Implementation of image analysis research on concrete lifetime prediction for thermal stability and cavitaion eriosion testing

Abstract

Lifetime prediction for construction material is essential and very often crucial for determination of impact on material application and service. Many models based on different parameters were used to monitor materials behavior subjected to different extreme conditions such as thermal shock and erosive wear. In this chapter, image analysis for lifetime prediction of refractory concrete, more precisely low cement high alumina castable, during the thermal shock and cavitation erosion was studied and discussed. Generally, analyzed material has the properties that depend on sintering temperature but usually is a material with very high strength, density, hardness, and good thermal stability resistance. Usage of image analysis for lifetime prediction of refractory concrete during the thermal shock and cavitation erosion were the goals of this study. Thermal stability was investigated using most common experimental method, water quench test. Destruction of samples during the testing was monitored by image analysis. Results obtained from the image analysis of samples surface and bulk give proof that the level of degradation induced by extreme conditions can be monitored by this way. Values of degradation level were used for lifetime modeling expressed as strength degradation, and correlated to the experimental values. Based on the models for strength degradation using degradation level as variable, model for lifetime was proposed. Similar approach was applied in case of monitoring the degradation level caused by cavitation erosion experiments. The fluid dynamic system of the experimental methodology used to produce ultrasonic erosive wear. Mass loss and level of material degradation were measured before and during the experiment. Level of degradation, that is average erosion area were monitored by using Image Pro Plus program for image analysis. Obtained results showed that after 180 minutes sample exhibited excellent erosion resistance compared to metallic and ceramic samples. Level of surface degradation did not overcome 8 % compared to the original surface.