Freezing and Thawing Resistance of Cement Asphalt Mortar

2008 ◽  
Vol 400-402 ◽  
pp. 163-167 ◽  
Author(s):  
Shu Guang Hu ◽  
Tao Wang ◽  
Fa Zhou Wang ◽  
Zhi Chao Liu ◽  
Tao Gao ◽  
...  
Keyword(s):  
Elastic Moduli ◽  
Crumb Rubber ◽  
Influential Factors ◽  
Freezing And Thawing ◽  
Asphalt Emulsion ◽  
Polymer Powder ◽  
Cement Asphalt Mortar ◽  
Ca Mortar ◽  
Asphalt Mortar ◽  
Redispersible Polymer Powder

In this paper, freezing and thawing resistance of CA mortar was investigated and some influential factors such as the ratio between asphalt emulsion and cement (A/C), cement types, various additives were also explored. Results indicated that a gain of mass was observed for every mixture after the test; mixtures with a higher A/C performed better in terms of higher relative elastic moduli. Mixtures proportioned by partially replacing ordinary Portland cement (OPC) with sulfoalumninate cement (SAC) underperformed in freezing and thawing property. Addition of crumb rubber powder (CRP), redispersible polymer powder (RPP) and organic fiber (FR) improved the resistance of CA mortar to freezing and thawing while that of silica fume (SF) undermined it.

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.

Study on Influencing Factors of Flow-Ability of Cement Asphalt Mortar

2011 ◽  
Vol 243-249 ◽  
pp. 4240-4243 ◽  
Author(s):  
Yun Liang Li ◽  
Yi Qiu Tan ◽  
Yang Jian Ou ◽  
Jin Feng Wang
Keyword(s):  
Time Delay ◽  
Influencing Factors ◽  
Direct Contact ◽  
Mixing Process ◽  
Asphalt Emulsion ◽  
Cement Asphalt Mortar ◽  
Suitable Amount ◽  
Ca Mortar ◽  
Asphalt Mortar

Flow-ability of CA mortar is characterized by fluidity, and the effects of the CA mortar fluidity according to water, time, and feeding sequence are studied. Studies have shown that the amount of the used of water affects the fluidity most, in which the suitable amount of water is between 0.23 and 0.28. With the time delay, the flow-ability of CA mortar is reduced. When mixed with SBR latex, the process of decay of the flow-ability is significantly reduced. Feeding sequence has great effect on fresh mixed CA mortar. In the mixing process, to avoid asphalt emulsion and cement dry material in direct contact, the speed of demulsification is reduced, which can effectively increase the flow-ability of CA mortar.

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.

scholarly journals The Effect of Polymer Powder on the Cracking of the Subbase Layer Composed of Cold Recycled Bitumen Emulsion Mixtures

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5867
Author(s):  
Jakub Krasowski ◽  
Przemysław Buczyński ◽  
Marek Iwański
Keyword(s):  
Fracture Resistance ◽  
Asphalt Emulsion ◽  
Bending Tests ◽  
Bitumen Emulsion ◽  
Polymer Powder ◽  
Two Temperatures ◽  
Cement Mixture ◽  
Polymer Modifier ◽  
The Right ◽  
Redispersible Polymer Powder

The research was aimed at assessing the effect of the redispersible polymer powder on the fracture resistance of a subbase made of a mineral–cement mixture with a bitumen emulsion. The test was performed at two temperatures, i.e., 0 °C and 20 °C. The prepared mixtures differed in the content of cement, asphalt emulsion, and polymer modifier. Cement and redispersible polymer powder were dosed in 1.5% steps from 0.5% to 3.5% while the amount of bitumen emulsion ranged from 0.0% to 5.0%. The SCB (semi-circular bending) tests carried out in the laboratory showed the dependence of the influence of the amount of binder and polymer modifier on the fracture resistance of the recycled subbase. Mixes containing a polymer modifier in their composition are characterized by a much higher resistance to cracking than traditional mineral–cement–emulsion mixtures. An example is the doubling of the framework’s fracture toughness (KIC) when the amount of the polymer modifier is increased from 0.5% to 2.0% with a constant cement content of 0.5%. The obtained results (KIC) in this case were 2.90 and 5.81. The key is the right ratio of polymer powder and cement in the base composition.

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.

Preliminary Study on Asphalt Emulsion Used in Cement Asphalt Mortar

2009 ◽  
Vol 37 (5) ◽  
pp. 000395 ◽  
Author(s):  
M. R. Mitchell ◽  
R. E. Link ◽  
Wang Fazhou ◽  
Zhang Yunhua ◽  
Liu Yunpeng ◽  
...  
Keyword(s):  
Asphalt Emulsion ◽  
Cement Asphalt Mortar ◽  
Preliminary Study ◽  
Asphalt Mortar

Influence of Particle Sizes of Asphalt Emulsion on the Properties of Cement and Asphalt Mortar

2012 ◽  
Vol 174-177 ◽  
pp. 336-340
Author(s):  
Yi Tian ◽  
Yang Yu ◽  
Yu Zhen Zhang
Keyword(s):  
Particle Size ◽  
Storage Stability ◽  
Emulsion Stability ◽  
Strength Development ◽  
Particle Sizes ◽  
Asphalt Emulsion ◽  
Early Strength ◽  
Ca Mortar ◽  
Asphalt Mortar ◽  
Stability Of Emulsion

The influences of particle sizes of asphalt emulsion on the storage stability of emulsion and properties of cement and asphalt mortar were studied. Results indicated that, the storage stability was improved with the decrease of particle size, while the emulsion stability was not improved significantly when the particle size was less than 3μm; the fluidity was improved while the separation rate was increased with the decrease of particle size; the early strength of CA mortar was increased when prepared with the emulsion with larger particle size; while the emulsion with smaller particle size was benefit to the late strength development of CA mortar.

Effect of Fine Sand on the Rheology of Fresh Cement Asphalt Mortar

2014 ◽  
Vol 1049-1050 ◽  
pp. 285-293
Author(s):  
Jian Wei Peng ◽  
De Hua Deng ◽  
Qiang Yuan ◽  
Lei Fang ◽  
Yong Wang
Keyword(s):  
Particle Size ◽  
Film Thickness ◽  
Rheological Properties ◽  
Apparent Viscosity ◽  
Strong Influence ◽  
Fine Sand ◽  
Cement Asphalt Mortar ◽  
Key Factor ◽  
Ca Mortar ◽  
Asphalt Mortar

Controlling the rheological properties of cement asphalt (CA) mortar has been of great importance to its construction properties. In the present paper, the effects of sand, i.e. particle size and fineness module of sand, sand to paste ratio (Rs/p) and paste film thickness (PFT) on the rheological properties of CA mortar were studied with the use of a rheometer. The results show that the properties and content of sand have a strong influence on the rheology of CA mortar. The yield stress and apparent viscosity of CA mortar is decreased with the increasing of particle size and fineness module of sand and PFT, and the decreasing of Rs/p. The key factor of sand to determine the rheology of CA mortar is the PFT.

Influence of Temperature on the Absorption Behaviour between Cement and Asphalt Emulsion in CA Mortar

2011 ◽  
Vol 295-297 ◽  
pp. 939-944 ◽  
Author(s):  
Yun Peng Liu ◽  
Fa Zhou Wang
Keyword(s):  
Particle Size ◽  
Size Variation ◽  
Asphalt Emulsion ◽  
Rotational Viscometer ◽  
Grouting Material ◽  
Cement Asphalt Mortar ◽  
Different Temperatures ◽  
Influence Of Temperature On ◽  
Cae System ◽  
Ca Mortar

Cement asphalt mortar (CA mortar) is a highly flowable grouting material used in the slab track structure. Temperature significantly influences the workable time of CA mortar. The workable time of CA mortar is controlled by the adsorption of asphalt droplets in the emulsion on cement grains. In the present study, the absorption behaviours under different temperatures were investigated to reveal the influences of temperature on workable properties of CA mortar. A laser particle size analyzer was employed to characterize the particle size variation in the cement and asphalt emulsion (CAE) system. The results indicated that the particle size increased more prominently at elevated temperature; The viscosity of the CAE system was measured by a rotational viscometer, results indicated that variation pattern of viscosity correlated well with that of the particle size in the CAE system and the increase of particle size was partially accountable for the increase of viscosity and impairing the flowability of CA mortar; the workable properties of CA mortar were also investigated, results showed that the slump flow increased and the workable time decreased with the increase of temperature. The addition of non-ionic emulsifier could retard the adsorption behaviour between cement and asphalt and prolong the workable time of CA mortar.

scholarly journals Analysis of the Impact of Redispersible Polymer Powder on the Water and Frost Resistance of Cold-Recycled Mixture with Bitumen Emulsion

2021 ◽  
Vol 1203 (2) ◽  
pp. 022006
Author(s):  
Jakub Krasowski ◽  
Marek Iwański ◽  
Przemysław Buczyński
Keyword(s):  
Frost Resistance ◽  
Impact Analysis ◽  
Void Content ◽  
Asphalt Emulsion ◽  
Mixture Density ◽  
Bitumen Emulsion ◽  
Polymer Powder ◽  
Aashto T283 ◽  
The Impact ◽  
Redispersible Polymer Powder

Abstract The subject of the research presented in the article is the assessment of the effect of redispersible polymer powder (RPP) on water and frost resistance of a cold-recycled mixture with bitumen emulsion (BE-CRM). The article presents the results of research on the influence of polymer powder EVA based on polymer (polyethylene-co-vinyl acetate) on the properties of BE-RCM. The impact analysis was determined using the assumptions of the Box-Behnken experiment plan in which three components are controlled. In this case, the variables were the content of: polymer, cement and asphalt emulsion. All ingredients were dosed with a step of 1.5% of the percentage share in the mixture composition. Polymer and Portland cement in an amount of 0.5% to 3.5%. On the other hand, the pure asphalt originating from the asphalt emulsion was 0.0%, 1.5% and 3.0%, respectively. The scope of the tests included the determination of: mixture density, void content (Vm), water absorption (nw), intermediate tensile strength (ITS), to water (TSR) as well as water and frost according to AASHTO T283.

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