Influence of aggregates on the shrinkage of concrete

Cilj ovog rada bio je istražiti utjecaj agregata na skupljanje betona. Mjerene su deformacije pri skupljanju uslijed sušenja betona s različitim vrstama agregata i istražen je utjecaj agregata na ta svojstva. U prvom dijelu napisane su najvažnije karakteristike betona, agregata i skupljanja betona. U eksperimentalnom dijelu rada proučeni su utjecaji modula elastičnosti, količine upijanja vode i gustoće agregata na beton i zaključeno je da nema povezanosti između tih karakteristika i deformacije betona uslijed skupljanja. U sljedećem koraku prikazane su specifične površine agregata dobivene BET metodom korištene vodenom parom jer su one pokazale veće vrijednosti nego one dobivene s dušikom. Zaključeno je da se deformacije betona pri skupljanju uslijed sušenja povećavaju sa specifičnim površinama korištenih agregata u betonskoj smjesi. Rezultati ispitivanja prikazuju kako specifična površina određena ovim metodama prikazuje učinkovit indeks ocjene utjecaja vrste agregata na skupljanje uslijed sušenja.The objective of this work was to determine how aggregate properties affect the shrinkage of concrete during drying. This was determined by measuring the deformations due to shrinkage of concrete made with different types of aggregates. The main properties of concrete and aggregate and the shrinkage of concrete were described in the first part of the paper. In the experimental part of the paper, the effect of Young's modulus, aggregate type, water absorption and density on the shrinkage of concrete was determined. They were found to have no effect on the shrinkage of the concrete. Moreover, the specific surface areas of the aggregates determined by the method BET were presented with both nitrogen and aerated water - and the values determined with H 2 O were higher, which is why they were used in the experiment. The experimental results indicate that a higher specific surface of the aggregates increases the shrinkage of the concrete. It was also found that the specific surface areas of aggregates determined by the water vapour method are an effective index to determine the influence of aggregate properties on the drying shrinkage of concrete