The Baltic Journal of Road and Bridge Engineering最新文献_第5页

Influence of the Aggregate Shape and Resistance to Fragmentation on Unbound Base Layer Resilient Modulus 骨料形状和抗破碎性对松散基层弹性模量的影响

The Baltic Journal of Road and Bridge Engineering Pub Date : 2022-09-28 DOI: 10.7250/bjrbe.2022-17.571

Vilius Filotenkovas, A. Vaitkus

{"title":"Influence of the Aggregate Shape and Resistance to Fragmentation on Unbound Base Layer Resilient Modulus","authors":"Vilius Filotenkovas, A. Vaitkus","doi":"10.7250/bjrbe.2022-17.571","DOIUrl":"https://doi.org/10.7250/bjrbe.2022-17.571","url":null,"abstract":"The performance of unbound base materials, exclusively of the upper base layers, besides compaction level and layer thickness, depends on unbound material type, aggregates shape, fine content and mechanical properties of aggregates. The response of the pavement structure to loading is expressed through stress and strain magnitudes, accumulation of which leads to layer permanent deformations. One of the key factors for designing unbound base layers is resilient modulus, which can be found from triaxial tests. The aim of the research is to analyse the effect of the aggregate particle shape, structure and the resistance to crushing properties on resilient modulus of the upper layers of the unbound base layers. The following properties have been determined during the tests: aggregate particle size distribution, particle shape and flakiness, percentage of crushed and broken particle surfaces, density, water absorption, resilient modulus under low stress level loading. According to the performed research with tested aggregate mixtures, it is assumed that most influence on resilient modulus is exerted by aggregate whole granular size distribution, water absorption and the largest aggregate particle surface angularity. Resilient modulus in the tested dolomite fraction mixtures differing from 32 mm to 56 mm showed any reasonable difference with mean nominal pressures being higher than 300 kPa.","PeriodicalId":297140,"journal":{"name":"The Baltic Journal of Road and Bridge Engineering","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117030218","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}

引用次数: 1

Compressibility of Fly Ash and Fly Ash-Bentonite Mixtures 粉煤灰和粉煤灰-膨润土混合料的可压缩性

The Baltic Journal of Road and Bridge Engineering Pub Date : 2022-09-28 DOI: 10.7250/bjrbe.2022-17.567

Mariola Wasil

{"title":"Compressibility of Fly Ash and Fly Ash-Bentonite Mixtures","authors":"Mariola Wasil","doi":"10.7250/bjrbe.2022-17.567","DOIUrl":"https://doi.org/10.7250/bjrbe.2022-17.567","url":null,"abstract":"Environmental protection, one of the most important issues nowadays, forces civil engineers to look for alternative solutions to the known ones. The use of substitute materials as an embankment fill or a ground material under the embankment instead of natural soil follows these trends. A great amount of fly ash is disposed of in landfills. It is a cost-effective material that can be used in construction instead of natural soil. The geotechnical properties of fly ash as a construction material in place of soil need to be examined. It includes laboratory tests to determine the chemical composition and geotechnical characteristics. In the present work, one-dimensional consolidation tests have been conducted to examine the compressibility behaviour of compacted fly ash and fly ash-bentonite mixtures used in the earth structures like road embankments. The analysis of the consolidation phenomenon is useful for predicting the magnitude and rate of settlement of the structure. Materials compacted at OMC to their MDD, according to Standard Proctor, were tested in Rowe-Barden type consolidometer on saturated and non-saturated samples. Coefficients of consolidation have been compared between values derived from log-time and square-root-of-time methods and direct hydraulic conductivity tests. Bentonite amount in fly ash-bentonite mixtures influences the vertical deformation of the sample.","PeriodicalId":297140,"journal":{"name":"The Baltic Journal of Road and Bridge Engineering","volume":"65 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124239263","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}

引用次数: 1

Determining the Optimum Sample Size for Quality Assurance (QA) of Asphalt Mixtures: A Case Study 确定沥青混合料质量保证(QA)的最佳样本量:一个案例研究

The Baltic Journal of Road and Bridge Engineering Pub Date : 2022-09-28 DOI: 10.7250/bjrbe.2022-17.570

H. Al-Khayat, Charles F. Gurganus, David E. Newcomb, Maryam S. Sakhaeifar

{"title":"Determining the Optimum Sample Size for Quality Assurance (QA) of Asphalt Mixtures: A Case Study","authors":"H. Al-Khayat, Charles F. Gurganus, David E. Newcomb, Maryam S. Sakhaeifar","doi":"10.7250/bjrbe.2022-17.570","DOIUrl":"https://doi.org/10.7250/bjrbe.2022-17.570","url":null,"abstract":"Acceptance plans for asphalt mixtures use a certain sample size that is often established based on the purpose of sampling, population size, risk, and allowable error for evaluation. The rate of quality control (QC) sample size is often higher than the quality assurance (QA) sample size. The test results obtained from the QA samples are commonly used to validate the QC test results and to assist the state department of transportation (DOT) with payment decisions. However, if the QA sample size is insufficient to make accurate judgments, the probability of making incorrect decisions regarding acceptance increases. On the other hand, oversampling needlessly consumes both time and cost. To identify the appropriate sample size for QA testing, a balance must be struck between a number of variables. In this case study, two models were developed using the Oregon Department of Transportation (ODOT) data to determine the appropriate QA sample size. The need for this work was realized when a review of ODOT paving projects revealed a large variability in lot size. These ranged from 3000 to more than 100 000 tons with commensurate QA sample size rates. The typical standard deviation (STDEV) values of asphalt content (AC) and in-place density were determined. The developed models show that using the STDEV values that represented more than 90 percent of the projects, ODOT needed to increase QA sample size for both AC and density in lots of less than 22 000 tons. The results also show that sample can be decreased for AC and remain as is for density in projects of more than 22 000 tons of asphalt mixtures. The proposed models can be used to determine the optimum sample size for different lots sizes.","PeriodicalId":297140,"journal":{"name":"The Baltic Journal of Road and Bridge Engineering","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125568284","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}

引用次数: 0

Numerical Analysis of the Influence of Prestressed Steel Wires on Vehicle-Bridge Coupling Vibration of Simply Supported Beams on High-Speed Railway 预应力钢丝对高速铁路简支梁车桥耦合振动影响的数值分析

The Baltic Journal of Road and Bridge Engineering Pub Date : 2022-09-28 DOI: 10.7250/bjrbe.2022-17.569

D. Chen, Yanchang Wan, Shizhan Xu, Zheng Li, Yilin Fang

{"title":"Numerical Analysis of the Influence of Prestressed Steel Wires on Vehicle-Bridge Coupling Vibration of Simply Supported Beams on High-Speed Railway","authors":"D. Chen, Yanchang Wan, Shizhan Xu, Zheng Li, Yilin Fang","doi":"10.7250/bjrbe.2022-17.569","DOIUrl":"https://doi.org/10.7250/bjrbe.2022-17.569","url":null,"abstract":"By the theory of vehicle-bridge coupled vibration analysis in railways, the dynamic analysis model for space of the train-track-bridge-steel wires coupled system was established. Moreover, a corresponding program was compiled based on the train-track-bridge-steel wires coupling vibration analysis method. Taking a 32 m simple beam which is in high-speed railways as the subject of study, the influence of effective prestress, steel wires eccentricity and vehicle speed on the dynamic response of the vehicle-bridge coupled vibration was analysed. The results show that the bridge dynamic response is remarkably influenced by prestressed steel wires. With the prestress increasing, the crest of the vertical dynamic response at the midspan decreased first, then increased. Moreover, the minimum peak value appeared when the prestress was 1300 MPa. When the steel wires were deflected downward relative to the design position, the vertical displacement of the bridge decreased by more than when the downshift occurred. The extreme values of the bridge lateral dynamic response and the train body acceleration response appeared when the train ran at 300 km/h. Prestressed steel wires had little effect on the dynamic response in the transverse direction of the bridge and train body.","PeriodicalId":297140,"journal":{"name":"The Baltic Journal of Road and Bridge Engineering","volume":"9 5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124418021","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}

引用次数: 0

Analysis of the Self-Healing Process of Asphalt and its Influencing Factors 沥青自愈过程及其影响因素分析

The Baltic Journal of Road and Bridge Engineering Pub Date : 2022-09-28 DOI: 10.7250/bjrbe.2022-17.573

Dandan Li, Yang Luo, Xiao Lei Jiao, Qianguo Li, Chuan Feng Zheng, Guo Cui Teng

{"title":"Analysis of the Self-Healing Process of Asphalt and its Influencing Factors","authors":"Dandan Li, Yang Luo, Xiao Lei Jiao, Qianguo Li, Chuan Feng Zheng, Guo Cui Teng","doi":"10.7250/bjrbe.2022-17.573","DOIUrl":"https://doi.org/10.7250/bjrbe.2022-17.573","url":null,"abstract":"Molecular dynamics was used in this study to understand the self-healing behavior and mechanism of asphalt. Density, solubility, and mean square displacement parameters were analyzed to confirm the validity of the matrix asphalt model. Molecular simulation software was used to develop a microscopic matrix asphalt self-healing model at the nanoscale. Cracking width of asphalt microcracks was represented by setting different vacuum layer thicknesses as the asphalt self-healing model. Density and diffusion coefficient of the self-healing model were obtained by running the molecular software to understand the entire process of asphalt healing. The self-healing mechanism of the matrix asphalt was analyzed. Results showed that the entire self-healing process of asphalt could be clearly divided into four stages, namely, external environment energy endowment, model end healing, asphalt microcrack healing, and self-healing model self-diffusion stages. Molecules of each component in the asphalt self-healing process diffuse and move mutually under constant temperature conditions. The diffusion coefficient of saturated components and polar aromatic was higher than that of asphaltenes and aromatic components.","PeriodicalId":297140,"journal":{"name":"The Baltic Journal of Road and Bridge Engineering","volume":"91 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133003089","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}

引用次数: 0

Comprehensive Performances of Hybrid-Modified Asphalt Mixtures with Nano-ZnO and Styrene-Butadiene-Styrene (SBS) Modifiers 纳米zno和苯乙烯-丁二烯-苯乙烯(SBS)改性沥青混合料的综合性能

The Baltic Journal of Road and Bridge Engineering Pub Date : 2022-09-28 DOI: 10.7250/bjrbe.2022-17.574

Xiaolong Li, Junan Shen, Zhen Dai, Tianqing Ling, Xinsheng Li

{"title":"Comprehensive Performances of Hybrid-Modified Asphalt Mixtures with Nano-ZnO and Styrene-Butadiene-Styrene (SBS) Modifiers","authors":"Xiaolong Li, Junan Shen, Zhen Dai, Tianqing Ling, Xinsheng Li","doi":"10.7250/bjrbe.2022-17.574","DOIUrl":"https://doi.org/10.7250/bjrbe.2022-17.574","url":null,"abstract":"An effort was made to improve the separation issue of styrene-butadiene-styrene modifiers in styrene-butadiene-styrene-modified asphalt binders and to further enhance their performance by adding nano-ZnO to the styrene-butadiene-styrene-modified asphalt binder to prepare compound modified binder. First, the optimum nano-ZnO dosage was determined based on conventional tests, i.e., penetration, ring and ball softening point, and ductility at a fixed styrene-butadiene-styrene dosage; then, dynamic shear rheometer, bending beam rheometer, and fluorescence microscopy tests were conducted to evaluate the properties of the nano-ZnO/styrene-butadiene-styrene hybrid-modified asphalt binders. Finally, the rutting test, trabecular bending test, submerged Marshall test, and the freeze-thaw splitting test was conducted to evaluate the properties of the asphalt mixtures produced with the hybrid-modified binders. The main results showed that: the optimum nano-ZnO dosage, which was 4% by weight to the asphalt binder, and an improvement of the separation issue of the styrene-butadiene-styrene, and the flexural tensile strength and the maximum bending tensile strain of the hybrid-modified asphalt mixtures increased by 13.4% and 16.4%, respectively. In addition, the residual stability and the tensile strength ratio also increased by 4.3% and 4.8%, respectively, compared to the styrene-butadiene-styrene-modified asphalt mixtures. In conclusion, nano-ZnO improves the low-temperature and water stability performances of the styrene-butadiene-styrene-modified asphalt mixture.","PeriodicalId":297140,"journal":{"name":"The Baltic Journal of Road and Bridge Engineering","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132647929","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}

引用次数: 0

Influence of Biaxial Geogrid at the Ballast Interface for Granular Earth Railway Embankment 双轴土工格栅对颗粒土铁路路基道砟界面的影响

The Baltic Journal of Road and Bridge Engineering Pub Date : 2022-09-28 DOI: 10.7250/bjrbe.2022-17.566

A. Bhardwaj, S. Mittal

{"title":"Influence of Biaxial Geogrid at the Ballast Interface for Granular Earth Railway Embankment","authors":"A. Bhardwaj, S. Mittal","doi":"10.7250/bjrbe.2022-17.566","DOIUrl":"https://doi.org/10.7250/bjrbe.2022-17.566","url":null,"abstract":"The development of reinforcements for soil has made an impact in most of the civil engineering sectors especially transportation. The use of geogrids is frequent in roadways but they are also finding use in railways. The major impact that geogrids could have is providing desired stiffness to a section by reducing material and serving as a proper reinforcement material. In the current study, an attempt has been made to redesign the railway embankment economically with the help of geogrids. Biaxial geogrid is used to substitute the blanket layer (thickness up to 100 cm) in the railway embankment by fulfilling the strain modulus requirement of the embankment, calculated using a plate bearing test as per DIN 18134. The experiment is performed on the embankment replicated in a metallic test chamber with granular soil as subgrade and geogrid is placed beneath the ballast. The experimental study is validated by a 3-D numerical model using Midas GTS NX software. The experimental analysis shows an improvement of 31.47% in the second modulus of the earth embankment. For the implementation of this study, a design section of Indian railways is adopted. With the help of geogrid, a reduction of 50% is observed in the embankment height, thereby reducing the overall costs.","PeriodicalId":297140,"journal":{"name":"The Baltic Journal of Road and Bridge Engineering","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129661856","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}

引用次数: 1

An Improved Neural Network Model for Enhancing Rutting Depth Prediction 一种改进的神经网络车辙深度预测模型

The Baltic Journal of Road and Bridge Engineering Pub Date : 2022-09-28 DOI: 10.7250/bjrbe.2022-17.572

Shuzhan Xu, Junxin Yang, Changbai Wang

{"title":"An Improved Neural Network Model for Enhancing Rutting Depth Prediction","authors":"Shuzhan Xu, Junxin Yang, Changbai Wang","doi":"10.7250/bjrbe.2022-17.572","DOIUrl":"https://doi.org/10.7250/bjrbe.2022-17.572","url":null,"abstract":"Rutting is the main distress form of asphalt pavement, and its prediction accuracy is directly related to the reliability of the designed road. This research developed a neural network model to improve the prediction ability about the rutting of a pavement performance criterion and compared it with the multiple linear regression model and the existing neural network model. The neural network model is developed using the Keras module from the TensorFlow package in Python. Two reports generated by the National Cooperative Highway Research Program project 01-37A and the Long-Term Pavement Performance website records have been used as data sources for training the neural network model, which are reliable data preserved after years of monitoring. The input variables include the pavement thickness, service time, average annual daily traffic of trucks and the deformation of the asphalt concrete layer, granular base layer and subgrade layer. This experiment used 440 samples, of which 352 samples (80%) were used for model training and 88 samples (20%) for testing. The training results of the model reveal that the neural network model is significantly better than the multiple linear regression model, and the newly built neural network model performs better than another similar neural network in predictive performance. For the multiple linear regression model, the correlation coefficient R2 value between the measured and predicted in the testing set increased from 0.265 to 0.712. In contrast, it promotes from 0.867 to 0.902 for the neural network model.","PeriodicalId":297140,"journal":{"name":"The Baltic Journal of Road and Bridge Engineering","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129933412","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}

引用次数: 0

Effects of Reclaimed Asphalt, Wax Additive, and Compaction Temperature on Characteristics and Mechanical Properties of Porous Asphalt 再生沥青、蜡添加剂和压实温度对多孔沥青特性和力学性能的影响

The Baltic Journal of Road and Bridge Engineering Pub Date : 2022-09-28 DOI: 10.7250/bjrbe.2022-17.575

V. Ranieri, N. Berloco, Francesca Garofalo, Liang He, P. Intini, Karol J. Kowalski

{"title":"Effects of Reclaimed Asphalt, Wax Additive, and Compaction Temperature on Characteristics and Mechanical Properties of Porous Asphalt","authors":"V. Ranieri, N. Berloco, Francesca Garofalo, Liang He, P. Intini, Karol J. Kowalski","doi":"10.7250/bjrbe.2022-17.575","DOIUrl":"https://doi.org/10.7250/bjrbe.2022-17.575","url":null,"abstract":"This paper describes physical and mechanical properties of porous asphalt mixtures with various RAP amount (0%, 10%, 20%, 30%) containing one WMA additive (organic wax). The samples were prepared using the Marshall compactor at two different temperatures (125 °C, 145 °C) by fabricating six series of porous mixtures. Air void content, particle loss, stiffness modulus, indirect tensile strength, and indirect tensile strength ratio were measured and the effects of RAP, wax, and compaction temperatures were evaluated, considering the results of statistical analyses. Based on the performed tests, it has been concluded that high RAP contents (30%) in WMA-RAP PAs result in decreased porosity, permeability, and moisture resistance, and in increased cohesiveness, stiffness, and indirect tensile strength compared to the reference PAs. On the other hand, for low RAP contents (10%), WMA-RAP PAs show lower cohesiveness and indirect tensile strength, at the same time demonstrating an increase in porosity, permeability, moisture resistance, and stiffness. Reduced compaction temperatures (125 °C) particularly affect the cracking resistance.","PeriodicalId":297140,"journal":{"name":"The Baltic Journal of Road and Bridge Engineering","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121145685","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}

引用次数: 2

Indirect Determination of Soil Young’s Modulus in Lithuania Using Cone Penetration Test Data 立陶宛土壤杨氏模量的间接测定

The Baltic Journal of Road and Bridge Engineering Pub Date : 2022-06-27 DOI: 10.7250/bjrbe.2022-17.558

T. Tamošiūnas, Gintaras Žaržojus, Š. Skuodis

引用次数: 0