Investigation of cement based composites made with recycled rubber aggregate

Abstract

The results of experimental investigations performed on cement based composites made with addition of recycled rubber as a partial replacement of natural river aggregate are presented in this paper. Different properties of cement based mortar were analyzed, both in fresh and in hardened state. The tested properties in the fresh state included density, consistency and volume of entrained air. In the hardened state, the following properties were tested: density, mechanical properties (compressive and flexural strength), modulus of elasticity, adhesion to concrete substrate, water absorption, freeze-thaw resistance and ultrasonic pulse velocity. The obtained results indicate that recycled rubber can be successfully applied as a partial replacement of natural river aggregate in cement based composites, in accordance with the sustainable development concept. The investigation showed that physical-mechanical properties of cementituous composites depend to a great extent on the percentage of replacement of natural river aggregate with recycled rubber, especially when the density, strength, adhesion and freeze-thaw resistance are concerned. The best results were obtained in the freeze-thaw resistance of such composites.

U radu su prikazani rezultati sopstvenih eksperimentalnih istraživanja sprovedenih na cementnim kompozitima spravljenim sa dodatkom reciklirane gume kao delimičnom zamenom sitnog rečnog agregata. Analizirana su različita svojstva cementnih maltera kako u svežem, tako i u očvrslom stanju. Od svojstava u svežem stanju ispitani su: zapreminska masa, konzistencija i sadržaj uvučenog vazduha. U očvrslom stanju, ispitana su sledeća svojstva: zapreminska masa, mehanička svojstva (čvrstoća pri pritisku i pri savijanju), modul elastičnosti, athezija za betonsku podlogu, upijanje vode, otpornost na mraz i brzina prostiranja ultrazvuka. Dobijeni rezultati pokazali su da se reciklirana guma može uspešno upotrebiti kao delimična zamena za klasičan (rečni) agregat kod kompozita spravljenih na bazi cementa, u skladu sa konceptom održivog razvoja. Istraživanje je pokazalo da od procenta zamene rečnog agregata recikliranom gumom u velikoj meri zavise fizičko-mehanička svojstva cementnih kompozita, a naročito zapreminska masa, čvrstoća, adhezija i otpornost na dejstvo mraza. Najbolji rezultati dobijeni su pri ispitivanju otpornosti na dejstvo mraza.