scholarly journals Effect of Silica Fume on the Rheological Properties of Cement Paste with Ultra-Low Water Binder Ratio

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 554
Author(s):  
Juan He ◽  
Congmi Cheng ◽  
Xiaofen Zhu ◽  
Xiaosen Li
Keyword(s):  
Hysteresis Loop ◽  
Rheological Properties ◽  
Yield Stress ◽  
Silica Fume ◽  
Plastic Viscosity ◽  
Rheological Parameters ◽  
Loop Area ◽  
Binder Ratio ◽  
Hysteresis Loop Area ◽  
Water Binder Ratio

The effect of silica fume on the rheological properties of a cement–silica fume–high range water reducer–water mixture with ultra-low water binder ratio (CSHWM) was studied. The results indicate that the W/B ratio and silica fume content have different effects on the rheological parameters, including the yield stress, plastic viscosity, and hysteresis loop area. The shear-thickening influence of CSHWM decreased with the increased silica fume content. When the silica fume content increased from 0% to 35%, the mixture with W/B ratio of 0.19 and 0.23 changed from a dilatant fluid to a Newtonian fluid, and then to a pseudoplastic fluid. When the silica fume content was less than 15%, the yield stress was close to 0. With the increase of silica fume content, the yield stress increased rapidly. The plastic viscosity and hysteresis loop area decreased slightly with the addition of a small amount of silica fume, but increased significantly with the continuous increase of silica fume. Compared with the Bingham and modified Bingham models, the Herschel–Buckley model is more applicable for this CSHWM.

Experimental Research on Rheological Properties of Cemented Mortar in Tail Void Grouting of Shield Tunnel

2011 ◽  
Vol 261-263 ◽  
pp. 1201-1205 ◽  
Author(s):  
Xiao Hui Yuan ◽  
Yue Wang Han
Keyword(s):  
Rheological Properties ◽  
Flow Pattern ◽  
Yield Stress ◽  
Plastic Viscosity ◽  
Rheological Parameters ◽  
Shear Yield Stress ◽  
Shear Yield ◽  
Binder Ratio ◽  
Water Ratio ◽  
Water Binder Ratio

Grout flow pattern and rheological parameters determine grouting pressure transfer process in annular tail void and filling rate for shield tail void. However, cemented mortar is a mixture of cement, fly ash, sand, bentonite and water, which lead to grout rheological properties and rheological parameters are difficultly determined. Based on orthogonal experimental design method, grout rheological properties were tested by rotational viscometer. Utilizing variance and poly-nonlinear regression analysis, the qualitative and quantitative relationships between mix ratios and rheological parameters were obtained respectively. It is shown that cemented mortar flow pattern commonly agree with Bingham fluid type, and plastic viscosity varies between 1 and 4Pa•s, and shear yield stress varies between 10 to 40Pa respectively. Water-binder ratio and bentonite-water ratio are key influencing factors for grout rheological parameters. With the water-binder ratio increasing and bentonite-water ratio decreasing, plastic viscosity and shear yield stress present reducing tendency.

Influence of Ground Slag on the Rheology of Mortar

2013 ◽  
Vol 438-439 ◽  
pp. 67-71
Author(s):  
Qian Qian Zhang ◽  
Jian Zhong Liu ◽  
Jia Ping Liu
Keyword(s):  
Film Thickness ◽  
Specific Surface ◽  
Yield Stress ◽  
Surface Area ◽  
Specific Surface Area ◽  
Water Film ◽  
Plastic Viscosity ◽  
Rheological Parameters ◽  
Water Film Thickness ◽  
Binder Ratio

The effects of ground slag with different specific surface area on the rheology of mortar at water-binder ratio of 0.25, 0.28 and 0.30 were investigated, and the combined effects of packing density and solid surface area on the rheology of mortar were evaluated in terms of the water film thickness. The results show that with the increasing of specific surface area of slag (220 m2/kg-784 m2/kg), plastic viscosity and yield stress decrease. The correlations of yield stress and plastic viscosity to the water film thickness are basically linear with high correlation R2 values. The action of the ground slag on the rheology of mortar can be characterized by water film thickness, and with the increasing of water film thickness the rheological parameters decrease.

scholarly journals Evolution of flow properties, plastic viscosity, and yield stress of alkali-activated fly ash/slag pastes

2020 ◽  
Vol 5 ◽  
pp. 141-149
Author(s):  
Mohammed Fouad Alnahhal ◽  
Taehwan Kim ◽  
Ailar Hajimohammadi
Keyword(s):  
Fly Ash ◽  
Yield Stress ◽  
Plastic Viscosity ◽  
Rheological Parameters ◽  
Time Intervals ◽  
Increasing Trend ◽  
Binder Ratio ◽  
Drastic Effect ◽  
Effect On Yield ◽  
Alkali Activated

The development of cementless concrete is attracting increasing attention in practice and research to reduce both greenhouse gas emissions and energy consumption of concrete. Alkali-activated materials (AAMs) are one of the viable alternatives to replace Portland cement due to their lower CO2 emissions. This study investigated the evolution of rheological parameters of alkali-activated fly ash/slag pastes as a function of time. Flowability and rheological measurements were carried out to determine the fluidity, plastic viscosity, and yield stress at different time intervals. The effects of the slag content, the concentration of SiO2 in the activator, and the solution/binder ratio were considered. Based on the results, the yield stress and plastic viscosity followed an increasing trend over time coinciding with a reduction in the paste fluidity. The plastic viscosity of AAM pastes was in the range of 1.3–9.5 Pa.s and 2.6–28.9 Pa.s after 5 min and 45 min of mixing, respectively. Given the same alkali activator, the higher content of slag the paste had, the higher yield stress the paste showed. In addition, this paper confirmed that the SiO2/Na2O ratio in the activator had no significant effect on yield stress, but a drastic effect of this ratio was found on the plastic viscosity of the paste.

scholarly journals Effect of polycarboxylate superplasticizer on fluidity and rheology of cement slurry containing silica fume

2021 ◽  
Vol 237 ◽  
pp. 03008
Author(s):  
Qingen Meng ◽  
Juan He ◽  
Congmi Cheng ◽  
Xiaofen Zhu
Keyword(s):  
Rheological Properties ◽  
Yield Stress ◽  
Silica Fume ◽  
Plastic Viscosity ◽  
Cement Slurry ◽  
Pseudoplastic Fluid ◽  
Plasticizer Content ◽  
Polycarboxylate Superplasticizer ◽  
Dispersion Degree ◽  
Fluid Characteristic

The effect of polycarboxylate superplasticizer on the fluidity and rheology of cement - silica fume - water paste was investigated. The changes of dispersion degree, yield stress and plastic viscosity of paste with different superplasticizer content were analyzed. The results show that the rheological properties of paste with different superplasticizer content conform to Herschel-Bulkley model. The shear thinning of the slurry is manifested as a typical yielding pseudoplastic fluid characteristic. When the content of superplasticizer is less than 1.0%, the plastic viscosity and yield stress decrease and the fluidity increase with the increase of plasticizer content. When the content of superplasticizer is more than 1.0%, the yield stress decreases slightly and the plastic viscosity increases with the increase of plasticizer content. The fluidity decreases with the increase of yield stress, and there is a good correlation between them.

scholarly journals Improving the texture and rheology of set and stirred kombucha fermented milk beverages by addition of transglutaminase

Mljekarstvo ◽  
2021 ◽  
Vol 71 (3) ◽  
pp. 155-164
Author(s):  
Mirela Iličić ◽  
Keyword(s):  
Hysteresis Loop ◽  
Rheological Properties ◽  
Control Sample ◽  
Great Influence ◽  
Fermented Milk ◽  
Milk Products ◽  
Loop Area ◽  
Hysteresis Loop Area ◽  
Sample Set ◽  
Fermented Milk Products

The possibilities of manufacturing fermented milk beverages by applying kombucha inoculum concentrated by evaporation and with addition of transglutaminase have been investigated. The main aims of this study were to investigate influence of concentrated kombucha inoculum and the addition of transglutaminase (TG) on textural, rheological and sensory properties of set and stirred fermented milk beverages. The results showed that the addition of transglutaminase had a great influence on textural characteristics and rheological properties of kombucha fermented milk beverages. Firmness and consistency of kombucha fermented milk products were significantly increased with the incorporation of TG compared to the control sample. Set samples with TG addition had approximately 90 % higher hysteresis loop area compared to stirred samples, while hysteresis loop area of stirred samples without TG was 60 % lower compared to set samples. The enzymatic treatment of milk with TG improved texture, rheology and sensorial characteristics of set and stirred fermented milk beverages obtained by concentrated kombucha inoculum.

scholarly journals A Rheological Model for Evaluating the Behavior of Shear Thickening of Highly Flowable Mortar

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 1011
Author(s):  
Mengyuan Li ◽  
Jianguo Han ◽  
Yuqi Zhou ◽  
Peiyu Yan
Keyword(s):  
Fly Ash ◽  
Yield Stress ◽  
Silica Fume ◽  
Rheological Model ◽  
Shear Thickening ◽  
Rheological Parameters ◽  
Bingham Model ◽  
Consistency Coefficient ◽  
Lubrication Layer ◽  
Binder Ratio

Neither the modified Bingham model nor the Herschel–Bulkley model can be used to characterize and calculate the performance of shear thickening of highly flowable mortar because of their incalculability of the rheological parameters. A new exponential rheological model was established to solve the characterization and calculation of shear thickening of the lubrication layer (highly flowable mortar) during the pumping of concrete in this paper. This new exponential rheological model has three rheological parameters, namely, yield stress, consistency coefficient, and consistency exponent. They can quantitatively describe the yield stress, differential viscosity, and shear thickening degree of highly flowable mortar. The calculating results of the rheological parameters of the newly established model for the mortars with different compositions showed that the consistency exponent of mortar decreased with the increase of its sand-binder ratio or the dosage of fly ash in the binder. This indicates that the shear thickening degree of mortar decreases. The consistency exponent of mortar initially decreases and subsequently increases with the increase in silica fume content or the dosage of the superplasticizer. It illustrates that the degree of the shear thickening of mortar initially decreased and subsequently increased. These varying patterns were confirmed by the rheological experiment of mortars.

Influence of Glass Powder on Rheological Properties of Ultra-High Performance Concrete Paste

2021 ◽  
Vol 1036 ◽  
pp. 419-431
Author(s):  
Xue Li Nan ◽  
Jian Rui Ji ◽  
Rong Yang Li ◽  
Yi Wang ◽  
Hao Chen ◽  
...  
Keyword(s):  
Rheological Properties ◽  
Yield Stress ◽  
Silica Fume ◽  
High Performance ◽  
Glass Powder ◽  
High Performance Concrete ◽  
Shear Thickening ◽  
Plastic Viscosity ◽  
Ecological Problem ◽  
Ultra High Performance Concrete

Replacing cement and silica fume with glass powder to prepare ultra-high performance concrete (UHPC) is beneficial to solve the ecological problem in the field of civil engineering, but the technologies of preparation, transportation, pumping, and hardening of UHPC mainly relate to its rheological property. Therefore, this paper studied the influence of glass powder on the rheological properties of UHPC paste by performing the flow and the rheological test. Experimental results showed that when the cement and silica fume partially replaced by glass powder, the UHPC paste appears shear thickening, yield stress, plastic viscosity, and area of hysteresis loop decrease. This means that mixing glass powder can somehow inhibit the problems of segregation and bleeding of UHPC during pumping. In this manner, the dosage of the superplasticizer in UHPC is appropriately reduced, the filling capacity of UHPC during pouring is improved, and the energy required for UHPC in the pumping process is weakened. Compared with replacing cement, replacing silica fume with glass powder significantly increases the shear thickening and fluidity of UHPC paste, and at the same, reduces its yield stress and plastic viscosity. This indicates that the construction performance of UHPC is greatly improved with the replacement of silica fume. The fluidity and yield stress of UHPC paste satisfy the quadratic polynomial function relationship, and the replacement of cement and silica fume with glass powder should be less than 33% and 50%, respectively. Under this condition, the rheological properties of the UHPC paste are greatly improved and result in little negative impact on the mechanical properties of UHPC.

HYSTERESIS STUDIES IN COUPLED MAP LATTICES

1999 ◽  
Vol 13 (22n23) ◽  
pp. 809-817 ◽  
Author(s):  
RENUKA RAI ◽  
HARJINDER SINGH
Keyword(s):  
Hysteresis Loop ◽  
Coupling Strength ◽  
Signal To Noise Ratio ◽  
Coupled Map Lattices ◽  
Hysteresis Phenomenon ◽  
Signal To Noise ◽  
Loop Area ◽  
Spatially Extended ◽  
Hysteresis Loop Area ◽  
Spatially Extended Systems

We have studied hysteresis phenomenon in spatially extended systems and investigated the effect of additive and parametric noises. We observe that the behavior of hysteresis loop area as a function of coupling strength is different for additive and parametric noises. It is interesting to observe that behavior of hysteresis loop area is analogous to the behavior of the signal-to-noise ratio [Phys. Rev.E56, 2518 (1997)].

scholarly journals Design of portable rheometer with new vane geometry to estimate concrete rheological parameters

2016 ◽  
Vol 23 (3) ◽  
pp. 347-355 ◽  
Author(s):  
Hamza SOUALHI ◽  
El-Hadj KADRI ◽  
Tien-Tung NGO ◽  
Adrien BOUVET ◽  
François CUSSIGH ◽  
...  
Keyword(s):  
Yield Stress ◽  
Coefficient Of Variation ◽  
Test Procedure ◽  
Plastic Viscosity ◽  
Rheological Parameters ◽  
Construction Site ◽  
Wide Range ◽  
Mineral Additions ◽  
High Plastic ◽  
Rheometer Test

This paper presents the development of a portable vane rheometer to estimate concrete plastic viscosity and yield stress. The apparatus can be used not only in laboratory but also on construction site. In this study, new blade geometry was proposed to minimize the effect of segregation of concrete during testing, and also to expand the wide range of concrete work­ability with a slump of approximately from 7 cm to fluid concrete, and concrete with high plastic viscosity such as concrete with mineral additions. The used blade (U shaped and reversed) allows reducing the vibration of the apparatus, and ob­taining more stable measurements. The obtained results permit validating the rheometer test procedure and confirmed that the results are reliable, with a low coefficient of variation of 9% for repetitive test and of 5.8% for reproductive tests.

Effect of Heat Treatment on Properties of Portland Cement Pastes: Determination through Ultra-Microhardness Test

2015 ◽  
Vol 820 ◽  
pp. 492-496
Author(s):  
D.C.S. Garcia ◽  
Roberto Braga Figueiredo ◽  
Maria Teresa Paulino Aguilar
Keyword(s):  
Heat Treatment ◽  
Portland Cement ◽  
Optical Microscopy ◽  
Silica Fume ◽  
Ordinary Portland Cement ◽  
Cement Pastes ◽  
Microhardness Test ◽  
Material Hardness ◽  
Binder Ratio ◽  
Water Binder Ratio

The aim of this paper was to investigate the influence of heat treatment on hardness evolution of cement pastes containing silica fume. The specimens were prepared with Ordinary Portland Cement, water/binder ratio of 0,40 and 25% wt. silica fume. The specimens were cast at room temperatures and after 24 hours, they were placed in a furnace for 24 hours, with heat regimes of 100°C, 200°C and 300°C and then submitted to the ultra-microhardness test. The microstructure was analyzed using optical microscopy. The results showed that the silica fume prevents the production of calcium hydroxide and the heat treatment increases the material hardness.

Sign in / Sign up

Export Citation Format

Share Document