Influence of superplasticizer on the rheology of fresh cement asphalt paste

Peng, Jianwei; Deng, Dehua; Huang, Hai; Yuan, Qiang; Peng, Jinghua

doi:10.1016/j.cscm.2015.05.002

Cited by 19 publications

(12 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…However, it is well known that the addition of polycarboxylate SP or an increase of its amount decreases the plastic viscosity. 30,31 The cement paste with higher flow values included more SP (Table 1), leading to a smaller plastic viscosity, so its compressive strength decreased with increasing flow values due to poor fiber dispersion. Consequently, the optimum flow value of cement-based sensors in terms of fiber dispersion was determined to be 150 mm.…”

Section: Experimental Programmentioning

confidence: 99%

Electrical and piezoresistive properties of cement composites with carbon nanomaterials

Yoo

You

Youn

et al. 2018

Journal of Composite Materials

View full text Add to dashboard Cite

This study investigates the effect of nanomaterials on the piezoresistive sensing capacity of cement-based composites. Three different nanomaterials—multi-walled carbon nanotubes, graphite nanofibers, and graphene oxide—were considered along with a plain mortar, and a cyclic compressive test was performed. Based on a preliminary test, the optimum flowability was determined to be 150 mm in terms of fiber dispersion. The electrical resistivity of the composites substantially decreased by incorporating 1 wt% multi-walled carbon nanotubes, but only slightly decreased by including 1 wt% graphite nanofibers and graphene oxide. This indicates that the use of multi-walled carbon nanotubes is most effective in improving the conductivity of the composites compared to the use of graphite nanofibers and graphene oxide. The fractional change in resistivity of the composites with nanomaterials exhibited similar behavior to that of the cyclic compressive load, but partial reversibility in fractional change in resistivity was obtained beyond 60% of the peak load. A linear relationship between the fractional change in resistivity and cyclic compression strain (up to 1500 με) was observed in the composites with multi-walled carbon nanotubes, and the gauge factor was found to be 166.6. It is concluded that cement-based composites with 1 wt% multi-walled carbon nanotubes can be used as piezoresistive sensors for monitoring the stress/strain generated in concrete structures.

show abstract

Section: Experimental Programmentioning

confidence: 99%

Electrical and piezoresistive properties of cement composites with carbon nanomaterials

Yoo

You

Youn

et al. 2018

Journal of Composite Materials

View full text Add to dashboard Cite

show abstract

“…Therefore, the best way to solve the problem of sudden loss of fluidity and abnormal change of expansion rate is to weaken the adsorption capacity of aluminate hydrates toward emulsifiers and asphalt particles. In this study, a certain number of superplasticizers (percentage of cementitious material mass) are added to CAM-I paste to study its effect on the working time and expansion ratio of paste based on competitive adsorption principle [26][27][28]. As shown in Figure 14, the fluidity of paste without superplasticizer increases from 23.2 s to 62.5 s after 10 min when the temperature is 45 • C, and the paste loses fluidity.…”

Section: Effect Of Superplasticizer On the Fluidity And Expansion Ratmentioning

confidence: 99%

Effects of Temperature on Fluidity and Early Expansion Characteristics of Cement Asphalt Mortar

et al. 2020

View full text Add to dashboard Cite

In order to solve the problems of the sudden loss of fluidity and low expansion rate of CAM I (cement asphalt mortar type I) in a construction site with high environmental temperature, this paper studies the effect of temperature on the fluidity, expansion ratio and pH value of CAM I. The mechanism of action was analyzed by IR (infrared spectrometry), SEM (scanning electron microscopy) and other test methods. The results showed that a high temperature accelerates aluminate formation in cement paste. Aluminate adsorbs emulsifiers leading to demulsification of emulsified asphalt, and wrapped on the surface of cement particles, this causes CAM I to lose its fluidity rapidly. The aluminum powder gasification reaction is inhibited, resulting in an abnormal change in the expansion ratio. Based on findings, the application of an appropriate amount of superplasticizers can effectively improve the workability and expansion characteristics of CAM I at a high temperature.

show abstract

“…Variation of four indexes manifests that the mix of WRA effectively improved the workability of fresh CGCBM for the mixing of WRA which contributes to increase the Advances in Materials Science and Engineering electrostatic repulsion between molecules, decrease surface tension of interface between solid and liquid, and decrease the wetting angle. In this test, the two WRAs are strong electrolytes with negative charges; if they were mixed, the lipophilic group will actively adhere to the surface of cement and fly ash particles, and the hydrophilic group will direct to water molecules [26][27][28][29][30]. is directional arrangement of WRA molecules makes the surface of cement and fly ash particles absorbed with like charge and form water film with a certain thickness which prevent forming flocculated structure.…”

Section: Slump and Slump Flowmentioning

confidence: 99%

Performance of Coal Gangue‐Based Cemented Backfill Material Modified by Water‐Reducing Agents

Yao

Wang

Feng

et al. 2020

Advances in Materials Science and Engineering

View full text Add to dashboard Cite

Coal gangue-based cemented backfill material (CGCBM) is developed for backfilling the goaf in coal mines. As fresh CGCBM slurry is generally transported into underground openings through a pipeline, and after hardening, it plays the role of supporting the overlying strata. The fluidity, stability, and mechanical (compressive strength) of CGCBM become the most important properties. Adding water-reducing agents (WRAs) is considered to improve the fluidity, stability, and mechanical properties of CGCBM, but there is a risk of increased bleeding. So, two types of WRA (naphthalene series (WRA1) and poly carboxylic acid (WRA2)) are used at different contents (1.0%-2% for WRA1, 0.2%–0.6% for WRA2) by mass of binder. Slump, slump flow, yield stress, and plastic viscosity test are used to evaluate the fluidity properties of CGCBM after adding WRA. Bleeding rate test is used to evaluate the stability of CGCBM after adding WRA. Compressive strength is the most important factor in measuring the mechanical properties. SEM and XRD tests are used to analyse the mechanism of strength change. Results show that the slump, slump flow, and plastic viscosity increase after adding WRA, which reduces the yield stress and improves the fluidity. The bleeding rate increases with the increase of WRA content, leading to a decrease in stability. Adding WRA increases the compressive strength, and it increases first and then decreases with the increase of the content at the later stage. Considering the effects of WRA on the fluidity, stability, and compressive strength properties of CGCBM, the reasonable content of WRA1 and WRA2 is 1.5% and 0.4%, respectively. The research results provide guidance for the design and preparation of CGCBM with favourable performance in practical production.

show abstract

Influence of superplasticizer on the rheology of fresh cement asphalt paste

Cited by 19 publications

References 14 publications

Electrical and piezoresistive properties of cement composites with carbon nanomaterials

Electrical and piezoresistive properties of cement composites with carbon nanomaterials

Effects of Temperature on Fluidity and Early Expansion Characteristics of Cement Asphalt Mortar

Performance of Coal Gangue‐Based Cemented Backfill Material Modified by Water‐Reducing Agents

Contact Info

Product

Resources

About