Title: Shear Strength of Reinforced Limestone Aggregate Concrete Beams

Author(s): Kenichiro Nakarai, Yuko Ogawa, Kenji Kawai, and Ryoichi Sato

Publication: Structural Journal

Volume: 114

Issue: 4

Appears on pages(s): 1007-1017

Keywords: design; fracture energy; limestone aggregate; loading test; reinforced concrete (RC); shear strength; shrinkage; size effect

DOI: 10.14359/51689725

Date: 7/1/2017

Abstract:
Use of limestone aggregate has been recently increasing to improve material properties such as shrinkage reduction. However, limestone aggregate may cause brittle failure of concrete and concrete structures. Therefore, this study compared the fracture properties of normal-strength concrete and the shear strength of reinforced concrete (RC) beams with limestone aggregate with those with rhyolite aggregate as the reference. The results showed that the shear strength of the limestone aggregate concrete beam was on an average approximately 24% less than that of the reference beam and it was only 57% of the ACI Code calculation at the minimum. The reduction was explained by the fracture properties of limestone aggregate concrete: small characteristic length with low fracture energy. The relationship between normalized shear strength and characteristic length, which was originally proposed based on the numerical studies, showed a trend similar to high-strength concrete, which was experimentally investigated.