Effect of particle distribution on the shear behavior of recycled concrete aggregate

• Published in: Arabian journal of geosciences Vol. 15; no. 10
• Main Authors: Zhu, Weihao, Wang, Jun, Wang, Long, Ying, Mengjie, Hu, Xiuqing, Fu, Hongtao
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 2022; Springer Nature B.V
• Subjects: Aggregates; Civil engineering; Coefficients; Concrete; Concrete aggregates; Concrete blocks; Concrete construction; Construction industry wastes; Construction materials; Dilatancy; Earth and Environmental Science; Earth science; Earth Sciences; Empirical analysis; Internal friction; Landfills; Original Paper; Particle distribution; Recycled materials; Shear rate; Shear strength; Shear stress; Shear tests; Shearing; Internal friction; Dilatancy; Apparent adhesion; Particle distribution; Recycled concrete aggregate
• ISSN: 1866-7511; 1866-7538
• DOI: 10.1007/s12517-022-10166-7

Recycled concrete aggregate is an environment-friendly and economical civil engineering material. The concrete blocks in a construction waste dump were crushed and screened to attain recycled concrete aggregate with different particle distributions. A series of monotonic direct shear tests were conducted through large direct shear apparatus to analyze the influence of different particle distributions on the shear characteristics of recycled concrete aggregate. Results show that during the shearing process, the various particle distribution samples experienced shear contraction then dilatation with the gradual increase of shear displacement. Shear strength of recycled concrete aggregate was optimal when the coefficient of uniformity was 13.67 and the coefficient of curvature was 2.44. An increase in normal stress led to an increase in the shear stress of each particle distributions. With the increasing of normal stress, the shear contraction of the shear surface increased, but dilatancy decreased. Under the same particle distribution, when the shear strength was maximized, shear dilatancy was also maximized. As the content of fine particles was increased, the apparent adhesion first decreased and then increased, while the internal friction angle first increased and then decreased. Multiple test results demonstrated that the effect of shear rate on shear characteristics is not obvious on the shear characteristics of the recycled concrete aggregate. An empirical formula for the dilatancy coefficient is established to describe the dilatancy characteristics of the recycled concrete aggregate quantitatively under different particle distributions and normal stresses.