scholarly journals Temperature Sensitivity of Mechanical Properties of Cement Asphalt Mortar with Nanoparticles

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Xi Wu ◽  
Xing-Lang Fan ◽  
Jin-Feng Wang
Keyword(s):  
Compressive Strength ◽  
Temperature Sensitivity ◽  
High Speed ◽  
Cement Asphalt Mortar ◽  
Strength Based ◽  
Different Temperatures ◽  
Increasing Temperature ◽  
Positive Effect ◽  
Asphalt Mortar ◽  
Electronic Microscope

Cement asphalt mortar (CAM) in high-speed lines is subjected to varying environmental conditions, which lead to the deterioration of CAM. The nanoparticles of nano-SiO2 and nano-TiO2 are added to improve the performance of CAM, and the temperature sensitivity of CAM with nanoparticles is primarily studied in this paper. The flexural strength and compressive strength of CAM with and without nano-SiO2 and nano-TiO2 were measured and compared to study the effect of nanoparticles on the performance of CAM subjected to different temperatures. Temperature sensitivity factors of flexural and compressive strength based on Arrhenius model were proposed to evaluate the temperature dependence of CAM by nanoparticles. Furthermore, the microstructure of hardened CAM was studied using scan electronic microscope (SEM) to investigate the mechanism of temperature sensitivity of CAM with and without nanoparticles. The results indicated that the flexural and compressive strength of CAM with and without nanoparticles decreased with the increasing temperature; however, the decreasing rate of strength with temperature was different in CAM with and without nanoparticles. The reduction in the decreasing rate of strength was obtained by using nano-SiO2 rather than nano-TiO2 in CAM. Based on the SEM results, the free asphalt was seen to be greatly reduced in the CAM with nano-SiO2, suggesting a positive effect of nano-SiO2 on the mitigation of temperature sensitivity of CAM.

Prepartion and Atypical Mechianical Performance of Epoxy Asphalt Cement Mortars Composite Material for High Speed Railway

2011 ◽  
Vol 90-93 ◽  
pp. 547-553 ◽  
Author(s):  
Xing Long Fang ◽  
Zhi Ming Chen ◽  
Zhen Jiao ◽  
Gang Hua Pan ◽  
Wen Ping Zhou ◽  
...  
Keyword(s):  
Compressive Strength ◽  
High Speed ◽  
Cement Mortar ◽  
Asphalt Emulsion ◽  
Asphalt Cement ◽  
Chemically Modified ◽  
Epoxy Asphalt ◽  
Cement Asphalt Mortar ◽  
Weather Resistance ◽  
Asphalt Mortar

Cement asphalt mortar is a key part of flexible adjusting layer in slab ballastless track structure. In this paper, new materials of epoxy asphalt cement mortar (EACM) was prepared with epoxy and chemically modified asphalt emulsionwhich showed excellent in terms of durability and weather resistance. This paper through changing the proportions of the eopxy-asphalt cement ration studies the relationship among fluidity, compressive strength, and elastic modulus of EACM and cement asphalt mortar (CAM) use chemical modification of asphalt emulsion and normal asphalt emulsion. The results showed that chemically modified epoxy asphalt emulsion cement mortar turned out to be relatively better in compressive strength, frost resistance and weather ability compared with CAM. The chemical reaction mechanism of epoxy asphalt emulsion were investigated by the means of environmental scanning electron microscope (ESEM) method.

Dynamic Mechanical Analysis of CRTS II Cement Asphalt Mortar

2014 ◽  
Vol 584-586 ◽  
pp. 1646-1651
Author(s):  
Hua Yang Zhang ◽  
Long Hua Yuan ◽  
De Wei Ren
Keyword(s):  
Viscoelastic Properties ◽  
High Speed ◽  
Mechanical Analysis ◽  
Asphalt Emulsion ◽  
High Speed Railway ◽  
Burgers Model ◽  
Cement Asphalt Mortar ◽  
Different Temperatures ◽  
Ca Mortar ◽  
Asphalt Mortar

Cement asphalt mortar (CA mortar) is one of key structures of slab ballastless high-speed railway. Cement and asphalt emulsion are the main two components of CA mortar, making it possess the viscoelastic properties of viscoelastic materials, which is one of the infancy of the current study. In this paper, DMA method was adopted to investigate the viscoelastic properties of CRTS II CA mortar. Viscoelastic properties of CA mortar at different temperatures were investigated and were compared with the numerical simulation results of Burgers model. The results of the simulation fit in well with the data from the experimental-scale column, so we can study the dynamic modulus of CA mortar using the Burgers model in the temperature range of CA mortar.

Compressive strength development and microstructure of cement-asphalt mortar

2011 ◽  
Vol 26 (5) ◽  
pp. 998-1003 ◽  
Author(s):  
Qiang Wang ◽  
Peiyu Yan ◽  
Xiangming Kong ◽  
Jinbo Yang
Keyword(s):  
Compressive Strength ◽  
Strength Development ◽  
Cement Asphalt Mortar ◽  
Compressive Strength Development ◽  
Asphalt Mortar

scholarly journals Effect of Water and Emulsifier on the Mechanical Properties of Cement Asphalt Mortar

2019 ◽  
Vol 271 ◽  
pp. 03002
Author(s):  
Tri Ho Minh Le ◽  
Dae-Wook Park ◽  
Jung-Woo Seo
Keyword(s):  
High Speed ◽  
Mechanical Performance ◽  
Strength Development ◽  
Mechanical Degradation ◽  
Asphalt Emulsion ◽  
Term Operation ◽  
Cement Asphalt Mortar ◽  
Rail Structure ◽  
Asphalt Mortar ◽  
Mixing Water

The long-term operation of high-speed railway leads to remarkable issues in ballast mechanical degradation and track irregularity. Particularly, in mainline of rail structure, the required time for ballast layer maintenance is strictly short. To systematically cope with this problem, a comprehensive study was proposed to develop a new cement asphalt mortar (CAM) stabilized ballast method. This solution is expected to improve the ballast structural durability with fast application time. However, the engineer properties of CAM paste with different level of initial mixing water as well as the influencing mechanisms are not clearly understood. In this work, the effects of initial mixing water and emulsifier on the mechanical performance of CAM are mainly discussed. The characteristics of the mortar were determined by conducting the flowability test, mixing stability test, and unconfined compressive strength (UCS) test. The test results revealed that the initial mixing water plays an important role in both fresh and hardened stage of CAM, especially the demulsification process of asphalt emulsion. Meanwhile, the emulsifier imposed a critical effect on the strength development of CAM mixture.

Effect of Emulsified Asphalt on Temperature Susceptibility of Cement Asphalt Mortar

2011 ◽  
Vol 335-336 ◽  
pp. 124-127 ◽  
Author(s):  
Yun Hua Zhang ◽  
Fa Zhou Wang
Keyword(s):  
Asphalt Emulsion ◽  
Thermal Dependence ◽  
Temperature Range ◽  
Cement Asphalt Mortar ◽  
Different Temperatures ◽  
Lower Temperature ◽  
Emulsified Asphalt ◽  
Temperature Susceptibility ◽  
Ca Mortar ◽  
Asphalt Mortar

Cement asphalt mortar (CA mortar, or CAM) is a composite material with equal presence of cement and asphalt emulsion and acts as a cushion layer in the structure of slab track. In the hardened matrix, asphalt accounts for about 30 vol. %, rendering the properties of CA mortar susceptible to temperature variation. In the paper, different kinds of emulsified asphalts (A70 emulsified asphalt, A90 emulsified asphalt, SBS modified emulsified asphalt and SBR modified emulsified asphalt) for CA mortar and the compressive strengths of CA mortar under different temperatures (-18°C, 10°C, 25°C, 40°C and 60°C) were studied to reflect its thermal dependence. Results indicate that temperature susceptibility of CA mortar prepared with modified emulsified asphalt is better than which prepared with unmodified emulsified asphalt. SBS modified emulsified asphalt -CAM (viz. CA mortar prepared by SBS modified emulsified asphalt) is alleviated at the whole temperature range, while that of SBR modified emulsified asphalt -CAM is improved primarily at the lower temperature region. As for types of unmodified asphalts, A90 emulsified asphalt -CAM outperforms A70 emulsified asphalt -CAM at lower temperature range.

scholarly journals Dynamic Characteristics of Rubber Powder Modified Cement Asphalt Mortar

2012 ◽  
Vol 5 ◽  
pp. 243-246 ◽  
Author(s):  
Yun Liang Li ◽  
Yang Jian Ou ◽  
Yi Qiu Tan ◽  
Ming Yu Lu
Keyword(s):  
High Speed ◽  
Damping Ratio ◽  
Beam Specimen ◽  
Rubber Powder ◽  
Cement Asphalt Mortar ◽  
Track System ◽  
Vibration Attenuation ◽  
Vibration Tests ◽  
The Impact ◽  
Asphalt Mortar

Cement asphalt mortar (CA) is mainly applied in track system of high-speed railways for vibration attenuation. The impact on dynamics performance of CA with the admixture of rubber powder was studied. The beam specimen made of CA was manufactured for analyzing its vibration frequency and damping characteristics by free attenuation vibration tests. Results showed that there was no big change for fundamental frequency after admixture of rubber powder. However, high order frequency and structural damping increased with the increase of admixture amount. Damping ratio of CA was increased by admixing rubber powder, which can be better for energy absorption and vibration attenuation.

scholarly journals Cement asphalt mortar for high-speed rail

2020 ◽  
Vol 65 (22) ◽  
pp. 2384-2394
Author(s):  
Dehua Deng ◽  
Qiang Yuan ◽  
Yong Wang
Keyword(s):  
High Speed ◽  
High Speed Rail ◽  
Cement Asphalt Mortar ◽  
Asphalt Mortar

A Study on Mechanical Performance and Mechanism of Cement Asphalt Mortar

2011 ◽  
Vol 197-198 ◽  
pp. 1023-1027
Author(s):  
Yun Liang Li ◽  
Yi Qiu Tan ◽  
Yang Jian Ou
Keyword(s):  
Compressive Strength ◽  
Mechanical Performance ◽  
Cement Ratio ◽  
Cement Asphalt Mortar ◽  
Ca Mortar ◽  
Asphalt Mortar ◽  
Performance And Mechanism ◽  
Solidified Body

This paper studies the effects of proportion of emulsion asphalt and cement, sand gradation and sand-to-cement ratio on 28d strength of CA mortar solidified body according to compressive strength. Results show that compressive strength of CA mortar evidently decreases with increase of quality ratio of emulsion asphalt and cement, and increases with sand gradation attenuated. 28d compressive strength of CA mortar obviously reduces when the sand-cement ratio is above 1.4. Mechanical performance and intensity capability of CA motor solidified body are determined by microstructure of solidified body and content of free asphalt, encapsulation and cementation state of microstructure.

Prediction of Cement Compressive Strength Based on Accelerated Curing Method

2011 ◽  
Vol 250-253 ◽  
pp. 118-121
Author(s):  
Yong Hui Luo ◽  
Zhen Guo Gao ◽  
Guo Lin Miao
Keyword(s):  
Compressive Strength ◽  
High Speed ◽  
Prediction Equation ◽  
Boiling Water ◽  
Estimation Of Parameters ◽  
Accelerated Curing ◽  
Strength Based ◽  
Curing Methods ◽  
The Difference ◽  
Curing Method

Prediction of cement compressive strength was studied with accelerated curing methods, e.g. warm water and boiling water curing. The results indicate that fineness and the type of cements is few influencing on the 28-day compressive strength, and the difference is not distinct between the two methods. The boiling water fast-curing method is recommended since it doesn’t need additional equipments and has the advantage of convenient and high-speed. The prediction equation adopts linear model, and robust estimation of parameters is also applied to eliminate influences of outliers.

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