Aggregate Concrete Specimens Research Articles

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.

Analysis of Impact Crushing Characteristics of Steel Fiber Reinforced Recycled Aggregate Concrete Based on Fractal Theory

The fractal theory can effectively describe the complexity and multi-scale of concrete under impact load and provide a scientific basis for evaluating concrete’s impact resistance. Therefore, based on the fractal theory, this study carried out the fragmentation size analysis by weighing the quality of SFRRAC fragments, disclosed the distribution characteristics of impact fragmentation size of steel fiber reinforced recycled aggregate concrete (SFRRAC) specimens under different recycled coarse aggregate (RCA) replacement ratio, different steel fiber (SF) contents and different impact pressures. The results indicate that the fractal dimension can describe the degree of fragmentation of the specimen. The greater the fractal dimension, the more the amount of fragmentation of the specimen subjected to impact load, the lesser the fragmentation size, and the greater the degree of fragmentation. Under the impact load, the fractal dimension of SFRRAC is between 1.36 and 2.28. As the impact pressure increases, the energy consumption increases, and the fractal dimension decreases. With the growth in replacement ratio, the fractal dimension gradually increases, and the energy consumption is negatively correlated with the fractal dimension. Along with the growth of SF content, the energy consumption gradually increases, and the fractal dimension continuously decreases. A new metric angle is provided to explore the inherent law between the impact-crushing characteristics of SFRRAC and the dynamic load, thereby offering foundational support for the application of SFRRAC in practical engineering.

Study on Sorptivity Test on Fly Ash Aggregate Concrete

Aggregate is most widely used in reinforced concrete construction. In this investigation, fly ash aggregates were used in concrete and its effect on durability of concrete was studied. The fly ash was collected from Mettur Thermal Power plant. Then the cement fly ash proportion of 10:90, 12.5:87.5, 15:85, 17.5:82.5, 20:80 and 22.5:77.5 were adopted to get fly ash aggregates. The Particle size distribution, Specific gravity and Water absorption tests on aggregates were conducted. M20 grade of concrete was considered. The fresh concrete tests like Slump test and Compacting factor test were conducted. For the plain concrete and fly ash aggregate concrete the cubes were cast. All the specimens were cured in a curing tank. The plain and fly ash aggregate concrete cube specimens were cast and tested at the age of 28days and 56days. Sorptivity and saturated water absorption tests were conducted on these plain and fly ash aggregate concrete specimens. The results were tabulated and compared by drawing graphs. Based on the results obtained, conclusions and suggestions were made.

Experimental Investigation on Ductility in Fly Ash Aggregate Concrete

Aggregate in concrete is structural filler, which occupies the most of the volume of the concrete The composition, shape and size of the aggregate have significant impact on the workability, durability, strength, weight and shrinkage of the concrete. In recent period some of the aggregates are chemically active and also that certain aggregates exhibit chemical bond at the interface of aggregate and paste. Aggregate occupy 60-80% of the volume of concrete is considerable. The utilization of fly ash in concrete as partial replacement of cement is gaining immense importance today, mainly on account of the improvement in the long term durability of concrete combined with ecological benefits. Three grades of ordinary Portland cement (OPC) are 33,43 and 53 as classified by Bureau of Indian Standard (BIS) are commonly used in construction industry. The main variable investigated in this study is variation of fly ash dosage in 10%, 20%, 30% and 40%. The compressive strength, durability and shrinkage of concrete were mainly studied. The fly ash is collected in Mettur Thermal Power Plant. Then the cement and fly ash proportions of 12.5:87.5, 15:85 and 17.5:82.5 will be adopted to get fly ash aggregates. The particle size distribution, specific gravity, bulk density, impact test on aggregate will be conducted. For the plain concrete and fly ash aggregate concrete of beams (Plain concrete and RCC beams), cubes and cylinders will be cast. All the specimens will be cured in a curing tank. The Ductility test and compressive strength test will be conducted on these plain and fly ash aggregate concrete specimens.

Bond performance of recycled coarse aggregate concrete with rebar under freeze–thaw environment: A review

Abstract In this article, a review focusing on the frost resistance of recycled coarse aggregate concrete (RAC) and the bond performance of RAC with rebar under freeze–thaw environment is carried out. The results show that there are still some controversies about the advantages and disadvantages of the frost resistance of RAC, and many influencing factors have not been considered. The mass of the RAC pullout specimens shows a trend of first increasing and then decreasing after freeze‒thaw cycles. The failure modes of the RAC pullout specimens after freeze‒thaw cycles include pullout failure, pullout-splitting failure, splitting failure, and rebar yielding failure. The bond performance of RAC with rebar shows a degradation trend after freeze‒thaw cycles, mainly in the decrease in bond strength and the increase in bond slip. The bond performance of RAC specimens is inferior to that of natural aggregate concrete specimens after freeze‒thaw cycles. The bond strength prediction models and the bond–slip constitutive relation prediction models of RAC with rebar after freeze‒thaw cycles have been summarized to ensure that engineers can better understand their applicability. The bond stress distribution between the RAC and rebar in the anchoring area is not uniform and constantly changes with the number of freeze‒thaw cycles. The degradation mechanism of the bond performance of RAC with rebar after freeze‒thaw cycles is analyzed.

Experimental study on mechanical properties of recycled aggregate concrete with polypropylene fiber under combined compression‐shear loading

AbstractTo investigate the mechanical properties of polypropylene fiber recycled aggregate concrete (PPFRAC) under compression‐shear, 69 recycled aggregate concrete (RAC) specimens were tested with the parameters of polypropylene (PP) fiber volume content (0, 0.6, 0.9, and 1.2 kg/m3), recycled coarse aggregate (RCA) replacement rate (0%, 30%, 50%, 70%, and 100%), and normal stress (0, 3, and 6 MPa). In the tests, the failure pattern of the specimens was observed, and the effects of the polypropylene fiber content on the direct shear stress, compression‐shear stress, initial shear stiffness, and shear ductility coefficient of the PPFRAC were thoroughly investigated. The results show that as the polypropylene fiber content increases, the direct shear stress of concrete (Natural aggregate concrete and 100% recycled coarse aggregate concrete [100%RCA]) first increases and then decreases gradually. Meanwhile, the best PP fiber content is 0.9 kg/m3 in this study. Furthermore, the compression‐shear stress‐displacement curves of specimens were obtained. The compression‐shear strength under normal stress at 6 MPa is approximately 230% greater than at 0 MPa. However, the peak shear stress of concrete is almost not affected by the replacement rate of RCA. Finally, based on the Mohr circle theory, the compression‐shear calculation model of PPFRAC is verified, and the optimal calculation formula is given.

Design, implementation and performance prediction of profiled steel sheet-mixed aggregate recycled concrete hollow composite slab

Profiled steel sheet-mixed aggregate recycled concrete composite slabs are widely studied and applied in engineering applications by virtue of their good durability and recyclability. As an alternative to concrete composite slabs, concrete hollow composite slabs that can reduce their self-weight are also attracting people’s attention. However, the internal holes will increase the risk of collapse and shear failure of the concrete composite slabs. In order to reduce the risk and ensure the flexural performance of the concrete hollow composite slabs, this paper designs the recycled concrete hollow composite slabs with PVC pipes. A full-scale experiment is carried out on five open-mouth profiled steel sheet-mixed aggregate recycled concrete hollow composite slab specimens, to explore the influence of whether the bottom of the plate is reinforced, the thickness of the concrete surface layer and the hollow size on the working performance of the composite slabs. In order to predict the mechanical performance of the proposed hollow composite slabs, a prediction model based on artificial neural network (ANN) consisting of several sub-ANN modules is established. Moreover, according to the priority of the factors affecting the mechanical performance of composite slabs, a decision tree is designed to select appropriate testing sub-ANN module and thus improve the testing accuracy. Predicted results and experimental results are given to validate the feasibility and effectiveness of the developed ANN-based prediction framework for the mechanical performance prediction of composite slabs.

A unified calculation method for temperatures of recycled aggregate concrete members exposed to fire: tests and numerical study

The utilisation of recycled aggregate in reinforced concrete structures can effectively reduce demolition waste and overcome the deficiency of natural aggregate. Because the thermal conductivity of recycled aggregate concrete differs from natural concrete, its temperature developments should be studied particularly to accurately predict the fire resistance of those members exposed to fire. However, few studies have been performed on the heat transfers of recycled aggregate concrete (RAC) members, especially for fine recycled aggregate concrete members. Therefore, an experimental and numerical study was conducted on the heat transfer in coarse and fine RAC members. Eighteen recycled aggregate concrete specimens were tested, among which the influences of aggregate replacement ratios (0, 50%, and 100%), aggregate types (coarse recycled aggregate, fine recycled aggregate) and dimensions of heat transfer (one-dimensional (1-D), two-dimensional (2-D)) were carefully investigated. Finite element models of concrete members were then developed using the program COMSOL Multiphysics and verified against the test results. Parametric studies were conducted to identify their influences on temperature distributions and developments. Finally, a unified simplified method was proposed for the cross-section temperatures of those coarse and fine RAC concrete members featuring 1-D and 2-D heat transferring (e.g. slabs, walls, beams and columns).

Longitudinal shear tests and design methods for corrugated steel–concrete composite slabs with recycled coarse aggregate

This study aims to investigate the effects of natural coarse aggregate (NCA) replacement ratio and end anchorage conditions on the longitudinal shear performance of corrugated steel-recycled aggregate concrete (CSRAC) composite slabs. Six composite slab specimens were tested to determine their failure mode, bearing capacity, and deformation behavior. A finite element model of CSRAC composite slabs was established using ABAQUS, and its reliability was validated based on the experimental results. A parametric analysis was conducted to determine the effects of each key parameter on the longitudinal shear performance of CSRAC composite slabs. A design method for the longitudinal shear capacity of CSRAC composite slabs was proposed, taking into account the NCA replacement ratio. The experimental results revealed that the incorporation of end anchorages can significantly improve the longitudinal shear performance of CSRAC composite slabs, resulting in an increase of 45.06% and 62.34% in ultimate bearing capacity for specimens with NCA replacement ratios of 50% and 100%, respectively, when compared to those without end anchorages. As the NCA replacement ratio increases, the longitudinal shear capacity of CSRAC composite slabs decreases. The reduction in longitudinal shear capacity was found to be 2.75%-4.98% and 5.55%-10.02% for specimens with 50% and 100% NCA replacement ratios, respectively, when compared to natural aggregate concrete (NAC) specimens. The NCA replacement ratio is a significant parameter that affects the longitudinal shear performance of CSRAC composite slabs and the proposed design method based on the m-k method for the longitudinal shear capacity of composite slabs can accurately predict the longitudinal shear capacity of CSRAC composite slabs by considering the NCA replacement ratio.

Axial stress–strain behaviour of bamboo composite tube-confined recycled aggregate concrete with different aggregate replacement ratios

ABSTRACT As an eco-friendly material, recycled aggregate concrete (RAC) has lower strength than natural aggregate concrete. To improve the compressive behaviour of RAC, a bamboo composite tube (BCT) is selected as the confining jacket. A total of 60 specimens were tested, which included 45 bamboo composite tube-confined recycled aggregate concrete (BTRAC) specimens and 15 unconfined RAC specimens. To investigate the influence of the replacement ratio of the recycled aggregate and thickness of BCT, a series of analysis were conducted on the failure modes, stress–strain response, dilation behaviour and effect of the replacement ratio. Test results showed that the axial stress–strain curves of the BTRAC specimens were approximately bilinear. The confinement ratio was found as the primary factor affecting the mechanical properties of the BTRAC column. Owing to a greater confinement stiffness in a thicker BCT, the slope of the second stage in the stress–strain curves increased correspondingly. Although the change in replacement ratio of recycle aggregate resulted in different dilation behaviours, the influence was regarded as limited on the BCT confinement effectiveness. Moreover, the ultimate stress, the ultimate strain, and the axial stress–axial strain curves of BTRAC specimens were calculated by the relevant models for FRP-confined concrete to evaluate their applicability.

Mechanical behavior of steel fiber reinforced recycled aggregate concrete under dynamic triaxial compression

An experimental study of cylindrical steel fiber reinforced recycled aggregate concrete (SFRAC) specimens subjected to hydrostatic pressure and dynamic axial loading in a triaxial cell was performed. A confining stress range of 0–40 MPa and strain rate from 10−5 s−1 to 10−2 s−1 were employed using a servo-hydraulic testing system. In addition, two other control variables – volume fraction of steel fiber and replacement ratio of recycled coarse aggregate were also considered. A series of complete stress-strain curves were obtained, and the results were discussed in the aspects of the failure modes, peak triaxial strength, toughness, octahedral stress and failure criterion. The results indicated that an increase in the confining pressure resulted in a change in the failure modes, a significant increase in the peak strength and ductility. In particular, with an increase in confining pressure, the enhancement of strain rate on the peak strength decreased, indicating that there was a coupling effect between these two. The steel fibers had little influence on the failure modes of SFRAC, but significantly improved its ductility and toughness. The addition of recycled coarse aggregates markedly reduced the peak strength and the reduction reached nearly 20%, which was larger than other reports in uniaxial and true triaxial loading. Finally, a failure criterion for SFRAC specimens subjected to dynamic loading was used for validating the experimental results.

Bond-slip Behaviour of NSM GFRP Bars in Reinforced Recycled-Aggregate Concrete: Experiments and a Modified Model

Bond-slip behaviour of glass fiber-reinforced polymer (GFRP) bars embedded in conventional concrete has been widely investigated. In contrast, the bond-slip behaviour of near-surface mounted (NSM) GFRP bars bonded in reinforced recycled aggregate concrete (RAC) seems to be less explored, while recycled materials have been increasingly used due to reasons of environmental pollution and resource exhaustion. This study aimed to experimentally and theoretically examine the bond-slip behaviour of NSM GFRP bars in reinforced RAC under monotonic and cyclic loadings. To achieve this aim, twenty-four tests were performed, which were divided into two groups by monotonic and cyclic loadings. In each group, twelve tests were performed on ten reinforced RAC specimens and two reinforced normal aggregate concrete (NAC) specimens. The test results confirmed the brittle shear failure of concrete in the proximity of a resin-concrete surface. Bond-slip behaviour can be characterized by nonlinear and linear branches, in which the linear branch dominates the behaviour. Under monotonic and cyclic loadings, the average slips of GFRP bars in reinforced RAC were 0.238 and 0.284 mm, and their coefficients of variation (COV) were relatively large at 0.142 and 0.130, respectively. In contrast, ultimate loads had a relatively low COV of around 0.038. The effect of cyclic loading significantly increased the ultimate slip by 19.3%, whereas it negligibly reduced the ultimate load; consequently, the stiffness was reduced by 19.4%. A modified smooth model was proposed to predict the bond-slip behaviour of NSM GFRP bars in reinforced RAC under monotonic and cyclic loadings. The simplicity and accuracy of the model can be useful for engineers in structural retrofitting using NSM FRP technique. Doi: 10.28991/CEJ-2023-09-02-01 Full Text: PDF

Investigation on the strength of expanded clay aggregate concrete specimens after thermal exposure

The article describes the results of a laboratory study of the properties of expanded clay blocks. Expanded clay concrete modular blocks are used to install chimney stacks. The research aims to determine how the physical-mechanical properties of the material change when they are exposed to high temperatures. The question is raised about how much the strength of the structural material can decrease if it is exposed to higher temperatures. To broader and more objectively determine the material properties, materials with different fillers were chosen for the sample blocks. 24 expanded clay concrete blocks were formed for the study. The samples were hardened under uniform conditions in the laboratory. After the anticipated hardening time, the weight of the samples was determined, and they were weighed again after thermal exposure. Having adjusted the mass of expanded clay samples, their compressive strength properties were investigated. The research was carried out in the KUT Building Materials Laboratory following the requirements for compressive strength established in the normative documents. After comparing the changes in the weight of expanded clay concrete sample blocks before and after thermal effects, the obtained results showed that the weight of the samples with coarse expanded clay filler and fibre decreased significantly after temperature exposure at 105 °C. After exposure of the same samples to temperatures of 300 °C and 600 °C, their mass decreased even more. Before performing the compressive strength test of expanded clay concrete samples, all sample cubes were numbered and divided into three groups after thermal exposure. To compare the research results, control samples were separated from each group of foamed cubes with different fillings. The results of the compressive strength of the control samples were compared with the results of the thermally affected samples. The research revealed that the samples with fine-grained filler retained the highest strength after exposure to high temperatures, while the strength results of all other samples with coarse filler and coarse filler with fibre were low. The comparison of the results of the compressive strength of expanded clay concrete samples with coarse fillers suggests that the samples with fibre remained stronger after exposure to high temperature (600 °C) than the samples without additives. To sum up the results of the laboratory test of expanded clay concrete samples, it can be assumed that their strength may decrease by up to 38 per cent when exposed to expanded clay concrete at high temperatures for a longer period.

The size of portlandite crystals in ITZ and its relation with ratios of ingredients and properties of LWAC

In this experimental study, nine different lightweight aggregate concrete (LWAC) specimens - in which natural lightweight scoria aggregate was used as coarse aggregate - were prepared for investigating the size of portlandite crystals in their interfacial transition zone (ITZ). Scanning Electron Microscope (SEM) was used to determine the size of portlandite crystals in ITZ of LWAC specimens. The size of portlandite crystals in ITZ of these LWAC specimens was determined quantitatively in order to identify its relation with ratios of ingredients and properties of LWAC that were investigated. It was determined that the size of portlandite crystals in ITZ of nine LWAC specimens is in the range of (0.91-2.047) µm. The size of portlandite crystals in ITZ is found to be increased when the water/cement (W/C) and coarse aggregate/total aggregate (Ac/A) ratios of LWAC get increased. On the other hand, the compressive strength and the oven-dry density of LWAC are found to be decreased when the size of portlandite crystals in ITZ gets increased. The best way to make portlandite beneficial from mechanical, physical and durability points of view is to transform it into so-called secondary hydration products by making it react with materials that have proper chemical properties for this transformation. In this case, the small portlandite crystals dissolve entirely, and the large portlandite crystals become smaller. Lightweight scoria aggregate used in this study is thought to have chemical properties to assist such a transformation in ITZ.

Effect of Steel Inorganic Fiber on Mechanical Properties of Lightweight Aggregate Concrete

In order to study the influence of steel-inorganic fiber on the mechanical properties of lightweight aggregate concrete, test parameters including single ceramic fiber and basalt fiber with different dosage and mixed steel-basalt fiber and steel-ceramic fiber reinforced lightweight aggregate concrete specimens with different doping methods were designed, and compared with the non-fiber reference group. The test results show that the compressive strength of cube is improved most obviously by steel-basalt fiber, with the maximum increase of 14.5%. Adding 1.35kg/m3 basalt fiber can increase the flexural strength of lightweight aggregate concrete by 62.2%. Adding ceramic fiber reduces the compressive strength of lightweight aggregate concrete, but improves the flexural strength.

Bond behavior of recycled coarse aggregate concrete with rebar after freeze–thaw cycles: Finite element nonlinear analysis

Abstract In this article, the bond performance of recycled coarse aggregate concrete with rebar after freeze–thaw cycles is analyzed by the ABAQUS finite element method. The result shows that the finite element simulation value of the ultimate bond strength of recycled aggregate concrete specimens is in good agreement with the experimental value, while the agreement between the finite element simulation value of the peak bond slip of recycled aggregate concrete specimens and the experimental value is low; the bond strength between rebar and recycled aggregate concrete increased with the increase of concrete strength and concrete cover depth; the calculation formula for the bond strength between recycled aggregate concrete specimens with different concrete strengths and different concrete cover depth after freeze and thaw cycles are obtained.

Influence of Unidirectional Cyclic Loading on Bond between Steel Bars Embedded in Lightweight Aggregate Concrete

The topic of present research is the experimental investigation of pull-out resistance of B500B-type ribbed reinforcing steel bars embedded in lightweight aggregate concrete (LWAC) under unidirectional cyclic loading. Only a limited amount of standardized data on bond strengths are available in the case of cyclic loading, especially for lightweight aggregate concrete. This paper deals with the experimental comparison of bond behavior of steel bars embedded in LWAC with expanded clay (Liapor) aggregate and normal weight aggregate concrete (NWAC) specimens by means of standard (non-cyclic) and cyclic pull-out tests. The LWAC and NWAC specimen’s mixes were identical except for the type of the coarse aggregate. It was found that the bond strength determined by non-cyclic pull-out tests showed a higher standard deviation compared to that for compression and splitting tensile strength tests. The shape of the characteristic bond strength–the slip curve was similar in the case of LWAC and NWAC and the failure mode was the same for both types of aggregate. Moreover, the maximum value of bond stress was identical for LWAC and NWAC and also no significant difference was found in the low cycle number fatigue. Both mixes were able to resist the maximum pull-out force multiple times in the case of cyclic loading because there was no time for the development of cracks.

Determination method and prediction model of fracture and strength of recycled aggregate concrete at different curing ages

Considering the effect of recycled coarse aggregate on the fracture of recycled aggregate concrete (RAC) specimens with limited size, the concept of relative size that applied to RAC is proposed, and a simplified calculation equation of the fictitious crack growth length of RAC at different curing ages under peak load is quantitatively determined. Fracture models able to simultaneously determine the tensile strength and fracture toughness of RAC at different curing ages are developed. Based on the proposed model, experimental data of RAC specimens of different curing ages are analysed, and the determined tensile strength and fracture toughness values are basically consistent with the experimental and determined values of size effect. Moreover, according to the normal distribution, the dispersion of the experimental data is analysed and the full failure curve of RAC at different curing ages is constructed. A linear relationship between peak load and fracture parameters is established, which can predict the peak load of large-scale structures.

Coefficient of Thermal Expansion of Concrete Produced with Recycled Concrete Aggregates

This study presents a comparison between the coefficient of thermal expansion (CTE) of concrete produced with natural aggregate and that of concrete produced with recycled concrete aggregate. In order to achieve this, natural aggregate concrete (NAC) specimens were produced, tested, then crushed and sieved in the laboratory to obtain recycled concrete aggregates, which was then used in the production of recycled aggregate concrete (RAC) specimens. The RAC samples were then tested and compared to the NAC samples. The CTE testing was carried out using a AFTC2 CTE measurement system produced by Pine Instrument Company. In addition to CTE testing, the water absorption, specific gravity, and unit weight of the aggregates was determined. A vacuum impregnation procedure was used for the water absorption test. The recycled aggregate properties showed a significantly higher absorption capacity than that of the natural aggregates, while the unit weight and specific gravity of the recycled aggregate were lower than that of the natural aggregates. The average CTE results showed that both the NAC and the RAC samples expanded similarly. The results show that the CTE of RAC depends on the natural aggregate used in the NAC, which was recycled to produce the RAC. Also, there was no significant difference between the average CTE values of the RAC and that of NAC that could discredit the use of recycled aggregate in concrete.

Experimental research on the mechanical properties of steel fiber recycled aggregate concrete subjected to true triaxial compression

This paper presents an experimental research on the triaxial behavior of 270 steel fiber recycled aggregate concrete (SFRAC) specimens under true triaxial compression (σ1≠σ2≠σ3). By using a servo-hydraulic closed loop testing system, triaxial loading experiments were conducted considering three variables - the volume fraction of steel fiber (Vf), the replacement ratio of recycled coarse aggregate (RAR), and the stress ratio (α). The influences of these parameters on the failure modes, the stress–strain curves and the peak triaxial strength are analyzed. The experimental results indicated: (i) the stress ratio had the most significant effect on the failure mode of SFRAC specimens, where four modes were observed; (ii) the peak triaxial strength of specimens was sensitive to Vf, and a value between 0.6% and 1.2% was found to be optimum; (iii) the minimum stress ratio σ1/σ3 and the second stress ratio σ2/σ3 exhibited opposite effects on the peak triaxial strength of specimens, while RAR showed the least effect. Finally, a three-parameter failure criterion for SFRAC under true triaxial compression was proposed. The experimental results will provide SFRAC triaxial mechanical behavior for future engineering design and applications.