An experimental investigation and optimization of the properties of concrete containing cellulose fiber based on system theory

Abstract

This study aims to provide an approach for the optimization and prediction of the properties of cellulose fiber-reinforced concrete using system theory. First, mechanical properties, drying shrinkage, and anticrack properties of mortar reinforced with cellulose fibers (CTF960, CTF850, and CTF800) at the contents of 0.6, 0.9, 1.2, 1.5, and 1.8 kg/m3 were evaluated by a three-point bending test, direct tensile test, drying shrinkage test, and a slab method with stress risers. The optimal fiber category and dosage range were initially selected based on the performance of the mortar using the comprehensive index method. Next, the Box–Behnken design (BBD) method was used to conduct a mix design and establish prediction models for the mechanical properties, resistance to freeze–thaw cycles, and chloride ion penetration of the cellulose fiber-reinforced concrete. Finally, the optimal mix scheme was selected using the grey target decision based on the entropy weight method. The experimental results showed that CTF960 most significantly improved the performance of the mortar. When the CTF960 ranged from 0.9 to 1.5 kg/m3, the best comprehensive performance of the mortar was acquired. In addition, CTF960 with appropriate content enhances the mechanical properties and durability of concrete. According to the grey target decision results, concrete with a CTF960 content of 1.2 kg/m3, sand ratio of 0.4, and superplasticizer content of 2% exhibited optimal mechanical properties and durability.