Critical Pore Radius Research Articles

Microfluidic Electroporation Arrays for Investigating Electroporation-Induced Cellular Rupture Dynamics.

Electroporation is pivotal in bioelectrochemistry for cellular manipulation, with prominent applications in drug delivery and cell membrane studies. A comprehensive understanding of pore generation requires an in-depth analysis of the critical pore size and the corresponding energy barrier at the onset of cell rupture. However, many studies have been limited to basic models such as artificial membranes or theoretical simulations. Challenging this paradigm, our study pioneers using a microfluidic electroporation chip array. This tool subjects live breast cancer cell species to a diverse spectrum of alternating current electric field conditions, driving electroporation-induced cell rupture. We conclusively determined the rupture voltages across varying applied voltage loading rates, enabling an unprecedented characterization of electric cell rupture dynamics encompassing critical pore radius and energy barrier. Further bolstering our investigation, we probed cells subjected to cholesterol depletion via methyl-β-cyclodextrin and revealed a strong correlation with electroporation. This work not only elucidates the dynamics of electric rupture in live cell membranes but also sets a robust foundation for future explorations into the mechanisms and energetics of live cell electroporation.

Micro formation mechanism of oil–water inversion in reservoirs based on water film theory—An example from the Dawangzhuang Oilfield in Bohai Bay Basin

In oil fields, the inverted oil–water phenomenon of “water above oil”, which cannot be explained by the traditional principle of gravity differentiation. In hydrophilic reservoirs, water films easily form on rock particle surface. Water films reduce the effective pore throat radius and the space between pores and throats, generate disjoining pressure, and significantly reduces the seepage capacity of pore fluids, which leading to the phenomenon of oil water inversion. Based on laboratory experiments, a model of the relationship between the disjoining pressure -water film thickness was established, and the dynamic mechanism of oil–water inversion was studied using water-film theory. The main factor controlling oil–water inversion is the interaction between the dynamic (buoyancy) and resistance (capillary force and disjoining pressure) forces of oil–water migration and the configuration relationship with the average pore throat radius. The effects of the water film thickness and pore throat radius on the disjoining pressure and capillary resistance were quantitatively analysed, and the critical pore radius model for oil–water inversion was determined. Combining the capillary pressure curve and pore throat distribution, a practical and feasible theoretical technology and method for judging whether oil–water inversion occurs in a reservoir was established. 22 sets of experiments were conducted to verify the reliability and sensitivity of the disjoining pressure - water film thickness model. Taking the Dawangzhuang Oilfield, Raoyang Sag, Bohai Bay Basin, China as an example, through laboratory experiments, specific strata and reservoir data were obtained in the study area, and the disjoining pressure, capillary resistance, and buoyancy were calculated using the disjoining pressure - water film thickness model. By comparing the relationship between the buoyancy and the sum of the equilibrium disjoining pressure and capillary resistance, combined with the distribution of the pore throat radius, it is determined whether there is oil water inversion phenomenon. The practical application based on the theory and method of water film thickness has strong promotion potential for medium–low porosity and permeability reservoirs with the phenomenon of oil water inversion distribution of “water above oil ” whcih can effectively guide oil fields to further select favorable exploration and development targets.

Estimating the permeability of soils under different tillage practices and cropping systems: Roles of the three percolating pore radii derived from X-ray CT

Soil permeability associated with pore characteristics is a critical factor affecting water and nutrient transport in agricultural fields. However, which soil pore characteristics determine soil permeability remains inconclusive due to high heterogeneity of soil pore structure affected by soil and crop management practices. The objective of this study was to compare the pore characteristics of soils under various field management and assess the performance of different pore radii in estimating soil permeability. In this study, we utilized X-ray computed tomography (XCT) to quantify the pore characteristics of soil cores from three treatments: no-tillage under continuous maize cropping (NT-MM), no-tillage under continuous soybean cropping (NT-SS) and conventional tillage under continuous maize cropping (CT-MM). Subsequently, we calculated the permeability with pore-scale numerical simulations directly based on XCT images. Our results revealed that compared to the NT-MM treatment, the NT-SS and CT-MM treatments significantly increased soil porosity of > 200 µm pore classes (soil depths of 2–8 cm and 2–14 cm), as well as pore compactness, specific surface area, fractal dimension, and global connectivity. Among the three XCT-derived pore radii, the critical pore radius (CR) exhibited excellent performance in estimating permeability for samples from the NT-SS and CT-MM treatments, surpassing the hydraulic radius (HR) and mean pore radius of the limiting layer (MRLL). For samples from the NT-MM treatment, the CR and MRLL had similar estimation capabilities (R2 = 0.429, P = 0.110), but both were not as good as the HR (R2 = 0.539, P = 0.060). Furthermore, when estimating the permeability of all the aforementioned soil samples, the CR demonstrated the best estimation performance (R2 = 0.838, P < 0.001). In conclusion, utilizing CR as a predictor for estimating permeability in naturally structured soils is a good choice, which provides valuable insights into improving the accuracy of estimating soil permeability.

Пористость консолидированных методом газовой экструзии компактов из никелевых нанопорошков

The method of hot gas extrusion differs from other methods of metal pressure treatment in that the processed material is subjected to intense plastic deformation by extrusion under conditions of high isostatic pressure of inert gas and heating in the area of plastic deformation. The method makes it possible to process powder materials, while inevitably there is a need to control mechanical properties by controlling porosity and pressure inside the pores. The paper presents a method for calculating the pressure inside the pores from the minimum size of the closed pore. The pore pressure was evaluated on materials obtained by the consolidation of nickel nanopowders by hot gas extrusion. Quantitative processing of the material cross-section view images obtained by scanning electron microscopy showed that the minimum pore size is 220 nm. The formula for calculating the pore pressure is derived from the formula for calculating the critical pore radius. It takes into account the external impact pressure (the gas pressure during the extrusion process was equal to 400 MPa), the surface tension coefficient and the yield strength of nickel (at the extrusion start temperature of 910 °С), as well as the minimum pore radius. The proposed method for calculating the pressure inside a closed pore will allow us to evaluate the mechanical properties of materials obtained by various methods of powder metallurgy.

Microstructure as a key parameter for understanding chloride ingress in alkali-activated mortars

This study aims to evaluate the influence of microstructural properties on the chloride diffusion resistance of alkali-activated materials (AAMs) based on blast furnace slag and/or fly ash, with variable activator doses (represented as Na2O%). Resistance to chloride penetration was tested using accelerated chloride penetration (NT BUILD 443) and chloride migration (NT BUILD 492) tests. Addition of slag to alkali-activated mortars mainly based on fly ash reduced porosity and chloride permeability. Chloride penetration decreased with increasing Na2O%, but porosity and pore structure did not follow the same trend. The pore threshold (dth) and critical pore radius (rcrit) determined by mercury intrusion porosimetry had a good correlation with the chloride diffusion coefficient. Both the quantification of reaction products and the correlation between chloride penetration and pore surface area indicated that physical chloride adsorption on the C-A-S-H/N-A-S-H gel surfaces predominated over chemical chloride binding.

Application of critical path analysis to streaming potential coupling coefficient in porous media

Streaming potential is a passive hydrogeophysical method that can be used to monitor water flow in porous media. However, a quantitative use of this method requires a good understanding of the streaming potential generation in water saturated porous media. In this work, we used the Critical Path Analysis (CPA) method to propose a new model to estimate the streaming potential coupling coefficient (SPCC) in porous media. By comparing the proposed model with 109 experimental data points for both unconsolidated samples such as uniform glass bead and sand packs and consolidated samples such as sandstones, carbonates and with 36 simulated data points, we demonstrated that the CPA is applicable to model the SPCC for porous media with both narrow and broad pore size distributions. Additionally, from the obtained result for the uniform grain packings, we found the rc–d relationship between the critical pore radius rc and grain diameter d that was validated by using 70 experimental data points available in literature. The obtained rc–d relationship may be helpful for applications of CPA-based models for uniform grain packings. We believe that the CPA-based model is an useful alternative approach for modeling the streaming potential coupling coefficient in porous media along with two other models available in literature.

Translocation kinetics of vesicles through narrow pores

We use extensive Molecular Dynamics (MD) simulations to study the osmotically induced translocation of partially filled vesicles through narrow pores. The dependence of the average translocation time, , on vesicle size M, pore radius R p , and strength of the driving force, , is examined for vesicles in a broad interval of sizes M. The time is found to grow with decreasing pore size by an universal scaling law, , where denotes the critical pore radius when the vesicle gets stuck in the pore. With regard to applied pressure, P, we find a power law relationship, , where with P cr being the least pressure that can still drive the vesicle through a pore of size R p . The exponent ω varies with R p and tends to unity as the pore size narrows, . In addition, is found to attain a minimum for an optimal value of the membrane bending rigidity. The variation of vesicle shape, surface area, volume and translocated fraction of the vesicle with time elapsed since the onset of the process is shown to change qualitatively with varying pore size.

Modeling phase behavior of nano-confined fluids in shale reservoirs with a modified Soave-Redlich-Kwong equation of state

• A m-SRK EOS for modeling the phase behavior of nano-confined fluids is proposed. • A more accurate empirical formula for critical temperature shift is developed. • Phase transformation of nano-confined fluid is revealed by nano-confined index. • There is a critical pore radius around 2 nm that phase behavior deviates sharply. The conventional cubic equation of state (EOS), as a robust and efficient method for phase behavior prediction of bulk fluids, is no longer applicable for nano-confined fluids because of the fluid phase behavior deviation induced by the confinement effect in shale reservoirs. In this work, a modified Soave-Redlich-Kwong (m-SRK) EOS is proposed for modeling the fluid phase behavior in nanopores. Three parameters, including the fluid distribution coefficient, relative effective molecular volume coefficient, and nano-confined index, are defined to revise the molar volume term in the SRK EOS. Then, the empirical formulas of adsorption layer thickness and critical temperature shift are established by correlating the data points collected from the literature to solve the m-SRK EOS. Finally, two analytical formulas are derived for calculating critical property shifts. Computational accuracy of critical temperature shift in this work is remarkably improved for the dimensionless pore radius more than 0.2 compared with analytic models proposed by other scholars. Besides, the nano-confined index can comprehensively reflect the phase transformation law of nano-confined fluids. Modifying the molar volume term in EOSs is crucial for the phase behavior prediction when the pore radius is less than 100 nm, especially for the pores less than 10 nm. There is a critical pore radius around 2 nm that the molar volume of nano-confined fluids changes sharply. When the pore radius equal 1 nm, the descend range of the bubble point pressure increases sharply as the temperature increases compared with that of bulk fluids.

Study of the Critical Pore Radius That Results in Critical Gas Saturation during Methane Hydrate Dissociation at the Single-Pore Scale: Analytical Solutions for Small Pores and Potential Implications to Methane Production from Geological Media

We examine the critical pore radius that results in critical gas saturation during pure methane hydrate dissociation within geologic porous media. Critical gas saturation is defined as the fraction of gas volume inside a pore system when the methane gas phase spans the system. Analytical solutions for the critical pore radii are obtained for two, simple pore systems consisting of either a single pore-body or a single pore-body connected with a number of pore-throats. Further, we obtain critical values for pore sizes above which the production of methane gas is possible. Results shown in the current study correspond to the case when the depression of the dissociation temperature (due to the presence of small-sized pores; namely, with a pore radius of less than 100 nm) is considered. The temperature shift due to confinement in porous media is estimated through the well-known Gibbs-Thompson equation. The particular results are of interest to geological media and particularly in the methane production from the dissociation of natural hydrate deposits within off-shore oceanic or on-shore permafrost locations. It is found that the contribution of the depression of the dissociation temperature on the calculated values of the critical pore sizes for gas production is limited to less than 10% when compared to our earlier study where the porous media effects have been ignored.

Immiscible/Near-Miscible relative permeability for confined fluids at high-pressure and high-temperature for a fractal reservoir

The complex interaction between fluids and solids in reservoirs includes interface slip, capillary confinement and the diffusion and mass transfer between CO2 and oil and results in intensely nonlinear flow complexity. This study proposes a relative permeability model that accommodates a fractal pore size distribution and honors these complex process interactions. The relative permeability to CO2 flooding, in the near-miscible region, is predicted through interpolation based on the Gibbs free energy (GFE). The thermodynamic phase behavior of the fluids in the nanopores is considered by applying critical shifts in the temperatures and pressures. A volume-translated Peng-Robinson equation of state is used to calculate the CO2 and n-alkane densities to high reservoir pressure. Fluid-based correlation and modified volumetric mixing rules are then used to extend the viscosity calculations to mixtures with heavy hydrocarbon components. Predictions from the proposed model better fit experimental observations relative to previous models similarly incorporating fractal theory. The nanopores are shown to increase the relative permeability of the non-wetting phase by decreasing the viscosity ratio of the two phases. Increasing key parameters that are related to the pore structure, e.g. the fractal dimension, Df, and critical pore radius, rc, increases the relative permeability of the non-wetting phase. The GFE-based interpolation contributes to the smooth and continuous change in the relative permeability parameters local to the critical point of the mixture, with the confined fluid more likely to be miscible at the same pressure than the bulk fluid. This model can be integrated with a compositional simulator to solve field-scale problems but accommodating the micro-scale physics of unconventional reservoirs.

Mitigation of mechanical membrane degradation in fuel cells – Part 1: Gas diffusion layers with low surface roughness

Hygrothermal variations that arise during dynamic fuel cell operation are known to generate mechanical stresses in the ionomer membrane. Previous research has indicated that membrane electrode assembly (MEA) interaction effects may influence membrane degradation under such loads. The present objective is therefore to evaluate novel MEA design strategies for mitigating mechanical membrane degradation in fuel cells. In this case (Part 1), a gas diffusion layer (GDL) with low surface roughness is applied to suppress buckling-driven membrane failures. Laboratory-based X-ray computed tomography is used in a customized, time-resolved workflow for non-invasive four-dimensional characterization of membrane damage evolution during accelerated stress testing. Membrane crack development is the key failure mode preceded by fracture of the cathode catalyst layer. In comparison to high surface roughness GDL, the severity of membrane buckling is substantially reduced by adoption of the smoother GDL, contributing 2x greater lifetime. Accompanying finite element simulations of the unit fuel cell assembly show plastic strain accumulation in the buckled membrane and identified a critical range of GDL void sizes that influence membrane buckling. Overall, the improvement in GDL surface demonstrates substantial mitigation effect against fatigue-driven mechanical membrane degradation and failure, which is also corroborated by the numerical simulation results. • Novel MEA design strategies are shown to mitigate mechanical membrane degradation • CCM buckling into GDL voids is identified as the key mechanism for membrane failure • 2× higher RH cycling lifetime is achieved with low surface roughness GDLs • Complementary finite element simulations corroborate the experimental findings • A critical GDL pore radius is demonstrated for CCM buckling to occur

Study on Permeability of Concrete Fortifications from WW2 Based on Mercury Intrusion Porosimetry

Quantification of water transport properties of concrete is crucial for prediction of the material degradation processes. In case of 80 years ́ old concrete of fortification structures of former Czechoslovakia, its permeability is the determining factor of the scale of degradation. Mercury intrusion porosimetry was used to characterize the porous system of seven existing bunkers from the defence line ”Pražská čára” and to calculate the permeability using model of Bágel and Živica. Results showed the altered structure of the old concrete, characterized by no notable peaks, which mark the critical pore radius most responsible for water intake. The majority of pores are small micropores, which does not contribute much in the water transport. However, calculated permeability is high enough to be the cause of several degradation processes. The performed program also confirmed high variability of permeability properties between individual structures.

Rock Typing Based on Wetting-Phase Relative Permeability Data and Critical Pore Sizes

Summary Rock typing based on mineralogical, hydraulic, or petrophysical similarities is important to reservoir characterization and simulation. In the literature, classifying rocks using single-phase data has been widely studied. Most methods use porosity and permeability measurements to identify rocks with similar characteristic pore sizes. In this study, we invoke concepts from critical-path analysis (CPA) and propose a new rock-typing method on the basis of two-phase flow data, such as water relative permeability krw. We classify rocks based on their similarities in the critical pore radius rc at the same effective water saturation Se. For this purpose, we first convert the Sw−krw plots to Se−rc curves and then apply a curve clustering method to identify similar rocks. To evaluate the proposed approach, we simulated flow in pore networks with many different pore-scale properties. By varying the pore-throat size distribution, contact angle, pore coordination number, pore-shape distribution, and clay content, we generated a wide range of pore networks. Overall, two-phase flow in 240 pore networks were simulated. In addition to synthetic pore networks, pore networks were generated based on properties of Berea, Mt. Simon, and Fontainebleau sandstones. By analyzing the single-phase simulation results, we identified 8 and 15 rock types using the porosity-formation factor and reciprocal formation factor-permeability data, respectively. However, using the two-phase data, we detect 12 rock groups.

Critical pore radius and transport properties of disordered hard- and overlapping-sphere models

Transport properties of porous media are intimately linked to their pore-space microstructures. We quantify geometrical and topological descriptors of the pore space of certain disordered and ordered distributions of spheres, including pore-size functions and the critical pore radius δ_{c}. We focus on models of porous media derived from maximally random jammed sphere packings, overlapping spheres, equilibrium hard spheres, quantizer sphere packings, and crystalline sphere packings. For precise estimates of the percolation thresholds, we use a strict relation of the void percolation around sphere configurations to weighted bond percolation on the corresponding Voronoi networks. We use the Newman-Ziff algorithm to determine the percolation threshold using universal properties of the cluster size distribution. The critical pore radius δ_{c} is often used as the key characteristic length scale that determines the fluid permeability k. A recent study [Torquato, Adv. Wat. Resour. 140, 103565 (2020)10.1016/j.advwatres.2020.103565] suggested for porous media with a well-connected pore space an alternative estimate of k based on the second moment of the pore size 〈δ^{2}〉, which is easier to determine than δ_{c}. Here, we compare δ_{c} to the second moment of the pore size 〈δ^{2}〉, and indeed confirm that, for all porosities and all models considered, δ_{c}^{2} is to a good approximation proportional to 〈δ^{2}〉. However, unlike 〈δ^{2}〉, the permeability estimate based on δ_{c}^{2} does not predict the correct ranking of k for our models. Thus, we confirm 〈δ^{2}〉 to be a promising candidate for convenient and reliable estimates of the fluid permeability for porous media with a well-connected pore space. Moreover, we compare the fluid permeability of our models with varying degrees of order, as measured by the τ order metric. We find that (effectively) hyperuniform models tend to have lower values of k than their nonhyperuniform counterparts. Our findings could facilitate the design of porous media with desirable transport properties via targeted pore statistics.

Relevance of the theoretical critical pore radius in mesoporous silica for fast crystallizing drugs.

Formulation of poorly water-soluble drugs with mesoporous silica has become a thriving field of pharmaceutics. The theoretical critical pore diameter has been introduced as a maximum value below which an undesired drug crystallization is suppressed by spatial confinement. Currently, only few values have been reported and study of fast crystallising drugs is missing especially at relevant storage temperatures. This study investigated the critical pore diameter of three model drugs with a poor glass-forming ability (i.e. haloperidol, carbamazepine and benzamide) using different mesoporous carriers (Parteck® SLC 500, Neusilin® US2, Syloid® XDP 3050 and Aeroperl® 300 Pharma) and subsequently monitored physical formulation stability over three months by X-ray powder diffraction. The selected drugs showed clear differences in their estimated critical pore diameters, whereas a temperature dependence was barely relevant for pharmaceutical storage conditions. Superior stability was noted for the formulations containing benzamide in line with its predicted relatively large critical pore diameter of 29.5nm. Contrarily, impaired physical stability depending on drug loading was observed in the case of haloperidol representing a compound with a rather small critical pore diameter (8.4nm). These findings confirm the importance of estimating the critical pore diameter, especially for poor glass-forming drugs.

Characterizing the pore size distribution of a chloride silt soil during freeze–thaw processes via nuclear magnetic resonance relaxometry

AbstractSoil pore size distribution (PSD) is typically used to predict the soil freezing characteristic curve and estimate the hydrological and mechanical properties during freeze–thaw cycles. However, direct measurements of frozen soil PSD remain a great challenge. This study proposed a method to determine the PSD of frozen soils based on nuclear magnetic resonance (NMR) relaxometry. Tests were performed on a saturated chloride silt soil at different salt contents (0.3, 1.0, 2.0, and 3.0%) and temperatures (between –30 and 0 °C) during a freeze–thaw cycle. The NMR‐detected PSD (only accounting for pores occupied by unfrozen water) varied with soil temperature, salt content, and freeze–thaw cycle. The sequence of the water–ice phase change and hysteresis were also identified in a freeze–thaw cycle. A regression analysis was performed on the cumulative NMR‐detected PSD via a variant van Genuchten model. The critical freezing pore radius and the thickness of unfrozen water film were computed and used to transform NMR‐detected PSD into the actual PSD of frozen soils on the basis of a pore radius transformation equation established in this paper. Notably, the actual PSD accounted for pores occupied by ice and unfrozen water. The actual PSD indicated that the water–ice phase change was more pronounced in macro‐ and mesopores, especially at lower temperatures and salt content. A comparison between the calculated average pore size and those presented in other studies showed that the proposed technique is a valuable alternative for the prediction of actual frozen soil PSD.

Experimental investigation on T2 cutoffs of tight sandstones: Comparisons between outcrop and reservoir cores

T2 cutoff is a key representative parameter of rock pore structure, which can reflect the degree of mobile fluid as a function of variable water saturation controlled by the extent of centrifuging. However, few studies of T2 cutoff have been done on tight sandstones. In this study, residual fluid of samples after a series of centrifuges were scanned by NMR to determine T2 cutoffs (the relaxation time separating mobile from immobile water) and the extent of mobile fluid as a function of variable water saturation controlled by the extent of centrifuging. Results indicate that all reservoir cores exhibit bimodal NMR T2 distributions, while outcrop cores mainly show unimodal NMR T2 distributions. Tight sandstones showlittle or no mobile fluid controlled by pore throats with radii ≥1 μm, including outcrops and reservoir samples. In conclusion, T2 cutoffs of cores with bimodal NMR T2 distributions and the ones with unimodal NMR T2 distributions were obtained,respectively,at 418 psi and 208 psi, while the former cores exhibit larger T2 cutoffs than the later ones. The critical mobile pore radius for outcrop samples exhibiting a unimodal spectral NMR T2 distribution is 100 nm, whereas the critical pore radius of 50 nm is identified for reservoir samples which display a bimodal T2 distribution. T2gm (The geometric means of T2 fluid distribution at 100% saturation) may propagate error when applying the Schlumberger Doll Research (SDR) model to tight sandstones, whereas T2wa (the weighted average NMR T2 values for the mobile fluid distribution) shows promise as a parameter to predict pore connectivity.

Fluid Permeability of Ground Steel Slag‐Blended Composites Evaluated by Pore Structure

The resource utilization of steel slag has attracted wide attention. In the present work, the pore structure of cement paste with and without ground basic oxygen furnace slag (BOFS) up to 180 days was investigated by mercury intrusion porosimetry. Permeability was evaluated from the tested pore structure. Results indicate that the porosity, critical pore radius, pore‐throat radius, and permeability are increased with the BOFS content and levels off after 28 days. Lower gel porosity and higher coarse capillary porosity were observed in BOFS‐blended composites. The calculated permeability (around 0.30–7.49 × 10−19 m2) based on the pore structure agrees well with the range of reported experimental measurements. Well‐correlated linear and power‐law relationship was noticed between permeability and porosity and characteristic pore radius, respectively.

DEM-aided method for predicting the hydraulic properties with particle-size distribution of porous media

Purpose The soil water retention curve (SWRC) and unsaturated hydraulic conductivity (UHC) are crucial indices to assess hydraulic properties of porous media that primarily depend on the particle and pore size distributions. This study aims to present a method based on the discrete element model (DEM) and the typical Arya and Paris model (AP model) to numerically predict SWRC and UHC. Design/methodology/approach First, the DEM (PFC3D software) is used to construct the pore and particle size distributions in porous media. The number of particles is calculated according to the AP model, which can be applied to evaluate the relationship between the suction head and the moisture of porous media. Subsequently, combining critical path analysis (CPA) and fractal theory, the air entry value is applied to calculate the critical pore radius (CPR) and the critical volume fraction (CVF) for evaluating the unsaturated hydraulic conductivity. Findings This method is validated against the experimental results of 11 soils from the clay loam to the sand, and then the scaling parameter in the AP model and critical volume fraction value for many types of soils are presented for reference; subsequently, the gradation effect on hydraulic property of soils is analyzed. Furthermore, the calculation for unbound graded aggregate (UGA) material as a special case and a theoretical extension are provided. Originality/value The presented study provides an important insight into the relationship between the heterogeneous particle and hydraulic properties by the DEM and sheds light on the directions for future study of a method to investigate the hydraulic properties of porous media.

Relating Rapid Chloride Migration Coefficient of Blast Furnace Slag Concrete to Capillary Pore Structure Parameters

Blast furnace slag blended concrete is widely used in infrastructure, and its chloride resistance is of great concern. This paper experimentally investigated the capillary pore structure and chloride resistance of blast furnace slag blended concrete. Blast furnace slag was proved to be able to optimize the critical pore radius and decrease the proportion of detrimental capillary pores (with radius between 50 nm and 10,000 nm). Meanwhile, the benefit of BFS in improving the chloride resistance was proved. Finally, regression analysis showed that the rapid migration coefficient is proportional to the critical pore radius and the detrimental capillary pore proportion. Nevertheless, the rapid migration coefficient is not closely related to the capillary porosity.