جستجوی مقالات مرتبط با کلیدواژه « مقاومت خمشی » در نشریات گروه « عمران »

The use of admixtures in concrete changes the mechanical properties and rheology of concrete. Reactive powdered concrete has a higher strength than ordinary concrete. In this study, the effect of adding polypropylene and metakaolin fibers on the compressive, tensile and flexural strength of reactive powder concrete separately and when these two materials are added together in reactive powder concrete, has been investigated. In this study, 69 samples have been tested to evaluate the performance of reactive powder concrete. The results show that with a 3% increase in metakaolin to reactive powder concrete, the compressive strength will increase to 23%. Adding 2% by weight of cement from polypropylene fibers to reactive powder concrete will increase the flexural strength by up to 32%. To simultaneously increase the compressive and flexural strength, the simultaneous use of metakaolin and polypropylene fibers will increase the compressive strength by up to 11% and flexural strength by up to 19%.

Nowadays, concrete roll is used in various fields of civil engineering and architecture. Therefore, improving the mechanical properties of this product is important in order to increase the scope of its using. In this study, the effect of yarn and weave of 3-D spacer fabric was investigated on flexural and tensile strengths of concrete roll. For this purpose, four samples of 3-D spacer fabrics with different yarns and weaves were prepared and the cement was injected into these samples. After hydration of concrete roll, the initial cracking stress, final stress and tensile strength were obtained. The results showed that the number of spacer yarns has a significant effect on the amount of initial cracking stress, and the final stress of flexural strength is also increased almost with increasing the initial cracking stress. The results also showed that the type of yarn used in the 3-D spacer fabric has a significant effect on the tensile strength. The tensile strength of concrete roll is increased with increasing the capillary ability of the samples, due to the better hydration of concrete.

Over the past decade, glass fabrics have gained significant attention for use in the construction of concrete railway sleepers. Advances in composite technology have spurred extensive research into glass-based composite materials, suggesting their potential as replacements for traditional sleepers. However, the impact of three-dimensional (3D) glass fabrics on reinforcing concrete sleepers and the optimal application of these fabrics has not been sufficiently explored. Additionally, there has been no comparative analysis of the flexural strength between concrete sleepers reinforced with glass fabrics and those reinforced with steel rebars. This study investigates the potential of Glass Fiber Reinforced Concrete (GFRC) fabrics as an alternative for concrete railway sleepers. Laboratory-scale concrete sleeper samples were prepared and reinforced with two-dimensional (2D) and three-dimensional (3D) glass fabrics, covering 50% and 70% of the surface area. Flexural strength tests were conducted on these samples, and their validity was confirmed through finite element analysis using Abaqus software. The empirical results from small-scale tests were extrapolated to estimate the performance of full-sized sleepers. The findings indicate that the use of 3D fabrics can increase flexural strength and crack resistance by up to 20% and 30%, respectively. Moreover, 3D fabrics with 70% surface coverage can further enhance flexural strength by 15%. GFRC sleepers meet all standards and performance requirements for commercialization, showing up to 25% higher flexural strength and up to 40% improved crack resistance compared to conventional concrete sleepers.

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.

Today, the proper use of waste and disposal that affects the environment around us, It has received a lot of attention, Because it is both environmentally and economically valuable to help with the environment we are in. According to that thousands of tons of steel waste is produced annually in the country's industrial community And through the collection of these wastes and their relocation to the factory and their smelting, they are again produced under steel conditions at high cost Or, because of its indivisibility, it is left unused in our environment and takes up a lot of space. Therefore reusing these wastes would be very beneficial. Research has shown that the use of iron filings in ordinary concrete has been repeatedly performed by different individuals, but in roller compacted concrete, it has not been done separately to reduce or increase resistances. This type of concrete pavement is known as the roller compacted concrete which has zero slump and is much cheaper and has a better performance than other concrete pavements. Due to the good advantages of this type of pavement over other asphalt and concrete pavements, the tendency to use this type of pavement is increasing. Therefore, the aim of this study was to investigate the effect of iron filings on the mechanical properties of roller compacted concrete in road pavement. In this research, after purchasing the aggregate, iron filing, cement and providing these materials in the laboratory, The process of screening the aggregates was performed.

Today, various types of industrial waste are used as sustainable mineral materials to replace part of cement in concrete production with an economic approach. The main purpose of this study is to compare and evaluate the effect of using two types of slag from Isfahan Steel Plant and Esfarayen Steel Plant as a replacement of different percentages of cement in ordinary concrete, which was done in three phases. Concrete samples with mixing design and different percentages of two types of slag with water-cement ratios equal to 0.54 and 0.43 were made in the first phase and after being placed in the water pool, at the ages of 28, 56 and 90 days. were tested for compressive strength. In the second phase, concrete samples with optimal percentages of slag were made to measure the samples. Reinforced concrete beams with dimensions of 1000 × 150 × 150 mm with 3 different mixing designs in the third phase and to check the structural performance of concretes containing optimal percentages of slag were made and a four-point bending beam test was performed to obtain the Ultimate capacity. became. The results of the tests showed that although the strength of concrete samples containing different percentages of slag at the age of 28 days was lower than that of normal concrete, but the strength of concrete samples containing 30% of Isfahan slag and 20% of Esfarayen slag at the age of 56 and 90 days was almost equal to normal concrete. And resistance was the goal. The results of the durability tests in the second phase showed that the durability of samples containing slag in sulfate environment was more than normal concrete. Also, the ultimate bending capacity of reinforced concrete beams containing 30% of Isfahan slag and 30% of Esfarayen slag showed a 10% increase and a 3% decrease, respectively, compared to the beam without slag.

The curing ambient temperature and the amount of Silica Fume are the effective factors on the mechanical properties of reactive powder concrete (RPC). In this research, the effects of the curing ambient temperature and also the effects of the amount of silica fume on reactive powder concrete have been investigated. The autoclave device has not been used so that these concretes can be used in different environments as in-situ concreting. The prepared specimens were cured by immersion in water. To investigate effects of the curing ambient temperature, specimens were cured in water at three temperatures of 27, 60, and 80°C and were tested for compressive, tensile, and flexural strength at the age of 3, 7, and 28 days. The results show that the curing ambient temperature has a significant effect on the early strength of RPC, which increases strength at high temperatures. In the curing in water, it was found that 60°C is an optimum temperature; Because the specimens with the curing ambient temperature of 80°C show higher compressive, tensile, and bending strengths, but the increase in strengths compared to the curing ambient temperature of 60°C is very small. The compressive strength of the specimens cured in the water pool with temperature of 80°C has increased by 43.7%, 43.5%, and 25.9% at the ages of 3, 7, and 28 days, respectively, compared to the specimens cured at temperature of 27°C; Also, the increases in bending strength in the mentioned cases are equal to 51.5, 53.4 and 25.8% respectively. Similar results are also observed in tensile strength. In the next step, to study the effect of the changes in the amount of silica fume, five concrete mixtures with different amounts of silica fume were produced. These values were considered as a percentage of cementitious material (cement + silica fume) of 0, 10, 15, 25, and 35%. The specimens made in this step were only cured in a water pool with temperature of 27°C at the ages of 3, 7, and 28 days and were tested for compressive, tensile, and bending strength. It should be noted that at this stage, cementitious material (cement + silica fume) is fixed and is equal to 1008 kg / m3 of RPC. The results indicate that the replacement of silica fume has increased the strengths, but the optimal value is in the range of 15 to 25%. The compressive strength of the specimens with 25% replacement of silica fume at the ages of 3, 7, and 28 days has increased compared to the specimens with 10% replacement of silica fume by 66.3%, 40.9%, and 64.0%, respectively. These increases are equal to 100.8, 93.8 and 107.7 percent, respectively, compared to the specimens with zero percent replacement (without silica fume)

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%.

In the present study, the effect of recycled glass fibers on the behavior and mechanical properties of concrete was investigated. The research was conducted by laboratory study method. Various cubic and cylindrical samples were made in the laboratory. In all mixing designs, the water to cement ratio was 0.35 and the sand to cement ratio was 1. First, a reference sample without fibers and additives was prepared and subjected to various tests. Examination of the samples after the experiment showed that failure occurred in the samples without recycled fibers and brittle glass waste; But failure in samples reinforced with recycled fibers and glass waste is gradual. Under these conditions, in samples made by spray method, the modulus of rupture and displacement of samples to the moment of failure, had much higher values ​​than samples made in the pre-mixed method. As the age of the samples increased from 7 days to 90 days, the modulus of specific rupture of the cement decreased; However, there is no definite trend in changes in the specific rupture modulus of the pozzolanic effect over time. According to the results, it can be seen that over time from 7 to 28 days, the specific compressive strength of cement and also the specific compressive strength of the pozzolanic effect has increased. Over time from 7 to 28 days, the specific compressive strength of cement as well as the specific compressive strength of the pozzolanic effect has increased.

Recycled concrete aggregates are one of the types of recycled aggregates that have the most abundance compared to other recycled aggregates. In this research, by using the replacement of recycled concrete aggregates instead of natural aggregates, the mechanical properties of this type of concrete have been investigated. The replacement of natural aggregates with recycled aggregates was done in four percentages of 0, 15, 30 and 45, and this replacement was done both independently (i.e. sand or gravel separately) and simultaneously (both sand and gravel together). According to the use of 50% sand and 50% sand in the reference mixing plan and by replacing the percentages with coarse and fine recycled concrete aggregates, 21 mixing plans were used. The ratio of water to cement was kept constant in all mixing plans and was considered equal to 0.42. To compensate for the decrease in strength due to the replacement of recycled aggregates, micro silica in different percentages of 7.5 and 15 and super plasticizers were used in the mixing designs. By performing various tests, the mechanical properties of concrete samples were investigated. The results showed that the best mixing design in terms of compressive strength is the design containing 7.5% micro silica and 15% recycled sand, in terms of tensile strength, the design containing 7.5% micro silica and 45% recycled sand, in terms of flexural strength, the design containing 7.5% micro silica and 30% recycled sand, the plan containing 15% micro silica and 15% recycled sand was determined. By examining the mechanical properties of concrete samples, it was determined that the recycled mixing plans contain 15%, 30% recycled gravel and 45% recycled sand with 7.5% microsilica, as well as the mixing plan of 15% recycled sand with 15% microsilica. , among the recycled mixing plans, they had the highest amount of overall utility.

The current research deals with the use of waste rubber powder with different forms and percentages as a replacement for the fine aggregates in concrete production for the purpose of examining different mechanical and structural properties at an experimental level. The mixed design of common concrete as well as other mixed designs having waste rubber powder were constructed. The amounts of waste rubber were equivalent to 5, 10, and 15% of actual volume of the aggregate. To remove the negative effects on some mechanical properties of the product such as compressive and tensile strength and impact resistance, the synthetic Polyphenylene Sulfide (PPS) fibers known as synthetic complex fibers with 0.75 and 1.5% were added to the concrete having waste rubber powder. The first part of this research examines the effects of the combination of fibers with waste rubber powder on the compressive, tensile, flexural strength, and impact resistance of specimens. Also, in the second part of this research, six concrete slabs were constructed with the structural performance of such concrete in road construction under elastic basement under direct loading. The displacement-load curve of the samples as well as the failure pattern of the samples were observed and analyzed. The result of the experiments on the standard specimen in the first part of this research showed that despite the decrease in compressive strength due to the simultaneous addition of rubber powder compared to the common concrete samples, the tensile, flexural strength, and impact resistance were improved compared to the samples constructed with common concrete. By replacing 15% rubber powder instead of the fine aggregates, the final impact resistance increased up to 48%. Simultaneous addition of 0.75 % fibers and 5% rubber doubled the impact resistance of the concrete. It is worth mentioning that 1.5% addition of fibers to the concrete having 5% rubber power increased final impact resistance up to 5.72 times of that of Ref concrete. The results of the second part of this research showed that the final capacity of fiber-rubber concrete slabs under elastic basement to have favorite flexural behavior as concrete pavement compared to common concrete slab increased up to 50%; meanwhile, the amount of absorbed energy and the strength of combined concrete slabs of rubber wastes and fibers were 3 times higher than those made by common concrete in the reference sample.

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.

Cement is one of the most widely used materials in the construction industry, which emits large amounts of carbon dioxide into the environment during production. Environmental challenges and the reduction of energy consumption and the use of natural raw materials have led to increased study and research to find a suitable alternative to cement. Zeolite and bentonite have cement properties. These materials are environmentally friendly and can be easily extracted and also have lower production costs than cement. Since concrete has a low tensile strength, straw fibers, which are natural fibers, have also been used. In this research, 9 different mixing ratios with the amount of 250 kg / m3 cement were made in which different percentages of bentonite and zeolite replaced part of the original cement and the percentage of fibers varied by 1% and 3%. After fabrication, the compressive strength and tensile strength of the samples compared to the reference sample at 7 and 28 days have been compared. Then, two concrete mixtures with 6% zeolite, 1% straw fiber and 6% and 16% bentonites were selected and three-point bending strength test was performed on beams with dimensions of 10 * 10 * 50 cm. The flexural strength of the reference sample in this section, which contains 350 kg / m3 of cement, is 5.37 MPa. The best composition contains 6% zeolite, 6% bentonite and 1% straw fiber, which was able to achieve 98% flexural strength compared to the reference sample.

The present study aimed to investigate the experimental performance of the effect of magnetic water on the mechanical properties of concrete containing basalt fibers. In this study, AQUA-Correct (AC) device made in Germany, which has a power of about 1300 Gauss, has been used to produce magnetic water. Concrete samples prepared (24 samples 7 and 28 days for compressive strength test and 24 samples 7 and 28 days for flexural strength test) are made by this machine with one and two times passing through the magnetic field. The fibers used are basalt fibers that it has a length of 3 cm and a diameter of more than 9-10 microns. It has high heat resistance and sound absorption and has effective applications in the manufacture and reinforcement of composite materials and is 0, 2 and 5% by weight of cement in the mixing plan. Basalt fibers have been studied on the properties of concrete such as compressive strength, flexural strength, slump and specific weight. The results showed that by increasing water magnetism, slump, specific weight and compressive strength and the flexural strength of concrete increases, also by increasing basalt fibers, slump and specific weight decreases and by increasing the percentage of fibers from 0 to 2, the compressive strength increases and from 2 to 5%, we face a decrease in compressive strength, resulting in that 2% is an optimal percentage of basalt fiber. However, by increasing percentage of fibers, flexural strength has been increased significantly.

This research aimed to investigate the mechanical and physical properties of Roller Compacted Concrete (RCC) used with Recycled Concrete Aggregate (RCA) as a replacement for natural coarse aggregate. The maximum dry density method was adopted to prepare RCC mixtures with 200 kg/m³ of cement content and coarse natural aggregates in the concrete mixture. Four RCC mixtures were produced from different RCA incorporation ratios (0%, 5%, 15%, and 30%). The compaction test, compressive strength, splitting tensile strength, flexural tensile strength, and modulus of elasticity, porosity, density, and water absorption tests were performed to analyze the mechanical and physical properties of the mixtures. One-way Analysis of Variance (ANOVA) was used to identify the influences of RCA on RCC’s mechanical properties. As RCA increased in mixtures, some mechanical properties were observed to decrease, such as modulus of elasticity, but the same was not observed in the splitting tensile strength. All RCCs displayed compressive strength greater than 15.0 MPa at 28 days, splitting tensile strength above 1.9 MPa, flexural tensile strength above 2.9 MPa, and modulus of elasticity above 19.0 GPa. According to Brazilian standards, the RCA added to RCC could be used for base layers.

In recent years, using too much cement has led to the production of greenhouse gases, one of the consequences was the heating of the earth. These destructive effects lead to more attention to the use of pozzolanic materials. In this study, the durability of geopolymer concrete (active alkali slag) containing silica fume and fly ash against corrosive acidic, sulfate and compressive strength, flexural strength, tensile strength, and chloride ion permeability were investigated. The corrosive properties of different environments by the compressive strength and weight loss tests were compared. After 7 days of operation in lime water, samples were placed in sulfuric acid solution, magnesium sulfate, and sodium sulfate for 180 days. At first, the weight loss of the samples, then the compressive strength of the samples after exposure to the medium corrosive was measured. The compressive strength, flexural strength, tensile strength, and chloride ion permeability were also measured. In this study, increasing the of silica fume and fly ash alternatives instead of slag in concrete, compressive strength, flexural strength, tensile strength, and durability and chloride ion permeability increased; In fact, the best sample is pure slag geopolymer concrete, which has a compressive strength of 53.45 MPa, flexural strength of 6.05 MPa, tensile strength of 5.5 MPa, chloride ion flow rate of 6067 Coulombs and compressive strength after placement in sulfuric acid, magnesium sulfate, and sodium sulfate are 43.92, 44.8 and 45.9 MPa, and also the weight loss after placing in these solutions is 21, 14 and 12 grams respectively.

Plastic waste control has always been a major concern in many countries. The amount of these substances increases every year due to continued public consumption. Given the high cost of plastic recycling in developing countries, returning these materials to the industry for the production of building materials can be a viable solution to protect the environment. Since concrete is one of the most widely used composite materials in the building industry, it, therefore, provides a suitable base for the utilization of plastic waste. In this research, different plastic granules are replaced with a certain amount of fine natural aggregates, and the physical and mechanical properties of the concrete made from these materials are evaluated by necessary tests. The target plastics are Polypropylene, High Impact Polystyrene, and Polyethylene terephthalate. The size and aggregation of the mentioned fine plastic particles are similar, replacing the sand with 15% and 30% by weight. The results show that the mechanical properties of the concrete decrease as the amount of substituted plastic aggregates increases. However, among the concrete made with plastic aggregates, the one which contains High Impact Polystyrene, has the best performance. In addition, the workability of the concrete was improved by increasing the amount of plastic aggregate present in the concrete. However, in the concrete containing Polyethylene terephthalate, this index declined. Also, among the physical and mechanical properties of concrete, flexural strength and ultrasonic pulse velocity of concrete were the most varied, but the compressive and tensile strength and workability have undergone fewer changes.

The use of self-compacting high performance composites due to its unique properties has attracted the attention of researchers.The high compressive strength and tensile strength, high flexural strength, have attracted the attention of researchers to this type of cement composites.In this research, in the form of a comprehensive experimental work, using six basic mixing designs, 24 rectangular composite slabs 300 to 400 mm, with two thicknesses of 30 and 50 mm, were built and tested under impact load. Compressive,tensile and flexural strength tests were made on each of the six mixing designs. Also, to determine the efficacy of high performance composite, slump flow, L-box, U-box and V-funnel on mix designs have been done. Steel fibers with percentages of 0, 0.5 and 1% by volume fraction, with lengths of 25 and 50 mm, were used for the construction of cementitious composites. The impact test apparatus was made from a 5.6 kilogram steel ball and a retaining system. The steel ball was raised to a height of 1.5 meters and was freed repeatedly until failure cracking in the samples have been Developed. According to the results of the experiment, It was noted that the maximum energy absorption in a slab with a thickness of 30 mm was 34.22 kJ, and in a slab with a thickness of 50 mm was 47.49 kJ. The results of this experiment shows the high effect of steel fibers on increasing the impact resistance and absorbed energy of the composite slabs.

In order to expand the application of roller Compacted concrete (RCC) in high speed roads,  casting a thin layer of concrete with high skid resistance immediately the after implementation and compaction of RCC has been suggested. In the present study, the mechanical and fracture properties of this kind of two lift concrete pavement (2LCP) evaluated and compared with common single lift concrete pavements. Therefore, a thin layer of plain concrete and polypropylene fiber reinforced concrete with relative thickness of 30% of total pavement thickness has been casted of RCC pavement.. </span>Compressive strength and mode I fracture tests were performed on samples after 28 days curing.</span>
Result showed that the addition of polypropylene fibers to plain concrete reduces the compressive strength of concrete slightly.  Also, replacement of normal concrete or fiber reinforced concrete with roller concrete in the upper layer of 2LCP did not have a significant negative effect on flexural strength and fracture of the specimens compared to single lift RCC pavement with equivalent thickness.