Failure mechanism of concrete: combined effects of coarse aggregates and strength level

GIACCIO, G.; ZERBINO, R.

Advanced Cement Based Materials

Lugar: Evanston Illinois; Año: 1998 vol. 7 p. 41 - 48

1065-7355

<!-- /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; mso-layout-grid-align:none; punctuation-wrap:simple; text-autospace:none; font-size:10.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman"; mso-ansi-language:EN-US;} @page Section1 {size:612.0pt 792.0pt; margin:70.85pt 3.0cm 70.85pt 3.0cm; mso-header-margin:36.0pt; mso-footer-margin:36.0pt; mso-paper-source:0;} div.Section1 {page:Section1;} --> Concrete is a composite, though its properties depend on the properties of the component phases and the interaction developed between them. As it is known that the interfaces are the weakest link in concrete, having a very important role in the process of failure. This process is strongly related with the characteristics of the aggregates (specially coarse aggregates) and with the relative differences in strength between matrix and inclusions. This paper analyses the mechanical behavior of High-strength and conventional concretes prepared with coarse aggregates with significant differences in strength, shape and surface texture, porosity and absorption, and interfaces bond strength. Two different gravel and two crushed stones were used. Concrete mixtures with water cement ratios 0.30 and 0.50 were designed. The effect of aggregate type and strength level on concrete failure mechanism, including tensile and compressive strength, stiffness, energy of fracture and crack pattern, is discussed.