Mechanical Performance and Numerical Simulation of Basalt Fiber Reinforced Concrete (BFRC) Using Double-K Fracture Model and Virtual Crack Closure Technique (VCCT)

摘要

This paper mainly investigates the fracture parameters of Basalt Fiber Reinforced Concrete (BFRC) with various fiber lengths and dosages using Double-K fracture model. The model was developed by fracture criterion using ABAQUS Virtual Crack Closure Technique (VCCT), and the results of the model and experiments were compared. The basalt fiber with length of 6?mm and 12?mm was added into concrete in the dosage of 0.0%, 0.1%, 0.2%, 0.3%, 0.4%, and 0.5% by volume of concrete, respectively. Concrete specimens were cast into three dimensions, i.e., 60?mm?×?180?mm?×?480?mm, 80?mm?×?240?mm?×?640?mm, and 100?mm?×?300?mm?×?800?mm. Then, three-point bending test was conducted on precast-notched beams. The load versus cracking mouth opening displacement (P-CMOD curve) was developed in order to evaluate cracking and breaking load. The initial fracture toughness and unstable fracture toughness were derived from the Double-K fracture model aimed to optimize the fiber length and dosage. The results showed that the initial fracture toughness and unstable fracture toughness increased first and then decreased with the increase in fiber dosage, and basalt fiber with length of 6?mm and dosage of 0.2% performed the best toughening effect on concrete. The comparison results showed that numerical simulation can better simulate the initiation and propagation of BFRC fractures and achieve the dynamic propagation process of fractures.