Basalt Fiber Content Research Articles

Experimental and numerical simulation study on the dynamic behavior of basalt-polypropylene fibers reinforced coral aggregate concrete

This study investigates the failure mode, dynamic compressive strength, strain rate effect and critical strain of basalt-polypropylene fiber-reinforced coral concrete (BPRCAC) under impact load using a 75mm diameter split Hopkinson pressure bar (SHPB). The Holmquist-Johnson-Cook (HJC) model is modified to obtain parameters such as strain rate effect and strength based on the test results, utilizing LS-DYNA for numerical simulation analysis. The results indicated that the dynamic compressive strength and critical strain of BPRCAC significantly respond to the strain rate, increasing with the strain rate. A relationship between the dynamic increase factor (DIF) and the strain rate of BPRCAC is developed, showing that the DIF increases linearly with the decimal logarithm of the strain rate. However, the critical strain of BPRCAC increases linearly with the strain rate. The addition of basalt fiber (BF) and polypropylene fiber (PF) improves the strain rate sensitivity of the dynamic compressive strength, with increases of 19.21%, 7.37%, 22.60%, and 11.37% observed for BCAC-0.1, PCAC-0.1, BPCAC-0.1, and BPCAC-0.2, respectively, compared to CAC at a strain rate of 133−143s-1. The combined content of BF and PF has a more significant effect on the strain rate sensitivity of the critical strain, with BPCAC-0.2 exhibiting a critical strain 50.79%−74.42% higher than that of the other groups compared to CAC. The stress-strain curves and failure modes of the specimens simulated by LS-DYNA agree with the experimental results, verifying the applicability of the improved HJC model to BPRCAC.

Study on the resistance of basalt fiber concrete to erosion of building structure by wind gravel flow

Concrete structures in the windy regions of the Gobi face constant erosion from wind gravel flow, leading to severe surface damage and significantly reduced durability. This paper investigates the erosion resistance of basalt fiber (BF) concrete under various erosion conditions using the air-flow sand injection method. The results indicate that adding 0.15% BF to concrete reduces its erosion rate by 20.7% to 21.5% compared to concrete without BF. Therefore, a BF content of 0.15% provides optimal erosion resistance for the concrete. The correct amount of BF bonds tightly with the cement mortar, forming a mesh structure inside the concrete that absorbs the kinetic energy of gravel impacts. The concrete erosion process can be divided into an early accelerated phase and a later stabilized phase. Throughout these phases, the erosion rate of concrete increases with the erosion angle (EA), erosion wind speed (EWS), and gravel flow rate (GFR). In particular, the erosion rate of BF15 concrete increased by 35.6 to 46.4mg/cm² when the EA changed from 15° to 90°. Notably, surface damage from low-angle erosion mainly consists of cut scratches, while high-angle erosion primarily results in erosion pits. As the grain size of the eroded gravel increases, the erosion rate of the concrete decreases. However, when a single large gravel particle impacts the concrete, it creates a larger and deeper erosion pit. Furthermore, the erosion rate of BF concrete exhibits a strong negative linear correlation with its mechanical properties, with an R² value exceeding 0.88. Moreover, erosion reduces both compressive and splitting tensile strengths of concrete. For BF15 concrete, however, the decreases are minimal: compressive strength drops by just 1.2MPa, and splitting tensile strength decreases by only 0.2MPa. Building on Bitter and Neilson’s theoretical erosion model, an improved erosion model for BF concrete has been developed under wind gravel flow. This model incorporates the BF mixing factor and particle size function while considering other erosion parameters comprehensively. The enhanced model provides a theoretical foundation and scientific basis for safeguarding concrete structures in Gobi wind-prone regions.

Study on the Effect of Basalt Fiber Content and Length on Mechanical Properties and Durability of Coal Gangue Concrete

The massive accumulation of coal gangue not only causes a waste of resources but also brings serious environmental pollution problems. To promote the utilization of coal gangue resources, mitigate environmental pollution from coal gangue, and address the shortage of natural aggregates, this study investigates the use of coal gangue to replace coarse aggregate at a 40% replacement rate to prepare coal gangue concrete (CGC). The current research on the modification of gangue concrete by BF has been less often compared with the research on the effect of basalt fiber (BF) on the properties of ordinary concrete, so in this study, BF with different admixtures and lengths were added into CGC. Additionally, basalt fibers (BFs) of varying amounts and lengths were incorporated into CGC. The study explored the effects of BF on the tensile strength, splitting tensile strength, and flexural strength of CGC. It was found that the mechanical properties of CGC improved significantly when the BF dosage was 0.10–0.15% and the length was 18 mm. This is evidenced by an increase in the compressive strength of 3.94–5.11%, split tensile strength of 11.20–16.18%, and flexural strength of 8.23–12.97%. BF was able to refine pore space, prevent crack development, and bridge cracks in CGC. To further investigate the effect of BF on the long-term service performance of CGC, the effects of BF on the appearance, quality, and compressive strength of CGC in sulfate and freeze–thaw environments were examined. The results indicated that a BF dosage of 0.10–0.15% significantly enhanced the sulfate erosion resistance and freeze–thaw resistance of CGC. This is shown by a 36.76–46.90% reduction in the rate of loss of compressive strength of CGC under the freeze–thaw cycling and a 6.21–8.50% increase in the corrosion resistance factor of CGC under a sulfate attack. BF improved the pore structure and reduced seepage channels, thereby enhancing the durability of CGC.

Study on resistance of basalt fiber reinforced concrete to sulfate erosion after cryogenic freeze-thaw cycles

This study aims to investigate the mechanical properties of concrete structures, such as liquefied natural gas (LNG) storage tanks, subjected to the effects of cryogenic freeze-thaw cycles and erosive environmental conditions. Mechanical properties of basalt fiber reinforced concrete (BFRC) with normal temperature (25 °C) and different temperature gradients (25 °C ∼ -80 °C, 25 °C ∼ -160 °C), fiber content (0 %, 0.1 %, 0.2 %), and sulfate erosion days (0, 60, 120) were determined. The morphology of the eroded specimens was examined, and the microstructural characteristics were investigated by scanning electron microscope (SEM). The findings revealed that the introduction of basalt fiber (BF) in the concrete significantly changes the failure mode following sulfate erosion, causing specimens to fail by ductile failure rather than brittle failure. Moreover, the mechanical properties of concrete specimens decreased significantly with increasing temperature gradients of freeze-thaw cycles. Under non-erosive conditions, the compressive strength of plain concrete after undergoing freeze-thaw cycles from 25 °C to -160 °C decreased by 22.4 % compared to plain concrete that did not undergo freeze-thaw cycles, and the tensile strength decreased by 32.5 %. Adding fibers increased the mechanical properties of specimens. Specially, after undergoing freeze-thaw cycles from 25 °C to -160 °C and being subjected to 120 days of sulfate erosion, compared with plain concrete, the compressive strength of specimens with 0.2 % fiber content increased by 20.6 %, the tensile strength increased by 37.8 %, while also increasing flexural toughness. In addition, the sulfate erosion days also had a considerable impact on the deterioration of the mechanical properties of specimens. Specially, after undergoing freeze-thaw cycles from 25 °C to -80 °C and being subjected to 120 days of erosion, the eroded specimen with 0.1 % fiber content, the compressive strength decreased by 10.9 %, the tensile strength decreased by 11.6 % compared to specimens that were not eroded, while also decreasing flexural toughness. Combined with the experimental results, the strength deterioration models of BFRC related to the sulfate erosion days and BF content were proposed at 25 °C, after freeze-thaw cycles from 25 °C to -80 °C, and after freeze-thaw cycles from 25 °C to -160 °C. The aim is to provide some data reference for the development and application of BFRC in cryogenic environments.

Study on the deterioration mechanism of hybrid basalt-polypropylene fiber-reinforced concrete under sulfate freeze-thaw cycles

This paper focuses on the deterioration mechanism of hybrid basalt-polypropylene fiber-reinforced concrete (HBPRC) under the coupling of sulfate freeze-thaw cycles. The changes in the macroscopic properties of HBPRC under the influence of different volume contents of basalt fiber (BF), polypropylene fiber (PF) and hybrid BF-BF were investigated. The microstructure of HBPRC was characterized using the nuclear magnetic resonance (NMR) technique, X-ray diffraction (XRD) and scanning electron microscopy (SEM), and the deterioration models of the BF- matrix interfacial transition zone (BF-ITZ) and the PF- matrix interfacial transition zone (PF-ITZ) in HBPRC were developed. The results showed that the fibers effectively reduced the cracking and macroscopic property damage induced by sulfate freeze-thaw cycles as the number of freeze-thaw cycles increased. When both BF and PF volume contents are mixed at 0.05 %, they can produce complementary effects, and their formation of a uniformly distributed three-dimensional mesh structure is more conducive to reducing the damage to the concrete, and their relative dynamic modulus of elasticity and compressive strength after 300 times of sulfate freeze-thaw cycles were increased by 67.10 % and 46.92 % compared with control concrete. At the same time, the addition of fibers resulted in a more stable evolution of the pore structure of the concrete, and the porosity of the specimens with fibers added at a volume admixture of 0.05 % and 0.1 % was reduced by 13.69–21.35 % after 300 cycles of sulfate freeze-thaw cycling, compared with control concrete. From the BF-ITZ and PF-ITZ deterioration models, it was concluded that the differences in the bonding performance of BF and PF to the concrete matrix affected the degree of frost damage to which they were subjected to coupling and the efficiency of salt solution replenishment, which in turn led to differences in the damage of each group of HBPRC. The reliability of the model was further verified by SEM observation of the morphological changes of different fiber-matrix ITZs before and after sulfate freeze-thaw cycles.

Experimental Study on the Frost Resistance of Basalt Fiber Reinforced Concrete.

In this paper, the effect of basalt fiber (BF) on the frost resistance of concrete under different curing conditions was investigated, and its frost resistance mechanism was analyzed. Three different curing conditions (normal curing, short-term curing, and seawater curing) were adopted, and concrete with different BF volume contents was designed. Freeze-thaw (FT) tests were carried out using the rapid freezing method to test the frost resistance of basalt fiber reinforced concrete (BFRC). Additionally, the mass loss rate (MLR), relative dynamic modulus of elasticity (RDME) change, and compressive strength reduction of specimens during the freeze-thaw cycles (FTCs) were evaluated. The results show that when the BF content is 0.15%, under normal curing, short-term curing, and seawater curing conditions, the residual compressive strength of BFRC after FTCs was increased by 5.4%, 28.1%, and 30.9%, respectively, compared to plain concrete. By incorporating BF into concrete, the development of microcracks can be effectively retarded, and damage generation during FTCs can be reduced. In addition, the microscopic morphological characteristics and pore structure characteristics of concrete further elucidate the frost resistance mechanism of BFRC from a microscopic perspective.

Study on design optimization, road performance verification and preparation process selection of hybrid fiber reinforced asphalt mixture composite

To achieve long-lasting, high-strength, and sustainable asphalt pavement, this study prepared a hybrid fiber asphalt mixture using micron-scale calcium sulfate whiskers (CSW) and millimeter-scale basalt fibers (BF). The response surface method was employed to optimize the mix design, develop a prediction model, and verify road performance. The preparation process was refined based on the optimal mix design. The findings revealed that the best overall road performance was obtained with 5 % CSW content, 6 mm BF length, and 0.32 % BF content. The mixture demonstrated optimal performance with CSW wet mixing and BF dry mixing. Additionally, testing the fiber asphalt mixture at the mixture level was found to be crucial, as results can vary from those obtained at the mastic level. This study provides an in-depth analysis of the hybrid fiber asphalt mixture’s action mechanisms in material optimization, performance verification, and preparation processes, offering valuable insights for related research and engineering applications of hybrid fibers.

Compressive mechanical performance and microscopic mechanism of basalt fiber-reinforced recycled aggregate concrete after elevated temperature exposure

To improve the mechanical properties of recycled aggregate concrete (RAC) after elevated temperature exposure, this study employed basalt fiber (BF) as reinforcing material incorporated into RAC. The replacement ratio of recycled coarse aggregate (RCA), the content of BF, and the temperature were utilized as the change parameters, and 27 groups of basalt fiber reinforced recycled aggregate concrete (BFRRC) specimens were designed to carry out the compressive strength test after elevated temperature. The heating rate was set at 2.5 °C/min to avoid any possible explosion of the cylindrical specimen during the heating process. The specimens were treated for 6h after reaching the desired temperature, and then the furnace door was opened for natural cooling to room temperature. After observing the physical properties of the specimens, the basic mechanical properties test was carried out, and the microscopic mechanism was analyzed in depth by electron microscopy. The results showed that the defects inherent in RCA and the continuous accumulation of elevated temperature damage gradually reduced the compressive mechanical performance of BFRRC but that the toughening and cracking-resistance action of BF effectively improved the compressive mechanical performance of BFRRC. BF enhanced the compressive mechanical performance of RAC through bridging and crack resistance action mechanisms, but the higher the temperature became, the smaller the enhancement was. The cube compressive strength and axial compressive strength of the specimens decreased with the increase of temperature. With the same replacement ratio and fiber dosage, increasing the temperature from 300 °C to 600 °C, the decrease in cube compressive strength and axial compressive strength was the most significant, which was between 36.4 %–48.1 % and 51.1 %–62.6 %, respectively.

Experimental Study on the Properties of Basalt Fiber–Cement-Stabilized Expansive Soil

Expansive soil is prone to rapid strength degradation caused by repeated volume swelling and shrinkage under alternating dry–wet conditions. Basalt fiber (BF) and cement are utilized to stabilize expansive soil, aiming to curb its swelling and shrinkage, enhance its strength, and ensure its durability in dry–wet cycles. This study examines the impact of varying content (0–1%) of BF on the physical and mechanical characteristics of expansive soil stabilized with a 6% cement content. We investigated these effects through a series of experiments including compaction, swelling and shrinkage, unconfined compressive strength (UCS), undrained and consolidation shear, dry–wet cycles, and scanning electron microscope (SEM) analyses. The experiments yielded the following conclusions: Combining cement and BF to stabilize expansive soil leverages cement’s chemical curing ability and BF’s reinforcing effect. Incorporating 0.4% BFs significantly improves the swelling and shrinkage characteristics of cement-stabilized expansive soils, reducing expansion by 36.17% and contraction by 28.4%. Furthermore, it enhances both the initial strength and durability of these soils under dry–wet cycles. Without dry–wet cycles, the addition of 0.4% BFs increased UCS by 24.8% and shear strength by 24.6% to 40%. After 16 dry–wet cycles, the UCS improved by 38.87% compared to cement-stabilized expansive soil alone. Both the content of BF and the number of dry–wet cycles significantly influenced the UCS of cement-stabilized expansive soils. Multivariate nonlinear equations were used to model the UCS, offering a predictive framework for assessing the strength of these soils under varying BF contents and dry–wet cycles. The cement hydrate adheres to the fiber surface, increasing adhesion and friction between the fibers and soil particles. Additionally, the fibers form a network structure within the soil. These factors collectively enhance the strength, deformation resistance, and durability of cement-stabilized expansive soils. These findings offer valuable insights into combining traditional cementitious materials with basalt fiber to manage expansive soil hazards, reduce resource consumption, and mitigate environmental impacts, thereby contributing to sustainable development.

Study on the stressing state features of basalt fibre concrete lining structure under sulphate erosion

Basalt fibre (BF) is an environmentally friendly material with excellent corrosion resistance. When tunnels cross gypsum rock strata, the gypsum rock will dissolve sulphate and erode the supporting structure, thus affecting the safe operation of the tunnels in the long term. Adding BF to the supporting structure of gypsum rock tunnels can improve its resistance to sulphate erosion. This paper took Wuzhishan Tunnel as a case, and first determined the sulphate concentration of the gypsum rock stratigraphic environment at the site; then, analysed the change of mechanical properties of basalt fibre concrete (BFC) before and after sulphate erosion by mechanical tests; finally, examined the deformation and force characteristics of the BFC secondary lining structure by numerical simulation. The results showed that the bridging effect of BF fibres and the stable spatial network structure formed inside the concrete enhanced the mechanical properties of BFC and its ability to resist sulphate erosion. However, due to the agglomeration effect of BF fibres, too much BF would reduce the mechanical properties and erosion resistance of BFC. At a BF content of 6 kg/m³, BFC had the strongest ability to resist sulphate erosion, and the cube compressive strength, axial compressive strength, and modulus of elasticity of BFC were the highest, with 47.8 MPa, 33.6 MPa, and 38.7 GPa, respectively. The dense calcium silicate hydrate (C-S-H) gel, generated near the BF, enhanced the connection between the cementitious and the aggregate, inhibited the development of microcracks within the concrete, and reduced the erosion channels for sulphate ions. The maximum displacement of the BFC secondary lining structure was reduced by 20.15 % compared to plain concrete (PC) after sulphate erosion. The secondary lining structures consisting of both BFC and PC were stressed the most at footing. The secondary lining structure composed of BFC had better deformation resistance and higher strength than PC.

Permeability and Disintegration Characteristics of Loess Solidified by Guar Gum and Basalt Fiber.

Loess has the characteristics of loose, large pore ratio, and strong water sensitivity. Once it encounters water, its structure is damaged easily and its strength is degraded, causing a degree of subgrade settlement. The water sensitivity of loess can be evaluated by permeability and disintegration tests. This study analyzes the effects of guar gum content, basalt fiber content, and basalt fiber length on the permeability and disintegration characteristics of solidified loess. The microstructure of loess was studied through scanning electron microscopy (SEM) testing, revealing the synergistic solidification mechanism of guar gum and basalt fibers. A permeability model was established through regression analysis with guar gum content, confining pressure, basalt fiber content, and length. The research results indicate that the addition of guar gum reduces the permeability of solidified loess, the addition of fiber improves the overall strength, and the addition of guar gum and basalt fiber improves the disintegration resistance. When the guar gum content is 1.00%, the permeability coefficient and disintegration rate of solidified soil are reduced by 50.50% and 94.10%, respectively. When the guar gum content is 1.00%, the basalt fiber length is 12 mm, and the fiber content is 1.00%, the permeability of the solidified soil decreases by 31.9%, and the disintegration rate is 4.80%. The permeability model has a good fitting effect and is suitable for predicting the permeability of loess reinforced with guar gum and basalt fiber composite. This research is of vital theoretical worth and great scientific significance for guidelines on practicing loess solidification engineering.

Mechanical Properties and Energy Damage Evolution Mechanism of Basalt Fiber-Modified Tailing Sand Cementation and Filling Body Mechanics

In order to investigate the mechanical properties of basalt fiber-doped tailing sand cemented filler and the evolution of energy damage, a uniaxial compression test was carried out on the basalt fiber-doped tailing sand cemented filler specimens to analyze the energy dissipation characteristics, and the damage constitutive equations with different basalt fiber contents were established based on damage mechanics. The results show that with the increase of fiber doping and fiber length, the uniaxial compressive strength and ductility of the filling body show a trend of increasing and then decreasing; the optimal value of fiber doping is 0.6%, and the optimal value of fiber length is 9 mm; the total strain energy, elastic strain energy and dissipation energy of basalt fiber-modified tailing sand cemented filling body at peak stress show a trend of increasing and then decreasing, and the energy dissipation energy of the filling body shows a trend of increasing and then decreasing. The energy dissipation energy shows a trend of increasing and then decreasing, and the energy dissipation energy shows a trend of increasing and then decreasing. The total strain energy, elastic strain energy, and dissipation energy at the peak stress show a trend of decreasing after increasing with the fiber doping and fiber length, and the energy damage evolution process can be divided into four stages: no damage stage, stable damage development stage, accelerated damage growth stage, and damage destruction; in addition, the existing damage constitutive model of the fiber-filled body was optimized, and the damage correction factor was introduced to obtain the damage constitutive model of the filled body with different fiber contents, and finally, after the verification of experimental and theoretical models, it was found that the two stress–strain curves coincided well. Finally, after the test and theoretical model verification, it is found that the stress–strain curves of the two are in good agreement, which indicates that the established theoretical model has a certain reference value for engineering practice, and at the same time, it has certain limitations.

Effects of basalt fibre and rubber particles on the mechanical properties and impact resistance of concrete

The application of waste rubber particles and basalt fibre (BF) in concrete can not only improve the performance of the resulting concrete but also alleviate the environmental pressures related to waste tire disposal. In this study, the impacts of rubber particles and BF on the mechanical and impact performance of concrete are experimentally investigated. Additionally, the macroscopic test phenomenon is explained based on the appearance of the microstructure. The results show that for basalt fibre-reinforced concrete (BFC), when the BF content increases from 0 to 0.4 %, the cube compressive strength and elastic modulus decrease from 71.5 MPa to 62.5 MPa and 44.5 GPa to 41.0 GPa, respectively, while the bending strength increases from 5.9 MPa to 6.6 MPa and then decreases to 6.3 MPa. A BF content of 0.3 % is selected to prepare basalt fibre-reinforced rubber concrete (BFRC). As the rubber particle content of BFRC increases from 0 to 20 %, the cube compressive strength, elastic modulus and bending strength decrease from 64.3 MPa to 51.5 MPa, 41.9 GPa to 33.5 GPa and 6.6 MPa to 5.9 MPa, respectively. However, the reduction rate of the mechanical properties of BFRC is approximately half that of fibre-free rubber concrete at the same rubber content. The shapes of the stressstrain curves of the BFC and normal concrete (NC) are similar, whereas the descending stage of the stressstrain curve of the BFRC is obviously gentler, and the whole BFRC stressstrain curve is much fuller, reflecting typical ductile failure. Both the BF and rubber particles contribute to impact performance improvement, but the effect of the rubber particles is much greater than that of the BF. Compared with that of the NC, the incorporation of 0.3 % BF increases the initial crack impact energy (W1) and final crack impact energy (W2) by 71 % and 79 %, respectively, but when 20 % rubber particles are additionally added, the increase rates of W1 and W2 reach 668 % and 686 %, respectively. The impact life evolutions of BFC and BFRC can be described effectively by a two-parameter Weibull distribution function.

Development and evaluation of fiber-enhanced RAP interlayer for HMA overlay treatment

To scientifically and efficiently utilize reclaimed asphalt pavement (RAP) generated during asphalt pavement maintenance, and to promote resource recycling and sustainable development, this paper developed and evaluated the Fiber-enhanced RAP interlayer for HMA overlay and preservation treatments. In this paper, RAP interlayer was designed based on the Response Surface Methodology (RSM) and the pull-out strength and the shear strength of were tested. Through double-objective optimization and analysis, the recommended proportions were determined as 2.22 kg/m2 of rubber asphalt, 10.57 kg/m2 of aggregate, and 30% RAP content. Subsequently, the effects of different basalt fiber contents on the pull-out strength, shear strength, flexural strength, fatigue life, and permeability coefficient of asphalt mixture with interlayer containing RAP were investigated. The results indicated a significant improvement in these properties with an 80 g/m2 basalt fiber content. The performance of asphalt mixture with Fiber-enhanced RAP interlayer was obviously superior to the asphalt mixture with interlayer without fiber and RAP. According to the test results of Digital Image Correlation (DIC), it was found that basalt fibers effectively reduce stress concentration, delaying the initiation and propagation of cracks.

Fatigue damage evolution of modified recycled aggregate concrete

Basalt fiber (BF) and nano-silica (NS) are used to improve the properties of recycled aggregate concrete (RAC) and produce modified RAC (MRAC). The fatigue failure patterns of the MRAC were observed through a uniaxial compression fatigue test, and the reasons for the different patterns were explained. The effects of the stress level, replacement rate, and loading frequency on the fatigue life were investigated, and the effects of BF and NS on the fatigue strain, damage evolution, and energy dissipation evolution of MRAC were analyzed. The enhancement mechanism of BF and NS on RAC was revealed using microstructural analysis techniques, such as scanning electron microscopy (SEM) and computed tomography (CT). The results showed that the fatigue failure modes of the MRAC could be divided into split, shear, and mixed failures. The fatigue life and fatigue strain of RAC exhibited a pattern of initially increasing and subsequently decreasing with an increase in the BF content (from 0 kg m−3 to 3 kg m−3 and then to 6 kg m−3). At stress level of 0.80, the average fatigue life of the specimens increased by 76.15 % compared to RAC when the BF doping was 3 kg m−3; however, when the BF doping was increased to 6 kg m−3, the average fatigue life of the specimens increased by only 47.68 % compared to RAC. The mixed BF and NS improved the fatigue life of RAC more than the single mixed BF or NS. Fatigue equations and unified single logarithmic fatigue equations, including fiber parameters, were established to accurately describe the relationship between the fatigue stress level, fatigue life, and failure probability. The fatigue strain gradually decreases with increasing NS content (0–2 %); with increasing loading frequency (from 1 Hz to 10 Hz and then to 15 Hz), the fatigue strain gradually decreases. The fatigue life of the MRAC decreased dramatically at low loading frequencies (1 Hz) and then steadily increased as the loading frequency increased. BF and NS have an improving effect on the porosity of microstructure, improve the fatigue life of RAC, and BF exhibits a more significant improvement than NS. A composite fatigue damage model that comprehensively considers the contribution rates of NS and BF was established, and the fatigue damage evolution of the MRAC was predicted.

Analysis of basalt fiber reinforcement on static shear properties of Beibu Gulf sea sand

Basalt fibers are a reinforcing material with excellent mechanical properties and durability. In contrast, although Beibu Gulf sea sand is widely in engineering, it exhibits low strength and poor stability, which can be improved by adding basalt fibers. In this study, the effects of fiber content, fiber length, and effective confining pressure on the static shear strength of fiber-reinforced sea sand were investigated using a triaxial shear test. The maximum improvement on the static shear characteristics and deformation resistance of sea sand were achieved for a fiber content and length of 0.8% and 12 mm, respectively. The cohesion and internal friction angle of sea sand were improved and the secant modulus and strain before and after basalt fiber reinforcement showed a nonlinear attenuation tendency. The reinforcement effect coefficient R and the basalt fiber content under different dosages were in accordance with the law of the Gaussian function. The value of R conformed to a linear growth and exponential function law under different fiber lengths and effective confining pressures, respectively. This study provides a solid theoretical basis for the sustainable utilization of sea sand resources and fiber reinforcement for road and coastal protection engineering in the Beibu Gulf region.

Grey modeling study on mechanical properties and pore structure of concrete with different basalt fiber contents based on NMR

This paper investigates the correlation between strength and pore characteristics of basalt fiber-reinforced concrete (BFRC) with different fiber contents and establishes a link between meso- and macro-properties. The research focuses on BFRC with differing fiber contents, analyzing compressive strength, flexural strength, and splitting tensile strength across eight admixture levels (ranging from 0 % to 0.35 %). Using the nuclear magnetic resonance (NMR) technique, T2 spectra of BFRC with varying fiber contents are obtained, deriving curves of the pore distribution. Additionally, considering the parameters of different pore size proportions, the paper delves into analyzing the impact of pore structure on BFRC's distinct mechanical properties using grey correlation. Utilizing the optimal pore structure parameters derived from GCA to forecast different strengths, this study establishes GM(1,3) prediction models for three strengths, respectively. The results showed that basalt fibers can enhance concrete strength. And, 0.25 % basalt fibers optimize concrete's the inner structure of BFRC by decreasing harmful pores. The comprehensive correlation between pore parameters and BFRC strength ranges significantly indicating a notable relationship between strength and pore alterations. The compressive strength was most related to the total porosity and the proportion of non-harmful pores, and the splitting tensile and flexural strengths were related to the fractal dimension and porosity of the harmful pores as well as to the total and non-harmful porosity, respectively. A BFRC strength prediction model formula was developed based on the most relevant pore structure parameters derived from GCA. This calculation formula showcases a high accuracy in predicting BFRC strength, establishing a mesoscopic-to-macroscopic quantitative relationship that effectively informs the production and application of BFRC.

Experimental Investigation on Partial Replacement of Cement by Fly ash with addition of Basalt Fibre and Coconut Coir

This study addresses the experimental investigation on basalt fibre fly ash concrete (BFFAC). The variables of study include the Basalt fibre content (0.25%, 0.3%, 0.35% and 0.4%) and coconut coir content is added 10%.The various percentage of Basalt fibre, Coconut coir and 30% of Fly ash as cement replacement are incorporated in all the concrete mix proportions considered in this study. The test results indicate that physical properties of materials such as sieve analysis, specific gravity and water absorption. The mix design is done for the grade of M30 concrete. The mechanical properties of concrete such as compressive strength, split tensile strength and flexural strength were obtained and the strength of control concrete and basalt fibre fly ash concrete was compared.

Experimental Investigation on Partial Replacement of Cement by Silica Fume and Fine Aggregate by Quarry Dust with Addition of Basalt Fibre

The main aim of this project is to found a suitable alternative for the natural river sand, which is reaching maximum level of scarcity. M-sand is used along with the addition of natural basalt fibres in to the concrete. In this study, the experimental investigation on basalt fibre silica fume concrete (BFSFC) was discussed. The variables of study include the Basalt fibre content (0.25%, 0.3%, 0.35% and 0.4%). The 30% of quarry dust as replacement for sand and 10% of Silica fume as cement replacement are incorporated in all the concrete mix proportions considered in this study. The test results indicate that physical properties of materials such as sieve analysis, specific gravity and water absorption. The mix design is done for the grade of M30 concrete. The mechanical properties of concrete such as compressive strength, split tensile strength and flexural strength will be obtained and the strength of control concrete and basalt fibre silica fume concrete will be compared.

Study on dynamic mechanical properties and microstructure of basalt fiber reinforced coral sand cement composite *

This study investigates the impact of basalt fiber on the static and dynamic compression of coral-sand cement-based composites, as well as the mechanisms for strengthening and toughening. The samples of basalt fiber-reinforced coral sand cementitious composite (BFRCSCC) with varying fiber volume fractions (0%, 0.2%, 0.4%, 0.6%, 0.8%) underwent quasi-static mechanical tests and impact dynamic tests using an MTS universal testing machine and a split Hopkinson pressure bar (SHPB). This study investigates the mechanical properties of BFRCSCC, focusing on static and dynamic compressive strength, dynamic stress-strain curve, strain rate effect, failure strain, toughness analysis, and energy dissipation mechanism. In terms of microstructure, specimens of BFRCSCC were tested using scanning electron microscopy (SEM). The results indicate that basalt fiber can significantly enhance the quasi-static compressive strength (fc)and dynamic compressive strength (fd)of coral sand cement-based composite materials. When the basalt fiber content is 0.4%, the static and dynamic compressive strength of BFRCSCC increases by 28.78% and 37.25% respectively compared to ordinary concrete. The analysis from a micro perspective indicates that the incorporation of basalt fiber in the concrete matrix enhances the hydration reaction between cement and the BFRCSCC interface. The spatial structure formed by basalt fiber contributes to the excellent toughening effect on the mechanical properties of BFRCSCC. As the content of basalt fiber increases (≤0.4%), the bridging effect becomes stronger. The dynamic increase factor (DIF) and toughness index of BFRCSCC exhibit a significant positive correlation with the strain rate effect. Basalt fibers can help drive the hydration products to fill the cracks or voids in the cement matrix, thereby increasing the material's density and enhancing the impact resistance of coral concrete. This can be utilized in practical engineering projects with high dynamic load demands.