Characteristics Of Cement Research Articles

Modified Magnesium Oxysulfate Foam Cement Doped with Iron Tailings

The enhancement of the utilization rate of solid waste, along with balancing the comprehensive performance of materials, presents a significant challenge in the development of new functional building materials. This study examined the effects of high concentrations of iron tailing powder on the crystallization characteristics, pore structure, compressive strength, and water absorption of modified magnesium oxysulfate (MOS) foam cement with different dry densities. Furthermore, employing chemical foaming technology, the study characterized and analyzed the microstructure of modified MOS foam cement hydration products through scanning electron microscopy (SEM) and X-ray diffraction analysis (XRD). The results indicated that the addition of an acidic modifier effectively facilitated the hydration reaction in the MgO-MgSO4-H2O system, enhancing the micro-crystallization characteristics of MOS foam cement. The internal pores were uniformly round, with a dense crystal structure within the pore walls. The compressive strength of the material with 40% dry density A08 grade iron tailing powder reached 6.83 MPa, and the lowest water absorption was 5.32% at a dry density of A09.

OPTIMISING THE FORMULATION OF CONCRETES USED IN RESIDENTIAL BUILDINGS IN CHAD

This study focuses on optimising the formulation of concrete used in residential buildings in Chad. Knowledge of the characteristics of materials through various laboratory tests, i.e. determination of the different characteristics of aggregates and cements, verification of the purity of the mixing water, and quality control of concretes, is of particular importance for compliance with the standard. Subsequently, this knowledge must be combined with the appropriate concrete formulation method: on the one hand, the Dreux-Gorisse method, which emphasizes the balance between concrete strength and workability, and on the other, the B. Scramtaiev method, which gives accurate results and seems to be the least well-known. The synthesis of all the analyses carried out in the course of this study can lead us to the kind of proposals for improvement that we consider useful and effective in the context of technical construction studies.It is in this context that our work is set, through experimental evaluation of the influence of cement dosage and type, E/C ratio, G/S ratio and aggregate cleanliness and grading, maximum aggregate diameter on compressive strength. The results obtained encourage new perspectives in the continuity of this work.The main objective of our work is to make a contribution to optimizing the formulation of concrete in the context of valorization of local materials, with the use of additives, in order to ensure adequate improvement of concrete characteristics.

Combined effect of jute fiber and corn cob ash on sustainability assessment and mechanical properties of roller compacted concrete using RSM modelling

The increasing demand for cement has substantially affected the environment, and its manufacturing requires substantial energy usage. However, most countries in the world recently encountered a significant energy problem. So, researchers are exploring the use of agricultural and industrial waste resources with cementitious characteristics to minimize cement manufacturing, cut energy consumption, and contribute to environmental protection. Therefore, this research is performed on roller compacted concrete (RCC) reinforced with 5%, 10%, 15%, and 20% of corn cob ash (CCA) as substitution material with different percentage of cement and 0.25%, 0.50%, 0.75%, and 1% of jute fibre (JF) together for determining the mechanical properties and embodied carbon (EC) by applying response surface methodology (RSM) modelling. The cubical samples were prepared to achieve the targeted strength about 30 MPa at 28 days and then obtained mix proportions were employed for all combinations at various water-cement ratios to maintain roller-compacted concrete’s zero slump. Results showed that at 0.50% JF and 10% CCA, the flexural strength, splitting tensile strength and compressive strengths, and modulus of elasticity of RCC obtained were 5.3 MPa, 3.8 MPa, 32.88 MPa, and 33.11 GPa at 28 days, respectively. Besides, the embodied carbon of RCC is recoded reducing with combined addition of different levels of JF and CCA as compared to control mixture. In addition, the generation of response prediction algorithms was performed using analysis of variance (ANOVA) at a threshold of significance of 95%. The coefficient of determination (R2) readings for the statistical models ranged from 96 to 99%. It is observed that the use of 0.50% of JF along with 10% of CCA as cementitious constituent in RCC provides best outcomes. Therefore, this method is a superior choice for the construction industry.

Effect of liquid-solid ratio on metakaolin-based geopolymer binder properties

AbstractThis article aims to achieve the hardening of geopolymer binder-based metakaolin under the same setting time and hardening temperature as traditional cement. It studied the hardening of the geopolymer binder-based metakaolin at two temperatures of 60 °C and room temperature using different liquid-to-solid ratios of 0.8, 0.95, and 1.1. The bulk density, compressive strength, sitting times, thermal conductivity, and microstructure were measured for geopolymer binders. Based on the specified range for cement characteristics, the geopolymer binder was solidified at room temperature, utilizing a liquid-to-solid ratio of 0.8 to achieve optimal results stratified according to the cement's ideal characteristics. It had a bulk density of 1.264 g cm−3, compressive strength of 19.12 MPa, initial setting time of 288 min, final setting time of 358 min, and thermal conductivity of 0.49 W m−1 K.

Integrated Techno-Environmental Analysis of Finely Ground Silica Sand in Sustainable Mortar Production

The environmental impacts of cement production are becoming more urgent concerns. This study examined the mechanical characteristics of cement when it is partially replaced with finely crushed sand. The experimental program consisted of three different levels of sand fineness of 459 m2/kg, 497 m2/kg, and 543 m2/kg, as well as four substitution ratios of 10%, 20%, 30%, and 40%. A total of thirteen combinations were formulated and then evaluated. The results demonstrated that increasing sand fineness from 459 m2/kg to 543 m2/kg substantially impacted the compressive strength (CS), increasing it by up to 30%, and increasing the substitution ratio from 10% to 40% reduced the mechanical strength by roughly 40%. An extensive techno-environmental evaluation showed that replacing cement with finely crushed sand is technically feasible and environmentally advantageous. This technique can decrease carbon dioxide (CO2) emissions by around 40%, emphasizing its ecological benefits and coinciding with worldwide initiatives to decrease the environmental impact of construction materials. In summary, this study demonstrates the advantages of improving the mechanical characteristics of cement while minimizing its ecological footprint. It suggests that finely crushed sand can be used as a sustainable alternative in cement manufacturing, promoting the use of more environmentally friendly construction methods.

Chronology and geofluids characteristics of calcite cement in the Upper Triassic Xujiahe Formation tight sandstone reservoir, Western Sichuan Basin, SW China

Geological fluid activities significantly influence diagenesis and hydrocarbon accumulations in reservoir rocks. However, it remains challenging to precisely determine the timing of these activities. This study aims to investigate the chronology and geofluids characteristics of calcite cement that leads to reservoir tightness in the Upper Triassic Xujiahe Formation in the Western Sichuan Foreland Basin, which is a critical exploration target for hydrocarbon resources. We examine calcite cement as a marker of fluid activities, employing petrological analyses, U-Pb dating, and in-situ carbon-oxygen isotope analysis. These methods are integrated with simulations of regional burial and thermal histories to assess pore evolution and hydrocarbon accumulation mechanisms in these tight sandstone reservoirs. Results reveal two main calcite cementation stages within the second member of the Xujiahe Formation (Xu-2 Member): early cements from the Middle Jurassic around 175 ± 11 Ma and late cements from the Late Jurassic between 161 and 156 Ma. Initially, basin-derived alkaline fluids and near-surface atmospheric freshwater supplied the calcium and carbon for early cements during ongoing basin subsidence. Calcium and carbon for the late calcite cements came from the dissolution of carbonate rock fragments by organic acids. The heavier δ13C is primarily associated with in-situ generation and consumption of carbon within the system, while the δ18Ofluid, which is close to modern seawater values, is mainly related to active water-rock reactions induced by processes such as the dissolution of carbonate rock fragments by organic acids. The closed diagenetic system due to calcite cementation in the Late Jurassic led to reservoir tightening. Therefore, basin-scale chronological constraints on calcite cement are of great significance for quantitatively studying sandstone reservoir densification and exploring the mechanism and control factors of hydrocarbon accumulation.

Effects of C-S-H Seed Prepared by Wet Grinding on the Properties of Cement Containing Large Amounts of Silica Fume

This study aimed to utilize the hydration characteristics of cement through wet grinding techniques to efficiently and conveniently prepare a stable C-S-H seed suspension, providing key parameters and a scientific basis for their large-scale production, which ensures the stability of the C-S-H suspension during production, transportation, and application. This preparation aimed to mitigate the adverse effects of high-volume silica fume on the early mechanical properties of high-performance cement concrete. The properties of C-S-H seed were characterized in detail by SEM, XRD, and TD. In the concrete performance test, silica fume was used to replace part of the cement, and different contents of C-S-H seed were added to test its effect on the compressive strength of concrete, with XRD and SEM used to analyze the performance differences. The results show that the particle size and hydration degree of cement no longer developed after 90 min of wet grinding. Polycarboxylate ether (PCE) superplasticizer can increase the fluidity of the crystal C-S-H seed suspension when the content exceeds 1.5%. When the content of PCE exceeded 2%, the C-S-H seed suspension precipitated. Adding 5% C-S-H seed can increase the compressive strength of cement concrete by 10% under the condition of reducing the amount of cement and increasing the amount of silica fume. And Ca(OH)2 (CH) was produced by cement hydration consumed by silica fumes to generate C-S-H gel, by which the concrete became denser with more strength. However, when the amount of C-S-H seed exceeded 7%, the compressive strength of the concrete decreased.

Cementation characteristics and hydration mechanism of magnesium slag-phosphogypsum composite cementitious materials

The selection and mixing proportion of cementitious materials in cemented backfills are of great engineering importance to ensure the quality of the backfill. Therefore, based on the mixing proportion test of magnesium slag-phosphogypsum composite cementitious materials, the strength change characteristics and volume change rate of the cemented backfill under different cementitious material proportions were investigated. Combined with indoor tests such as hydration heat test, X-ray diffraction, thermogravimetric-differential thermogravimetric, scanning electron microscopy, and mercury intrusion porosimetry, the hydration mechanism of the cemented backfill under different cementitious material proportions was investigated. The results showed that the highest strength of the cemented backfill was observed with only magnesium slag as the activator. The strength of magnesium slag-phosphogypsum and magnesium slag-desulfurized gypsum cemented backfill was greater than that of cement cemented backfill, yet lower than that of magnesium slag alone cemented backfill. The shrinkage trend and magnitude of magnesium slag alone excites blast furnace slag cemented backfill and cement cemented backfill were similar. With the increasing content of phosphogypsum and desulfurized gypsum, the shrinkage of the backfill tended to increase, especially when the content was 18%. The gel-like products of backfill with magnesium slag-based cementitious materials increased rapidly at 7 days, which strongly bonded the aggregates and filled the backfill pores, resulting in high backfill strength. Although the porosity of backfill with magnesium slag-based cementitious material showed an increasing trend with the increase of age, its most available pore size decreased and harmful pores became less. The results can provide a reference for the application of magnesium slag-phosphogypsum composite cementitious materials.

Hydration and Mechanical Properties of High-Volume Fly Ash Cement under Different Curing Temperatures.

This study aimed to investigate the effects of different curing temperatures on the hydration and mechanical properties of high-volume fly ash (HVFA) concrete. The key variables were curing temperature (13 °C, 23 °C, 43 °C) and fly ash (FA) content (0%, 35%, 55%). The hydration characteristics of HVFA cement were examined by evaluating the setting time and heat of hydration under different curing temperatures. The mechanical properties of HVFA concrete were analyzed by preparing concrete specimens at various curing temperatures and measuring the compressive strength at 7, 28, 56, and 91 days. The results indicated that concrete with high FA content was more sensitive to curing temperature compared to ordinary Portland cement.

Evaluation of dental cements derived from mixtures of highly reactive ionomer glasses and bottle glass: Cement manipulation, mechanical, fluoride ion releasing, radiopaque and setting properties

ObjectivesTo evaluate the mechanical properties, fluoride release, radiopacity, and setting characteristics of dental cements derived from highly reactive ionomer glasses and bottle glass mixtures. MethodsTwo highly reactive glass series, LG99 and LG117, were synthesized, milled, sieved, and characterized using XRD and laser particle size analysis. These glasses were mixed with predetermined ratios of ground bottle glass, poly(acrylic acid), and aqueous tartaric acid to form glass ionomer cements. The cements' working time (WT), setting time (ST), fluoride release, radiopacity, compressive strength (CS), and elastic modulus (EM) were evaluated. Mean differences in CS were analyzed using multivariate ANOVA with Tukey’s post hoc test at p = 0.05. ResultsThe WT and ST for both groups ranged from 1.5 to 2.5 min. LG99 series cements showed significantly higher CS (∼65 MPa) and EM (∼2 GPa) than LG117 series (p < 0.05). Both series showed similar fluoride release profiles, peaking at 1.2 mmol/L at 28 days. Radiopacity for LG99 ranged from 0.97 to 1.34, while LG117 ranged from 0.60 to 0.95. Solid state 27Al magic-angle spinning-nuclear magnetic resonance (MAS NMR) confirmed the presence of Al(IV) and Al(VI), indicating setting completion by one day for both series. Bottle glass showed a chemical shift at 55.8 ppm, overlapping with LG99′s Al(IV) signal. The 19F MAS NMR spectra revealed Al-F and F-Sr(n) species in all glasses, with LG117 forming CaF2 after one day in deionized water. ConclusionMixtures of highly reactive ionomer glass and bottle glass produced cements with satisfactory properties for dental applications. Further research is needed to optimize their formulation and properties.

Strength characteristics of cement stabilized construction waste slurry modified by polyacrylamide with different moisture contents

Waste slurry is a major component of construction waste, and its resource utilization can effectively reduce its environmental impact. The effect of polyacrylamide (PAM) content and moisture content on the strength characteristics of PAM modified cement stabilized construction waste slurry (PCMS) was studied using unconfined compressive strength (UCS) and triaxial tests. It can be concluded that, 1) The UCS of PCMS increases with the increase of curing age and significantly decreases with the increase of moisture content. As the content of PAM increases, it first increases and then decreases, with UCS reaching its maximum at a PAM content of 0.5%. 2) When the moisture content is 50%, PAM can increase the elastic modulus of PCMS. When the content of PAM is 0.5%, the elastic modulus reaches its maximum value. When the moisture content is 80% and 100%, the effect of PAM on the elastic modulus of PCMS is not significant. 3) The addition of PAM can improve the shear strength of PCMS. Under the same confining pressure, the shear strength of PCMS increases first and then decreases with the increase of PAM content, and the optimal content is 0.5%. 4) The variation pattern of PCMS cohesion is basically consistent with the shear strength. PAM improves the shear strength of PCMS by enhancing its cohesion. The addition of PAM has a relatively small impact on the internal friction angle of PCMS. These findings provide valuable insights for research into modification technology and the resource utilization of construction waste slurry.

Evaluation of calcium carbonate production and cementitious characteristics of enzymatically induced carbonate precipitation during environmental adjustment

Enzymatically induced carbonate precipitation (EICP) is an emerging and eco-friendly technology, which is considered a green alternative to traditional cement in soil stabilization. When stabilizing soil use one-phase grouting method, the activity of urease is often adjusted, leads to changes in the composition and cementitious characteristics of CaCO3. Previous studies primarily focused on the mechanical properties of solidified soil samples, while the production and cementitious characteristics of CaCO3 influenced by the control of urease activity is rarely discussed. This study investigated production and cementitious characteristics of CaCO3 under different reaction environment (pH adjustment, temperature adjustment, and addition of inhibitors), during which the urease activity tests, pH tests, CaCO3 production tests and ultrasonic oscillation tests are conducted. Meanwhile, the morphological characteristics and mineral composition of CaCO3 are revealed through Scanning Electron Microscope-Energy Dispersive Spectrometer (SEM-EDS) tests and X-ray Diffraction (XRD) test. The results demonstrate that all three one-phase grouting methods can delay the production of CaCO3 at early-stage of EICP, while the pH should be maintained above 4 to prevent significant urease deactivation. The CaCO3 generated in EICP mainly consists of calcite and vaterite, and the size of CaCO3 increases with the urease activity increased. The cementitious characteristics of CaCO3 is mainly determined by the percentage composition of calcite and vaterite, where higher vaterite content results in weaker cementitious characteristics. This study provides insights for evaluating the cementitious characteristics of CaCO3, which is beneficial for guiding the promotion and application of one-phase grouting method.

Improvements in the Characteristics of Plant Fiber Reinforced Concrete

Plant Fiber is lightweight, has a high specific strength, and the ultimate elongation is high and can improve the shortcoming of concrete. Concrete is easy to crack and break, and its tensile strength and other mechanical properties are not high. The chemical composition and mechanical properties of some plant Fibers that are often used are analyzed first. The modification of plant Fiber will also be discussed. Firstly, the chemical composition and mechanical properties of some plant Fibers are analyzed, and the modification methods of plant Fibers are also discussed; then, the mechanical properties of plant Fiber-reinforced concrete, hydration properties, heat preservation properties, durability, and other properties of plant Fiber-reinforced concrete are analyzed and summarized in detail. The conclusions are as follows. When the strength of concrete is increased by plant Fiber, the long Fiber is the best tensile strength method, the short Fiber is the most practical, and the length and content of the Fiber. The influence of factors such as water-cement ratio; plant Fiber can delay the release of the heat of hydration of cement by changing the hydration characteristics of cement, thereby improving the anti-cracking ability of mass concrete; concrete plant Fiber can improve the thermal stability and durability, and the lyotropic effect of plant Fiber on concrete Affect the flowability of paste. Plant Fibers can improve the thermal insulation and durability of concrete and reduce the thermal cracking of concrete. The plant Fiber is used as a reinforcement in the concrete of the railway foundation, which can enhance its tensile strength, impact strength, and flexural strength. The optimal loading range is 0.6-0.9%, and the long Fiber lay-flat method is the best. In the mixed method, these five physical reverse effects can be prepared in the range of 1.2-2.0%. The single tensile squeezing capacity of 30 plants using the mixed method is up to 3.69 MPa, which is the only chemical evaluation capacity of 46.5%.

Enhancement of mechanical and microstructural characteristics of magnesium oxychloride cement with metasteatite

Magnesium oxychloride cement (MOC) has recently garnered considerable research attention as an environmentally sustainable building material. Nevertheless, the mechanical characteristics of MOC have effectively hindered its extensive implementation in engineering structures owing to their inefficient water resistance. In this regard, this study investigates the novel application of steatite to MOC to augment the water resistance of paste. First, steatite was thermally processed to improve the reactivity of the particle and was introduced as a metasteatite with rich magnesium silicate. Furthermore, metasteatite is substituted for MgO in the MOC paste by varying the replacement level from 0 % to 25 % with an interval of 5 %. Thus, metasteatite's effect on MOC paste water resistance is investigated in terms of compressive strength, strength retention under water exposure, and microstructural characterization. Compressive strength results revealed that the influence of metasteatite deteriorated the strength of the matrix with an increased dosage of metasteatite. Moreover, the compressive strength of MOC paste susceptible to water enhanced the strength retention coefficient to 42.9 % for MS10 compared to control specimens. FE-SEM analysis exhibits the formation of M-S-H gel that leads to dense microstructure and contributes to water resistance. In addition, the porosity of the paste is decreased owing to the reaction of Phase 5 with SiO2. The EDS analysis and mapping showed the occurrence of hydration products and the binding affinity between Mg and Si, which improved the continuity of microstructure and water resistance of MOC paste. Therefore, the optimum enhancement is observed for the MOC paste with 10 % metasteatite, demonstrating its efficacy in bolstering water resistance. Finally, this investigation elucidates the feasibility of using metasteatite as a supplementary material for MgO in MOC for developing water resistant MOC.

Modification of magnesium phosphate cement with steel slag powder and ground blast furnace slag: Mechanism of hydration and electrical conductivity

This paper delves into the impacts of steel slag powder (SSP) and ground granulated blast furnace slag (GBFS) on the workability, compressive strength, conductivity, and microstructural characteristics of magnesium phosphate cement (MPC). The findings reveal that the incorporation of mineral admixtures ranging from 10 % to 30 % enhances the fluidity of MPC. Despite a slight reduction in the 28d compressive strength of MPC with the inclusion of SSP and GBFS, there is a significant reduction in raw material costs. A notable presence of unreacted MgO, with struvite identified as the principal hydration product. Furthermore, the interaction of SSP, GBFS, and MgO with ADP yielded a dense compound that bolstered the mechanical attributes of MPC. The modified MPC exhibits diminished resistance and markedly enhanced conductivity, suggesting promising applications as an energy storage material. This research introduces an innovative approach to cost reduction in MPC, recycles industrial by-products, and promises to enable the application of MPC in the field of electrode materials for energy storage.

Resistivity and Piezoelectrical Behavior of the Smart Oil Well Cement Incorporated with Aluminum Oxide and Iron Oxide Nanoparticles—Experimental and Analytical Study

Abstract The effects of individually adding 1 % nano aluminum oxide (NA) and 1 % nano iron oxide (NF) on the curing, compressive piezoelectric, and stress-strain characteristics of cement (Class H) were studied and quantified. X-ray diffraction and thermogravimetric analysis were used to evaluate the cement (class H) with and without the 1 % NF and 1 % NA modification. The cement’s initial electrical resistivity (ER) incorporated with 0.1 % conductive filler was improved by 16 and 31 %, respectively, with 1 % NF and 1 % NA. Including 1 % NF and 1 % NA enhanced the stress at the failure of the cement paste by 26 and 39 % and 17 and 42 %, respectively, after curing times of 1 and 28 d. The nonlinear Vipulanandan p-q curing model was employed to anticipate ER change with curing age. Depending on the curing period and type of nanomaterial, the piezoelectrical (piezoresistivity) of “smart” cement containing NF and NA was more significant than normal cement by 500 times. The nonlinear curing model has been applied to model variations in ER with the curing period. The gauge factor model relating strain to resistivity changes under compressive stress was also developed using a relation model.

Hydration mechanism of limestone calcined clay cement containing calcined coal gangue

Coal gangue (CG), a byproduct of coal washing and mining, has experienced a substantial increase in production in tandem with rising energy consumption trends. The utilization of calcined CG as an additive to cementitious materials is considered a potentially effective strategy for CG management and expanding its applicability on a large scale. This research investigates the impact of calcined CG on the characteristics of blended cements by applying isothermal calorimetry, X-ray diffraction (XRD), Mercury Intrusion Porosimetry (MIP), and mechanical assessments. This paper investigates four separate binder systems: Ordinary Portland Cement (OPC), OPC incorporating 30 % calcined CG, OPC with 15 % limestone addition, and limestone calcined clay cement (LC3). The XRD analysis of the hydrate phase assemblage indicated that the hydrates in LC3 systems exhibit a notable increase, consequently leading to a significant reduction in porosity by MIP results. Furthermore, LC3 systems show greater refinement in pore structure compared to other blended cements. These findings present novel opportunities for furthering the utilization of coal gangue and extending the applications of LC3 cement.

Effect of different curing temperatures on the hydration of polyacrylate emulsion polymer-modified cement

Polyacrylate emulsion polymer-modified cementitious material is a widely used building material, and its hydration characteristics at room temperature have been widely studied, but its actual use environment usually varies with seasonal temperatures, so its hydration characteristics at different temperatures still need to be understood. Here, we investigated the hydration characteristics of polyacrylate emulsion polymer-modified cement (PMC) at 5, 20 and 40 °C. A variety of methods including calorimetry, thermal analysis, X-ray diffraction analysis, Fourier infrared spectroscopy and mercury intrusion porosimetry were used to gain a comprehensive understanding of the different behaviors. In conclusion, low and high temperatures have similar effects on the reduction and increase of compressive strength of the modified mortar, whereas the compressive strength of the unmodified mortar decreased substantially at low temperatures and increased slightly at high temperatures. This phenomenon is confirmed by the results of XRD and thermal analysis. The addition of the polymer increases the number of harmless and harmful pores in the cement and high temperature further increases the number of harmful pores. The change in mechanical properties is the result of the combined effect of the degree of hydration and the pore structure parameters.

Rheological Analysis and Evaluation of Measurement Techniques for Curing Poly(Methyl Methacrylate) Bone Cement in Vertebroplasty.

Vertebroplasty is a minimally invasive surgical procedure used to treat vertebral fractures, which conventionally involves injecting poly(methyl methacrylate) (PMMA) bone cement into the fractured vertebra. A common risk associated with vertebroplasty is cement leaking out of the vertebra during the injection, which may occur due to a lack of understanding of the complex flow behavior. Therefore, experiments to quantify the cement's flow properties are necessary for understanding and proper handling of the bone cement. In this study, we aimed to characterize the behavior of PMMA bone cement in its curing stages to obtain parameters that govern the flow behavior during injection. We used rotational and oscillatory rheometry for our measurements, as well as a custom-made injector setup that replicated a typical vertebroplasty setting. Our results showed that the complex viscoelastic behavior of bone cement is significantly affected by deformations and temperature. We found that the results from rotational tests, often used for characterizing the bone cement, are susceptible to measurement artifacts caused by wall slip and "ridge"-like formations in the test sample. We also found the Cox-Merz rule to be conditionally valid, which affects the use of oscillatory tests to obtain the shear-thinning characteristics of bone cement. Our findings identify important differences in the measured flow behavior of PMMA bone cement when assessed by different rheological methods, an understanding that is crucial for its risk-free usage in downstream medical applications.

Experimental and operations viability assessment of powder-to-powder (P2P) mixture of graphene and cement for industrial applications

Studies have demonstrated that a minute quantity of graphene is sufficient to boost cement characteristics, but the attainment of good dispersion and uniformity of the resultant graphene-cement mixture remains a challenge. To alleviate these challenges, this study proposes a low-energy powder-to-powder homogeniser for dispersing reasonably large quantities of graphene powder into cement powders. Microscopic analysis of graphene dispersion from two samples (1% and 0.02% graphene) at 5x, 10x and 20x objectives revealed that graphene accounts for 1.3% and 0.09% over the cement area respectively, which is relatively uniform across all selected samples. Furthermore, four different dosages of graphene were used to validate the impacts of various proportions of graphene, i.e., 0%, 0.02%, 0.04% and 0.06% (by mass of cement) on two types of cement (i.e., Portland cement CEM I 52.5 N and Portland cement CEM II 42.5 N) which also revealed compressive strength increases up to 25% at 7 and 28 days.