Freeze-thaw Test Research Articles

Research on the Road Performance of Ring Diamond Resin Modified Asphalt Mixture

In order to solve the problems of ineffective modification and high cost of most asphalt modifiers, a new type of high viscosity and high elasticity asphalt modifier - ring diamond resin is introduced, and this modifier is injected into 70 # base asphalt. Through high-temperature rutting, low-temperature bending, immersion Marshall and freeze-thaw splitting tests, the road performance of 70 # base asphalt and ring diamond resin modified asphalt mixture is compared and analyzed. Intended to improve the quality of asphalt pavement while reducing economic costs, thereby extending the service life of the road. The research results indicate that the ring diamond resin modifier can greatly improve the high-temperature performance of asphalt mixtures, and to a certain extent improve their low-temperature crack resistance and water stability. It is a resin modified material with great potential and high advantages. It is recommended to use a dosage of 1% in practical road engineering applications.

An experimental investigation on freeze-thaw resistance of fiber-reinforced red mud-slag based geopolymer

An experimental investigation on freeze-thaw resistance of fiber-reinforced red mud-slag based geopolymer

Study on durability of concrete under alternating positive and negative temperature curing in plateau area

Study on durability of concrete under alternating positive and negative temperature curing in plateau area

The stability of foamed asphalt concrete based on different soaking conditions

The stability of foamed asphalt concrete based on different soaking conditions

Comparative study on the effect of crystalline agents for improving frost resistance of concrete from the perspective of reaction mechanism

Comparative study on the effect of crystalline agents for improving frost resistance of concrete from the perspective of reaction mechanism

Effect of Cyclic Ice Plug Deformation on Microstructure and Mechanical Behaviors of Nuclear-Grade Low-Carbon Tubular Steel.

This study subjected nuclear-grade 20# pipeline steel to cyclic freeze-thaw ice plugging tests, simulating the plastic deformation experienced by pipes during ice plug removal procedures. Subsequently, the dislocation morphology and mechanical properties of the specimens post cyclic ice plugging were examined. The cyclic ice plugging process led to an increase in the dislocation density within the specimens. After 20 and 40 cycles of ice plugging, the internal dislocation structures evolved from individual dislocation lines and dislocation tangles to high-density dislocation walls and dislocation cells. These high-density dislocation walls and cells hindered dislocation motion, giving rise to strain hardening phenomena, thereby resulting in increased strength and hardness of the specimens with an increasing number of ice plugging cycles. In addition, a large stress field was generated around the dislocation buildup, which reduced the pipe material's plastic toughness. The findings elucidate the effects of cyclic ice plugging on the microstructure and properties of nuclear-grade 20# pipeline steel, aiming to provide a theoretical basis for the safe and stable application of ice plugging technology in nuclear piping systems.

Unified failure criteria for freeze-thaw damaged concrete under multiaxial stress state: An innovative uniaxial strength-dependent prediction method

Unified failure criteria for freeze-thaw damaged concrete under multiaxial stress state: An innovative uniaxial strength-dependent prediction method

Proportioning of Oil Shale Ash for Sustainable 3D Printable Mortars

To achieve optimal strength and printability, mortars used in 3D printing typically contain high proportions of cement and other fine-grained powders. Consequently, the majority of mixtures used in 3D printing have high carbon footprint. Hence, there arises a critical need to study alternative supplementary cementitious materials aimed at reducing the environmental impact of mortars used in 3D printing. The use of oil shale ash as a partial substitute for cement not only addresses this issue but also presents an opportunity to repurpose waste from power plants in the Baltic states, where oil shale is intensively utilized.In this study, the influence on mechanical properties and durability of cement-based mortars was evaluated by substituting cement with oil shale ash in varying quantities. Specifically, 0% to 40% of cement mass was replaced with oil shale ash. Life cycle assessment (LCA) was performed for each mixture. By analyzing the material properties alongside the environmental impact for each mixture, the optimal percentage of substitute was determined.For the determination of the mechanical properties of each mixture, compressive and flexural strength tests were conducted on 3D printed samples in various directions, as well as on cast samples. To assess the durability of each mixture, freeze-thaw tests were performed on both 3D printed and cast samples.From the obtained results, we developed an algorithm that chooses the optimal mixture proportioning. Depending on material performance requirements set in the beginning, this algorithm gives the exact proportions of oil-shale ash and cement for the mixture, by taking into account both desired material properties and carbon dioxide emissions. As a result, an environmentally friendly cement-based mixture is obtained without losing the desired properties. By using this algorithm, it is possible to create a mortar with properties comparable to concrete with strength class C30/37 while reducing carbon emissions by 15% to 30%.

A damage prediction method for building concrete based on improved BP neural network

Concrete is widely used in civil engineering, and fiber materials are usually added to building concrete to enhance its durability. In order to study the freeze-thaw damage performance of different fiber reinforced concrete mixtures and accurately predict the degree of freeze-thaw damage of fiber reinforced concrete with different ratios under salt freezing conditions, this paper proposes an improved BP neural network-based method for predicting freeze-thaw damage in building concrete. Firstly, freeze-thaw cycle tests were conducted on fiber reinforced concrete with different proportions to study the variation patterns of concrete quality loss rate and dynamic elastic modulus; Then, based on BP neural network and particle swarm optimization algorithm, a concrete damage prediction model is established; Finally, conduct optimization based on the learning samples and compare and analyze the prediction errors of the model. The method proposed in this article has been verified to have good accuracy and stability.

A prediction method for salt frost resistance of dam rock foundation based on improved BP neural network

Hydraulic resources can be utilized in a cascade manner, with the advantages of energy conservation, economy, and environmental protection. In order to study the anti salt freezing performance of rock foundation in hydroelectric power dams and accurately predict the degree of rock and soil freeze-thaw damage under salt freezing conditions, this paper proposes a prediction method for the anti salt freezing performance of dam rock foundation based on an improved BP neural network. Firstly, freeze-thaw cycle tests were conducted on the rock foundation materials of dams poured with different proportions of fiber reinforced concrete to study the changes in soil mass loss rate and dynamic elastic modulus; Then, based on BP neural network and particle swarm optimization algorithm, a prediction model for rock and soil freeze-thaw damage is established; Finally, using the historical data of the Baihetan hydropower station, optimization was carried out and model prediction errors were compared and analyzed. The method proposed in this article has been verified to have good accuracy and stability, providing guidance for the operation and construction design of hydropower projects.

Effect of silicon impregnant on freeze–thaw durability of silane-treated recycled aggregate concrete

Effect of silicon impregnant on freeze–thaw durability of silane-treated recycled aggregate concrete

Optimizing the Utilization of Steel Slag in Cement-Stabilized Base Layers: Insights from Freeze-Thaw and Fatigue Testing.

This paper presents a study on the mechanical properties of cement-stabilized steel-slag-based materials under freeze-thaw cycles for a highway project in Xinjiang. Using 3D scanning technology the specimen model conforming to the real steel slag shape was established. The objectives of the study are as follows: to explore the sensitivity between the macro- and micro-parameters of the specimen and to establish a non-linear regression equation; and to study the changes in mechanical properties of materials under freeze-thaw cycles, fatigue loading, and coupled freeze-thaw cycle-fatigue loading. The results show that there are three stages of compression damage of the specimen, namely, linear elasticity, peak plasticity, and post-peak decline. Maximum contact forces between cracks and particles occur mainly in the shear zone region within the specimen. The compression damage of the specimen is a mixed tensile-shear damage dominated by shear damage. When freeze-thaw cycles or fatigue loads are applied alone, the flexural strength and fatigue life of the specimens show a linear relationship of decline. The decrease in flexural modulus at low stress is divided into the following: a period of rapid decline, a relatively smooth period, and a period of fracture, with a tendency to change towards linear decay with increasing stress. In the case of freeze-thaw-fatigue coupling, the flexural modulus of the specimen decreases drastically by about 50% in the first 2 years, and then enters a period of steady decrease in flexural modulus in the 3rd-5th years.

Mechanical performance degradation investigation on FRP reinforced concrete based on neural network design method

To predict the effect of chemical-freezing coupling erosion on the properties of four kinds of FRP-reinforced concrete. Rapid freeze–thaw tests were conducted. The mass loss rate, relative dynamic elastic modulus, compressive strength, and flexural capacity were tested to investigate the Mechanical Performance of specimens. The compression specimens are cylindrical specimens wrapped with FRP, and the flexural specimens are pasted with FRP prismatic specimens on the pre-cracked side. A database was built based on 45 groups of experimental test results, and the prediction effect of the BP neural network and CNN model on compressive strength and flexural capacity was compared, respectively. The results showed that CNN did a better job. Finally, the maximum number of freeze–thaw cycles of different FRP-reinforced specimens was predicted based on the CNN model with mass loss rate and relative dynamic modulus as the evaluation criteria. This method can provide a new perspective for predicting the durability of FRP-reinforced concrete.

Assessment of hydraulic and thermal properties of the Antarctic active layer: Insights from laboratory column experiments and inverse modeling

To better understand the changes in the hydrologic cycle caused by global warming in Antarctica, it is crucial to improve our understanding of the groundwater flow system, which has received less attention despite its significance. Both hydraulic and thermal properties of the active layer, through which groundwater can flow during thawing seasons, are essential to quantify the groundwater flow system. However, there has been insufficient information on the Antarctic active layer. The goal of this study was to estimate the hydraulic and thermal properties of Antarctic soils through laboratory column experiments and inverse modeling. The column experiments were conducted with sediments collected from two lakes in the Barton Peninsula, Antarctica. A sand column was also operated for comparison. Inverse modeling using HydroGeoSphere (HGS) combined with Parameter ESTimation (PEST) was performed with data collected from the column experiments, including permeameter tests, saturation-drain tests, and freeze-thaw tests. Hydraulic parameters (i.e., Ks, θs, Swr, α, β, and Ss) and thermal diffusivity (D) of the soils were derived from water retention curves and temperature curves with depth, respectively. The hydraulic properties of the Antarctic soil samples, estimated through inverse modeling, were 1.6×10-5-3.4×10-4cms-1 for Ks, 0.37-0.42 for θs, 6.62×10-3-1.05×10-2 for Swr, 0.53-0.58cm-1 for α, 5.75-7.96 for β, and 5.11×10-5-9.02×10-5cm-1 for Ss. The thermal diffusivities for the soils were estimated to be 0.65-4.64cm2min-1. The soil hydraulic and thermal properties reflected the physical and ecological characteristics of their lake environments. The results of this study can provide a basis for groundwater-surface water interaction in polar regions, which is governed by variably-saturated flow and freeze-thaw processes.

Experimental Study of Shear Strength of Loess under Freeze-thaw Cycles

In order to study the shear strength characteristics of loess under the action of freeze-thaw cycle, through the freeze-thaw test, straight shear test, to analyze the change rule of water content and freeze-thaw cycle on loess cohesion, internal friction angle and shear strength. The test results show that: loess cohesion gradually decreases with the increase of water content and the number of freeze-thaw cycles, when the freeze-thaw 7 times, the change of cohesion gradually tends to stabilize; the angle of internal friction decreases gradually with the increase of water content and the number of freeze-thaw cycles, but the rate of decrease is smaller than the rate of cohesion; the change of shear strength is affected by the cohesion more than the angle of internal friction, and the shear strength at different times of freezing and thawing increased linearly with the vertical stress, and the relationship equations between the shear strength and the water content and the number of freezing and thawing cycles were established.

Experimental Study on the Microfabrication and Mechanical Properties of Freeze-Thaw Fractured Sandstone under Cyclic Loading and Unloading Effects.

A series of freeze-thaw cycling tests, as well as cyclic loading and unloading tests, have been conducted on nodular sandstones to investigate the effect of fatigue loading and freeze-thaw cycling on the damage evolution of fractured sandstones based on damage mechanics theory, the microstructure and sandstone pore fractal theory. The results show that the number of freeze-thaw cycles, the cyclic loading level, the pore distribution and the complex program are important factors affecting the damage evolution of rocks. As the number of freeze-thaw cycles rises, the peak strength, modulus of elasticity, modulus of deformation and damping ratio of the sandstone all declined. Additionally, the modulus of elasticity and deformation increase nonlinearly as the cyclic load level rises. With the rate of increase decreasing, while the dissipation energy due to hysteresis increases gradually and at an increasing rate, and the damping ratio as a whole shows a gradual decrease, with a tendency to increase at a later stage. The NRM (Nuclear Magnetic Resonance) demonstrated that the total porosity and micro-pores of the sandstone increased linearly with the number of freeze-thaw cycles and that the micro-porosity was more sensitive to freeze-thaw, gradually shifting towards meso-pores and macro-pores; simultaneously, the SEM (Scanning Electron Microscope) indicated that the more freeze-thaw cycles there are, the more micro-fractures and holes grow and penetrate each other and the more loose the structure is, with an overall nest-like appearance. To explore the mechanical behavior and mechanism of cracked rock in high-altitude and alpine areas, a damage model under the coupling of freeze-thaw-fatigue loading was established based on the loading and unloading response ratio theory and strain equivalence principle.

The Collapse Mechanism of Slope Rill Sidewall under Composite Erosion of Freeze-Thaw Cycles and Water

The composite erosion of freeze-thaw and water flow on slope rills is characterized by periodicity and spatial superposition. When revealing the collapse mechanism of slope rill sidewalls under the composite erosion of freeze-thaw and water flow, it is necessary to fully consider the effect of water migration and its impact on the stability of the rill sidewall. In this paper, we placed the self-developed collapse test system in an environmental chamber to carry out model tests on rill sidewall collapse on slopes under the composite erosion of freeze-thaw and water flow. We utilized three-dimensional reconstruction technology and the fixed grid coordinate method to reproduce the collapse process of the rill sidewall and precisely locate the top crack. We obtained the relationship between the water content of the specimen and mechanical indexes through the straight shear test. The main conclusions are as follows: The soil structure of the rill sidewall is significantly affected by the freeze-thaw cycle, which benefits capillary action in the soil. One freeze-thaw cycle has the most serious effect on the soil structure of the rill sidewall, and the change in the moisture field is more intense after the soil temperature drops below zero. The friction angle of the soil increases with the number of freeze-thaw cycles and tends to stabilize gradually. The effect of the freeze-thaw cycle on the rate of change of the water content of the soil at each position of the wall can be accurately described by a logarithmic function. The expression of the two-factor interaction effect on the rate of change of water content of soil at each position of the rill sidewall can be accurately fitted. We propose a calculation system for locating cracks at the top of the rill sidewall and determining the critical state of instability and collapse of the rill sidewall during the process of freeze-thaw and water flow composite erosion. The results of this research can help improve the accuracy of combined freeze-thaw and water flow erosion test equipment and the development of a prediction model for the collapse of the rill sidewall under compound erosion. This is of great significance for soil and water conservation and sustainability.

Study on the influence of fractal dimension and size effect of coarse aggregate on the frost resistance of hydraulic concrete

Study on the influence of fractal dimension and size effect of coarse aggregate on the frost resistance of hydraulic concrete

The Performance of Modified Asphalt Mixtures with Different Lengths of Glass Fiber

AbstractOne practical option for modifying an asphalt mixture’s performance is to use additives. This will help the mixture perform better against the damaging effects of traffic, loads, and climatic variations. In this regard, glass fiber (GF) has drawn much interest because of its positive effect. Therefore, this paper attempts to study the effect of glass fiber length and content on the performance and strength of asphalt mixtures. It also aims to determine the optimum glass fiber content and the best glass fiber length of modified asphalt mixtures. An experimental program is carried out, which includes the Marshall test, volumetric properties, freeze-thaw splitting test, immersion Marshall test, and wheel tracking test to characterize related properties of glass fiber incorporated in asphalt mixtures. Seven different percentages (0, 0.25, 0.5, 0.75, 1, 1.25, and 1.5) of glass fiber by total weight of aggregates in three various lengths are used to design 19 asphalt mixtures. Based on the results obtained, the performance of the asphalt mixture was enhanced remarkably after adding glass fiber. The use of various lengths of glass fiber led to a better-quality asphalt mixture in terms of volumetric properties, moisture damage resistance, and permanent deformation resistance. Specifically, asphalt mixtures made with (0.5%) glass fiber illustrated the highest quality, and adding (20 mm) length of glass fiber was better than (10 mm and 30 mm) glass fiber lengths. The results also show that adding (10 mm and 30 mm) lengths of glass fiber can improve the resistance of asphalt mixtures to water damage and permanent deformation compared with the control mixture (M0). The findings indicate the applicability of 20 mm glass fiber length in asphalt mixtures to achieve better resistance against moisture and reduce the chance of irreparable permanent deformation under growing traffic loads and hot climate changes. Although the inclusion of glass fiber in asphalt mixtures led to a modest increase (6%) in overall cost, the effective improvement in performance and extension of the service life of the asphalt pavement constitute a convincing argument for this approach, making it an attractive option. Finally, it was concluded that a higher amount of glass fiber (i.e., > 0.5%) and a length greater than (20 mm) could diminish the positive effect of glass fiber to improve the properties of glass fiber asphalt mixtures.

Study on the Degradation Law of Physical and Mechanical Properties of Granite under the Action of Freeze-thaw Cycle

This study demonstrates the effect on the mechanical properties of granite through the freeze-thaw cycle test method, and investigates the mechanical property parameters and its changing law of the rock samples under different numbers of freeze-thaw cycles. The results show that with the increase of the number of freeze-thaw cycles, the physical property parameters such as mass and longitudinal wave speed of the samples show a tendency of attenuation. Mechanical property parameters such as peak strength and elastic modulus of the specimen also showed a trend of decay.