Effect of Bitumen Emulsion Application in Water Movement by Capillarity in Different Textures of soil

Abstract

In order to investigate the possibility of reducing the main harmful effects of saline water movement by capillarity in degradation of soils structure and salts accumulation on their surface, an experiment was conducted to evaluate effect of the Bitumen emulsion application on the mechanism movement of different qualities of water by capillary action in three different soils texture (clay, sandy loam and sandy soils), air dried and passed through (2) mm sieve. Half of each soil been mixed thoroughly with Bitumen emulsion of (1%) on dry soil bases and the other half was left without treatment. Soils have been placed into fifty four glass tubes of (100) cm length and (0.8) cm diameter. Three qualities of water (tap water of 1.85 dS m^-1, mixed water of 6.22 dS m^-1 and drainage water of 10.48 dS m^-1) were used. All treatments have been done three times. The height of rising water by the capillarity (cm) at time of measurement (minute) was measured and capillary water velocity (cm h^-1) was calculated for all treatments (Bitumen, soils and water qualities). All obtained data were statically analyzed by using the SPSS program.

        From using the tab, mix and drainage qualities of water, results of the capillary action indicate differences in the water rising values with the different soils and Bitumen treatments. Increasing of salts concentration in the water caused significant decreases in the capillary water rise values throughout the time of measurements of all treatments. The application of Bitumen caused large reduction in cumulative capillary rise and capillary water velocity values at the start and the end of the capillary action time, the reduction percentage values was 70.08% at the beginning and 12.66% at the end of the measurement time. The reduction in upward movement of saline water by capillary action was recorded in all experiment treatments. The results concluded that, coating of Bitumen emulsion to the soil particles and its penetration into aggregates of the soils caused an improvement in the soil structure units and porosity. These newly formed units of soil structures were not affected by the salt level present in the rising water by capillarity. The application of Bitumen caused increasing in the macro pore spaces (drainage pores) and reduction in the micro pore spaces (capillary pores) of the soils, which, consequently, resulted in a decline in rising movement velocity of saline water by capillarity in all soils.