Understanding the role of coarse aggregate on tensile fatigue behaviors of ultra-high performance concrete. (May 2023)

• Record Type: Journal Article
• Authors: Li, Lijian; Xu, Lihua; Zeng, Yanqin; Cui, Kai; Chi, Yin; Huang, Le
• Is Part Of: Cement & concrete composites. Volume 139(2023)
• Publication Date: 2023-05
• Subjects: Ultra-high performance concrete (UHPC) -- Coarse aggregate -- Tensile fatigue behavior -- Microscale characterization -- Mesoscale modeling -- Underlying mechanisms; Composite-reinforced concrete -- Periodicals; Concrete -- Periodicals; Composite materials -- Periodicals; Composites de ciment -- Périodiques; Béton -- Périodiques; Composites -- Périodiques; Béton léger -- Périodiques; Cement composites; Composite materials; Composite-reinforced concrete; Concrete; Lightweight concrete; Periodicals; Electronic journals; 620.135
• DOI: 10.1016/j.cemconcomp.2023.105069
• Languages: English
• ISSNs: 0958-9465

Abstract

Abstract: This work investigated the tensile fatigue behaviors of ultra-high performance concrete containing coarse aggregate (UHPC-CA), with an emphasis on exploring the underlying mechanisms induced by CA incorporation. Upon constant-amplitude fatigue tests at four different stress levels, CA incorporation-induced variations in fracture morphology, deformation capacity, and fatigue life of UHPC-CA were analyzed, which were further revealed through multiscale characterization of hydration products, pore structures, and stress state alterations within UHPC matrix. The results showed that despite the considerable enhancement in elastic modulus in comparison with CA-free UHPC, weakened fatigue deformability and accelerated damage evolution are observed for UHPC-CA. As the CA content increased, the performance degradation was continually exacerbated, and it was experimentally evidenced to be highly linear with the loss of bound water and the increase in macropore volume. Compared to CA-free UHPC, the premature fatigue failure of UHPC-CA was primarily attributed to the magnified stress concentration within the matrix.