Title: Fracture Energy of Rice-Husk Ash Concrete

Author(s): G. Giaccio, G.R. de Sensale, and R. Zerbino

Publication: Symposium Paper

Volume: 228

Issue:

Appears on pages(s): 111-122

Keywords: energy of fracture; high-strength concrete; rice-husk ash; stiffness; strength

DOI: 10.14359/14465

Date: 6/1/2005

Abstract:
As with other mineral admixtures, the use of rice-husk ash leads to an improvement of the concrete internal structure, reducing the pore size and particularly an improvement in the interface bond. In this sense it can be assumed that the failure mechanism can be modified, and the concrete will exhibit a more brittle behavior. That has a special interest in high-strength concrete and in the design of large concrete structures. This paper focuses on the fracture behavior of rice-husk ash concrete. A wide range of concrete strengths are analyzed including normal and high-strength mixtures. The flexural behavior was analyzed following the general guidelines of the RILEM 50-FMC using a center-point loading arrangement on notched beams of 400 mm span, measuring deflections and the crack mouth opening displacement (CMOD). In addition, the compressive strength and the elastic modulus were measured on standard cylinders. The effects of water-cementitious material ratio and the age of testing on the strength, energy of fracture and the characteristic length on concretes with and without rice-husk ash incorporation are discussed.