9 research outputs found
Characterize Cold Bituminous Emulsion Mixtures Incorporated Ordinary Portland Cement Filler for Local Surface Layer
تمتلك الخلطات الاسفلتية ذات المستحلب البتيوميني الباردCBEM عده مزايا بيئية ، اقتصادية ، ولوجستية بالمقارنه مع الخلطات الاسفلتية الحارهHMA . وبالرغم من ذلك ، هكذا نوع من الخلطات الاسفلتيه لا تجذب الباحثين والمنظمات بسبب ضعف ادائها وحساسيتها للماء . علاوة على ذلك، فأنه من المستحيل استخدامها لتبليط الطبقات السطحية بدون معالجتها او تحسينها. تهدف هذه الدراسة الى تعزيز الخلطات الاسفلتية الباردة على امل استخدامها كطبقة سطحيه في الطرق. تم استخدام السمنت البورتلاندي الاعتياديOPC لتحسين الخواص الميكانيكية والحجمية وخواص الديمومة ، واستبداله بالماده المالئه التقليديةCMF وبثلاث نسب (0و50و 100%). تم تقييم الخصائص الميكانيكية للخلطات باستخدام فحص مارشال ، وفحص الشد غير المباشرITS، وفحص مسار العجلهWTT. في حين تم استخدام فحص الثبات المتبقي لمارشالRMS في تقييم مقاومه الخلطة لضرر الماء. بينت النتائج ان اضافة 100% من الاسمنت كماده مالئه يمكن ان تحسن الخواص الميكانيكية وخواص الديمومة للخلطات المستحلبة الباردة بكافئة عالية. حيث تبين من خلال الخصائص الميكانيكية والديمومة ان هكذا نوع من الخلطاتCBEM-100%OPC يمكن استخدامها كطبقة سطحيه للطرق بالاعتماد على المواصفات العراقية للطرق والجسور ، حيث ان الخلطه ذات المحتوى الاسمنتى 100% قد تحسنت بمقدار 1.9 ، 1.78، 9.4، و2.6 مره من حيث ثبات مارشالMS ، الانسيابMF، فحص الشد غير المباشرITS، فحص مسار العجلةWTT، وفحص تأثير الماءRMS مقارنة بالخلطة الغير معالجة على التوالي. وكذلك اظهرت النتائج ان الخلطة الجديدة مقاربه (وفي بعض الاحيان تفوق) خواص الخلطة الحاره الاعتيادية ومثال على ذلك مقاومة الخلطة للتخدد قد تحسن بمقدار 6.2 مره. ومن الجدير بالقول ان ماده الاسمنت قد حسنت خواص الخلطة الاسفلتية الباردة الميكانيكة وخواص الديمومة الى حد ما يسمح باستخدامها كطبقة سطحية للطرق.Cold Bituminous Emulsion Mixtures have many environmental, logistical, and economic advantages over conventional Hot Mix Asphalt. Nevertheless, their inferior performance and high water sensitivity at early life attract little attentions. Moreover, it is impossible to apply CBEM as a structural surface layer if left without treatment or enhancement. The main aim of this study is to enhance the properties of CBEM for the hope of using it as a structural layer. Thus, a trial has been made to improve CBEM mechanical and durability properties by replacing the Ordinary Portland Cement by the Conventional Mineral Filler with 3 percentages; namely, 0, 50%, and 100%. CBEM mixtures mechanical properties were evaluated in term of Marshall Stability and Flow, Indirect Tensile Strength, and Wheel Track Test. While Moisture damage was evaluated in terms of Retained Marshall Stability. Test results showed that the addition of 100%OPC filler can improve CBEM mechanical and durability properties efficiently. In terms of mechanical properties results, CBEM comprised 100%OPC, can be used as a structural Surface layer based on local Iraqi specifications limits, where mixture enhanced about 1.9, 1.78, 9,4.85, and 2.6 times in term of MS, MF, rutting deformation resistance, resistance to tensile cracking, and moisture damage resistance, respectively as compared to untreated CBEM. Also, CBEM-100%OPC mix seemed comparable (and sometime superior) to HMA, e.g., resistance to rutting of CBEM is about 6.2 times higher than that of HMA. It’s worth to say that OPC upgrades CBEM to a significant level that enables it to use as a structural layer in terms of the mechanical and the durability properties
Seismic behavior of a strengthened full scale reinforced concrete building using the finite element modelling approach
In Iraq, the increase in earthquake activity was observed, but most of the existing buildings can still suffer from severe injury or destruction, and therefore can cause major issues. In this paper, we performed numerically analyses by experimental modeling to demonstrate efficiency using final element analysis (FEA) in the development of modern solutions (FEA) in the development of modern solutions to maintain existing structures from the risk of earthquakes. Using ABAQUS software that supports dynamic analysis, and uses this model to use models for several ways to enhance the earthquake center. This model was a large-scale 4 building tested using a doctor dynamic test (PSD). Experimental models were performed by extending RC walls with various connectivity details in existing buildings to comply with gravity design only for this building. The goal of this study was to determine the impact of adding an above RC wall as a way of modernization, including the design of Dowels and their contribution to the new mouse wall's connection to the existing RC buildings. These enhancements are performed by converting the selected compartment to the new inlet wall RC [2]. The result of analysis modeling is 4.11% of the proportion of differences in the X direction in the upper layer displacement of Abaqus software and the experimental test of Elsa results, and 2.15% of the negative direction X is 4.11%. an accurate similarity and exact building modeling. After verification process, three earthquake enhancement methods are used Next analysis
Estimating parking generation rate for Karbala holy city using multi-variables approach
Car parking planning, design, and management processes are very important to all cities and places to ensure efficient traffic system. Estimating the demand of car parking represents the significant start point for the success of these processes. Generally, there are many local and international estimating criteria, but such criteria need continuing update due to many reasons related to socioeconomic factors, lifestyle changes, development in technology, etc. Moreover, the majority of these criteria depend on single parameter for the estimation of parking demand; such as bed or employee for hospital, gross floor area or employee for office, and so on. The main aim of this research is to estimate the park generation rate for specific land uses depend on multivariable to increase the accuracy and limiting the effect of variation in parameters. Statistical analysis was conducted to create predicting models for each land use. The collected data was nominated for Karbala holy city, where different parameters are scaled for different city sectors. Groups of statistical models (i.e., simple, multi linear and nonlinear statistical models, and Weighted Linear Regression (WLR)) were used to create best representative relationship between the number of demands for car parking and multivariable parameters or factors affecting these lands used demands. Resulted statistical models were tested for best fit using statistical indices for model verification. Results disclose the significant of multivariable model compare with simple models. Also, WLR model shows it validity compare with multi-regression model for almost land use models. Consequently, for more accurate estimation the multi variable models are initiated with continuous need for updating
Application of paper sludge ash and incinerated sewage ash in emulsified asphalt cold mixtures
Certain disadvantages could have appeared while using hot mix asphalt (HMA), such as the release of unhealthy gases into the environment (environmental issues), difficulty in sustaining the temperature over long distances (logistical issues), and consuming a sufficient amount of energy while preparing and laying down (practical and economic issues). To overcome the aforementioned issues, this study aimed to develop rapid-curing emulsified asphalt cold mixes (EACM) comprising a cementitious filler made from industrial by-product materials. Paper sludge ash (PSA) is used as an active filler for application in the EACM rather than conventional mineral filler. Additionally, to maximize the effect of PSA’s hydraulic activity, incinerated sewage ash (ISA) is utilized as an activator at a concentration of 0%–4% by mass of the aggregates. The results demonstrate that the use of waste PSA significantly improves the indirect tensile stiffness modulus (ITSM) by around 10 times more after 2 days than the traditional emulsified asphalt cold mixes. In addition, the improvement in ITSM was around 30% and 65% for 6%PSA+1%ISA and 6%PSA+4%ISA mixes, respectively. Furthermore, the rutting for the 6%PSA+1%ISA and 6%PSA+4%ISA mixes decreased to around 19% and 11% in comparison to the traditional 131-pen HMA. The formation of hydration products and rapid demulsification of asphalt emulsion, which results in binding within the mixtures, are responsible for the increased ITSM and rutting resistance. As a result, environmental issues are minimized, and energy preservation may be maintained
Finite element approach to simulate performance of reinforced concrete beams with multiple openings
This paper presents a comparative designed to manipulate using the ABAQUS/CAE finite element approach package to performance characteristics of ten reinforced concrete beams with and without openings under an only one monotonic maximum stress at mid-span, depending on the configuration and size of the openings. All the beams had the very same cross-section, configuration, same opening sizes as that of the test beams. The aim of the comparison with experimentally tests was to ensure that all simulation processes are correct and adequate. The numerical analysis results displaced that good agreement was obtained between experimentally testes and numerical analysis results in terms of the failure load by the rate of 94%. In addition, it was shown that concentrated shear stresses at the corners of the openings causing the failure of the posts between the openings. The numerical study revealed that the influence of increasing main longitudinal steel reinforcement by 28% and 44% more efficient to enhance the ultimate load capacity by rates of 7.61% and 9.61%, respectively, compared to increasing the compressive strength of the beams by 24 %, which led to increasing the ultimate load capacity by 3.72%. Therefore, From the standpoint of difficulty and timesaving, the finite element approach is a very dependable technique for investigating the nonlinear behavior of beams with many apertures
Determination of Difference Amount in Reference Evapotranspiration between Urban and Suburban Quarters in Karbala City
Evapotranspiration represents one of the main parameters in the hydrological cycle. It is usually expressed by the term reference evapotranspiration (ETo) that is affected by certain meteorological parameters. This study aimed to find the difference amount in ETo between urban and suburban quarters in Karbala city. The study methodology involved selecting once urban area and four suburban quarters. Two methods of determining the reference evapo- transpiration were applied: first, a direct method which measured ETo at selected fields by using a hand-held device, and second, an indirect method using the Penman-Monteith equation. The findings showed that the magnitudes of ETo by the Penman-Monteith equation are higher than the values measured by the direct method for urban and suburban quarters. Moreover, it was found that the absolute percentage of difference in the average amount of ETo between urban and suburban quarters is 13% by using the direct method and 61% by using Penman-Monteith equation. The study conclusion is that suburban area has higher magnitude of ETo than urban quarter by using any of direct method and indirect method (Penman-Monteith equation)
Improving the Mechanical Properties and Durability of Cold Bitumen Emulsion Mixtures Using Waste Products and Microwave Heating Energy
Scientists have effectively demonstrated that the introduction of a waste product comprising cementitious chemical compositions can enhance the mechanical properties and durability of cold bitumen emulsion mixes (CBEMs). On the other hand, the high air void content of the CBEM mix remains a challenge that is considered unsatisfactory by paving engineers. As a result, this investigation highlights two major changes that were made. The first is the use of waste paper sludge ash (PSA) as a filler in CBEM instead of the conventional mineral filler (CMF). The second change was made to further improve the mixture by reducing the amount of CBEM air voids using microwave (MW) heating energy as a post-treatment method. When compared to typical hot mix asphalt (HMA), the new CBEMs showed great mechanical properties and durability. Moreover, the proposed method, using CBEMs, has lower environmental risks, is safer, and is more cost-effective than existing paving mix technologies. This study presents a method for controlling air voids within pavement specifications without affecting mechanical behaviour or generating additional environmental or economic considerations. When compared to typical mixtures, laboratory test results showed that MW-heating can enhance both the stiffness modulus and the air void content. Furthermore, these results revealed a minor reduction in creep stiffness and water sensitivity. Nevertheless, in terms of mechanical, volumetric, and economic properties, the suggested post-mix treatment was comparable to HMA. The findings point to the need to adopt CBEM post-heating approaches, particularly the MW treatment procedure
A Sustainable Cold Mix Asphalt Mixture Comprising Paper Sludge Ash and Cement Kiln Dust
Concerns about the environment, the cost of energy, and safety mean that low-energy cold-mix asphalt materials are very interesting as a potential replacement for present-day hot mix asphalt. The main disadvantage of cold bituminous emulsion mixtures is their poor early life strength, meaning they require a long time to achieve mature strength. This research work aims to study the protentional utilization of waste and by-product materials as a filler in cold emulsion mixtures with mechanical properties comparable to those of traditional hot mix asphalt. Accordingly, cold mix asphalt was prepared to utilize paper sludge ash (PSA) and cement kiln dust (CKD) as a substitution for conventional mineral filler with percentages ranging from 0–6% and 0–4%, respectively. Test results have shown that the incorporation of such waste materials reflected a significant improvement in the mixture’s stiffness and strength evolution. The cementitious reactivity of PSA produces bonding inside the mixtures, while CKD is used as an additive to activate the hydration process of PSA. Therefore, based on the results, it will be easier to build cold mixtures by shortening the amount of time needed to reach full curing conditions