bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of construction time on the performance of cement treated base
Authors: Win Maung A N , Lee Y P K , Ho N Y 
Published: March 2021

Abstract
Cement treated base (CTB) has been widely used as a stabilized base layer in pavement for highways, roads, airports, parking areas and some storage areas. CTB comprises mainly three components, namely, cement, water and either natural soil or aggregates. The mixture will become strong and durable after proper compaction and curing. CTB can be produced in central plant, haul to the laying area by dump trucks or can be mixed in-placed using proper materials and equipment. One of the key factors which can affect the performance of CTB is the construction time which consists of mixing to transportation, laying and compaction. This paper describes a study that was conducted to analyse the effects of construction time on the performance properties of CTB. Laboratory tests were conducted for various CTB mixtures. The CTB mixtures were compacted at different time frames and then tested for dry density and unconfined compressive strength. The results were then analysed to study the effects of construction time.
Evaluating the mechanical performance of asphalt mixtures in cyclic torsional shear test
Authors: Yokota S , Shibuya S , Lohani T N , Kamada O , Hisaro Y 
Published: March 2021

Abstract
In this paper, the mechanical performance of asphalt mixtures was examined in cyclic torsional shear test, in which the relationship between the averaged shear strain, γav, and the number of cyclic loading, N, was obtained by using a short, about 25mm height, specimen. In these tests, the effects of some influencing factors such as the type of asphalt mixture, the thickness of specimen and the temperature were examined. In each test, four indices; i.e., the slope of plastic flow line, the slope of stripping line, the number of load applications at the inflection point for stripping and the averaged shear strain at the inflection point for stripping, were defined for the relationship between γav and N. As a result of this study, we clarified that various performances such as rutting resistance, fatigue failure resistance and the stripping resistance of asphalt mixture can be appropriately evaluated by using the cyclic torsional shear test.
Prediction of unconfined compressive strength of cement stabilized pavement materials
Authors: Premarathne R P P K , Sawangsuriya A 
Published: March 2021

Abstract
This paper evaluated and justified suitable prediction equations for unconfined compressive strength (UCS) of cement stabilized pavement materials. Equations by multiple linear regression analysis were also proposed. Data including pavement recycling base and subbase layers were collected from the Bureau of Material, Analysis, and Inspection, Department of Highways, Thailand. Multiple linear regression was conducted using the SPSS software. Three equations obtained from multiple linear regression and past researches were compared. Two criteria were considered in the selection of equations in order to check the accuracy and precision of each equation. First criterion was based on the predicted UCS vs. actual UCS graph. The slope and interception values of each graph were evaluated. Second criterion used two indices: ranking distance (RD) and ranking index (RI). For a good correlation, both these indices shall approach zero. By considering the statistical analysis outputs from the two criteria, a relationship between UCS and California Bearing Ratio – water cement ratio [CBR/(w/c)] proposed by Sunitsakul in 2012 was justified as a suitable equation to predict the UCS of cement stabilized pavement materials. The study also confirmed that the relationship proposed by Sawangsuriya in 2016 for fine-grained soil with plasticity index was not appropriate for the prediction of UCS because the majority of the samples were non-plastic.
Sustainable pavement: A review on the usage of pavement as a mitigation strategy for UHI
Authors: Al-Humairi SFI , Alias AH , Haron NA , Hassim S , Mohd Jakarni F 
Published: March 2021

Abstract
Urban Heat Island (UHI) phenomenon is currently affecting many millions of people worldwide. The higher temperatures are experienced in urban areas as compared to the surrounding countryside. The UHI effect has been a great threat to human habitation, and the way to mitigate this problem has been a global concern over decades. Artificial and manmade pavements have been recognised as one of the major origins that deteriorate the thermal environments for living. On the one hand, commonly used pavement materials could lead to a reduced latent heat flux and an increased sensible heat flux to the environment. Following this, there is a series of experiments and numerical analysis that has been conducted by researchers. The selection of pavement type requires an understanding of a local context of an area and characteristics of the pavements. This current study emphasises on reviewing the features, factors and impacts of different type of pavements, as well as determining the suitability of different types of pavements. It is expected that the outcome from this study can assist in further understanding of pavements and its effects on UHI, as well as can ultimately assist in reducing the effect of UHI on human population.
Investigation on effects of aggregate roughness on bond strength of aggregate-bitumen systems
Authors: Mishra V , Singh D 
Published: March 2021

AbstractIt is critical to understand bonding-behavior of aggregate with bitumen. The surface chemistry and roughness of aggregates play an important role to create sufficient bond with bitumen. Usually, asphalt-bond-strength (ABS) test is used to directly quantify bonding-behavior of aggregate-bitumen system, further, surface-free-energy (SFE) approach has also been used by some researchers. AASHTO T-361 recommends to use aggregates polished with 280-silicon-carbide (SiC) powder to determine bond-strength with bitumen. However, increase or decrease in polishing-level can alter aggregate-roughness and may affect bond-strength. Further, there can be numerous roughness-scale for aggregates such as, arithmetic (Ra), root-mean-square (Rq) and box-roughness (Sa), which needs detailed study. Therefore, one of the strong motivations of this study was to evaluate effects of aggregate-roughness on bond-strength using ABS approach. Similarly, aggregate SFE may change with change in its roughness, thereby affecting aggregate-bitumen bonding. The present study evaluates effects of aggregate-roughness on aggregate-bitumen bond-strength using ABS and SFE approaches. Basaltic substrates and viscosity-grade binder (VG30) were selected for this study. To generate different roughness-levels, aggregate substrates were polished with 220SiC and 1000SiC powders. At each polishing-level, Raand Saparameters were evaluated using zeta-profilometer. The ABS and SFE measurements were conducted on combination of aggregate and bitumen. The results showed that bond-strength increased with increase in aggregate-roughness, indicating better bonding for rough aggregates. Further, Saparameter which remained unaddressed in earlier research studies was recommended to quantify aggregate roughness rather than Raparameters, because it measures roughness over area, which is one of the major contributions of present study.
Dynamic Viscosity Standard of High Viscosity Modified Asphalt Considering Temperature and Load Coupling Effect
Authors: Li Jun , Li Yingtao , Li Mingliang , Lu Haizhu , Cao Dongwei 
Published: March 2021

Abstract
The anti-ravelling and anti-rutting performances of porous asphalt pavement are significantly affected by dynamic viscosity of high viscosity modified asphalt. Climatic and traffic conditions vary greatly due to the vast territory of China, and dynamic viscosity standard has not been recommended up to now aiming at different temperature and load conditions. The influence of high viscosity additive dosage on key property indexes was firstly analysed for asphalt and asphalt mixture, and appropriate dosage was recommended. The dynamic stability changing law of porous asphalt mixture was revealed under different temperature, load and their coupling conditions. Multiple regression relation of them was established. Finally dynamic viscosity standard was proposed considering temperature/load coupling effect. The research results show that when high viscosity additive dosage exceeds 10% for 70# base asphalt, the increasing trend of dynamic viscosity becomes slowing down. Semi-logarithmic relations of dynamic stability with ravelling loss, Marshall stability were respectively found, and double-logarithmic relation of that with dynamic viscosity was found. The appropriate dosage of high viscosity additive is recommended as 12%. Based on multiple regression formula of dynamic stability with dynamic viscosity, temperature and load, the lower limit of 60°C dynamic viscosity is recommended as 50000Pa•s for normal region, 100000Pa•s for heavy-load region, 200000Pa•s for high-temperature region, and 400000Pa•s for heavy-load & high-temperature region.
Application of asphalt rubber cape seal as asphalt pavement surface course for rehabilitated trunk highway in east Gansu
Authors: Han L , Han H , Guo H , Zhu J 
Published: March 2021

Abstract
Although been frequently used as a preventative maintenance measure for asphalt pavements, the Cape seal process has not been widely adopted as a possible alternative for rehabilitated pavement. This research evaluated the feasibility of applying asphalt rubber Cape seal structure into the surface course of reconstructed highway in west China. The Cape seal is composed of 11-16 mm chips spread over asphalt rubber membrane sprayed in advance, by which followed a micro surfacing layer with SBR latex modified asphalt emulsion. Based on a test section in the Banxiao highway project, the construction of asphalt rubber Cape seal and micro-surfacing were investigated experimentally. In addition, to guide the engineers, major issues during construction of the Cape seal were discussed and corresponding countermeasures were suggested.
Feasibility study of low density polyethylene modified bituminous mix in DBM layer of flexible pavement
Authors: Islam SK S , Ghosh A , Ransinchung GDRN , Roy T K 
Published: March 2021

Abstract
An efficient and adequate system of transportation is inevitable for the development of any country. A high traffic intensity in terms of overloaded commercial vehicle, introduction of new axle configuration, significant variations of daily and seasonal temperature of the pavement are significant factors contributing to early development of distress symptoms like ravelling, rutting, cracking, bleeding, shoving and pot holing of bituminous surfacing, which demand a proper strengthening of pavements. The early development of distress in the pavement with the conventional mixes revealed the need of design specification based on performance tests. To overcome such kind of distress, properties of bitumen and bituminous mixes can be improved to meet the requirement of pavement with the incorporation of certain modifiers. The present study evaluates the Low-Density polyethylene (waste milk pouches) modified bituminous mix properties corresponding to the optimum binder content by conducting different performance test. Experimental studies demonstrated that waste milk pouches (6% by weight of the binder) modified bituminous mix gives the best result in terms of stability and durability. Experimental results indicated that using the waste milk pouches in bitumen is not only a cost-effective mix but also a very good solution in terms of improving bitumen pavement mix properties. The present paper aims to highlight the change in properties by addition of modifiers in bitumen and develop a procedure to estimate the reliability of a particular mix design. By considering these aspects, statistically it has been proved that the bituminous mix obtained experimentally, is also reliable to be used in real life scenario.
Prediction of Temperature Cooling Trend of Asphalt Mixtures
Authors: Chu L. , Zhu B. , Fwa T. F. 
Published: March 2021

Abstract
Monitoring of the temperature changes of asphalt mixtures during the mix production and pavement construction phases is important to avoid over-heating, and to ensure that optimum mixing and compaction is achieved. Over-heating or prolonged heating of asphalt mixtures would cause ageing, while inadequate mixing or compaction would result in mixtures with a strength and durability less than design optimal. Careful temperature monitoring would help to avoid such undesirable problems. This study develops a finite-element asphalt mixture cooling temperature prediction software as an asphalt pavement mix design planning tool. For any given asphalt paving design mix, it is able to predict the temperature cooling characteristics of the design mix during the laying and compaction phase. The software can provide the temperature cooling characteristics during a multi-lift paving of asphalt pavement layer. The factors affecting the temperature cooling trend are determined and analysed. They include ambient temperature, laying temperature, solar influx intensity, wind velocity, number of lifts, and lift thickness. A sensitivity analysis is conducted to identify the most influencing factors under different paving conditions.
Effect Dimensions and Shape of Specimens on Some Mechanical Properties of Concrete
Authors: Salman Heba Kadhm , Yaseen Mohammed Hazim , Hamid Rana Mishal , Numan Hesham A. , Noori Abdul_Qader Nihad 
Published: March 2021

Abstract
Due to the effect of the structure element size on concrete’s mechanical properties, larger concrete structures fail under lower stresses than smaller ones. Hence, the laboratory data need to re-evaluate and updated to establish structural design rules and safety regulations. From this standpoint, this research is concerned with studying the effect of dimensions and shapes on the concrete specimen under different amounts of super-plasticizer on the concrete properties. Cubes, prisms, and cylindrical specimens are prepared and subjected to four experimental tests: compressive strength, impact resistance, abrasion resistance, and flexural strength. Besides, four concrete admixtures prepared with different amounts of super-plasticizer, 0.0, 0.50, 1.00, and 1.50 %, as a percentage of cement weight content, respectively. The obtained results from this research proved that both the highest thickness and super-plasticizer dosage resulted in 910% increases in the impact strength and improved in the flexural strength by 56.5%. On the other hand, under all super-plasticizer dosages, an increase in compressive strength, flexural, and impact resistance has resulted. Finally, based on the obtained experimental records, the statistical analysis conducted to present basis formulations illustrated the effect of the dimensions and sizes of concrete specimens with super-plasticizer content on some concrete properties.
A Proposed Approach of Improving Soil Around a Single Lateral Loaded Pile Model by using Nano-Silica Sandy Soil Mixture Material
Authors: Muhammad Ali Rafea Muha , Aziz Laith Jawad 
Published: March 2021

Abstract
This research presented a new method to improve the individual pile’s lateral behavior embedded into sandy soil using silica oxide nanoparticles material. A small-scale model test with many percent of nano-silica material (0, 0.3, and 0.6%) is used at different locations around the pile, such as an adjacent or at a distance of 10 mm away pile face and along pile front or pile behind in additional to untreated soil condition. The nano-silica material is placed into a steel box model as a plane-strain form. The obtained results are presented as relationships among applied lateral load with horizontal, vertical displacement, and rotation. The experimental work results have been validated by comparing with some of the present results (ultimate lateral pile of untreated soil) published by other workers. It clear that the obtained result is in good agreement with Hansen (1961). It is concluded that the perfect percentage of improving the soil by silica oxide nanoparticles was in the (0.6)% because this percentage gave the highest lateral load than that of other percentages at the same lateral and vertical displacement. This is because nanoparticles found in the soil improve the soil’s strength by improving the interaction between soil particles by nanoparticles and filling the voids between soil particles with nanoparticles. All the tests that were obtained for the nanomaterial were mixed and let for three days, and one test was mixed and let for 30 days. This process was for the percentage 0.6 %, so from the results, the perfect period was for three days from the beginning of the mixture of the nanomaterial; this may occur due to the evaporation of the water from the mixture and that lead to a decrease in the interaction between the mixture and the sand in the container when adding the mixture to the physical model.
Assessment of Solar Power Tower System for Closed Space Ventilation: Numerical Investigation
Authors: Wahhab Hasanain A Abdul 
Published: March 2021

Abstract
The small closed space demand increase as a secondary station for commercial production. It leads to the need to improve these stations by enhancing proper self-ventilation and daylighting. The natural air ventilation system significantly works in small closed stations; this system can be improved using different thermal storage materials in the solar collector and integrated approaches in closed space for heating, ventilation, and space conditioning. Three models were simulated; the first model is the normal model (single-pass roof solar collector). The second and third models are solar tower systems; chimney height is 6 m, with external collectors using water and wax containers. Results demonstrated that increasing thermal absorbance (wax container) of the thermal storage unit in the solar collector system enhances system performance. The mean percentage of increasing air velocity between the numerical results of Model-A and Model-B from the standard model is 18.9 % and 11.4%, respectively. Also, the mean percentage of increasing the collector’s efficiency between Model-A and Model-B’s numerical results from the normal model is 8.4 % and 5.3%, respectively.
Optimization of Automotive Bosch-140 Alternator to use as a Generator for Small Wind Turbine
Authors: Abdullah Rawaa J , Mustafa F F , Kadhim H T 
Published: March 2021

Abstract
The generator is one of the costly elements of a small wind turbine. This paper developed a suitable low-cost small wind turbine generator, which can be modified to be easily manufactured. The experiment was conducted in two parts, the first part involves monitoring the current, voltage, power, and temperature for the Bosch 140 alternator before re-winding (initial case), and the second part includes monitoring of parameters (current, voltage, power) with modifying the alternator (Bosch 140) by re-winding depending on the results of the JAMG program simulation (last case). The Bosch 140 alternator was modified consistently by reducing the wire diameter to half to double the windings to evaluate the maximum torque. A genetic algorithm was used to optimize the stator’s design optimization to achieve a maximum torque of the magnet. The final result shows a good indication of the modified alternator’s efficiency, where it is increased by about 30% from the initial case, and the generation of voltage started at a low rotation speed. It was observed that the new optimization of claw-pole alternator provides fairly the double torque with at least 16% reduction in rotation speed.
The Application of Supra_Malleolar Orthosis (SMO) in Iraq: Design and Fabrication Approach
Authors: D Al-Bayati  , Kadhim Ahmed M 
Published: March 2021

Abstract
Due to the importance of the Supra-Malleolar Orthosis in providing treatment for the Iraqi patients, the design and fabrication of Supra-Malleolar Orthosis is presented. This includes studying the material properties and behaviour, and gait cycle for the patient. The experimental part incudes, ratification, molding with inner layer (soft). The material used is called (P-lite or EVA), molding with hard layer. It is polypropylene, reaching the final shape of SMO. Gait cycle for the patient was examined using force plate. Thus, it is found that the orthosis can be manufactured; and tests proved its successful application to satisfy the patient in a sense of comfort. SMOs improve the gait cycles. SMO manufacturing is successful and give good treatment results with low cost.
Investigating the Effects of Climate Change and Sustainable Development of Iraqi Engineers Ethics
Authors: Abbas Yousif H , Hasson Ahmed 
Published: March 2021

Abstract
The impact of heat island is urban in Baghdad, which is a major city colder than the surrounding areas. This study is intended to explain what sectors of the Iraqi society are seen as a concrete challenge to their urban and lifestyle features. Issues about the impacts that climate change and UHI have had on staff were addressed including students and architects, and graduates. The study found that the acceptances of complex issues such as urban heat island as part of climate change and much less recognition of it as the product of human action is moderated in the segments of population of academics, scientists and low among urban residents of Iraqi society. However, low acceptance reflected rather than universal open cynicism a significant degree of confusion among urban citizens. Uncertainty amongst local citizens may be due to theoretical disputes on the causes and potential effects of Urban Heat Island. The findings suggest that scientists are manipulating climate change to follow their own agendas, weakening their faith in research and evidence. This is because of these differences. With just 52 percent of respondents who thought it was easy to comprehend the knowledge presented by climate change and Urban Heat Island, there was a strong need to amend marketing policies in universities and institutes. Results suggest that the Iraqi population’s limited responses to local climate change, current and past extremes of weather warming, water insufficient, and storm seasons support results suggest that Urban Heat Island was not an immediate problem for society. The short to medium term vulnerability Urban Heat Island, defined by their urban climate or lifestyles, was typically not understood or overlooked by a well-educated population.
Experimental Investigation of Sub-Cooled Flow Boiling Heat Transfer in Single Rectangular Metallic Micro-Channel
Authors: Al-Nakeeb Qahtan A , Fayyadh Ekhlas M , Hasan Moayed R 
Published: March 2021

Abstract
In this study, an experimental investigation on the flow boiling heat transfer in single rectangular micro-channel was carried out. The micro-channel was formed by machining 300 μm wide x 700 μm deep groove (i.e. a hydraulic diameter 420 μm) into the surface of brass block having length of 60 mm. The working fluid was deionized water. The experiments were carried out with the mass flux range (300-600 kg/m2.sec), and flux of heat (based on wall) 5.4 to 376.5 kW/m2, inlet sub-cooling of 20 K and 1 atm. working pressure. The results of this study have shown that at heat fluxes with lower range, the local coefficient of heat transfer increased with increasing the flux of heat. This trend is reversed when heat fluxes exceed 64.2, 77.9, 93.8 and 116.7 kW/m2 for mass fluxes 300, 400, 500 and 600 kg/m2.s respectively, where the heat transfer coefficient decreases as the heat flux increases and reach a constant value at the highest heat flux. The experimental results are compared to heat transfer correlations of minichannel and microscale, these correlations gave the results reasonably well.