Influence of fiber on the shrinkage performance of alkali-activated slag recycled concrete.

Alkali-activated slag recycled coarse aggregate concrete (AAS-RAC) is a novel type of green building material with significant growth potential, utilizing waste slag and construction waste effectively. However, its large shrinkage and poor toughness limit its further utilization. Adding fiber is the crucial way to limit its shrinkage. Therefore, the effects of fiber type and content on the shrinkage performance of AAS-RAC were systematically studied. The results show that the incorporation of recycled aggregate increases the shrinkage of AAS-RAC, and AAS-RAC of full recycled aggregate is 59% higher than that of undoped aggregate. The addition of steel fiber, polypropylene fiber and basalt fiber can effectively reduce the shrinkage of AAS-RAC. Among them, steel fiber has the best inhibition effect, and 0.6% steel fiber can reduce the shrinkage of AAS-RAC by 30.6%. The AAS-RAC shrinkage model considering the influence of fiber content and recycled aggregate is established. The research results provide an effective way to reduce the shrinkage of AAS-RAC. [ABSTRACT FROM AUTHOR]