PURPOSES : This study aims to provide quantitative profile values for the objective evaluation of concrete surface profile (CSP) grades in concrete structures. The main aims are to quantify the CSP grade required for concrete surface pretreatment and proposing a more suitable CSP grade for structural maintenance. METHODS : Initially, the challenges in measuring concrete surface profiles were outlined by analyzing pretreatment work and profile samples of concrete pavements. Theoretical foundations for quantifying concrete surface roughness were established, and regression models including linear regression, cubic regression, and log regression were selected. Additionally, the interquartile range anomaly removal technique was employed to preprocess the data for regression modeling. RESULTS : Concrete CSP profiles were measured through indoor tests, and the measured data were quantified. Linear regression, cubic regression, and log regression models were applied to each CSP grade for comparative analysis of the results. Furthermore, comparative studies were conducted through adhesion strength tests based on the CSP grade. CONCLUSIONS : Our results are expected to establish objective standards for the pretreatment stage of concrete repair and reinforcement. The derived reference values can inform standards for the restoration and reinforcement of concrete structures, thereby contributing to performance improvement. Moreover, our results may serve as primary data for the repair and reinforcement of various concrete structures such as airports, bridges, highways, and buildings.

PURPOSES : This study proposes a method to automatically analyze the shape of asphalt concrete aggregate using computer image analysis technology. METHODS : To develop automatic aggregate shape analysis technology, we developed an aggregate shape boundary analysis algorithm that combines Watershed algorithm and morphology technology. After the algorithm was developed, it was mounted on a separate prototype and compared with the manual aggregate shape analysis method. RESULTS : As a result of the algorithm comparison, the accuracy of the aggregate shape analysis was about 90%, and there was a problem that some noise occurred. This problem was derived from external roughness, the shape of the overlapped aggregate, and sand as the main causes. Therefore, we devised a method to analyze the shape of the aggregate by adjusting the external illuminance constant or using an artificial intelligence model. CONCLUSIONS : The results of this study can be used as basic research data to help improve quality control techniques in the production of asphalt concrete in the future.

This study was conducted to investigate the effects of sugars and stabilizers on the qualitative properties of frozen-yogurt. To prepare the yogurt mix, market milk was fermented using a commercial starter culture and sugars, trehalose and sucrose, and to prepare the ice cream mix, stabilizers, carboxy methyl cellulose (CMC) and guar gum, were used. The yogurt and ice cream preparations were mixed in a 1:1 (v/v) ratio to produce frozen-yogurt. Yogurt prepared using trehalose showed a significantly faster increase in pH, titratable acidity, and viable cell count than that prepared using sucrose (p<0.05). Ice cream prepared using guar gum showed a significantly higher viscosity and overrun than the CMC-stabilized preparation (p<0.05). Frozen-yogurt produced using the yogurt-trehalose mix and ice cream-CMC mix showed the highest hardness and lowest overrun. The melt-down rate of frozen-yogurt prepared with the yogurt-trehalose mix was significantly slow (p<0.05). However, there were no significant differences among the yogurt mixes in terms of changes in the viable cell count at 0, 7, 15, 30, and 45 days (p>0.05). In a sensory evaluation, most panels preferred the frozen-yogurt with sucrose over that with trehalose. However, it is expected that using trehalose with other sugar substitutions and guar gums in manufacture of frozen-yogurt have high potentiality than using sucrose and CMC, and it is considered that it could reignite the stagnant domestic milk processing industry.