An experimental program was carried out to investigate the behavior of steel, fiber reinforced concrete (SFRC) under abrasion and cycles of freeze and them. Compression and flexural tests were also performed in order to reach a comprehensive conclusion of the response. In total, over 200 specimens were tested The test variables included two concrete strength., (i. e., 28 MPa as Normal Strength (NSFRC) and 42 MPa as Medium Strength (MSFRC)), four volumetric percentage of fibers (i.e., 0%, 0,5%, 1.0% and 1.5%) and two fiber lengths (i.e.. 25mm and 35rnrn). Cube specimens were tested according to ASTM C6661n-ocedrrre B using 100 cycles of freeze and thaw. The Los Angeles test method for testing aggregate was used to evaluate the abrasion resistance of SFRC. Test results of1VSFRCptesertted improvements up to 39% and 32 % in cylindrical and cubic compressive strength, respectively. and 88°o in modulus of rupture, 57% in resistance against abrasion based oil weight loss and 40% against compressive strength reduction due to freeze and thaw cycles. The corresponding improvements for MSFRC were 18%, 16%, 48%, 53% and 46% respectively. Increase in cocncrete strength from 28 Ala to 42 MPa provided higher freeze and thaw; and abrasion resistance than addition of 1.5% of steel fibers to the normal strength concrete matrix.

In the present work, an attempt is made to investigate shear strength and ductility of fiber reinforced concrete beams by using hooked steel fibers. All the test beam specimens were 100mm in width, 150mm in depth and 1200mm in length and the primary variables of the investigation were percentage of fibers (0.5 to 5 %), percentage longitudinal tension steel (0.8 to 3.22 %) and cube compressive strength of concrete (in the range of 34 to 41 MPa), with a view to cover a wide spectrum of concrete strength in shear. The shear span-to-depth ratio (a / d ratio) was kept constant at 3.20. This has resulted into casting and testing of twenty SFRC beam specimens. All the beam specimens were tested under four-point loading (2-active, 2-passive) test set-up and the failure load, crack pattern and deflections were recorded concisely and precisely. The experimental results clarify the enormous influence of hooked mild steel fibers on shear strength of concrete. At low fiber volume fraction, the influence of fibers is negligible and is significant with the increase in the fiber volume fraction. The concrete beam specimens exhibited substantial increase in their ultimate load as well as in the load at first cracks, enhanced deformation characteristics at all stages of loading up to failure.In general, the significant improvement in various strengths is observed with the inclusion of steel fibers in the plain concrete. However, maximum gain in strength of concrete is found to depend up on the amount of fibre content.

Experiments on circular steel tubes filled with steel fibre reinforced concrete (SFRC) and normal concrete have been performed to investigate the contribution of steel fibres to the load bearing capacity of short composite columns. The main variables considered in the test study are diameter to thickness ratio of the steel tube and the percentage of steel fibres added to the in-filled concrete. All the specimens were tested under axial compression until failure state realization. Extensive strain and deformation measurements were taken at compression and tension zones and the results show that 1.00% SFRC in-filled steel columns exhibit enhanced ultimate load carrying capacity, stiffness and ductility coefficient. Also a nonlinear finite element model was developed to study the load carrying mechanism of CFTs using the Finite Element software version ABAQUS. This model was validated using the experimental load–deformation curves and the corresponding modes of collapse. A comparison of the observed load carrying capacity and flexural stiffness with various codal recommendations has been carried out to check the applicability of the expressions recommended by the various codes of practice. Of all the codes compared, Eurocode 4 showed the least variation and is found to be more viable to predict the strength of normal as well as SFRC in-filled steel tubes under axial compression.

The present paper offers a meso-scale numerical model to investigate the effects of random distribution of aggregate particles and steel fibers on the elastic modulus of Steel Fiber Reinforced Concrete (SFRC). Meso-scale model distinctively models coarse aggregate, cementitious mortar, and Interfacial Transition Zone (ITZ) between aggregate, mortar, and steel fibers with their respective material properties. The interfaces between fibers and mortar have been assumed perfectly bonded. Random sampling principle of Monte Carlo's simulation method has been used to generate the random size, orientation, and position of aggregate particles as well as steel fibers in concrete matrix. A total of 2100 two-dimensional and three-dimensional cube specimens (150 mm) with varying volume fractions of aggregate and fiber have been randomly generated. The commercial code ABAQUS has been used to analyze the specimens under tensile loading and the calculated elastic modulus has been compared to other analytical and experimental values. Results indicate that the non-homogeneity of the matrix and random distribution of aggregate and fibers manage to disperse calculated efficiency factor of fiber with a standard deviation of 2.5% to 3.0% (for 150 mm cube specimens, it can be different for other specimens). Nevertheless, the mean value of the calculated efficiency factor agrees well with the value, recommended by Hull (1981), for uniformly-distributed fibers, equal to 0.353, and 0.151 for two and three-dimensional models respectively.

Finite element analyses are conducted to model the tensile capacity of steel fiber-reinforced concrete (SFRC). For this purpose dog-bone specimens are casted and tested under direct and uniaxial tension. Two types of aggregates (brick and stone) are used to cast the SFRC and plain concrete. The fiber volume ratio is maintained 1.5 %.Total 8 numbers of dog-bone specimens are made and tested in a 1000-kN capacity digital universal testing machine (UTM). The strain data are gathered employing digital image correlation technique from high-definition images and high-speed video clips. Then, the strain data are synthesized with the load data obtained from the load cell of the UTM. The tensile capacity enhancement is found 182-253 % compared to control specimen to brick SFRC and in case of stone SFRC the enhancement is 157-268 %.Fibers are found to enhance the tensile capacity as well as ductile properties of concrete that ensures to prevent sudden brittle failure. The dog-bone specimens are modeled in the ANSYS 10.0 finite element platform and analyzed to model the tensile capacity of brick and stone SFRC. The SOLID65 element is used to model the SFRC as well as plain concretes by optimizing the Poisson’s ratio, modulus of elasticity, tensile strength and stress-strain relationships and also failure pattern as well as failure locations. This research provides information of the tensile capacity enhancement of SFRC made of both brick and stone which will be helpful for the construction industry of Bangladesh to introduce this engineering material in earthquake design.Last of all, the finite element outputs are found to hold good agreement with the experimental tensile capacity which validates the FE modeling.