Chapters authored
Fracture Theory Under Freeze-Thaw Cycles and Freeze-Thaw Resistance of Alkali-Slag Concrete
Despite the widespread research on alkali-activated concrete, its fracture properties under freeze-thaws are rarely studied; the response surface methodology (RSM) theory has not been put forward; and unstable fracture toughness, KICS, influenced by freeze-thaws and slag content has not been researched. The purpose of this article is to investigate the calculation method of alkali-slag concrete (ASC) fracture parameters and provide theoretical support for RSM model of ASC prepared with Na2SiO3 and NaOH composite activator. The influence law of freeze-thaw and slag content on unstable fracture toughness, KICS, is put forward. Results show that after crack mouth opening displacement (CMOD) is measured, other fracture parameters including concrete effective fracture length; crack tip opening displacement (CTOD); and stress intensity factors KICC,KICC, and KICS from closure stress σ(w) can be obtained according to double-K fracture criterion and DL/T 5332-2005 “Hydraulic concrete fracture test procedures”. RSM principles and advantages, its optimization content and procedure, the data processing software Design-Expert and verification analysis procedure of RSM model are put forward. Since the ASC structure is compact, characterized for water and air penetration resistance, its antifreezing characteristic is desirable.
Part of the book: High Performance Concrete Technology and Applications