Normal statistical fracture analysis of Roller-compacted concrete on the basis of non-linear elastic fracture mechanics

Abstract

Roller-compacted concrete (RCC) is widely used in dam structures; the fracture properties of RCC directly affect the cracking resistance of RCC dams. Solving the discrete problem of the RCC fracture properties and obtaining real material parameters is important for the healthy and stable operation of RCC structures. The tensile strength (ft) and fracture toughness (KIC) are two critical parameters that have a direct impact on the fracture properties of RCC structures. In this study, the relative ligament depth [(W − a0)/di] is associated with the fictitious crack growth length (Δafic). A normal statistical fracture model is developed to describe the dispersion of the RCC ft and KIC to obtain the real material parameters of RCC with different cement-to-aggregate (C/A) ratios. For an increase in the C/A ratio from 12 % to 17 %, the ft and KIC for each group of RCC structures are 4.05–6.35 MPa and 0.90–1.41 MPa·m1/2, respectively. Based on the results of the normal statistical analysis, fracture failure curves are constructed with 95 % reliability, revealing that the fracture behavior of RCC is quasi-brittle fracture. Additionally, a relationship between the peak load (Pmax) and the material parameters is proposed, this confirms the correctness of the proposed model. Finally, the relationship between indoor small-size specimens and actual engineering-scale RCC dams regarding fracture failure is discussed based on the fracture failure curve.