In many structural applications, concretes reinforced with short metal or synthetic fibers (fiber-reinforced concrete (FRC)) have a number of advantages over traditional concretes reinforced with steel rebars reinforcement, such as easier and more economical production, wear resistance, impact resistance, integrity, etc. In the present study, several concrete mixes were developed and prismatic FRC specimens were fabricated. Their structural behaviors were studied using bending tests until prisms were fractured. Two types of fibers, namely, steel and polypropylene (PP) and three different concrete matrixes were investigated, testing in total 12 FRC prismatic specimens. Every group of FRC had the same concrete matrix, but different internal fiber architecture. All specimens were tested by Four-Point Bending (4PBT). The analysis was carried out with a goal to determine the workability and flexural tensile strength of all FRC groups, comparing these parameters with fracture modelling results. Single crack formation and opening model were established. Crack is crossing whole stretched part of the prism’s orthogonal crossection. Crack is opening, fibers are bridging the crack and are pulling out. Load bearing curves in the model were compared with experimentally obtained.

In the present study, the mechanical behavior of Fiber-Reinforced Concrete (FRC) beams was studied under bending until rupture. Each beam was reinforced with a hybrid mix of short fibers randomly distributed in its volume. Concrete beams with three different fiber combinations were investigated, namely, beams reinforced with (1) a homogeneously distributed mix of short polypropylene fibers (PP) and steel fibers, (2) PP fibers and Alkali Resistant Glass (ARG) fibers, and (3) PP and composite fibers (CF). The amount of short PP fibers was the same in all FRCs. The investigation focused on the fracture mechanisms and the load-bearing capacity of FRC beams with the developing macro cracks. In total, 12 FRC composite prismatic specimens were casted and tested in four-point bending experiments (4PBT). The current load value versus the Crack Mouth Opening Displacement (CMOD) for all FRCs was analyzed. The crack opening relationship and the influence of fibers on the fracture energy and flexural tensile strength were determined. Rupture surfaces of all samples were investigated using an optical microscope.

Different authors conducted studies on fiber reinforced concretes (FRC) with carbon fibres of different lengths and some results showed that concrete mix with homogeneously distributed short fibres in their volume have good strength and ultra-strain compared to normal plain concrete mix. However, this study is focused more on 3-dimensional (3D) carbon fibre reinforced plastic (epoxy) CFRP composite thin rods frame used as a reinforcement in concrete which shows good increase in loadbearing and ductility. Were investigated concrete mixes with superplasticizer, nano-silica, quartz sand, fine natural sand and gravels. Diagonal cross bracing carbon fibre epoxy frames were used as a reinforcement giving better ductility results. Proposed study approach is to show that the reinforced concrete with provided materials have an increased performance in terms of ductility, sustainability, and load bearing in cracked statement. Total, four groups of concrete and each group with three beams were casted and tested in this experiment, three groups with three different shapes of carbon frames and three beams without frames to compare the mechanical properties after 28 days. Failure mechanisms in any particular case were analysed.

Utilizing fibre-reinforced concrete is still a difficulty for present engineers. Generally, it is acknowledged that the mechanical, cracking and fracture qualities of fibre-reinforced concrete are much better than those of conventional concrete. The addition of fibres to the concrete matrix mitigates its fragility. Typically, short fibres are utilised in concrete to prevent cracks caused by drying and autogenous shrinkage. Currently, there is a substantial increase in the use of short alkali-resistant glass fibres. This experiment was conducted to examine the influence of glass fibre reinforcement on the compressive and flexural behaviour of concrete. This research investigates the characteristics of glass fibres reinforced concrete (GFRC) after 7 and 28 days of curing, such that GFRC may be employed in construction. Concrete containing short alkali-resistant glass fibres of 36 mm in length and 1% volume fraction (VF) was developed for this purpose. The testing findings revealed that the average compressive strength of GFRC after 28 days of curing was 72.06 MPa. The flexural properties of GFRC are determined, and the 7-day and 28-day average bending strengths of GFRC concrete samples are 6.46 MPa and 7.94 MPa, respectively, indicating that GFRC responds well under loading conditions.

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