scholarly journals Establishment of a Shear Strength Prediction Model for Asphalt Mixtures with Raw Materials Properties and Design Parameters

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Bangwei Wu ◽  
Xing Wu ◽  
Liping Liu ◽  
Peng Xiao
Keyword(s):  
Shear Strength ◽  
Prediction Model ◽  
Raw Materials ◽  
Design Method ◽  
Asphalt Mixtures ◽  
Design Parameters ◽  
Strength Prediction ◽  
Factors Affecting ◽  
Gyratory Compaction ◽  
Asphalt Content

Shear strength is one of the important mechanical properties of asphalt mixtures, which is affected by a combination of various parameters such as asphalt property, gradation, and asphalt content, so it often requires a large number of tests to obtain a satisfactory asphalt mix design result. Thus, a shear strength prediction model considering the effects of various factors is proposed to guide the design of asphalt mixes. Firstly, on the foundation of analyzing the factors affecting the shear strength of asphalt mixtures, composed bulk specific gravity of mineral materials, aggregate surface energy, nonrecoverable creep compliance Jnr3.2, gradation index, aggregate specific surface area, asphalt content, and gyratory compaction number were selected as the input parameters for modeling. Secondly, the effects of modeling parameters on shear strength were analyzed, and an appropriate model was established using the software Origin with 101 sets of test results. In the end, the prediction model was verified using extra 18 sets of test data. The result showed that the correlation coefficient between the predicted and measured value reached 0.8 or more, indicating that the model has satisfactory prediction accuracy. This prediction model proposed in this article can be used to reduce the workload for designing asphalt mixtures and promote the establishment of the performance-based design method of asphalt mixtures.

The Variables Reduction for Concrete Strength Prediction Model Using a Rough Sets Method

2011 ◽  
Vol 311-313 ◽  
pp. 1911-1915
Author(s):  
Bin Chen ◽  
Xi Jun Liu
Keyword(s):  
Prediction Model ◽  
Rough Sets ◽  
Raw Materials ◽  
Concrete Strength ◽  
Variable Number ◽  
Strength Prediction ◽  
Concrete Mixtures ◽  
Forecast Precision ◽  
Variable Reduction ◽  
Independent Variable

Based on the test results of 448 sets of concrete mixtures (which have been divided into three groups), a concrete strength prediction model has been established using a stepwise regression method. The kinds and qualities of raw materials, which has a total comes to 17 factors, has been considered as the independent variables. It has been found that the forecast precision is not always improving along with the increase of independent variable number, so one or more factors may be "redundant" and should be reducted. A rough sets (RS) method has been adopted for the variable reduction, with different parameter combinations are tested. The results has shown that in each cases the forecast precision of the model are higher than the Bowromi formula’s. Some regularities for the parameters’ selections are existed, but not all the parameters can be given positively, so a trial process is still necessary.

scholarly journals Impact of Compaction Mode on Strength Properties of Sustainable Asphalt Concrete

2021 ◽  
Vol 4 (4) ◽  
Author(s):  
Saad Issa Sarsam
Keyword(s):  
Tensile Strength ◽  
Shear Strength ◽  
Asphalt Concrete ◽  
Testing Temperature ◽  
Strength Properties ◽  
Concrete Mixture ◽  
Gyratory Compaction ◽  
Indirect Tensile ◽  
Asphalt Content ◽  
Made In

Various modes of compacting the asphalt concrete mixture can createmechanically different behaviour of the prepared specimens and can alterits sustainability. An attempt has been made in the present assessment toprepare asphalt concrete specimens by implementation of three modesof compaction, the gyratory, the roller, and the Marshall hammer. Thespecimens were prepared at the target bulk density of Marshall methodat optimum asphalt content. Extra specimens were prepared at 0.5 %asphalt below and above the optimum. Core specimens have been obtainedfrom the roller compacted slab samples. The specimens were tested forthe Marshall stiffness, tensile, and shear strength. It was observed that atoptimum asphalt content, the indirect tensile strength declines by (18.8and 70.5) % for gyratory and roller compacted specimens respectively ascompared with hammer compacted specimens. At optimum asphalt content,the shear strength declines by (70.5 and 82.2) % while Marshall stiffnessdeclines by (10.2 and 44.8) % for hammer and roller compacted specimensas compared with that of gyratory compacted specimen. Specimensprepared by gyratory compaction are less susceptible to the change inthe testing temperature as compared with other modes of compaction. Itis recommended to consider the mode of compaction to suit the requireddesign property of sustainable asphalt concrete mixture.

scholarly journals Shear Strength Prediction Model of FRP Bar-Reinforced Concrete Beams without Stirrups

2020 ◽  
Vol 2020 ◽  
pp. 1-11 ◽  
Author(s):  
Danying Gao ◽  
Changhui Zhang
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
Size Effect ◽  
Prediction Model ◽  
Concrete Beams ◽  
Reinforced Concrete Beams ◽  
Strength Prediction ◽  
Longitudinal Reinforcement ◽  
Proposed Model ◽  
Frp Bar

The shear strength prediction model for fiber-reinforced polymer (FRP) bar-reinforced concrete beams without stirrups in ACI440.1R-2015 does not consider the “size effect” and the effect of shear span-to-depth ratio and predicts the zero-shear strength for concrete members without longitudinal reinforcement. A modified shear strength prediction model for FRP bar-reinforced concrete beams without stirrups was presented in this paper. The proposed model takes into account the effect of concrete strength, size of the beam, shear span-to-depth ratio, reinforcement ratio, and modulus of elasticity of the longitudinal reinforcement and the “size effect.” The superiority of the proposed model has been evaluated by comparing the calculated shear strength of FRP bar-reinforced concrete beams without stirrups by the proposed model with the experimental results and calculated values by the models in design codes, respectively. It confirmed that the shear strength of FRP bar-reinforced concrete beams without stirrups by the proposed model was in better agreement with the experimental results.

A Hybrid Model to Predict the Gyratory Compaction of Hot Mixed Asphalt

2019 ◽  
Author(s):  
Teng Man
Keyword(s):  
Hybrid Model ◽  
Asphalt Binder ◽  
Asphalt Mixture ◽  
Aggregate Size ◽  
Asphalt Mixtures ◽  
Compaction Process ◽  
Particle Rearrangement ◽  
Compaction Behavior ◽  
Grain Size Distributions ◽  
Gyratory Compaction

The compaction of asphalt mixture is crucial to the mechanical properties and the maintenance of the pavement. However, the mix design, which based on the compaction properties, remains largely on empirical data. We found difficulties to relate the aggregate size distribution and the asphalt binder properties to the compaction behavior in both the field and laboratory compaction of asphalt mixtures. In this paper, we would like to propose a simple hybrid model to predict the compaction of asphalt mixtures. In this model, we divided the compaction process into two mechanisms: (i) visco-plastic deformation of an ordered thickly-coated granular assembly, and (ii) the transition from an ordered system to a disordered system due to particle rearrangement. This model could take into account both the viscous properties of the asphalt binder and grain size distributions of the aggregates. Additionally, we suggest to use the discrete element method to understand the particle rearrangement during the compaction process. This model is calibrated based on the SuperPave gyratory compaction tests in the pavement lab. In the end, we compared the model results to experimental data to show that this model prediction had a good agreement with the experiments, thus, had great potentials to be implemented to improve the design of asphalt mixtures.

Solid Waste Management on Romanian Households

2018 ◽  
Vol 68 (12) ◽  
pp. 2941-2947
Author(s):  
George Ungureanu ◽  
Gabriela Ignat ◽  
elena Leonte ◽  
Carmen Luiza Costuleanu ◽  
Nicoleta Stanciu ◽  
...  
Keyword(s):  
Waste Management ◽  
Solid Waste ◽  
Agricultural Development ◽  
Management Practices ◽  
Solid Waste Management ◽  
Raw Materials ◽  
Rapid Development ◽  
Disposal Site ◽  
Solid Waste Disposal ◽  
Factors Affecting

The problem associated with the household behavior on solid waste disposal site in today�s society is complex because of the large quantity and diverse nature of the wastes. Due increase the population, rapid development, global agricultural development has moved rapidly, limitations of financing, emerging limitations of both energy and raw materials and also add to the complexity of any waste management system, large quantities of wastes are being generated in different forms such as solid, liquid and gases. This research explored factors affecting the level of participation in solid waste segregation and recycling of households in Romania, as well as examining current Romania households waste management practices and their knowledge of waste management. This study investigated the solid waste situation and the organization of solid waste management in both urban and rural settings from the perspective of households. Solid waste management is a key component of public services which needs to serve the urban and rural municipalities in an efficient way in order to maintain a decent standard of public health.

scholarly journals A modular design method based on TRIZ and AD and its application to cutter changing robot

2021 ◽  
Vol 13 (7) ◽  
pp. 168781402110343
Author(s):  
Mei Yang ◽  
Yimin Xia ◽  
Lianhui Jia ◽  
Dujuan Wang ◽  
Zhiyong Ji
Keyword(s):  
Modular Design ◽  
Design Method ◽  
Idea Generation ◽  
Design Parameters ◽  
Problem Analysis ◽  
Concept Design ◽  
Functional Requirements ◽  
Shield Tunneling ◽  
Structural Hierarchy ◽  
And Performance

Modular design, Axiomatic design (AD) and Theory of inventive problem solving (TRIZ) have been increasingly popularized in concept design of modern mechanical product. Each method has their own advantages and drawbacks. The benefit of modular design is reducing the product design period, and AD has the capability of problem analysis, while TRIZ’s expertise is innovative idea generation. According to the complementarity of these three approaches, an innovative and systematic methodology is proposed to design big complex mechanical system. Firstly, the module partition is executed based on scenario decomposition. Then, the behavior attributes of modules are listed to find the design contradiction, including motion form, spatial constraints, and performance requirements. TRIZ tools are employed to deal with the contradictions between behavior attributes. The decomposition and mapping of functional requirements and design parameters are carried out to construct the structural hierarchy of each module. Then, modules are integrated considering the connections between each other. Finally, the operation steps in application scenario are designed in temporal and spatial dimensions. Design of cutter changing robot for shield tunneling machine is taken as an example to validate the feasibility and effectiveness of the proposed method.

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