used construction material in the world, lacks strength in direct tension and flexure. Attempts to reinforce concrete in tension include the use of steel rebars to strengthen the tensile side of concrete as well as the use of discrete fibers as a reinforcing medium. The study conducted in this manuscript details the effects of including alkali-resistant glass fibers in concrete. Mechanical strength, such as strength in compression and flexure, chord modulus of elasticity and bond pull-out strength, have been measured along with porosity and resistance to accelerated carbonation. Five different water to binder ratios in a range of 0.4 to 0.6 had been used to prepare the design mix proportions. The optimum fiber dosage was found to be 1.5% by weight of cement used. The same had been adopted in the design mix proportions. The average increase in compressive strength and flexural strength was 13% and 28%, respectively. Alkali-resistant glass fiber concrete showed less resistance to carbonation when compared to control mix. Results indicate that glass fibers play a predominant role in providing flexural strength to concrete. The pull-out strength of fiber was added to extra post-cracking flexural strength. The inclusion of alkali-resistant glass fibers imparted a maximum addition of 44% increase in the flexural strength compared to control concrete. The inclusion of alkali-resistant glass fibers in concrete paves the way for a leaner mix and eradicates the possibility of congestion of steel reinforcement for certain structures. KEYWORDS: Alkali-resistant glass fibers, Accelerated carbonation, Bond strength, Compressive strength, Flexural strength.","PeriodicalId":51814,"journal":{"name":"Jordan Journal of Civil Engineering","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2023-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42188373","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The reuse of reclaimed asphalt material (RAM) and polyethylene terephthalate (PET) plastic waste is a reliable approach to limit the use of virgin aggregates for road construction and mitigate environmental challenges. This study highlights the structural performance of the cementitious base or cement-treated base (CTB) layer by incorporating reclaimed asphalt and plastic waste material. Structural compatibility of CTB layer with different proportions of RAM (20%, 45%, 70% and 95%), virgin aggregates and plastic waste (5%) is recognized by the moisture-density relationship, unconfined compressive, indirect tensile strength, flexural strength and California bearing ratio tests. In the current study, a ranking methodology is used to analyze the overall suitability of the cementitious base mix proportions using different laboratory test parameters. Furthermore, a finite element analysis using the ANSYS software is performed to investigate the effect of CTB layer on the pavement structural responses. Also, using the central public works department guidelines, a cost comparative study is provided. Experimental results showed that all the cementitious base mixes met the requirements for the unconfined compressive strength, except for the 95% and 70% RAM mixes. Therefore, 20%-45% of RAM can partially be used in the CTB layer to replace virgin aggregates partially. The finite element analysis results showed that CTB reduced fatigue strain by 57% and surface deformation by 47%. Moreover, it has been concluded that by utilizing a cementitious base with RAM, there is a 30% cost reduction. KEYWORDS: Reclaimed asphalt material, Cement-treated base, Polyethylene terephthalate, Finite element analysis, Unconfined compressive strength.
{"title":"Structural Performance of Cement-treated Base Layer by Incorporating Reclaimed Asphalt Material and Plastic Waste","authors":"A. Banerji, P. Topdar, A. Datta","doi":"10.14525/jjce.v17i2.08","DOIUrl":"https://doi.org/10.14525/jjce.v17i2.08","url":null,"abstract":"The reuse of reclaimed asphalt material (RAM) and polyethylene terephthalate (PET) plastic waste is a reliable approach to limit the use of virgin aggregates for road construction and mitigate environmental challenges. This study highlights the structural performance of the cementitious base or cement-treated base (CTB) layer by incorporating reclaimed asphalt and plastic waste material. Structural compatibility of CTB layer with different proportions of RAM (20%, 45%, 70% and 95%), virgin aggregates and plastic waste (5%) is recognized by the moisture-density relationship, unconfined compressive, indirect tensile strength, flexural strength and California bearing ratio tests. In the current study, a ranking methodology is used to analyze the overall suitability of the cementitious base mix proportions using different laboratory test parameters. Furthermore, a finite element analysis using the ANSYS software is performed to investigate the effect of CTB layer on the pavement structural responses. Also, using the central public works department guidelines, a cost comparative study is provided. Experimental results showed that all the cementitious base mixes met the requirements for the unconfined compressive strength, except for the 95% and 70% RAM mixes. Therefore, 20%-45% of RAM can partially be used in the CTB layer to replace virgin aggregates partially. The finite element analysis results showed that CTB reduced fatigue strain by 57% and surface deformation by 47%. Moreover, it has been concluded that by utilizing a cementitious base with RAM, there is a 30% cost reduction. KEYWORDS: Reclaimed asphalt material, Cement-treated base, Polyethylene terephthalate, Finite element analysis, Unconfined compressive strength.","PeriodicalId":51814,"journal":{"name":"Jordan Journal of Civil Engineering","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2023-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47346506","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study investigated the performance of rural public bus transport services in Jordan Valley. The performance measures included availability, comfort and convenience, waiting time, mobility, productivity and safety. The data used in this research was collected from three sources: field survey of existing bus routes, operational data from Land Transport Regulatory Commission and questionnaire surveys which were distributed to a sample of passengers and bus drivers. The obtained data was used to compute the performance measures, as well as to develop statistical models to estimate the average waiting time of buses at peak and off-peak hours. The results indicated that the waiting time at off-peak hours was two and a half times the waiting time at peak hours. It was found that 40% of the external bus routes were within the range of overall Level of Service (LOS) C & D, 26.67% between B & D, 13.33% between B & C, 13.33% between C & E and 6.67% between D & E. Also, it was found that 60% of internal bus routes’ LOSs were between C & D, 20% between C & E and 20% with LOS C. It was found that the average perceived waiting time depends on the total travel time regardless of on-peak or off-peak trips. KEYWORDS: Public transport, Bus services, Performance measures, Waiting time, Jordan Valley.
本研究调查了约旦河谷地区农村公共汽车运输服务的绩效。性能指标包括可用性、舒适性和便利性、等待时间、移动性、生产率和安全性。本研究使用的数据来自三个来源:现有巴士路线的实地调查，陆路运输管理委员会的运营数据，以及对乘客和巴士司机抽样的问卷调查。获得的数据用于计算性能指标，并建立统计模型来估计高峰和非高峰时段公交车的平均等待时间。结果表明，非高峰时段的候车时间是高峰时段的2.5倍。发现40%的外部公交线路范围内整体的服务水平(LOS) C和D, B和D之间的26.67%,13.33% B和C, C & E之间的13.33%和6.67%之间D & E .也发现60%的内部公交线路的损失是C和D之间,20%与洛杉矶C . C和E - 20%发现认为平均等待时间取决于供需的总旅行时间不管或非高峰出行。关键词:公共交通，公交服务，绩效指标，等待时间，约旦河谷。
{"title":"Performance Analysis of Public Bus Transport Services in Rural Areas","authors":"T. Al-Suleiman, Rawan Al-Torkman, R. Mujalli","doi":"10.14525/jjce.v17i2.09","DOIUrl":"https://doi.org/10.14525/jjce.v17i2.09","url":null,"abstract":"This study investigated the performance of rural public bus transport services in Jordan Valley. The performance measures included availability, comfort and convenience, waiting time, mobility, productivity and safety. The data used in this research was collected from three sources: field survey of existing bus routes, operational data from Land Transport Regulatory Commission and questionnaire surveys which were distributed to a sample of passengers and bus drivers. The obtained data was used to compute the performance measures, as well as to develop statistical models to estimate the average waiting time of buses at peak and off-peak hours. The results indicated that the waiting time at off-peak hours was two and a half times the waiting time at peak hours. It was found that 40% of the external bus routes were within the range of overall Level of Service (LOS) C & D, 26.67% between B & D, 13.33% between B & C, 13.33% between C & E and 6.67% between D & E. Also, it was found that 60% of internal bus routes’ LOSs were between C & D, 20% between C & E and 20% with LOS C. It was found that the average perceived waiting time depends on the total travel time regardless of on-peak or off-peak trips. KEYWORDS: Public transport, Bus services, Performance measures, Waiting time, Jordan Valley.","PeriodicalId":51814,"journal":{"name":"Jordan Journal of Civil Engineering","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2023-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48729422","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
One of the problematic issues with the recycling of used automobile tires is the production of unwanted fiber waste. This waste is considered as a major burden and as an industrial waste which constitutes an extra cost to industries. In this project, thermal and noise insulators were produced from the fiber waste of automobiles. The insulation materials were used in insulating different types of rooms to study their thermal and noise insulation effectiveness (Caravan rooms and brick rooms). Results were also compared to identical rooms without insulation. Results showed that the thermal properties of the obtained sheets are similar to those used currently in construction. The differences between the insulated rooms and the non-insulated rooms were about 2⸰C and 1-4 dBA for thermal and sound level, respectively, for both construction models during day and night all over the year period. KEYWORDS: Automobile tires, Fiber, Thermal insulation, Sound insulation.
{"title":"Production of Thermal and Sound Insulators from Used Automobile Tires' Fiber","authors":"M. Kandah, A. Al-Otoom","doi":"10.14525/jjce.v17i2.02","DOIUrl":"https://doi.org/10.14525/jjce.v17i2.02","url":null,"abstract":"One of the problematic issues with the recycling of used automobile tires is the production of unwanted fiber waste. This waste is considered as a major burden and as an industrial waste which constitutes an extra cost to industries. In this project, thermal and noise insulators were produced from the fiber waste of automobiles. The insulation materials were used in insulating different types of rooms to study their thermal and noise insulation effectiveness (Caravan rooms and brick rooms). Results were also compared to identical rooms without insulation. Results showed that the thermal properties of the obtained sheets are similar to those used currently in construction. The differences between the insulated rooms and the non-insulated rooms were about 2⸰C and 1-4 dBA for thermal and sound level, respectively, for both construction models during day and night all over the year period. KEYWORDS: Automobile tires, Fiber, Thermal insulation, Sound insulation.","PeriodicalId":51814,"journal":{"name":"Jordan Journal of Civil Engineering","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2023-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47584038","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Abdullah, S. I. Ahmed, Etikaf Husain, Farahbakhsh Hasan, Shoaib Ahmed
Pakistan continuously remains under the threat of drought, as approximately 88% of its area falls under arid and semi-arid regions. The most affected province due to drought is Balochistan, facing migration, scarcity, famine and economic strain. The insufficiency of meteorolgical and hydrological data in the area intensifies the problem because of the late or non-diagnosis of drought. Therefore, this study proposes a methodology to quantify the drought in a watershed with inadequate meteorological and hydrological data. This study aims to design a method to find the extent and duration of drought conditions for watersheds where only basic meteorological data is available. For this purpose, Quetta Valley, Balochistan, Pakistan, is chosen as the study area. First, the hydrological components of water balance for the watershed are calibrated for 10 years using a distributed hydrological model (MIKE-SHE). The modeling results and other observed meteorological data are then used to evaluate eight drought indices to assess the existence and extent of drought, including those which use the hydrological parameters as input from MIKE-SHE. Reconnaissance drought and Palmer drought severity indices, which use detailed hydrological parameters, are found to provide more accurate results coupled with early drought detection of historical events. The results showed that the proposed method could be effectively used to determine the secondary parameters from the hydrological model, which in turn gives more realistic drought conditions for such regions. KEYWORDS: Meteorological drought indices, Hydrological modeling, MIKE SHE, Drought, Palmer drought severity index.
{"title":"Drought Assessment of a Data-scarced Watershed – Quetta Valley, Pakistan","authors":"S. Abdullah, S. I. Ahmed, Etikaf Husain, Farahbakhsh Hasan, Shoaib Ahmed","doi":"10.14525/jjce.v17i2.11","DOIUrl":"https://doi.org/10.14525/jjce.v17i2.11","url":null,"abstract":"Pakistan continuously remains under the threat of drought, as approximately 88% of its area falls under arid and semi-arid regions. The most affected province due to drought is Balochistan, facing migration, scarcity, famine and economic strain. The insufficiency of meteorolgical and hydrological data in the area intensifies the problem because of the late or non-diagnosis of drought. Therefore, this study proposes a methodology to quantify the drought in a watershed with inadequate meteorological and hydrological data. This study aims to design a method to find the extent and duration of drought conditions for watersheds where only basic meteorological data is available. For this purpose, Quetta Valley, Balochistan, Pakistan, is chosen as the study area. First, the hydrological components of water balance for the watershed are calibrated for 10 years using a distributed hydrological model (MIKE-SHE). The modeling results and other observed meteorological data are then used to evaluate eight drought indices to assess the existence and extent of drought, including those which use the hydrological parameters as input from MIKE-SHE. Reconnaissance drought and Palmer drought severity indices, which use detailed hydrological parameters, are found to provide more accurate results coupled with early drought detection of historical events. The results showed that the proposed method could be effectively used to determine the secondary parameters from the hydrological model, which in turn gives more realistic drought conditions for such regions. KEYWORDS: Meteorological drought indices, Hydrological modeling, MIKE SHE, Drought, Palmer drought severity index.","PeriodicalId":51814,"journal":{"name":"Jordan Journal of Civil Engineering","volume":null,"pages":null},"PeriodicalIF":1.1,"publicationDate":"2023-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42188858","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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