Yousef Azimi; Salman Zare; Hamid Sarkheil; Javad Bodaghjamali; Siayamac Heshmati
Abstract
Mulching on the ground surface is one of the common approaches for fixing the sandy dunes and controlling dust. Despite the frequent use of oil mulch, due to its heavy costs and environmental problems, researches are focused on producing new environmentally friendly mulches. In this research, different ...
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Mulching on the ground surface is one of the common approaches for fixing the sandy dunes and controlling dust. Despite the frequent use of oil mulch, due to its heavy costs and environmental problems, researches are focused on producing new environmentally friendly mulches. In this research, different treatments of cement, lime, wind sands and steel-slag, as cement-slag mulch, have been used to fix the sand dunes samples prepared from Robat-Karim region. Steel-slag is added to the mulch composition because of the benefits of waste reduction from environment and replacement of a part of the cement in the mulch composition because of Steel-slag pozzolanic property. To reduce the number of tests and find the optimal composition of the mulch, statistical mixture design approach was used. Furthermore, the effect of different percentages of the ingredients on shear, compression and impact strength and moisture content of cement-slag treatments were investigated. Results show that the addition of steel-slag increases the compressive and shear strength as well as the ability to maintain soil moisture in the proposed mulch. Finally, developing the mathematical model of the experiments, six different objective functions were considered for optimizing the composition of the proposed cement-slage mulch. As a result combination of 68.731% sand, 27% cement, 2.979% steel-slag and 1.3% lime were the best mulch considering all the objective functions. To validate the results of the optimization, six optimal compositions were re-constructed and the tested again. Obtained results showed an acceptable consistency between the predicted and tested values.
Mohammad Reza Ekhtesasi; Fateme Hazirei
Abstract
Mulching is one of the methods of sand movement control to prepare condition for permanent fixation. Oil mulches have been used in Iran. Because of high cost and negative environmental impacts of oil mulches, changes in mulches type and mulching methods is vital. Therefore, for the first time in Iran, ...
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Mulching is one of the methods of sand movement control to prepare condition for permanent fixation. Oil mulches have been used in Iran. Because of high cost and negative environmental impacts of oil mulches, changes in mulches type and mulching methods is vital. Therefore, for the first time in Iran, different combinations of cement and lime were examined as stabilizer. Sandy soil from the Yazd-Ardakan plain is used as bed treatment and Portland cement were used as the mulch in this research. The treatments were prepared using different ratios of the above mentioned materials. One liter of water was added to each mulch combinations and were sprinkled on the plot of 100 cm (length) × 30 cm (width) ×4 cm (height) sands. A completely randomized design is used as research plan with three repeating. Physical parameters, such as thickness, compressive strength, which are created by mulches, and wind erodibility of the treatments were measured. The measured data were analyzed using SPSS statistical software. Results show that by increasing the amount of cement, soil crust resistance increases. The combination mulch of cement 400 gr, sand 800 gr, and lime 10 gr is selected as the best treatment, because it can be prepare optimum physical conditions for sand dune fixation. In addition, the cost of field cement mulching estimated 30% lower than oil mulching.