Search

Geopolymer composites have been widely researched during recent years as an alternative to sustainable construction materials, which can minimize CO2 emission for its application of industry by-products. Past researches on geopolymer show that it has comparable strength and better high temperature stability compared to ordinary Portland cement. In this paper, the high-temperature behavior of geopolymer paste has been discussed through the last data regarding geopolymer, mainly including its bonding performance with steel, stress-strain characteristics, structural analysis of different observation scales and the performance of special geopolymer paste. In summary, some problems that need to be studied in future researches are put forward.

The localization of damage for bridges to ensure their safety is investigated in this paper. Equivalent element concept is introduced into this study at the beginning. Support reaction data of each bearing under truck load are found to be able to lend themselves to indicate damage. A novel index termed as symmetrical support reaction difference index (SSRDI) is then developed. The reverse mapping between the local flexural stiffness change induced by damage and the SSRDI is generated. The proposed method based on SSRDI can be sensitive to tiny damages, and comparatively simple measurements are required during the application procedure. Another significant attraction of this method is that it can work in the presence of random uncertainties and actual support condition, which means it is suitable for real-world bridges. The effectiveness of the proposed method is demonstrated by numerical simulations performed on two kinds of bridges with reasonable damage severities. Its comparative advantage over the previous frequency method is also investigated. [ABSTRACT FROM AUTHOR]

This study presents a new idea of using only mid-span displacement measurement for damage detection of simply supported beams. Equivalent element concept is introduced at the beginning. In order to relate the damage detectability by means of mid-span displacement measurement with the damage-caused local stiffness change, a novel index termed as symmetrical mid-span displacement difference index (SMDDI) is proposed. The proposed method based on SMDDI is sensitive to tiny damage and comparatively small quantities of measurements are required during the application process. Another significant attraction of this method is putting aside the knowledge a-priori of the intact state. An example using simulated data has been conducted to examine the suitability of this method and assess its comparative advantages over the previous modal method. [ABSTRACT FROM AUTHOR]