Effect of time on the performance of Road Packer Plus (RPP) matter in the swelling control of forest roads soil (Case study: Kheyrood Forest)

Document Type : Scientific article

Authors

1 Faculty of Natural Resources, University of Tehran

2 Faculty of Natural Resources, Tehran University

Abstract

Due to fine-texture and moderate to high plasticity, the swelling capacity of forest soils is normally high. High volume variability, as a consequence of fluctuating soil moisture, is considered a destructive phenomenon in forest road construction. In this study, Road Packer Plus (RPP) was used as a new proxy agent to improve the swelling behavior of high plastic clay soil. To this end, compression tests, swelling and swelling pressure were conducted on the control samples and samples treated with values recommended by the manufacturer company, to understand the potential of volume changes in the treated soils. Also, to evaluate the effect of time on the performance of the RPP, swelling and swelling pressure tests were conducted on the treated samples seven and 14 days following the treatment. The results showed that the RPP agent relatively increased the maximum dry weight per unit volume and decreased swelling and swelling pressure, while treatment time could only slightly decrease the swelling capacity of the corresponding soil. With respect to soil type, adding the proposed doses and matter and curing time of treated samples of this chemical, has no significant effect on the amount soil swelling reduction. On the other hand, the closure of roads to traffic for a certain period of time following soil stabilization has no significant effect on the performance of this agent. Thus, neither the recommended dose nor the treatment processing time had significant impact on decreasing forest soil swelling potential. In conclusion, we propose to apply a similar approach on a wider array of soil types with different swelling properties.

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