Cracks are the main cause for structural failure. One way to circumvent costly manual maintenance and repair is to incorporate an autonomous self-healing mechanism in concrete. This study exploited the potential to apply calcite-precipitating bacteria as a crack-healing agent in concrete. These bacteria were prepared in different cell concentrations and incorporated in the concrete mix. Compressive strength tests were performed at the stage of 28th day of curing. The effects of different cell concentrations of Bacillus sphaericus on concrete, reducing the crack, were studied. We used mortar cubes with 30mL of bacteria/mortar cube and sequentially increased up to 50mL (10, 20, 30, 40 and 50mL) in the ratio of mortar cubes in 1:6. The concrete grade used for the study was M25. At last, we had made concrete blocks of size 150×150×150 mm with concrete of grade M25. For those blocks, the compressive strength and non-destructive tests such as, rebound hammer and ultrasonic pulse velocity tests were performed. The results obtained in the work are that the compressive strength of blocks of size 150×150×150 mm is good when compared to control concrete. When load is applied to control concrete, the crack gets developed earlier and when bacterial concrete is used, the crack does not develop at an early stage.

Mountain flood that causes landslide and other geological disasters can damage the fragile ecological environment in mountain areas. In this paper, threshold and distribution model of accumulated temperature based on snowmelt flood magnitude are designed in mountainous watershed. Meanwhile, input data for this model make use of ample reliable data that include remote sensing and so on. In detail, this model simulates the average watershed temperature by using the meteorologic re-analysis data of the National Center for Atmospheric Research and calculates the average snow depth by using hyperspectral remote sensing data. In addition, the model related data comprise long-term observation experiments of the watershed, including the characteristics of accumulated snow and result of correlation between runoff and infiltration in runoff simulation experiment through distributed hydrological models (i.e., Soil and Water Assessment Tool and Distributed Hydrology Soil Vegetation Model). Finally, the average accumulated temperature of the watershed that causes snowmelt flood can be obtained through the aforementioned method, and the characteristics of the accumulated temperature distribution of the watershed area are determined based on the temperature lapse rate. The characteristics of accumulated temperature distribution can provide decision-making reference for monitoring the ecological environment in mountain areas and preventing and reducing disasters.