Abstract

TOBON, JORGE IVAN; ANGEL, ERIKA  and  GOMEZ, VANESSA. BEHAVIOR OF CONCRETES ELABORATED WITH DIFFERENT STONY AGGREGATES OF THE SURROUNDINGS OF MEDELLIN. Dyna rev.fac.nac.minas [online]. 2007, vol.74, n.152, pp.251-262. ISSN 0012-7353.

This paper presents comparisons in compressive strengths to ages of 3, 7, 28 and 101 days (according to NTC-673); durability and petrographic analysis among concretes of 28 MPa of design, made with Portland type I cements and aggregates of five different quarries of the surroundings of Medellin (igneous, metamorphic rocks and alluvial deposits). The results of strengths to 28 days showed that the highest values were obtained with aggregates of igneous rocks, becoming evident, for this study, the influence of the strength, rigidity and hardness of the rock type in properties of concrete. The comparisons of durability were made in concrete cylinders elaborated with the materials of each quarry after 28 days of curing. Finding out that the cylinders elaborated with aggregates of CC presented better stability in front of the chemical agents, still in high concentrations that the other types of rocks. The petrographic analysis included description under the optic microscope and in SEM, of probe made of cylinders fragments failed to compression to the 28 days, to compare the relationship between the cement paste, the thick and fine aggregates. It was found that the samples with smaller strengths presented bigger quantity of pores in the paste and reaction between the paste and the aggregates.

Keywords : Concrete; Durability; Compression strength; Petrography; Aggregates.

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