Poređenje svojstava određenih nedestruktivnim metodama na betonima na bazi korunda sa i bez dodatka elektrofilterskog pepela

Abstract

Analiza i određivanje svojstava betona u ovom radu izvršeni su pomoću nedestruktivnih metoda: metode brzine ultrazvuka i metode analize slike. Cilj istraživanja je bio da se utvrdi veza između procesa sinterovanja i konačnih performansi betona na bazi korundnog agregata. Ispitivana su dva tipa betona otporna na visoke temperature:beton (C1) koji je spravljen na bazi visoko-aluminatnog cementa i korunda, i beton (C2) baziran na istim polaznim materijalima i dodatkom elektrofilterskog pepela koji je potencijalno opasna materija za životnu sredinu, ali ujedno i vrlo korisna sekundarna sirovina. Pritisna čvrstoća je ispitivana na sobnoj i na povišenim temperaturama (110, 300, 500, 800, 1000, 1300 i 1500 ºC) pomoću metode brzine ultrazvuka. Nivo površinske poroznosti na sobnoj temperaturi i nakon svakog termičkog tretmana je ispitan pomoću Image Pro Plus - programa za analizu slike. Rezultati nedestruktivnih metoda su zatim upoređeni sa rezultatima standardnih laboratorijskih metoda. Nedestruktivne metode su se pokazale kao pouzdane u karakterizaciji mikrostrukturnih defekata i optimizaciji mešavine viskotemperaturnog betona za konkretnu primenu.

The analyses of the concrete properties performed in this study were conducted by means of the nondestructive methods: ultrasonic pulse velocity technique and image analysis. The goal of the investigation was to establish mutual correlation between the sintering process and the final performances of the concretes based on corundum aggregate. Two types of high-temperature resistant concrete were investigated: concrete (C1) based on high aluminates cement and corundum, and concrete (C2) based on the same starting materials and the addition of fly ash, which can be considered as potentially harmful waste material for the environment but at the other side as useful secondary raw material. The mechanical strength of concretes was investigated at ambient temperature and at elevated temperatures (110, 300, 500, 800, 1000, 1300 and 1500 ºC) by means of ultrasonic pulse velocity technique. The level of the superficial porosity, present at ambient temperature as well as after thermal treatments, was investigated using Image Pro Plus - program for image analysis. Non-destructive measurements were afterwards compared with results of the standard laboratory procedures. Nondestructive methods proved to be reliable means for the characterization of micro-structural defects and the optimization of high-temperature concrete design for an application. .