Experimental Investigation of the Densification Properties of Clay Soil Mixes with Tire Waste

The annual increase in production of industrial wastes, including scrap tire, has created several challenges for societies. Incorporating the wastes as raw materials has been proposed in different industries, using waste tire as physical additives and investigating the geotechnical properties of this mixture can reduce the environmental pollution, as well as offering economic and technical benefits. Clay soils are abundant in southern regions of Tehran where scrap tire is also produced in large quantities every year. Therefore, provided the chance, incorporating these wastes into the soil mix is significant as regards both geotechnical properties and environmental considerations. As a fundamental means of investigation in construction activities, in particular road construction, the compaction test is useful in determining the maximum density and the optimum moisture content of the soil. In this study, considering that this research has not yet been investigated for Tehran clay and has environmental benefits while having engineering application, the optimum moisture content and maximum dry density of the clay mixed with two types of additives (waste tire powder and granules) at various mass fractions (2, 4, 6, 8, 10, 20, and 30 wt%) using standard compaction tests were investigated. The results suggested that the variations of the optimum moisture content and the maximum dry density in both clay mixes demonstrate a certain and predictable trend as the waste content increases. In other words, by increasing the percentage of waste in the mixture, the optimum moisture content is increased, and this increase in the mixture of the tire powder and clay is more than granule and clay. In addition, by increasing the percentage of waste, the maximum dry weight of the mixture was reduced, and this reduction in the mixture of tire powder and clay is almost higher than that of tire granule and clay. Furthermore, relations were presented to estimate the maximum density and the optimum moisture content of the mix to be applied in practice

Exploration of potassium chloride from Khur Playa

The Great Kavir is located in the centre and extended to the eastern part of Iran. The low rainfall (86.5 mm/yr) and high evaporation (2857 mm/yr) in this region have led to the presence of a number of playas. This study summarizes the most important and economical minerals such as halite and potash which are deposited in the Great Kavir, especially in Khur Playa. There is thus a strong motivation for extracting this material. The evaporate minerals precipitating from the playa brine are influenced by the progressive change in brine salinity and its composition. Research was then undertaken to elaborate a common extraction method based on a programmed scheme. A series of test-pits and boreholes were drilled in the playa to a depth of maximum 63 m to produce brine. The pre-constructed ponds were then used to extract KCl by evaporation of water under the sun. Our investigations show that the average content of potassium at Khur Playa is at least 2600 ppm