Behavior of Ultra-High-Performance Concrete with Hybrid Synthetic Fiber Waste Exposed to Elevated Temperatures

Abstract

The reinforcement of ultra-high-performance concrete (UHPC) with fibers was investigated in this study. Concrete is the most widely used manmade construction material, and UHPC has remarkable mechanical properties. The mechanical properties of UHPC can be modified by a variety of curing procedures and the amount of cement used. This study aimed to examine the impact of fiber reinforcement, temperature, and exposure time on UHPC. Initially, the temperature for UHPC was changed from 300 °C to 500 °C and the exposure time set to 1 and 2 h. Various combinations of the ultrasonic pulse, thermal conductivity, compressive strength, flexural strength, splitting, modulus of elasticity, and drop hammer impact (impact resistance, impact energy, and ductility index) were investigated after 91 days of steam curing. For steam curing, the temperature was kept at 90 °C for three days. The mechanical characteristics of UHPC were the primary focus of this research. The test results showed that the accelerated curing regime achieved a maximum compressive strength of 102.6 MPa for UHPC specimens without fibers and 124.7 MPa for UHPC specimens with fibers, which represents a 22% increase in compressive strength. When compared to UHPC without fibers, all the qualities of UHPC with fibers were improved, especially when subjected to high temperatures. The incorporation of hybrid synthetic waste fibers was a key aspect in developing new ultra-high-strength concrete features.

Experimental Characterization of the Thermal and Mechanical Properties of Earth Bricks Stabilized by Alkaline Solution and Reinforced with Natural Fibers: A Comparative Study

“…This is due to the fibers creating air spaces within the bricks, which act as thermal insulation. These air pockets impede the transfer of heat through the material, resulting in an increase in thermal resistance [16,17,18]. This study's results align with previous research demonstrating the impact of natural fibers on the thermal properties of construction materials [19,20].…”

Effect of modified nano‐titanium and fly ash on ultra‐high‐performance concrete properties

“…Recently, researchers have been interested in producing and developing ultra‐high‐performance concrete (UHPC) properties and their applications, 1–3 in addition to studying the possibility of using nanomaterials (NMs) of industrial waste to improve concrete properties and reduce production costs 4–8 . The main distinguishing features are the superior UHPC's mechanical strength, which is not less than 150 MPa; the tensile strength, which is greater than 8 MPa at 28 days test age of; and its ultra‐durability 9,10 .…”

“…industrial waste to improve concrete properties and reduce production costs. [4][5][6][7][8] The main distinguishing features are the superior UHPC's mechanical strength, which is not less than 150 MPa; the tensile strength, which is greater than 8 MPa at 28 days test age of; and its ultra-durability. 9,10 Other distinguished mechanical properties that have attracted researchers and developers include high strength, flexural, splitting tensile, bonding, freezing and thawing, shrinkage and high modulus of elasticity, 11,12 in addition to superior durability properties, such as low rate of air content, water sorptivity, chloride permeability, water and gas permeability, and water absorption.…”

An Analytical Algorithm for Determining Optimal Thin-Walled Hollow Pier Configuration with Sunlight Temperature Differences

“…For thin-walled hollow high-piers in the state of the construction stage, any change in sunlight temperature leads to an uneven temperature field on a pier that typically presents with a nonlinear distribution [1,2]. This can lead to a large nonlinear temperature difference in the pier structure that can cause structural deformation, the temperature difference is affected by atmospheric temperature, sunlight radiation, section position, and other factors [3][4][5]. With the recent development of highway construction in China, the amount of high-pier bridge construction has been correspondingly increasing, and the height of piers has also been gradually increasing.…”