Papers by Author: Ren Yu Zhang

Abstract: Based on available test data and fracture criterion, by using probability fracture mechanics and mathematical statistical method, the distribution feature of fracture toughness, IC K , of interface between coarse aggregate and hardened cement mortar is analyzed, and a method of defining the least number of specimens for testing fracture toughness is provided. Weibull distribution or lognormal distribution is often used to analyze lifetime problem, so the two models are preferentially considered. The analysis shows that the fracture toughness conforms to lognormal distribution with degree of confidence g =0.9, relative deviation d =0.05 and the least number of specimens of 13. The study results can be used in the probability fracture analysis and construction quality control of interface between coarse aggregate and hardened cement mortar.

Abstract: In this paper, the main characteristic of definition, property, requirement of raw material, mix proportion design and performance improvement of high volume fly ash concrete (for short HVFAC) are summarized. The applications of HVFAC in dam, highway, building and port are introduced. The research results have shown that HVFAC have outstanding properties of physical mechanics, but some problems need to be further studied. It is believed that an operable strict corresponding technical criterion would be set down as soon as possible for engineering practice.