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.

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.

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.

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.

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 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.

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.

scholarly journals Determination of Load-Carrying Capacity of C-Profile Glued Ti-Al Column under Temperature Environment

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3013
Author(s):  
Leszek Czechowski
Keyword(s):  
Carrying Capacity ◽  
Tensile Tests ◽  
Discrete Models ◽  
Image Correlation ◽  
Load Carrying Capacity ◽  
Lagrange Equations ◽  
Load Carrying ◽  
Different Temperatures ◽  
Influence Of Temperature On

The paper deals with an examination of the behaviour of glued Ti-Al column under compression at elevated temperature. The tests of compressed columns with initial load were performed at different temperatures to obtain their characteristics and the load-carrying capacity. The deformations of columns during tests were registered by employing non-contact Digital Image Correlation Aramis® System. The numerical computations based on finite element method by using two different discrete models were carried out to validate the empirical results. To solve the problems, true stress-logarithmic strain curves of one-directional tensile tests dependent on temperature both for considered metals and glue were implemented to software. Numerical estimations based on Green–Lagrange equations for large deflections and strains were conducted. The paper reveals the influence of temperature on the behaviour of compressed C-profile Ti-Al columns. It was verified how the load-carrying capacity of glued bi-metal column decreases with an increase in the temperature increment. The achieved maximum loads at temperature 200 °C dropped by 2.5 times related to maximum loads at ambient temperature.

The Use of Rheology for Sludge Characterization

1982 ◽  
Vol 14 (6-7) ◽  
pp. 475-489 ◽  
Author(s):  
H W Campbell ◽  
P J Crescuolo
Keyword(s):  
Particle Size ◽  
Sewage Sludge ◽  
Test Procedures ◽  
Particle Size Reduction ◽  
Rotational Viscometer ◽  
Polymer Addition ◽  
Rheological Measurements ◽  
Acceleration Rate ◽  
Sludge Characterization ◽  
Potential Use

Rheological measurements were conducted on a variety of anaerobically digested sewage sludges to evaluate the potential use of rheology in describing the effects of chemical conditioning on the physical characteristics of sludges. The objectives of the study were to evaluate the influence of the method of chemical conditioning on rheological measurements; to determine the response of the viscometer system to changes in the instrument variables; and to evaluate interrelationships between rheology and other physical properties. All rheological measurements were made using a coaxial rotational viscometer. Evaluation of a variety of test procedures identified that both the method of adding chemical conditioners, and the acceleration rate of the rotational viscometer, could significantly alter the shape of the rheograms. A suggested methodology was identified and selected samples were analyzed in triplicate to test the reproducibility of the procedures. Existing mathematical models do not adequately describe the variety of flow behaviour patterns observed with sewage sludge. The concepts of yield stress and apparent viscosity also have limited value due to problems of definition and calculation. A parameter termed the “instantaneous viscosity”, defined as the derivative of the flow curve, is suggested as being more suitable for describing sludge behaviour. The relationships between chemical conditioning, particle size distribution and applied shear were explored. As polymer addition increased, the sludge particles became more susceptible to shear breakup. The extent of particle size reduction was a function of the rate of shear and the time during which the shear was maintained.

scholarly journals Experimental Investigation of Wave Velocity-Permeability Model for Granite Subjected to Different Temperature Processing

Geofluids ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Guanghui Jiang ◽  
Jianping Zuo ◽  
Teng Ma ◽  
Xu Wei
Keyword(s):  
Particle Size ◽  
High Temperature ◽  
Wave Velocity ◽  
Pore Fluid ◽  
Rock Matrix ◽  
Permeability Model ◽  
Wave Velocities ◽  
Before And After ◽  
Different Temperatures ◽  
Increasing Temperature

Understanding the change of permeability of rocks before and after heating is of great significance for exploitation of hydrocarbon resources and disposal of nuclear waste. The rock permeability under high temperature cannot be measured with most of the existing methods. In this paper, quality, wave velocity, and permeability of granite specimen from Maluanshan tunnel are measured after high temperature processing. Quality and wave velocity of granite decrease and permeability of granite increases with increasing temperature. Using porosity as the medium, a new wave velocity-permeability model is established with modified wave velocity-porosity formula and Kozeny-Carman formula. Under some given wave velocities and corresponding permeabilities through experiment, the permeabilities at different temperatures and wave velocities can be obtained. By comparing the experimental and the theoretical results, the proposed formulas are verified. In addition, a sensitivity analysis is performed to examine the effect of particle size, wave velocities in rock matrix, and pore fluid on permeability: permeability increases with increasing particle size, wave velocities in rock matrix, and pore fluid; the higher the rock wave velocity, the lower the effect of wave velocities in rock matrix and pore fluid on permeability.

Intermetallic Effects on the Ductility of Sintered Aluminium

2008 ◽  
Vol 587-588 ◽  
pp. 380-384
Author(s):  
Jesus Cintas ◽  
José A. Rodríguez ◽  
Francicso Gomez Cuevas ◽  
José M. Gallardo
Keyword(s):  
Heat Treatment ◽  
Particle Size ◽  
Intermetallic Particle ◽  
Quantitative Metallography ◽  
Mechanically Alloyed ◽  
Aluminium Powder ◽  
Attrition Milling ◽  
Different Temperatures ◽  
Alloyed Aluminium ◽  
Milled Powders

Mechanically alloyed aluminium powder was prepared by attrition-milling for 10 hours in the presence of a wax. Milled powders were annealed in vacuum at different temperatures (500, 575, 600, 625 and 650°C). Compacts were consolidated starting from unannealed and from 600°Cannealed powders. Studies by SEM microfractography and quantitative metallography, to investigate the influence of Fe-Al intermetallics on compacts fracture, have been carried out. It is concluded that fracture takes place at regions where the area occupied by the intermetallics is high and intermetallics particles are big. Intermetallic particle size can be controlled by an appropriated heat treatment.

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