A Study of the Flexural Behavior of Fiber-Reinforced Concretes Exposed to Moderate Temperatures

Abstract

The use of synthetic fibers in fiber-reinforced concretes (FRCs) is often avoided due to the mistrust of lower performance at changing temperatures. This work examines the effect of moderate temperatures on the flexural strengths of FRCs. Two types of polypropylene fibers were tested, and one steel fiber was employed as a reference. Three-point bending tests were carried out following an adapted methodology based on the standard EN 14651. This adapted procedure included an insulation system that allowed the assessment of FRC flexural behavior after being exposed for two months at temperatures of 5, 20, 35 and 50 °C. In addition, the interaction of temperature with a pre-cracked state was also analyzed. To do this, several specimens were pre-cracked to 0.5 mm after 28 days and conditioned in their respective temperature until testing. The findings suggest that this range of moderate temperatures did not degrade the behavior of FRCs to a great extent since the analysis of variances showed that temperature is not always a significant factor; however, it did have an influence on the pre-cracked specimens at 35 and 50 °C.

Strength and microscale properties of bamboo fiber-reinforced concrete modified with natural rubber latex

“…The distribution of C-S-H decreases voids and boosts the specimen's strength. The rather porous textured features displayed in this matrix indicate a level of porosity typical of regular mixtures (Castillo-Lara et al, 2020;Sanchez-Echeverri et al, 2020;Zhang et al, 2020;Caballero-Jorna et al, 2021;Aisheh et al, 2022;Najm et al, 2022). Depending on the amount of latex in the mix, modified mixes on the other hand have displayed more compact characteristics.…”

Behaviour of Hybrid Fibre-Reinforced Ternary Blend Geopolymer Concrete Beam-Column Joints under Reverse Cyclic Loading

“…The structural integrity of FRC is mainly based on the properties of the fibres, such as fibre geometry, the orientation of the fibre in the concrete, the type of fibre and the volume fraction of the fibre [ 6 , 7 , 8 , 9 , 10 ]. Several studies have addressed that incorporating fibres in concrete can improve properties such as impact resistance, flexural strength, thermal resistance, fatigue resistance and ductility [ 11 , 12 , 13 , 14 , 15 ]. Brandt [ 16 ] evaluated the orientation effect of parallel fibre systems and concluded that the maximum fracture energy was due to the fibres being subjected to axial tension.…”