جستجوی مقالات مرتبط با کلیدواژه « الیاف فولادی » در نشریات گروه « عمران »

In the present study, the mechanical properties of heavy weight geopolymer concrete reinforced with steel fibers including compressive and splitting tensile strength were investigated. In addition, fracture parameters were also investigated according to WF and SE methods. In this research, first, a sample containing natural aggregates without fibers was tested. Then, an example in which heavy recycled aggregates were considered as a complete substitute for natural aggregates. Then, steel fibers were added to the same sample in volume fractions of 0.5, 0.75, 1, 1.25 and 1.5% and its effects were investigated. The results obtained from the tests showed that the addition of steel fibers with any volume fraction led to an increase in indirect compressive and tensile strengths. The results showed that the fracture energy (GF) obtained by the fracture mechanics method (WFM) in the sample with steel fibers with 1.5 percent is higher than the control sample. However, increasing the percentage of steel fibers has led to an increase in fracture energy. Examining Cf values showed that in samples with 0.5% and 0.75% steel fibers, its value is lower than the control sample and in other samples it is higher than the control sample. However, increasing the percentage of steel fibers has steadily led to an increase in Cf. The GF/Gf ratio for different designs in this research was between 0.81 and 1.14.

In this article, the ground granulated blast furnace slag and red mud, which are the waste products of iron and aluminum factories, were used as aluminosilicate base materials in the mix design of geopolymer repair mortar. The activation of base materials was done with a combination of sodium hydroxide solution (soda) and sodium silicate (water glass).The effect of steel fibers on compressive strength, toughness and drying shrinkage of mortar was investigated. Fiber mortars were used as a repair layer to retrofit brick beams. The results showed that the use of steel fibers in geopolymer mortar can effectively improve compressive strength and toughness, reduce drying shrinkage, and change the brittle fracture behavior of brick beams to a ductile behavior. The results of SEM-EDS test and measurement of Si/Al molar ratio indicated the existence of a three-dimensional and chained structure of geopolymer in the mortar microstructure. The conducted research is an effective and forward step in achieving geopolymeric products with an environmental and economic approach.

Concrete is one of the widely consumed building materials in the construction industry, Among the specifications of the concrete which have been paid attention to by the researchers are compressive strength and tensile strength. So, to attain this goal, in the recent years, using a less ratio of water to cement with superplasticizers and natural and or synthetic pozzolans and also with fibers of different materials and specifications in the concrete mixture is a normal method. In this research, the effect of the combined use of fibre microgels and steel fibres on the mechanical properties and durability of concrete has been studied in a laboratory. Fiber microgels include micro-silica (silica fume), polypropylene fibers (pp fibers) and superplasticizers. Consumable steel fibers are 5 cm long and 0.8 mm in diameter with a hooked end. The effect of microgels and steel fibers were each compared and evaluated in five ratios of fibrous microgels 0, 0.5, 1, 2, 5% and steel fibers in ratios of 0, 05, 1, 1.5, 2%. A total of 25 mixing designs were tested for compressive and flexural strength to evaluate mechanical properties. The results of compressive and bending strength tests have shown that by adding different percentages of fibers, the percentage of increase in compressive strength in most of the 7-day samples has improved more than the 28-day samples. The highest resistance growth was related to the samples containing 5% fibrous microgel and 2% steel fibers.

The use of roller-compacted concrete in construction projects, such as road paving, parking lots, dam construction, and industrial pavement, is attributed to its quick implementation, relatively low cost, and sufficient strength without the need for steel bar. However, the brittle nature of roller-compacted concrete prompted an investigation into how steel fibers could improve its mechanical behavior. This research focused on the effect of steel fibers on fracture strength, compressive strength, and tensile strength of roller-compacted concrete. The study involved testing semicircular samples with edge cracks under three-point bending loading to simulate pure tension, pure shear, and their combination. Additionally, the compressive and tensile strength of roller-compacted concrete samples with steel fibers were evaluated at 7 and 28 days. The laboratory results showed that adding 0.1%, 0.3%, and 0.5% steel fibers improved the 28-day compressive strength by 12%, 15%, and 36%, respectively, and the tensile strength by 14%, 21%, and 39%, respectively. Moreover, the failure load of all samples increased in all loading modes with higher percentages of steel fibers, leading to greater resistance to crack growth. The study identified 0.3% of steel fibers as the most effective amount for improving the fracture resistance of roller-compacted concrete in different loading modes, while the optimal percentage for enhancing the compressive and tensile strength was determined to be 0.5%.

Considering the high consumption of concrete, especially in structures, and the increasing need for cement production, it seems necessary to pay attention to the harmful environmental effects of this material. In the construction industry, to solve this problem, alternative adhesives are used in concrete, and geopolymers are one of these alternatives. Making geopolymer concretes based on slag can be one of the ways to produce environmentally friendly materials that reduce the harmful effects of cement production. Also, using lightweight concrete has valuable advantages, such as reducing the structure's dead load, and combining geopolymer with lightweight concrete can be beneficial. In this research, two series of lightweight geopolymer concrete have been used. In the first series, by keeping geopolymer ratios constant (Al/Bi=0.65, SS/SH=1 and sodium hydroxide concentration 2 M), Geopolymer concretes with different percentages (50, 60, 70, 80, 90, and 100) of scoria were made instead of coarse aggregate. Then, the designs with structural conditions (compressive strength above 17 MPa and specific weight below 2000 Kg/m3) were selected by comparing the samples' specific weight and compressive strength. In the second series of making lightweight geopolymer concretes by adding steel fibers (0.5, 1, and 1.5%), polypropylene fibers (0.1%), and hybrid, the mechanical characteristics of the samples were evaluated. By examining the compressive strength test, as expected, the compressive strength of the light geopolymer samples increases with the increase in the percentage of steel fibers. Also, samples containing 0.1% of polypropylene fibers face decreased compressive strength. When combined with steel fibers with percentages (0.5, 1, and 1.5), this decrease in compressive strength will be increased. By checking the compressive strength and specific weight, the samples containing 70, 80, and 90% scoria has structural conditions.  By examining the tensile strength test, it can be concluded that adding steel and polypropylene fibers both increase the tensile strength can be seen. In the flexural strength test, flexural strength increases with an increase in the percentage of steel fibers.  It can also be seen that the effect of steel fibers is more significant than polypropylene fibers in increasing the bending strength. An ultrasonic pulse speed test determines the quality of manufactured concrete. According to the observed results, it can be concluded that with the increase in the percentage of fibers (steel and polypropylene), the speed of the ultrasonic pulse also increases. The samples of 70% scoria-containing steel fibers are of excellent quality; this indicates that this design has a better quality geopolymer paste than other samples. Also, the geopolymer concrete sample containing 90% scoria has the lowest value of ultrasonic pulse speed. This reduction can be attributed to many voids in the scoria aggregate. The modulus of elasticity test results showed that the samples containing steel fibers were far more than the other samples, and the most significant increase was seen in steel fibers with a percentage of 1.5. Finally, by examining the microstructure of fiber geopolymer lightweight concrete using scanning electron microscope (SEM) images, it can be seen that the geopolymer sample without fibers contains voids, which are filled to a large extent when steel and polypropylene fibers are added.

The use of fibers is often aimed at increasing the ductility and load-bearing capacity of the desired concrete, and controlling the spread of cracks by adding fibers to the concrete causes this. The fibers improve the behavior of the concrete after the first crack due to the bridging property on the micro-cracks. In this paper, 15 concrete mixing designs in the form of 90 cubic specimens with dimensions (15 * 15 * 15) cm for the compressive strength test and 42 specimens with dimensions (15 * 15 * 60) cm for the flexural strength test have been made. Three mixing designs were made as a reference with 3 water-to -cement ratios (0.24, 0.29, 0.34) without fibers and with fibers with 3 different lengths of polypropylene fibers with lengths of (6, 12, 18) mm, respectively. A mixing scheme with 40 mm long hook metal fibers and another mixing scheme with a combination of 40 mm hooked metal fibers and 12 mm polypropylene fibers were investigated. Microsilica gel and super-lubricant were used to increase the smoothness and efficiency of concrete. The highest average compressive strength of 28 days was related to samples with composite fibers with a resistance of 72.52 MPa, which was 12.9% higher than the reference sample. The concrete sample with metal fibers with an average bending strength of 12.85 MPa has the highest strength among all the concrete mixing designs of this research and shows a 60% increase in bending strength compared to the sample without fibers. In the concrete samples tested with polypropylene fibers, after the compressive strength test, with the increase in the length of the polypropylene fibers, the workability and compressive strength of the concrete decreased, but the plasticity of the concrete samples increased. After the flexural strength test, the flexural strength and ductility of the concrete samples increased with the increase in the length of the polypropylene fibers, but it led to a decrease in the workability of the concrete.

By adding fibers as well as additional materials in concrete, the properties of concrete can be increased in terms of durability, flexibility and tensile strength. Another use of artificial fibers to improve mechanical properties and reduce shrinkage of fresh and hardened concrete, increase energy absorption and resistance to impact and explosion can be mentioned. The use of fiber concrete has many advantages compared to the use of reinforced concrete, while it also has disadvantages, such as the lack of uniform distribution of fibers in the concrete matrix and the lack of proper adhesion between polymer fibers in cement mortar. Generally, fiber concrete is used in concrete parts due to smaller cracks and less width and more durability in case of uniform distribution of fibers. Research shows that fibers significantly increase the tensile strength, plasticity of mortar and concrete. In fact, after cracking, the fibers bridge between the crack plates and cause a significant increase in toughness and energy absorption capacity. Adding artificial fibers to concrete brings advantages such as reducing plastic grip cracks, reducing plastic drop cracks, increasing impact resistance and increasing resistance to crushing. In this research, the effect of different types of fibers with different volume percentages on the compressive, bending and tensile strength of the samples at different ages compared to the control sample has been measured by laboratory method. All kinds of samples have been tested to determine the resistance against surface explosions.

Concrete is the most used construction material in the world. Today, there are various concretes with different applications in the industry. One of the types of concrete is fiber concrete. In this study, several concrete samples were made with steel, glass and polypropylene fibers and the effect of the volume and weight percentages of each of the fibers in improving the compressive strength of the samples at temperatures Different has been checked. In order to check the results and the possibility of comparing it with the behavior of normal concrete, a type of concrete without fibers was also made using common materials and similar tests were performed on it. Based on the investigations, the results showed that the concrete samples with steel fibers tolerated higher temperature levels and had higher resistance compared to other samples. In the samples, by adding 0.25% and 0.5% by volume of steel fibers to concrete, respectively, the compressive strength of the sample at high temperatures was improved. The strength of concrete samples with 3400 Kg/m was slightly decreased by increasing the percentage of fibers from 0.5% to 0.75%. The compressive strength of concrete containing steel fibers is 20% higher than that of concrete containing propylene fibers.

The flexural performance of steel fiber reinforced concrete (SFRC) is significantly influenced by fiber properties such as fiber quality, shape, aspect ratio, orientation, and distribution. Digital image processing is an optical and non-contact measurement method that can determine the extent of sample size and deformation under any loading conditions. In this paper, eight reinforced concrete beams with and without steel fibers were selected, including four separate groups containing different volumetric percentages of steel fibers, designed and loaded with four-point bending test in accordance with the rules of ACI 318-19 design regulations. The first group consisted of two ordinary concrete beams as reference samples and six other concrete beams reinforced with steel fiber with a percentage of 0.5, 1.0, and 1.5%. Different longitudinal reinforcements (one state of minimum reinforcement and one state of maximum reinforcement in accordance with the provisions of the design regulations) were examined and analyzed in these specimens. Strain gauges were installed on the longitudinal bars to measure the strain during the loading process. Experimental results showed that the loads, flexural strength, ductility, and energy absorption of fiber-reinforced concrete beams were improved compared to similar conventional concrete beams. The highest ductility ratio among the samples made with tensile reinforcement was observed in the beam with a minimum longitudinal bar and 1.0% of fibers. The ductility of this sample was 30% higher than the similar non-fibrous sample with minimum longitudinal tensile reinforcement. The results showed that the ratio of ductility of the sample with maximum tensile reinforcement was decreased up to 46% compared to the companion beam with minimum tensile reinforcement. Significant increases in flexural strength, equal to 16, 23, and 29%, respectively, were observed in beams with minimum tensile reinforcement and containing steel fibers 0.5, 1.0, and 1.5%.

Nowadays, the need to move towards sustainable development emphasizes the need to investigate the behavior of environmentally friendly concrete. So far, several studies have investigated the mechanical properties of this type of concrete, but their impact properties have rarely been investigated. In this research, impact performance of environmentally friendly fiber reinforced concrete was investigated under drop weight impact, according to the method proposed by ACI C544. In order to achieve environmentally friendly concrete, natural aggregates (NA) was replaced by recycled concrete aggregate (RCA) with amounts of 0, 50, and 100%, and ordinary Portland cement (OPC) was replaced by ground granulated blast furnace slag (GGBFS) with amounts of 0, 15, and 30%. Moreover, specimens made in this study were reinforced by 0, 0.5, and 1% hooked-end steel fibers. The results of this test include the number of impacts to create the first visible crack, the number of impacts to create ultimate destruction, and impact energy absorption. The results of investigations showed a 20.1% and 3.6% reduction in ultimate impact resistance due to the use of 100% RCA and 30% GGBFS, respectively, while the addition of 1% steel fibers increased this parameter by 8 times. Finally, statistical analysis on the results of impact tests showed that two-parameter Weibull distribution is a suitable statistical distribution for the statistical investigation of the impact resistance of concrete containing RCA and GGBFS.

In recent years, a new type of fiber-reinforced concrete, consisting of several different types of fibers, known as hybrid fibers reinforced concrete, has attracted the attention of researchers. The aim of this paper for experimental evaluation of the effect of replacement ratio of recycled aggregates with natural aggregates on the mechanical properties of reinforced concrete with hybrid fibers (steel and polypropylene fibers). To this end, reinforced concrete with hybrid fibers with volume fractions of "0.0%" , "0.5%" , and "1%" of steel fibers and "0.0%" and "0.4%" of polypropylene fibers and replacement ratios of "0.0%" , "25%" , and "50%" recycled coarse aggregate of natural coarse aggregates were tested for compressive strength, Brazilian tensile strength, and flexural strength by four-point bending tests. The results show that increasing the replacement ratio of recycled aggregate leads to a decrease in compressive, tensile, and flexural strength. If polypropylene and steel fibers are added to concrete containing recycled aggregates, the compressive, tensile, and flexural strengths of concrete increase, whose steel fibers are more efficient in improving the tensile and flexural strength of concrete than polypropylene fibers. The combination of polypropylene fibers with steel fibers increases energy absorption and increases the flexural toughness of concrete containing recycled aggregates. Moreover, reinforced concrete with hybrid fibers does not disintegrate after breaking, and hybrid fibers play an important role in maintaining the cohesion of concrete.

Concrete may be loaded at an early age for a variety of reasons. This loading can have negative and sometimes destructive effects on the hardened properties of concrete. Therefore, in the present study, the mechanical properties of fiber-reinforced geopolymer concrete after loading at an early age have been investigated. In the present study, the effect of preload on compressive strength at the ages of 28 and 90 days for geopolymer concrete containing fibers has been investigated. For this purpose, the samples were loaded at ages of 1, 3, and 7 days, equivalent to 30 and 70% of their compressive strength at the same age. The samples were then treated again in a humid environment and subjected to compressive loading at 28 and 90 days of age. The effect of preload on flexural strength as well as energy absorption of geopolymer concrete containing fibers was also investigated. Steel fibers with volumetric percentages of 0.25, 0.5, 0.75, and 1 and polypropylene fibers with volumetric percentages of 0.25, 0.5, and 0.75 were used in fabricating laboratory samples. The results demonstrate the positive effect of fibers on reducing the destructive effects of preload on compressive and flexural strength. The effect of fibers on reducing the destructive effects of 1-day preload is higher at higher loading percentage (70% pre-loading), such that the samples containing fibers with preload of 30% at the age of one day experienced a 28.8% increase in 28-day compressive strength, while this increase was 33.2% for the samples with preload of 70%. Samples containing 0.75% polypropylene fibers at 28 and 90 days of age compared to those containing 0.25 and 0.5% polypropylene showed less energy absorption on average due to preloading. In general, the design containing 0.25 polypropylene fiber and 1% steel fiber had the best result of flexural strength among preloaded samples.

Ultra-high-performance concrete (UHPC) is a type of concrete with high mechanical strengths in which silica fume, quartz powder, superplasticizer and fibers, in addition to cement and water are usually used in its mixture design. In spite of vast studies on the mechanical properties of UHPC, very few comparative studies have been made on the effects of fiber types on the mechanical characteristics of this type of concrete, subjected to high thermal changes. This study aims at providing test results for the effects of temperature changes on the mechanical properties of UHPC that are reinforced with different types of fibers. Six types of fibers, either recycled or industrially manufactured, are utilized in the mixture design. After exposure to high temperature changes, compressive strength, tensile strength in bending, ultrasonic pulse velocity and sorptivity were evaluated and compared. Results of this study can be used in other research studies and can be used in decision making in industrial projects.

The advantages of reinforced concrete structures , in comparison with other structures, have made concrete one of the most widely used construction materials. However, concrete has brittle performance under flexural loads. Therefore, the present study investigates the influence of different fibers on the flexural performance of large-scale reinforced concrete beams. In order to achieve this goal, four reinforced concrete beams, with similar reinforcement details, measuring 150 cm long, 20 cm wide, and 30 cm high were made. The beams were reinforced using 0.5% by volume of steel, polypropylene, and korta fibers. Based on ASTM C78, four-point flexural test was performed and the parameters of flexural strength, energy absorption, ductility, and strain of the rebars were studied. The results indicated that reinforced concrete beam containing steel fibers shows better performance, in terms of flexural strength, energy absorption, and capacity of tensile rebars, in comparison with reinforced concrete beams containing polypropylene and korta fibers. In addition, this study showed that korta fiber reinforced beam has better ductility than polypropylene fiber reinforced beam.

With the increasing development of concrete structures, properties such as strength and durability of concrete have become particularly important. Therefore, it is necessary to use special concretes and obtain new combinations. Ordinary concrete is brittle and frangible, and if rebar is not used, other materials such as fibers should be added to the mixture to remove the brittleness of the concrete. Fiber is used to control cracks in concrete, which in addition to controlling cracks, improves impact resistance, fatigue, shear, bending, as well as energy absorption of concrete. In this research, fiber concrete made of steel, barchip, and macro synthetic fibers and the combination of each fiber with different volume ratios is subjected to explosive load and the failure rate of each sample and the resistance of fiber concrete with hybrid fibers to explosion have been investigated in laboratory and field. Also, the special electrical resistance of hybrid fiber concrete against the electric current has been evaluated, which can be considered as a measure to evaluate the permeability and parallel absorption of concrete water. The results showed that concrete with macro synthetic fibers had greater explosion resistance than other samples. Also, the electrical resistance of concrete with macro-synthetic fibers has been higher than that of other samples, which will have special applications in corrosive areas with high penetration of chloride ions due to higher electrical resistance and consequently lower permeability. Also, for estimating the cost of fiber performance in concrete, the lowest excess cost of using fibers in concrete was related to the use of 1.5% of the concrete volume of macro synthetic fibers due to the low cost of these fibers and its high resistance to electrical resistance and resistance to explosive load. The use of these fibers in concrete to withstand explosion and electric current has been cost effective.

Nowadays, the use of recycled concrete has increased significantly for economic and environmental reasons. Increasing the replacement percentages of recycled aggregates change the mechanical properties of concrete. In this research, the mechanical properties of concrete containing recycled aggregates with different percentages of steel fibers and polypropylene fiber has been investigated in the structural laboratory. A total of 36 cylindrical compression specimens, 36 cylindrical tensile specimens with dimensions of 20 * 10 cm and 36 flexural specimens with dimensions of 10 * 10 * 35 cm were tested. Recycled aggregates (coarse aggregates) in ratios of 25 and 50% (weight ratio) replaced with natural materials (coarse aggregates). Also, steel and polypropylene fibers were added to recycled concrete samples in ratios of 0%, 0.5%, 1% and 0%, 0.4%, respectively. Fiber concrete samples containing recycled aggregates under compressive force, indirect tension and three-point bending are tested and factors such as compressive strength, tensile fracture toughness, modulus of elasticity, flexural strength and fracture energy were investigated. The results show that the increase in porosity in recycled concrete is affected by the increase in the percentage of replacement of recycled aggregates and reduces the specific gravity of concrete. Increasing the composition of 1% steel fibers with polypropylene fibers without the presence of recycled aggregate has a greater effect on increasing the specific gravity of concrete than polypropylene fibers (alone). By increasing 25 and 50% replacement of recycled aggregate, 0.8% and 2.5% of specific gravity of concrete were reduced, respectively. Compressive strength decreases with increasing replacement percentage of recycled aggregate. Increasing the percentage of replacement of recycled aggregate due to poor transmission area reduces the amount of energy absorption. So that by replacing 25% and 50% of recycled aggregate, the energy absorption rate decreases by 21.7% and 26%, respectively, compared to the control samples. Polypropylene fibers have a positive effect on increasing compressive strength and combination of polypropylene fibers with 0.5 and 1% steel fibers increases the energy absorption. Also, increasing the replacement percentage of recycled aggregates reduces the hardness. Maximum tensile strength decreases by 3% and 13% with 25 and 50% increase in replacement of recycled aggregate, respectively. The results of flexural strength test show that increasing the replacement percentage of recycled aggregate has a negative effect on reducing the final load and reduces the final load in flexural specimens. Also, polypropylene fibers have a positive effect on increasing the loads and preventing the collapse of concrete, and combining polypropylene fibers with 0.5 and 1% steel fibers, respectively, increases the final load by 20% and 95% in 25%, replacing recycled aggregates and increasing 19% and 21% of rainfall in 50% recycled aggregate replacement. Increasing the percentage of steel fibers, the amount of deformation in the area after cracking and the amount of energy absorption increases, so that by increasing the amount of steel fibers to 0.5% and 1% by volume of concrete, the amount of energy absorption to 2 and it increases 3 times. The use of polypropylene fibers in the area after cracking has little effect and increases the load capacity.

Nowadays, concrete is known as one of the most used building materials in the world. Being economical, the availability of constituents, good resistance under the fire and atmospheric factors, the ability to fit in shapes and molds, and also the high compressive strength are factors that have made public acceptance in the use of concrete as a building material. The use of fiber in concrete has increased dramatically over the last few decades. The use of fiber in concrete causes the concrete to become flexible to a considerable extent and the resulting concrete is highly homogeneous. Since the concrete specimens are used worldwide to determine the mechanical properties of concrete, in this study, 160 samples of fiber concrete containing 64 cube samples with dimensions of 5×5×5, 10×10×10, 15×15×15, 20×20×20 cm for testing of compressive strength, 64 cylindrical cylinders with dimensions (diameter × height) of 15 × 30 and 10 × 20 cm for compressive strength and tensile strength tests and 32 samples of beam with dimensions of 10×45×10 and 15×60 ×15 were used for flexural strength testing. Furthermore, in this study, 4 concrete ranges of 20MPa, 25MPa, 30MPa and 35MPa were tested. Of each concrete grade and each dimension, four samples were made; one of which was non-fibrous (as the base sample) and three samples with fibers. The steel fibers used were two-end hooks of 3.5 cm in length and 0.8 mm in thickness, with 0.5% of the volume of concrete used. The results showed that the flexural strength, tensile and compression strength of the concrete increased with the presence of fibers and some new conversion factors were proposed for the fiber-containing specimens.

The aim of this study is the experimental and numerical investigation of the simultaneous effect of PET and steel fibers on the rheological properties, flexural strength, and compressive stress-strain curve of self-compacting concrete. For this purpose, 30 mixing designs by response surface method (RSM) were designed by combining different percentages of PET, steel fibers, stone powder, and superplasticizer variables. The results demonstrate that with increasing the percentage of PET and steel fibers, the viscosity of concrete decreased. Also, the highest flexural strength was obtained from the combination of 0.4% fibers, 8% PET, and 1% superplasticizer. The stress-strain curves plotted for the mixtures showed that the steel fibers had little effect on the ascending part of the stress-strain curve and improved the stability on the descending part of the curve. PET particles also reduce the slope of the ascending part of the stress-strain curve. In general, Steel fibers and PET caused the soft failure of the samples so that PET increased the strain corresponding to the maximum compressive strength, and steel fibers increased the rupture strain of concrete.

In recent years, the use of synthetic fibers to improve mechanical properties and reduce the shrinkage of fresh and hardened concrete, increase energy absorption and impact resistance of concrete, and replace thermal reinforcement with fibers have greatly expanded. The use of various types of fiber has led to the improvement of some properties and the weakening of other properties. Simultaneous use of several types of fibers with designed ratios can enhance the mentioned properties simultaneously and prevent possible weaknesses. In this study, the effect of fibers with various volumetric percentages on compressive, flexural and tensile strength of the samples at different ages compared to the control sample has been measured. The simultaneous combination of steel, barchip and macro-synthetics fibers with different ratios, compressive performance, flexural and tensile performance of concrete has been tested. Among the constructed concretes, the best performance of reinforced concrete with steel fibers in different tensile, compressive, and bending strengths has shown that these fibers perform better than other constructed samples. In hybrid fiber concrete, the best performance in bending and compressive strength and tensile strength has been related to hybrid fiber concrete consisting of macrosynthetics fibers and steel fibers.

Producing enormous quantities and continuous stockpiling of granite industrial by-product enforced researchers to utilize this waste in a sustainable state in concrete to diminish its adverse impacts on the ecosystem. This study aims to experimentally investigate the possibilities of reusing granite waste sourced from Lorestan Province in fiber-reinforced self-compacting cementitious composite using hooked-end steel fibers. The L-box and U-box tests were performed to assess the fresh properties of mixes, whereas compressive strength, flexural strength, ductility, flexural toughness, and tensile strength tests were conducted for measuring the hardened properties of self-compacting concrete mixes. Results of the fresh properties tests for all of the steel fiber reinforced-recycled aggregate mixtures were found within the satisfactory limit of standard. In other words, the incorporation of granite waste in self-compacting concrete augmented the hardened properties. It should be noted that the effects of simultaneous use of granite waste and steel fiber in improving the tensile strength, flexural performance, ductility, and bending toughness of the specimens are higher than the compressive strength. In specimens without steel fiber, brittle failure occurred immediately after the formation of the first crack. With the increasing percentage of steel fibers in the samples, the ductility increased, and the ductile failure occurred in samples.