ESTIMATION OF TYPE AND AMOUNT OF AGGREGATES IN HARDENED CONCRETE

Abstract

Sometimes happens that certificated concrete products, in which declarations of performance refer high strength and frost resistance indexes, start to deteriorate in first exploitation years. Due to aggressive environment this occurrence is frequent in concrete articles used for tiding surroundings: concrete paving blocks, slabs, curbs used for streets, parking places and pavements. Frequently, the main reason of deterioration is that concrete products are produced from the different concrete composition like samples, which have been used for certification. There are standard methods to estimate the amount of cement in concrete and to do a determination of air void characteristics in hardened concrete, but there are no methods how to estimate the amount and type of aggregates in concrete. For this reason, a new method was created. For the testing, the deteriorating paving zone, which had been built three years ago, was selected. The types of aggregates used in the production of concrete paving blocks have been estimated analyzing the cuts of the blocks. The test results show that the main aggregate, used for concrete paving block production, is gravel and it was used in higher amount as declared, while the granite breakstone and crushed gravel was used for production in lesser amount. In this case, the producer applying different amounts of aggregates reduced cost price as well as worsened the properties of concrete.

Keywords: aggregates, concrete composition, early deterioration, paving blocks.

Article DOI: http://doi.org/10.15544/RD.2015.009