High-strength Fiber-reinforced Concrete Research Articles

Mechanical Properties and Microstructure of Cellulose Fiber- and Synthetic Fiber-Reinforced High-Strength Concrete

Mechanical Properties and Microstructure of Cellulose Fiber- and Synthetic Fiber-Reinforced High-Strength Concrete

Influence of Drying Conditions on the Durability of Concrete Subjected to the Combined Action of Chemical Attack and Freeze-Thaw Cycles.

The durability of concrete is critical for the service life of concrete structures, and it is influenced by various factors. This paper investigates the impact of the relative humidity (RH) of the curing environment on the durability of five different concrete types. The aim is to determine a suitable approach for designing concrete that is well-suited for use in the salt lake region of Inner Mongolia. The concrete types comprise ordinary Portland cement (OPC), high-strength expansive concrete (HSEC), high-strength expansive concrete incorporating silica fume, fly ash, and blast furnace slag (HSEC-SFB), steel fiber-reinforced high-strength expansive concrete (SFRHSEC), and high elastic modulus polyethylene fiber-reinforced high-strength expansive concrete (HFRHSEC). All these concrete types underwent a 180-day curing process at three distinct relative humidities (RH = 30%, 50%, and 95%) before being subjected to freeze-thaw cycles in the Inner Mongolia salt lake brine. The curing environment with a 95% RH is referred to as the standard condition. The experimental results reveal that the durability of OPC and HSEC decreases significantly with increasing relative humidity. In comparison with the control sample cured in 95% RH, the maximum freeze-thaw cycles for concrete cured in lower RHs are only 31% to 76% for OPC and 66% to 77% for HSEC. However, the sensitivity of the durability of HSEC-SFB, SFRHSEC, and HFRHSEC to variations in RH in the curing environment diminishes. In comparison with the corresponding reference value, the maximum freeze-thaw cycles for samples cured in dry conditions increase by 14% to 17% for HSEC-SFB and 21% for SFRHSEC. Specifically, the service life of HFRHSEC cured in a low RH is 25% to 46% higher than the reference value. The durability of HSEC-SFB, SFRHSEC, and HFRHSEC has been proven to be appropriate for structures located in the salt lake region of Inner Mongolia.

Experimental study on the fully encased composite short columns made with high-strength fibre-reinforced concrete

Experimental study on the fully encased composite short columns made with high-strength fibre-reinforced concrete

Abrasion and Maintenance of High-Strength Fiber-Reinforced Pervious Concrete

This study examines the properties of ordinary and high-strength fiber-reinforced pervious concrete, aiming for a 28-day compressive strength exceeding 40 MPa with a target porosity close to 15%. Utilizing glass fiber (at 0.25% and 0.5% volume ratios) and steel fiber (at 1% and 2%), the study conducts mechanical and abrasion resistance testing on pervious concrete specimens. Sand dust clogging experimental simulations assess permeability coefficients for both application and maintenance purposes, revealing optimized maintenance, including vacuum cleaning and high-pressure washing, can restore water permeability to over 60%. The specific mix designs demonstrate high-strength pervious concrete achieves a 28-day compressive strength ranging from 40 to 52 MPa, with corresponding porosities ranging from 7% to 16%. Results highlight the significant impact of the ASTM C1747 impact abrasion test, where ordinary pervious concrete exhibits a cumulative impact abrasion rate reaching 60%, contrasting with approximately 20% for other high-strength specimens.

Sustainable design framework for enhancing shear capacity in beams using recycled steel fiber-reinforced high-strength concrete

According to a recent estimate, over 1.5 billion wasted tyres which containing over 40% of vulcanised rubber and 15% of steel fibre are discarded yearly, which posing a serious threat to circular economy implementation and transition to net zero. To minimise the greenhouse gas(GHG) emission and the environmental side effect caused by burning and burying these waste tyres, recycling and reusing these materials for sustainable structural designs has become the centre of attention. This paper focuses on applying recycled bead steel fibre to improve the shear capacity of fibre-reinforced concrete beams. Moreover, the existing national standard known as Eurocode 2 and TR63 can hardly illustrate the relationship between fibre and high-strength concrete. This study is the first to investigate shear behaviours of high-strength industrial and recycled steel fibre reinforced concrete beams with consideration of different shear span ratios. Therefore, twenty real-scale beams are constructed to examine the shear capacity of high-strength industrial and recycled steel-fibre reinforced concrete beams, which aims to compare the improvement of shear strength through experiments and identify different shear strength improvements of the two categories of steel fibre. Besides, comprehensive data of 164 beams from previous studies have been collected to benchmark with the experimental results for the formula design. This study proves the feasibility of replacing industrial steel with recycled steel fibre to improve the shear capacity of fibre-reintroduced concrete beams. Moreover, there are six novel equations designed developed using Eurocode 2 and TR63 as a basis in this study. Based on the findings of the paper, the proposed formulas demonstrate remarkable accuracy, with an average value of 0.982 and standard deviation of 0.213, respectively. Following an exhaustive comparison of RSF and ISF reinforced concrete beams, with a focus on economic expenditure and GHG emissions, it can be concluded that RSF offers superior economic and environmental benefits, which reduce the emissions up to 25.39% and price up to 28.04% when replacing ISF 0.8% RSF, respectively.

Bond durability performance of sand-coated BFRP bars in high-strength fiber reinforced concrete

The ever-increasing utilization of fiber-reinforced polymer (FRP) bars has led to a surge in research regarding their bonding properties with concrete. In this study, the bond durability behavior between high-strength fiber-reinforced concrete (FRC) and sand-coated basalt FRP (BFRP) bars was examined under three different environmental conditions including immersion in seawater solution at 50 °C for 3, 6, and 9 months, immersion in the sulfuric acid solution for 3, 6, and 9 months with an ambient temperature range of 20 to 30 °C, and exposure to 270 freeze–thaw cycles. A total of 60 pull-out samples were prepared using either basalt (B) fibers or polypropylene (PP) fibers. Plain concrete pull-out samples were served as controls. Test results revealed that all exposures have degraded the bond, leading to pull-out failure in all of the specimens. Exposure to 50 °C seawater was found to cause the most significant degradation. However, the use of basalt fibers helped to mitigate the loss of bond strength in the specimens when compared to plain concrete specimens. For example, after 3, 6, and 9 months of exposure to 50 °C seawater, bond strength retentions of 73.58%, 56.04%, and 34.47% were observed for basalt FRC (BFRC) specimens, compared to 39.64%, 49.37%, and 29.61% for plain concrete specimens. On the other hand, a lower retention in bond strength of 16.28% was recorded for polypropylene FRC (PPFRC) specimens at 9 months of exposure to 50 °C seawater. The bond stress-slip relationship of the tested bars was accurately predicted using two calibrated analytical models: the Eligehausen, Popov, and Bertero (BPE) model and the Cosenza, Manfredi, and Realfonzo (CMR) model. Notably, both models showed a strong correlation with the observed bond stress-slip relationships in the experiments.

Seismic performance of corroded non-seismically and seismically detailed RC beam-column joints rehabilitated with High Strength Fiber Reinforced Concrete

The experimental investigation was undertaken to restore the seismic performance of the corrosion-damaged beam-column joint (BCJ) rehabilitated with High Strength Fiber Reinforced Concrete (HSFRC). A total of eight exterior beam-column sub-assemblages were cast following two types of reinforcement detailing as per IS 456:2000 and IS 13920:2016, respectively. Three specimens from each reinforcement detailing regime were subjected to three different levels of corrosion and thereafter rehabilitated with HSFRC. The hysteresis behavior, energy dissipation, stiffness degradation, crack patterns, and damage index of all rehabilitated specimens are analyzed and compared with the conventional specimens. Test results indicate that the replacement of damaged concrete with HSFRC can recover the strength of corrosion-damaged BCJ when the corrosion ratio is within 10 %. The peak load-carrying capacity and initial stiffness of rehabilitated specimens showed a significant increase up to 36 % and 84 % respectively, when compared to control specimens. The ductile detailing rehabilitated specimens showed up to 90 % higher equivalent viscous damping ratio than the non-ductile ones, exhibiting close stirrups arrangement superiority. Despite recovering the load-carrying capacity at initial drifts, the seismic performance of non-ductile and ductile rehabilitated specimens having 17.76 % and 20.32 % corrosion ratio were not recovered at higher drifts.

Shear behaviours of steel-HSFRC welded stud and perfobond rib connectors under static push-out experiments

In this study, high-strength fibre-reinforced concrete (HSFRC) was introduced into steel–concrete composite girders owing to its high strength, good cracking, and impact resistance. Sixteen push-out specimens were tested to study the shear behaviours of the welded stud and perfobond rib connectors used in steel-HSFRC composite girders. The failure modes, load–slip curves, and shear behaviours of the push-out specimens were analysed and compared. The experimental results indicate that the shear capacity and stiffness of these two types of connectors are improved when they are used in steel-HSFRC composite girders, whereas the ductility of the welded stud and one-hole perfobond rib connectors decreases. The stud diameter has a significant effect on the shear behaviour of welded studs, unlike the stud length. The shear capacity of perfobond rib connectors increases with an increase in the perforating rebar diameter and hole number. The initial stiffness and ductility of perfobond rib connectors were larger than those of welded stud connectors with similar shear capacities. Finally, shear capacity prediction equations for welded studs and perfobond rib connectors embedded in HSFRC are proposed and verified to have good accuracy and applicability.

Behavior of reinforced concrete ring beams strengthened with sustainable materials

Reinforced Concrete Ring Beams (RCRBs) have been used in Reinforced Concrete (RC) buildings, tanks, and roof shell structures, such as domes and cones. The curviness feature of RCRBs may result in excessive tensile stresses that may consequently generate critical cracks in concrete, particularly when the beams are constructed with Normal Concrete (NC). This paper presents experimental and numerical investigations on the structural behavior of RCRBs strengthened with sustainable materials. The experimental results on 12 RCRBs constructed with various types of concrete and strengthened with several techniques are presented and discussed. The specimens were made of NC, Engineered Cementitious Composite (ECC), High Strength Concrete (HSC), and High Strength Fiber Reinforced Concrete (HSFRC). Three strengthening techniques were employed for strengthening, including the External Bonded Reinforcement (EBR) with stainless-steel plates (SSPs), the Near Surface Mounted (NSM) with steel bars, and the pre-stressing system. Three-dimensional Finite Element Models (FEMs) were developed by using ABAQUS software to simulate the nonlinear performance of RCRBs. The test results show that the use of sustainable materials in RCRBs can remarkably improve the strength and ductility of RCRBs. In addition, the strengthening techniques are effective in enhancing the responses of RCRBs against the applied loads. Moreover, the thickness and configuration of SSPs significantly affect the ultimate and energy absorption capacities of RCRBs. Finally, a good agreement is observed between numerical predictions and experimental results, suggesting that the finite element model can be employed for further investigations.

Response of high-strength concrete beams with corrugated discrete steel fibers to small shear span-depth ratios

The behavior of high-strength, fiber-reinforced concrete (HSFRC) beams under concentrated loads was affected by many different aspects, such as the type of fibers used and the volume percent of the fibers; nevertheless, the behavior was primarily affected by modifying the shear span-to-depth ratio (a/d). In this experimental investigation, the influence of a/d ratios (ranging from 1.5 to 2.2) is investigated on the response of twelve high-strength fiber-reinforced concrete (HSFRC) beams containing varying amounts of discontinuous steel fiber (vf) in the concrete mixture. The purpose of this study was to analyze the manner of failures of the tested beams and to identify a limiting a/d for effective beam depth. Shear failure was observed in high-strength concrete (HSRC) beams with a vf of 0% at a/d ratios as high as 2.2, according to the findings of the study. Altering either the a/d ratios or the vf had an effect on the way in which the HSFRC beams responded to the stimulus. Some of the HSFRC beams that were put through the shear–flexure test failed. In addition, the findings demonstrated that, as the a/d ratio increased up to 2.2, the beams with a vf of 0.5% and 0.75% broke in pure flexure with multi-cracking. This indicates that the a/d ratio has a substantial impact on the various failure behaviors of HSFRC beams.

High strength fiber reinforced concrete with steel slag as partial replacement of coarse aggregate: Overview on mechanical and microstructure analysis

The growth in construction development and an increase in the number of predisposed waste products has instigated vendors and investigators in studying the use of substitute resources that valor preserve usual resources and defend ecology, helping the reduction of aggregate occupying 70% volume in concrete. Steel slag, a byproduct of steel industry can be used to substitute aggregates in standard concrete mixtures. Steel slag has essentially identical properties to ordinary aggregates and is easily obtained as a byproduct of the steel industry. Steel slag usage conserves natural resources and cleans the environment. This work primarily intends to study the mechanical behaviour of high strength fiber reinforced concrete (HSFRC) of M70 grade such in compression and tension tests, by replacing coarse aggregate by 40 %, 45 % and 50% with steel slag and pondering 1 % of steel fibers. The microstructure of concrete mixes is analysed, results indicated that 50% replacement has better performance in the strength and microstructural aspects.

Influence of Heat–Cool Cyclic Exposure on the Performance of Fiber-Reinforced High-Strength Concrete

Sometimes civil engineering infrastructures have been constructed in hot and cold weathering regions such as desert areas. In such situations, the concrete is not only smashed by hot and cold processes but also spoiled by shrinkage cracking. Therefore, this study intends to examine the influence of heat–cool cycles on high-strength concrete comprising various fibers, such as natural date palm, polypropylene, and steel fibers, and their different volume percentages. The most popular technique for improving the structural behavior of concrete is fiber insertion. Fibers decrease cracking occurrences, enhance early strength under impact loads, and increase a structure’s ability to absorb additional energy. The main goal is to examine the effects of three different types of fibers on regular concrete exposed to heat–cool cycles. For each type of fiber, three dosages of 0.2%, 0.6%, and 1% were used to create high-strength concrete. After 28 days of regular water curing and six months of exposure to heat-and-cold cycles, all specimens were tested. The heat–cool cycles entailed heating for two days at 60 °C in the oven and cooling for another two days at room temperature. The results of the experiment showed that fiber reinforcement in concrete improves its strength and durability. The flexural strength was substantially improved by increasing the date palm, polypropylene, and steel fibers into the high-strength concrete with and without heat–cool cycles. Adding increments of date palm, polypropylene, and steel fibers into high-strength concrete revealed a significant improvement in energy absorption capacity in both cases, i.e., with or without the implementation of heat–cool cycles. Therefore, the natural date palm fibers might be utilized to produce sustainable fibrous high-strength concrete and be applicable in severe weathering conditions.

Cyclic loading test for reinforced concrete columns strengthened with high-strength engineered cementitious composite jacket

This paper intends to investigate the enhancing effect of high-strength engineered cementitious composite (HS-ECC) jacket on the seismic performance of reinforced concrete (RC) column subjected to cyclic loading. Totally eighteen column specimens were prepared, including conventional RC columns, high-performance mortar (HPM), high-strength fiber-reinforced concrete (HSFRC), and HS-ECC jacketed columns. The effect of different strengthening materials, axial compression ratio (0.2, 0.3, and 0.4), scheme of HS-ECC jacket (strengthening height, cast-in-place or prefabricate), and stirrup spacing on the hysteresis characteristics of the RC columns were explored. Three typical failure modes can be observed depending on different strengthening materials, including shear failure mode, flexural failure mode, and multiple cracking mode. The test results indicate that fiber-reinforced concrete jacketed columns exhibited both high bearing capacity and superior ductility under different axial compression ratios. In particular, HS-ECC jacketed full-column possesses the best overall performance. Under the axial compression ratio of 0.2, the ductility value and the accumulated energy absorption of the HS-ECC jacketed column were improved by 67.7% and 394.8%, respectively, compared with ith conventional RC column. The superior ductility and saturated cracking behavior of HS-ECC ensure jacketed columns have higher damage tolerance and crack closure ability. Compared with HPM and HSFRC jacketed columns, the ultimate displacement of HS-ECC jacketed column was improved by 113.4% and 26.5%, respectively. The accumulated energy dissipation was 866.6% and 111.7% higher than that of HPM and HSFRC jacketed columns. Additionally, the increase in strengthening height could significantly enhance the seismic performance of HS-ECC jacketed columns. In terms of the strengthening scheme, the deformation capacity of cast-in-place HS-ECC jacketed column was better than that of column strengthened by prefabricate HS-ECC slab.

Experimental and numerical simulation study of fiber-reinforced high strength concrete at high strain rates

With the widespread use of fiber-reinforced high strength concrete (FRHSC) in military and civil fields, it is necessary to have an accurate understanding of the mechanical properties and failure modes of FRHSC under impact. The dynamic compression experiments were performed on FRHSC using the large-size split Hopkinson pressure bar (SHPB) apparatus. The experimental results were analyzed to determine the reasonable strain rate range of FRHSC under large-size SHPB loading conditions. The strain rate effect, critical strain, and failure mode of FRHSC under dynamic impact were studied. The strain rate and strength parameters in the Holmquist-Johnson-Cook (HJC) model were determined based on the experimental results, and the numerical simulation of SHPB was completed by LS-DYNA. The results revealed that the reasonable strain rate of FRHSC under large-size SHPB loading did not exceed 100 s−1. The material presented an obvious strain rate effect, and the critical strain was almost unchanged with the increased strain rate. Steel fiber improves the toughness of FRHSC. Under quasi-static loading, the tensile-compression ratio of the material was 0.13, and there was no apparent damage under impact. The rationality of the strain rate and strength parameters in the HJC model was verified by comparing the stress wave curve of the pressure bar, the stress-strain curve, and the failure mode of the specimen obtained by experiment and simulation.

High-Strength Fiber-Reinforced Concrete in Structures for General Construction and Special Purposes

High-Strength Fiber-Reinforced Concrete in Structures for General Construction and Special Purposes

The fracture energy and mechanical properties of high-strength concrete containing polyolefin macro-fibres

In this study, the mechanical properties and fracture energy of high strength fibre reinforced concrete (HSFRC) have been investigated. For this purpose, eight mix compositions have been made in two water-to-binder (W/B) ratios of 0.32 and 0.37. The quantity of coarse and fine aggregates in the two W/B ratios were not the same. The polyolefin macro-fibres were used at three different fibre volume fractions of 0.2, 0.4 and 0.6%. The compressive strength, flexural strength, fracture energy, capillary water absorption, electrical resistivity and ultrasonic pulse velocity tests of concrete mixes were studied. The results showed that polyolefin macro-fibres had negligible effect on the compressive strength. However, the use of polyolefin macro-fibres improved the flexural strength of high-strength concrete. The highest improvement of flexural strength was obtained in the volume fraction of 0.4% at the W/B ratio of 0.32, which improved by 22.1% in comparison to the control mix. Moreover, the fracture energy of high-strength concrete highly depended on the amount of macro-fibres. For instance, the use of 0.2, 0.4 and 0.6% macro-fibres has led to the improvement of fracture energy by 133, 228 and 190% for mixes with W/B ratio of 0.32, respectively. Furthermore, by increasing the amount of fibres, the capillary water absorption coefficient of concrete enhanced; therefore, its water penetration increased.

Mechanical Properties and Absorption of High-Strength Fiber-Reinforced Concrete (HSFRC) with Sustainable Natural Fibers

This study aimed to determine the mechanical properties and absorption of high-strength fiber-reinforced concrete (HSFRC), using sustainable natural fibers. In this analysis, two types of fibers were used, namely, ramie and abaca. Two different HSFRC mixtures were also designed, where one composition emphasized ordinary Portland cement (OPC) as a binder, and the other prioritizing calcined diatomaceous earth (CDE) as a mineral additive to replace 10% weight of OPC. Furthermore, ramie and abaca fibers were separately added to the mixtures at three different volumetric contents. Based on the results, the addition of these fibers in the concrete mixtures improved the mechanical properties of HSFRC. The improvements of compressive strength, splitting tensile strength, and flexural strength, due to the addition of ramie fiber were 18%, 17.3%, and 31.8%, respectively, while those for the addition of abaca fiber were 11.8%, 17.2%, and 38.1%, respectively. This indicated that the fibers were capable of being used as alternative materials for sustainable concrete production. The effects of ramie and abaca fibers on the absorption of HSFRC were also not significant, and their presence for the same amount of superplasticizer reduced the flow speed of fresh reinforced concrete mixtures.

Semi-circular bending setup for predicting fracture characteristics of high-strength fiber-reinforced concrete

Semi-Circular Bending (SCB) Setup is commonly used to investigate the fracture parameters of the road materials like asphalt mixtures. This paper examines the performance of the SCB setup in extracting the fracture characteristics of high-strength fiber-reinforced concrete (HSFRC). Monofilament and fibrillated polypropylene fibers with polyolefin coatings of 19, 30, and 50 mm length were added to a high-strength concrete mixture at three volume percentages of 0.5, 1, and 1.5 %. Standard cube and cylinder specimens were initially fabricated for conventional material properties tests. Subsequently, the three-point bending test specimens, i.e., intact rectangular beam, notched beam, and SCB, were made using the same concrete mix of different fibers lengths and percentages. A total of 36 beam and SCB tests with three replications was conducted to find the fracture energy and pick load of each specimen. Results showed that selecting the shortest fibers (19 mm) of 0.5 % and 1.5 % by volume increased the elastic modulus and the splitting tensile strength by 70.5 % and 43 %, respectively. Also, increasing the fiber length and volume enhanced the fracture energy of the notched beam and SCB specimens up to 90 times and 40 times, respectively. However, increasing the volume of the fibers was more effective than using longer fibers in fracture energy increase. For these three test setups, finite element models were generated and analyzed to develop a numerical framework capable of predicting the fracture characteristics of HSFRCs with acceptable accuracy (maximum error of 4 %). The concrete damaged plasticity (CDP) model in ABAQUS software package were adopted to simulate the damage initiation and progression in concrete using the material properties from the conventional tests. Comparing the results of beam setups with SCB tests, it was found that SCB can be a reliable and economical setup to find the fracture characteristics of the HSFRCs.

The Effect of Mineral Admixtures and Fine Aggregates on the Characteristics of High-Strength Fiber-Reinforced Concrete.

the article discusses the effect of the complex of active mineral additives consisting of silica and fly ash, and a fine aggregate, including finely ground natural-white quartz sand for partial replacement of river sand, on the mechanical properties of high-strength concrete containing steel fiber. high-strength concrete containing Dramix®3D 65/35 steel fiber in the amount of 100 kg per 1 m3 of concrete mixture was suggested where 22% to 100% of river sand was replaced by finely ground white natural sand of the particle size of 5 to 1800 μm and containing the complex of active mineral additives for partial replacement of cement as part of a multicomponent binder, consisting of low-calcium fly ash of thermal power plants and silica and containing, respectively, 20, 30, 40% fly ash and from 5 to 15% silica by weight of the binder. research results have shown that 100% replacement of river sand with finely ground natural white sand, in concrete containing 20% of the mass as part of a multicomponent binder, fly ash and from 5 to 15% by weight of silica, contributes to the increase of its strength properties: the values of concrete compressive strength after 28 days were in the range from 118.5 to 128 MPa, tensile strength during bending and splitting, respectively, from 18.8 to 25.4 MPa and from 10.2 to 11.9 MPa, which is higher than the strength of concrete samples containing river sand. the achieved results have demonstrated the efficiency of using finely ground natural white sand as an alternative to river sand for producing high-strength concrete, thus helping to save the river sand resources in Vietnam. The use of fly ash and micro silicon, which are power and metallurgy wastes, as part of a multicomponent binder in order to partially replace cement reduces the carbon footprint in the production of binders and will also have a beneficial effect on environmental protection against industrial waste pollution.

Residual mechanical properties of steel fiber reinforced concrete damaged by alkali silica reaction and subsequent sodium chloride exposure

Infrastructures treated with de-icing salts and those which are in direct contact with sea water are subjected to degradation by chloride ingress. Concrete composed of reactive sources of silica and used near such regions can suffer from both, alkali silica reaction (ASR) and chloride ingress subsequently. This research aims at empirically investigating the residual mechanical properties of plain and steel fiber reinforced concrete damaged by alkali silica reaction (ASR) and subsequent chloride ion ingress. Accelerated degradation tests on three concrete mixes such as plain concrete (PC,control), steel fiber reinforced concrete (SFRC) and high strength fiber reinforced concrete (HSFRC) were done. Specimens were initially damaged by ASR, and then submerged in chloride solution at temperature ranges of 5 o C, 25 o C and 40 o C. 1 mol/L NaOH solution and 3% NaCl solution were used for a period of 20 and 40 weeks. Steel fibers were found to be effective in reducing surface crack widths at 5 o C and 25 o C. Accelerated mortar bar test showed that steel fibers were able to reduce expansion by 31.5% and 65.3% using single and double hooked fibers. By examining the residual compressive and flexure strengths, it was found that exposure to chloride environment aided in hydration reaction which counter-balanced the damage due to ASR. Fiber-matrix bonding developed over time inducing friction which led to higher ductility and less damage in flexure strength in steel fiber reinforced concrete prisms.