A simple fracture model for dam concrete based on the Fuller and Thompson formula

Abstract

This study presents a simple model for determining the fracture parameters of dam concrete, by introducing the Fuller and Thompson formula for estimating the average aggregate size d av when only the maximum aggregate size d max is known. The crack propagation mechanism of dam concrete is analyzed at the mesoscopic level. The calculation method of fictitious crack growth length Δa fic and characteristic crack length a à ∞ of dam concrete is also described. A normally distributed fracture model for the variation of fracture toughness K IC and tensile strength f t with d av is proposed for different specimen patterns (wedge splitting, compact tension, and three-point bending) and different relative sizes. The fracture parameters derived by this model show consistent with the results obtained in the laboratory. The fracture failure curve of a dam concrete is established, and the peak state of a true structure of large size is also predicted satisfying linear elastic fracture. K E Y W O R D S dam concrete, fracture toughness, Fuller and Thompson formula, normal distribution, tensile strength 1 | INTRODUCTION After the construction of the world's first hydroelectric power plant in France in 1878, dam construction gradually entered the era of intelligence, developed from manual, mechanized, automated, to digital construction. 1 Many 300 m class concrete arch dams are currently under construction and proposed in southwest China: Xiluodu Arch Dam (285.5 m), Baihetan Arch Dam (289 m), Wudongde Arch Dam (240 m), Yebatan Arch Dam (224 m) and Longpan Arch Dam (276 m) in the Jinsha River Basin, Jinping Grade I Arch Dam (dam height 305 m), Ertan Arch Dam (dam height 240 m), and Mengdi Ditch Arch Dam (dam height 210 m). Many key technologies of China's extra-high arch dam project exceed the world's existing experience, and the comprehensive technical difficulty is among the highest in the world. Full-graded hydraulic concrete is generally used in the construction of extra-high arch dams (divided into four continuous grades according to the size of coarse aggregate, namely, 5-20,

Study on the Influence of Particle Size Distribution on the Separation of Pyrite from Coal Gangue by Jigging

“…In recent years, particle size analysis [18,19] has been widely used in the study of fine dust materials. The normal distribution [20], lognormal distribution [21], Fuller distribution [22] and Rosin-Rammler (RRSB) distribution [23]. These are the functional models commonly used to express the grain size distribution of fine powder materials.…”