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An increase in the number of distressed bridges and the limited financial resources emphasize the need for an efficient bridge management system (BMS) for India. Assessment of the remaining life of bridges becomes an essential step in BMS, which involves modeling of complex deterioration mechanisms in concrete due to chemical attacks, such as carbonation, chloride, sulfate, and so on. Lack of information on material properties used in bridge construction, construction techniques, exposure condition, and maintenance quality adopted make the remaining life assessment of bridges more complicated. Therefore, a parametric study has been carried out to understand the deterioration of concrete bridges due to carbonation. Effect of carbonation on the initiation and propagation time of corrosion was also included in the study. Based on the study, modifications are suggested in the clauses of Indian concrete bridge design standard IRC: 21 (2000) so as to enhance the service life of bridges. [ABSTRACT FROM AUTHOR]

Evapotranspiration (ET) is likely to be greatly affected by global warming because of the dependence of ET on surface temperature. The increasing atmospheric concentration of carbon dioxide (CO2) and other greenhouse gases is expected to increase precipitation and evaporation proportionally. However, a few studies have shown a decreasing trend for evaporation over the last 50 years globally. In India, earlier works showed that there was a significant increasing temporal trend in surface temperature and a decreasing trend in grass reference ET (ETo). To study the temporal trend of ETo along with its regionwise spatial variation, 32 years (1971–2002) monthly meteorological data were collected for 133 selected stations evenly distributed over different agro-ecological regions (AERs) of India. ETo was estimated by the globally accepted Food and Agriculture Organization (FAO) Penman Monteith (PM) method (FAO-56 PM). These ETo values were then analyzed by a nonparametric Mann–Kendall (MK) test (with modified effective sample size approach for serially correlated data) and Sen slope to determine the existence and magnitude of any statistically significant trend over the time period considered in this study. The same analysis was also performed on governing meteorological variables to identify the cause of existence of such trend in ETo. A significant decreasing trend was found in ETo all over India during the study period, which was mainly caused by a significant increase in the relative humidity and a consistent significant decrease in the wind speed throughout the country. However, a general increase in rainfall was not found in recent years. [ABSTRACT FROM AUTHOR]