Title: Effect of Aggregate Type on Mechanical Behavior of Dam Concrete

Author(s): Qingbin Li, Zongcai Deng, and Hua Fu

Publication: Materials Journal

Volume: 101

Issue: 6

Appears on pages(s): 483-492

Keywords: aggregate; compression; cracking; modulus of elasticity; stress; tension

DOI: 10.14359/13487

Date: 11/1/2004

Abstract:
This paper deals with the effect of the aggregate type on the behavior of dam concrete (or mass concrete) in uniaxial tension and compression with two types of aggregates by full size specimens of 450 x 450 x 900 mm (18 x 18 x 35 in.) for tension and 450 x 450 x 450 mm (18 x 18 x 18 in.) for compression and by standard size specimens 150 x 150 x 550 mm (6 x 6 x 22 in.) for tension and 150 x 150 x 150 mm (6 x 6 x 6 in.) for compression, respectively. The complete stress-strain responses both in tension and compression were acquired through a systematic experimental program. Models with hyperbolic form were proposed to estimate the basic mechanical properties and the fracture parameters of the concretes with specimen ages. Relationships between the tensile and compressive strengths were established. Theoretical models for normalized axial stress-strain curve in compression and for normalized axial stress versus normalized maximum crack width curve in uniaxial tension were proposed. In addition, the axial stress-crack width curves, fracture energy, and brittleness were also obtained based on the stress-deformation curves. It was found that: the strengths, modulus of elasticity, and fracture energy increase with specimen age; the specimen size and maximum aggregate diameter significantly affect the fracture energy, peak strain, and crack width of concretes in uniaxial tension; and the performance of concrete with crushed coarse aggregate is higher than that of concrete with natural coarse aggregate.