Viscometer Tests Research Articles

Paste-like cemented backfilling technology and rheological characteristics analysis based on jigging sands

To make backfilling body meet strength requirement, physical-chemical evaluation and proportioning tests were conducted on several backfilling materials. Jigging sands, #32.5 cement and fly ash were determined as backfilling aggregate, binding material and modified material, respectively. An optimized proportion of backfilling materials with a solid mass fraction of 78% and cement: fly ash: jigging sands mass ratio of 1:2:14, was suggested to Jiangan Pyrite Mine, China. The slurry made by optimized proportion produced obvious shear thinning phenomena, and was confirmed as paste-like slurry. To analyze its rheological characteristics, L-type pipeline test and Haake VT550 rotational viscometer test were conducted. Bingham and Casson fluid models were applied to several paste-like slurry samples to simulate flow and stress states; Casson fluid model was proved to have better simulation effect on paste-like slurry with shear thinning phenomena; rheological parameters of backfilling slurry made by suggested proportion were measured. Initial yield stress, average apparent viscosity and limiting viscosity are 55.35 Pa, 1.216 Pa·s and 0.48 Pa·s, respectively. Compared with Bingham fluid model, Casson fluid model has a better simulation effect on paste-like slurry with shear thinning phenomena, through calculating the residual standard deviations.

Optimization of biodiesel production via methyl acetate reaction from cerbera odollam

Cerbera Odollam (sea mango) is a proven promising feedstock for the production of biodiesel due to its high oil content. Fatty acid methyl esters (FAME) were produced as the final reaction product in the transesterification reflux condensation reaction of sea mango oil and methyl acetate (MA). Potassium methoxide was used as catalyst to study its reacting potential as a homogeneous base catalyst. The initial part of this project studied the optimum conditions to extract crude sea mango oil. It was found that the content of sea mango sea mango oil was 55%. This optimum amount was obtained by using 18 g of grinded sea mango seeds in 250 ml hexane. The extraction was carried out for 24 hours using solvent extraction method. Response surface methodology (RSM) was employed to determine the optimum conditions of the reaction. The three manipulated variables in this reaction were the reaction time, oil to solvent molar ratio, and catalyst wt%. The optimum condition for this reaction determined was 5 hours reaction time, 0.28 wt% of catalyst and 1:35 mol/mol of oil: solvent molar ratio. A series of test were conducted on the final FAME product of this study, namely the FTIR test, GC-FID, calorimeter bomb and viscometer test.

Effects of extended short-term aging duration on asphalt binder behaviour at high temperatures

Many factors affecting pavement performance include variations in binder composition and environmental conditions during asphalt mixture production. Hence, predicting pavement performance is a difficult task. This paper aims to investigate the effects of short term aging on binder viscosity at high temperature. In order to predict the effects of short term aging on the asphalt binder viscosity at high temperatures, a Response Surface Method was performed on the Rotational Viscometer test results. An experimental matrix was planned based on the central composite design for aging duration and test temperature. The test results showed that aging increased the binder viscosity, while increasing test temperature decreased the corresponding value. However, aging effects differ and depend on binder types, test temperatures and aging conditions. It was also found that the Response Surface Method is a fast, effective and reliable method to predict the effects of aging on binder viscosity behaviour at high temperatures.

Cemented Backfilling Technology of Paste-Like Based on Aeolian Sand and Tailings

Aeolian sand, tailings, and #32.5 Portland cement were used to produce backfilling aggregate, and physicochemical evaluations and proportioning tests were conducted. It is revealed that a mixture of aeolian sand and tailings can be used as a backfilling aggregate for the complementarities of their physicochemical properties; e.g., high Al2O3 content in the aeolian sand and CaO content in the tailings, coarse particles of aeolian sand and fine particles of tailings, etc. In addition, the optimal backfilling aggregate was shown to have a mass fraction of 72%–74%, a cement–sand ratio of 1:8, and an aeolian sand proportion of 25%. Furthermore, viscometer tests were used to analyze the rheological characteristics, and the slurry in these optimized proportions exhibited shear thinning phenomena with an initial yield stress, which belongs to paste-like—a cemented backfilling slurry with a higher mass fraction than a two-phase flow and better flowability than a paste slurry. Finally, the application of this backfilling technology shows that it can not only realize safe mining, but also bring huge economic benefits, and has some constructive guidance for environmental protection.

Rheological properties of crude oils in Yaregskoye and Yaraktinskoye oil fields

Rotary viscometer tests of crude oil with a high content of resins and asphaltenes (Yaregskoye oil field) and crude oil with high paraffin content (Yaraktinskoye oil field) have been conducted. The typical flow curves for these oil types have been plotted. It has been detected that these oils are non-Newtonian fluids, viscosity of which is dependent on shear rate. Based on Arrhenius-Eyring equation, calculations of viscous flow activation energy and complex structural unit (CSU) sizes have been performed. It has been stated that there is a tenfold reduction in CSU size in asphaltic crude oil with the increase in shear rate in a rotary viscometer, while particle size in paraffinic crude oil does not essentially change under the same hydrodynamic conditions.

Properties of asphalt modified with devulcanized polyethylene terephthalate

ABSTRACTThe objective of this research is to investigate the effectiveness of the devulcanized polyethylene terephthalate in enhancing the performance characteristics of modified asphalt binders. The physical and rheological behavior of four binder samples were investigated using the penetration, softening point, storage stability, rotational viscometer, and dynamic shear rheometer tests. The polymer tends to decrease penetration and increase softening point, viscosity, and permanent deformation resistance of modified binders in comparison with base asphalt binders. However, this processed polymer could not be considered storage stable blend at high temperatures.

Ethanol based foamed asphalt as potential alternative for low emission asphalt technology

Abstract Foamed asphalt typically relies on water as a foaming agent because water becomes gaseous at elevated temperatures, generating numerous tiny bubbles in the asphalt and causing spontaneous foaming. In this study, ethanol was used as a potential alternative to water as a foaming agent. Ethanol is expected to be a physical blowing agent in the same manner as water, except it requires less energy to foam due to its 78 °C boiling point. This study compares the performance of water and ethanol as foaming agents through the measurements of rotational viscosity, the reduction in temperature during foaming, and volatile loss. The ethanol-foamed asphalt binders were prepared at 80 °C and 100 °C, while the water-foamed asphalt binders were prepared at 100 °C and 120 °C. Additionally, the rolling thin film oven (RTFO) was used to generate short-term aging of the foamed asphalt binders. A rotational viscometer was used to determine the viscosity of the asphalt binders at 80 °C, 100 °C, 120 °C, 140 °C, and 160 °C. Overall, ethanol can function in the same manner as water but requires less energy to foam. It is proven based on the smaller drop in temperature of the asphalt binder foamed using ethanol compared with that prepared with water. This is due to the lower latent heat capacity of ethanol, which requires less energy to vaporize compared with water. Through the rotational viscometer test, ethanol performs better in lowering the viscosity of asphalt binders, which is essential in allowing production processes at low temperatures, as well as a better workability and aggregate coating. Ethanol can be expelled from the foamed asphalt binders at a higher rate due to its lower boiling point and latent heat.

Correlation between vane shear and viscometer tests on clayey soils under high water content

Correlation between vane shear and viscometer tests on clayey soils under high water content

Effect of Liquid Nano Material and Hydrated Lime in Improving the Moisture Behaviour of HMA

It may be stated that the main reason for the failure of asphalt pavement, especially early damage, is due to destruction and loss of adhesion properties of bitumen in the asphalt mix. Stripping is the weakening or the loss of adhesion between the aggregate surface and bitumen in asphalt mixtures due to moisture that has a direct relationship with behavior of bitumen in the asphalt mixes. Therefore researchers are always looking for solutions to eliminate or at least reduce asphalt mixture problems by modifying bitumen. Nano materials were introduced as a new and effective option in this context. Therefore, one of the objectives of this study was to investigate and compare classical and rheological behavior of the base bitumen having penetration grade 85/100 and the same bitumen modified with 0.1, 0.3 and 0.5% of Zycosoil Nano materials by bitumen weight. Another objective was to compare the moisture behavior of asphalt mixtures with and without Zycosoil and mixtures containing hydrated lime. Then rheological properties of bitumen, including viscosity, failure temperature and rutting potential, as well as bitumen classical properties, by rotational viscometer test, Dynamic Shear Rheometer test and multiple stress creep and recovery test were evaluated. Moisture sensitivity of asphalt mixes also using boiling test and indirect tensile strength tests were evaluated. Test results indicated that improved mixing conditions; reduce the temperature of asphalt mixtures, increasing rutting resistance, increasing the bitumen failure temperature and significant improvements in reducing moisture sensitivity to asphalt mixtures.

Investigation of the potential application of biodiesel by-product as asphalt modifier

The potential application of biodiesel by-product as an asphalt modifier was investigated in terms of chemical composition and performance grades tests. Modified asphalt binders were prepared by adding four contents of biodiesel by-product into control binder. First, Fourier transform infrared spectroscopy (FT-IR) test was conducted to investigate the chemical composition and modification mechanism of experimental materials. Then, rotational viscometer test for original asphalt, dynamic shear rheometer test for original, rolling thin film oven-aged and pressure ageing vessel (PAV)-aged asphalt, bending beam rheometer test for PAV-aged asphalt were carried out to investigate the effect of biodiesel by-product on performance grades of control asphalt binder. Finally, storage stability test was conducted to analyse the segregation tendency of by-product-modified asphalt binders. The FT-IR test results indicated that no chemical reaction occurred between control asphalt and biodiesel by-product. Meanwhile, the addition of biodiesel by-product reduced the rotational viscosity of the asphalt binder, hence lowered the optimum mixing and compaction temperatures of asphalt concrete. Moreover, the addition of biodiesel by-product decreased the high-temperature performance of asphalt binder, while improved the low-temperature performance and fatigue resistance performance. In addition, a good storage stability of by-product-modified asphalt binders was noticed. Finally, considering the performance variations of by-product-modified asphalt and environmental requirements, the content of by-product recommended to be used as PG64-16 asphalt binder's modifier in cold region was 4%.

Dispersants for Dual Binding System Kaolin - Calcium Aluminate Cement

Calcium aluminate cement CAC is able to increase strength of green body distintly. Influence of typical ceramic dispersants – sodium hexametaphosphate SHMP, sodium carbonate SC and sodium silicate (water glass) SWG – on the rheological properties (viscosity) of calcium aluminate cement – kaolin slurries with different ratio between CAC and kaolin was determined. In all cases sodium carbonate is the most effective dispersant but deflocculation is not very intensive – decrease of torque during the rotational viscometer test was not higher than 15 % (from 68,8 N.mm to 58.3 N.mm for ratio 1:1 of CAC:kaolin suspension when 0,06 %-wt of sodium carbonate was used).

Effect of furfural-derived thermoset furan resin on the high-temperature performance of bitumen

Furfural is an important derivate of hemicelluloses and is used in the production of furan-based non-petroleum chemicals. Thermoset resins obtained from furfural exhibit extreme physical strength. Furan is a furfural-derived thermoset resin. Previous work about the usage of furan resin (FR) as a bitumen modifier reported that FR modification increases the consistency and ageing resistance of bitumen and decreases the temperature and moisture susceptibility. The aim of this study is to examine the high-temperature performance of FR-modified bitumen. Dynamic shear rheometer and rotational viscometer tests were carried out on the modified samples. Results show that FR modification increases the stiffness and elasticity of bitumen and develops rutting resistance. The maximum temperature where the binder provides the required performance of the Superpave grading system was raised from 64°C to 76°C.

Microstructure and Temperature Characterization of Compound Crumb Rubber Modified Asphalt

Compound Crumb Rubber Modified Asphalt (CCRMA) is a mixture of waste rubber tire powder, SBS modifier and asphalt in order to modify the characteristics of asphalt. The application of using crumb rubber powder in making CCRMA is important in improvement of working characteristics of asphalt as well as in pollution control and environment protection. CCRMA, crumb rubber particles, SBS modifier and base asphalt have been examined by Scanning Electron Microscope (SEM) to observe the microcosmic appearance and the characteristic distribution of crumb rubber particles and SBS modifier in asphalt. The rotary viscometer test and dynamic shear test of CCRMA were carried out by rotational viscometer and Dynamic Shear Rheology (DSR). The influences of rubber powder content and reaction time to viscosity of CCRMA have been studied. In the stage of current study, complex modulus and phase angle of CCRMA are parameters reflecting viscoelasticity, the relation between them and temperature are researched.

Degradation of a Polycaprolactone/Eggshell Biocomposite in a Bioreactor

The biodegradation process of a polycaprolactone (PCL)/eggshell (ES) biocomposite (50/50 w/w) was studied for 8 weeks, using a bioreactor, which allowed to control: temperature, moisture, soil pH, light and anaerobic condition during composting. Scanning electron microscopy showed that the degradation process occurred mainly on the sample surface, attributable to the microbial attack and the weight loss showed a higher degradation for the PCL/ES samples than for pure PCL. Viscometric tests showed that the viscosity of the PCL phase in the biocomposite decreased more than when PCL was used alone, due to the higher depolymerization in the biocomposites. Differential scanning calorimetric thermal scans showed that the crystallization temperature changed for 8 weeks. In conclusion, it was noted that soil pH, heat and an aerobic environment accelerate the degradation process, while a photo-controlled, anaerobic and moisture-saturated environment delays this process, as compared with the composting system used as control.

Effects of HTPB with Different Molecular Weight on Mechanical Properties of HTPB/TDI System

t is found that the molecular weight of Hydroxy-terminated polybutadiene (HTPB) influences curing behaviors of HTPB/2,4-toluene diisocyanate (TDI) system and the mechanical properties of PBXs. Effects of the molecular weight of HTPB on the viscose viscosity,the cure time, and mechanical properties of polymer were studied by brookfield viscometer, hardness tester and tension test with the molecular weight of HTPB varying from 1500~4000.The experimental results show that the viscose viscosity increases slowly and the cure time is extended obviously,tensile strength decreases and elongation at break increases when the molecular weight of HTPB increases. Dynamic mechanical studies show that glass transition temperature and dynamic storage modulus decrease with the molecular weight of HTPB increasing.

Effect of solid‐state stress induced reaction on morphology and structure of metallocene polyethylene

ABSTRACTMetallocene‐catalyzed polyethylene (mPE) powder was prepared through a mechanochemical reactor in solid state at ambient temperature. The changes of morphology and structure of mPE were investigated by SEM, FTIR, DSC, viscosimetry, GPC, WAXD, dynamic rheometer, and high pressure capillary rheometer methods. FTIR measurement illustrated that the branching degree of mPE increased after mechanochemical reaction. Combined with the dynamic rheological analysis, it was proved that the rupture and combination of macromolecular chain undergo strong shear resulted in the formation of long chain branches. X‐ray diffraction analysis showed that the crystal form of mPE transferred from rhombic to monoclinic system partly, and the crystalline degree increased slightly in the initial mechanochemical reaction period. Viscometer test results exhibited that molecular weight of mPE dropped during the mechanochemical treatment. Rheology measurement indicated that the critical shear rate of the shark‐skin failure enhanced and the extruded stands exhibited smooth face for the mPE after mechanochemical treatment. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 1691–1699, 2013

Impact of viscous dietary fibres on the viscoelastic behaviour of gluten-free formulated rice doughs: A fundamental and empirical rheological approach

The significance of the incorporation of associated viscous dietary fibres (hydroxypropylmethylcellulose semi-firm – SFE – and weak – NE – gel like forming, and barley β-glucan, BBG) at different amounts (1.6–7.5%, flour basis) into gluten-free rice-based dough formulations, on the rheological profile of hydrated (70–110%, flour basis) fibre–flour composite blends has been investigated. A dual fundamental (dynamic oscillatory and creep-recovery tests) and empirical (consistency, and viscometric profile) rheological approach was adopted to assess the viscoelasticity of fibre-enriched rice-based dough matrices. Retrieved functional variables were analyzed for dependence on dough hydration and on viscous dietary fibres, and for correlations within parameters from both small and large deformation tests. The water competition of fibre macromolecules expliciting different water binding and gelling abilities resulted in additive, synergistic and/or antagonistic effects on major rheological features. Higher consistent doughs corresponded to those with larger dynamic moduli with poorer frequency dependence, lower elastic deformation at a constant stress, and higher viscosity at steady state. In addition, doughs exhibiting higher viscous component (oscillatory dynamic test) showed concomitantly lower viscosity profiles during cooking (mimetic viscometric test).

Investigations of Physical and Rheological Properties of Aged Rubberised Bitumen

Several road pavement distresses are related to rheological bitumen properties. Rutting and fatigue cracking are the major distresses that lead to permanent failures in pavement construction. Influence of crumb rubber modifier (CRM) on rheological properties of bitumen binder such as improvement of high and intermediate temperatures is investigated in the binder’s fatigue and rutting resistance through physical-rheological changes in this research. The bitumen binders were aged by rolling thin film oven (RTFOT) to simulate short-term aging and pressure aging vessel (PAV) to simulate long-term aging. The effects of aging on the rheological and physical properties of bitumen binders were studied conducting dynamic shear rheometer test (DSR), Brookfield viscometer test, softening point test, and penetration test. The results showed that the use of rubberised bitumen binder reduces the aging effect on physical and rheological properties of the bitumen binder as illustrated through lower aging index of viscosity, lower aging index of , and an increase in with crumb rubber modifier content increasing, indicating that the crumb rubber might improve the aging resistance of rubberised bitumen binder. In addition, the results showed that the softening point increment () and penetration aging ratio (PAR) of the rubberised bitumen binder decreased significantly due to crumb rubber modification. Furthermore, the higher crumb rubber content, the lower after PAV aging, which led to higher resistance to fatigue cracking bitumen.

Investigation of the effects of wax additive on the properties of asphalt binder

To protect the environment and reduce the consumption of energy, warm asphalt has been used widely in recent years. In this paper, Brookfield rotational viscometer test and dynamic mechanical analysis method are employed to investigate the effect of a kind of commercial wax named Sasobit® on the properties of three kinds of asphalt. It can be found that this kind of wax can increase the value of softening point, complex modulus, anti-rutting factor and reduce the value of the penetration and the phase angle; when the temperature is higher than 110°C, the Sasobit® modified asphalt has a lower viscosity, comparing with the original sample; when the temperature is lower than 70°C, the complex viscosity of Sasobit® modified asphalt is higher than the original sample, and the higher the Sasobit® content, the higher the complex viscosity. From the statistics analysis, it can be found that the effects of Sasobit® on rheological properties of asphalt are significant.

Synthesis and characterization of liquid crystalline copolymers containing poly (ether sulfone) segments

A new block copolymers (BCP) containing poly (ether sulfone) (PES) with different chain lengths and thermotropic liquid crystalline polyester (TLCP) segments were synthesized by high temperature solution polymerization of the constituent monomers of TLCP and PES oligomers terminated with a hydroxyl group. The chemical structure and inherent viscosity of BCP were characterized by Fourier transform infrared spectroscopy, Ubbelohde viscometer and solubility test, respectively. The thermal behavior, liquid crystallinity, texure and thermal stability of liquid crystalline block copolymer were investigated by a variety of experimental techniques including differential scanning calorimetry, polarizing light microscopy and thermogravimetric analysis. BCP showed a single glass transition temperature and melting point but blends of corresponding homopolymers were biphasic. It showed the typical nematic texture above its Tm depending on the composition and good thermal stability. Such block copolymers can be used as compatibilizer or melt viscosity modifying agent for the blends due to their chemical structure similar to the blend partners, respectively.