Research on influencing factors and time-varying model of thermal conductivity of concrete at early age

2021 ◽  
pp. 125638
Author(s):  
Jinpeng Dai ◽  
Qicai Wang ◽  
Ruixiao Bi ◽  
Chong Wang ◽  
Zhuowei Han ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Influencing Factors ◽  
Early Age ◽  
Time Varying

Resistance Analysis of Reinforced Concrete Structures in Construction

2011 ◽  
Vol 368-373 ◽  
pp. 1535-1538
Author(s):  
Nan Zhao ◽  
Wen Yan
Keyword(s):  
Concrete Strength ◽  
Early Time ◽  
Reduction Factor ◽  
Resistance Force ◽  
Early Age ◽  
Time Varying ◽  
Structural Components ◽  
Utilization Coefficient ◽  
Flexural Member ◽  
Early Age Concrete

This paper analyses the characteristics of resistance of structural components, puts forward the concept of early resistance force of structural components, and discuss the main factors which affect it based on the field measurement investigation and theoretical analysis. Besides, in the paper the reduction factor is applied to reflect time-varying features of early-age concrete strength, and utilization coefficient of concrete strength is utilized to present the influence of early time-varying features of cohesive action on resistance. The paper finally deduces the formula of early-age resistance force of typical flexural member, and gives the time-changing law of early resistance by using a case.

Dependence of Thermal Conductivity of Carbon Black Filled Rubber on Several Factors

2009 ◽  
Vol 87-88 ◽  
pp. 536-541 ◽  
Author(s):  
Jun Ping Song ◽  
Lian Xiang Ma
Keyword(s):  
Thermal Conductivity ◽  
Carbon Black ◽  
Natural Rubber ◽  
Influencing Factors ◽  
Specific Area ◽  
Volume Percent ◽  
Filled Rubber ◽  
Two Factors

Five kinds of carbon black filled natural rubber were prepared, and thermal conductivity was studied considering two factors, which include temperature and volume percent of the filler. It was found that thermal conductivity had relevance to temperature and volume percent of carbon black, besides, structure and specific area of carbon black were also very important influencing factors. Moreover, reuniting phenomenon of nanometer grade of carbon black has much effect on thermal conductivity.

Performance Analysis of Bentonite-PVA Fiber Cement-Based Composites for Building Based on BP Neural Network

2020 ◽  
Vol 852 ◽  
pp. 209-219
Author(s):  
Zhe Shen
Keyword(s):  
Neural Network ◽  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Composite Materials ◽  
Influencing Factors ◽  
Bp Neural Network ◽  
Analysis Method ◽  
System Input ◽  
Prediction And Simulation ◽  
Pva Fiber

The paper will use BP neural network analysis method to study the thermal conductivity of bentonite and its influencing factors as a system. The heat conduction of bentonite was used as the output of the system, and its influencing factors were used as the system input to simulate. The corresponding simulation model was established to verify the thermal conductivity data. In addition, the analysis of the mechanical properties of the bentonite-PVA fiber cement-based composite materials for construction has not only laid a theoretical and realistic foundation for the prediction and simulation of the thermal conductivity of bentonite, but also has opened up the mechanical properties of the bentonite-PVA fiber cement-based composite materials a new path.

scholarly journals Rate-Type Age-Dependent Constitutive Formulation of Concrete Loaded at an Early Age

Materials ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 514 ◽  
Author(s):  
Seung-Gyu Kim ◽  
Yeong-Seong Park ◽  
Yong-Hak Lee
Keyword(s):  
Elastic Modulus ◽  
Constitutive Equations ◽  
Experimental Result ◽  
Early Age ◽  
Time Varying ◽  
Numerical Application ◽  
Age Dependent ◽  
Sustained Loads ◽  
Constitutive Formulation ◽  
Ageing Phenomenon

A general formulation framework for an age-dependent constitutive equation of concrete is presented to account for the development of the elastic modulus at an early age. This is achieved by expanding the total stress vs. strain relation with respect to the time-varying elastic modulus. Two types of constitutive formulation frameworks are derived depending on whether (or not) the time-varying effect of the elastic modulus was taken into account in the linearized series expansion. The causes for the age-dependent deformations under sustained loads are defined in the formulation based on the two internal mechanisms of delayed elasticity and the ageing phenomenon. The ageing phenomenon is incorporated in a conventional delayed strain concept in terms of the variable elastic modulus with time. Four cases of age-dependent constitutive equations are formulated within the presented formulation framework by employing different types of creep models. The mechanical characteristics of the terms that comprise the various constitutive equations are examined and compared. Numerical application of the time-dependent test results of cylindrical specimens indicate that the creep formulation that considered the elastic modulus development showed a good agreement with the experimental result while the formulation that did not consider the elastic modulus development underestimated the result by 15%.

Multi-Step Prediction Algorithm for State Prediction Model

2010 ◽  
Vol 143-144 ◽  
pp. 634-638
Author(s):  
Zi Li Zhang ◽  
Hong Wei Song
Keyword(s):  
Prediction Model ◽  
Bayesian Networks ◽  
Influencing Factors ◽  
Dynamic Bayesian Networks ◽  
Prediction Algorithm ◽  
Time Varying ◽  
System State ◽  
Reasoning Process ◽  
State Prediction ◽  
The Relationship

Dynamic Bayesian networks can be well dealt with the time-varying multivariable problem. The state model based on Dynamic Bayesian networks can more accurately describe the relationship between the system state and the influencing factors. In this paper, the width of the reasoning is used to simplify the amount of data in the reasoning process. Multi-step state prediction is achieved by extending time-slice. Experiment has shown that the proposed algorithm can achieve better prediction results.

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