Soil contamination through petrochemical activities and leakage of organic hydrocarbon is not just an environmental problem and also can be considered as an important geotechnical issue. Adding amendment material is one of the most suitable and economical solutions to improve the geotechnical parameters of contaminated soil. In this study, the effect of Portland cement content (3, 6 and 9%) and lime content (10, 20 and 30%) on kaolinite clay contaminated with glycerol content (3, 6 and 9%) was investigated through an experimental program. For this purpose, the samples were prepared as mixtures of clean or glycerolcontaminated clay with different Portland cement and lime contents for 7 days curing time. Then, unconfined compressive strength (UCS) tests were conducted on the samples. The results showed a reduction of the strength of glycerol-contaminated kaolinite clay. The strength reduction increased with increase in degree of contamination. Based on the scanning electron microscopy (SEM) analysis, it was found that the presence of glycerol prevents the interaction between soil-cement particles. However, adding Portland cement and lime to uncontaminated and contaminated soil increased the strength. The rate of increase in UCS increased with Portland cement and lime content. Also, the results of soil improvement showed that the strength of soil-cement mixture containing 9% Portland cement is approximately equal to that of the soil mixed with 10% lime. In other contents, the degree of improvement was dependent to the applied cement content. The main reasons were polar behavior of glycerol and its dielectric constant. The results were also analyzed and proved using the images taken by SEM.

The efficiency of Ab-Bandans is reduced with water leakage from them, so one solution is adding different materials to the soil of Ab-Bandans. In this study, different percentages nanoclay, 10% cement and 5% lime was used to reduce hydraulic conductivity of the soil of Ab-Bandans. The hydraulic conductivity reduced from 1. 58*10-4 to 2. 88*10-5 with the addition of %0. 5 nanoclay. Measurement of piezometric pressure showed that nonlocal, cement and lime decreasing the phreatic surface on banks. Composition of the soil with nanoclay, cement and lime, respectively, decreased 58%, 51% and 28% losses that nanoclay further reduces leakage. Statistically significant differences between water seepage losses of natural soil with other materials exist at 95%. So the use of different materials such as nanoclay, cement and lime, respectively their impact on reducing of seepage, recommended for control the leakage of Ab-Bandan that lime was more economical in the case study.

Due to the great importance of creating roads in coastal areas in the economy and connecting highways between eastern and western cities, these soils need to be improved. One of the conventional methods to improve the mechanical properties of soils is the use of stabilizers such as lime and cement. Another method that has been used in recent years is the use of synthetic or natural fibers to strengthen soils. Considering the environmental problems created by conventional stabilizers (cement/lime) and also their economic costs, the use of pozzolan, which has a lower cost, can be a suitable solution as a substitute for these materials. Considering the importance of the topic in the field of improvement, in this research, the effect of two types of pozzolanic additives (zeolite) and rubber fibers on the compressive strength of sand samples stabilized with cement and lime has been investigated using a uniaxial test. The results of the tests show that cement has more effective effects than lime in increasing the compressive strength of the soil. The ratio of compressive strength of cement samples to lime samples is about 650%. Also, lime-stabilized fiber-reinforced samples and cement-stabilized fiber-reinforced samples have an increase in compressive strength by about 50 and 110%, respectively, compared to the case of cement or lime-stabilized samples without fibers. Replacing cement and lime with zeolite does not show a change in compressive strength, which indicates a more appropriate behavior from an economic and environmental point of view.

Evaluation of the strength of deep mixing columns as a soil improvement method is the main subject of this study. In this research, cylindrical laboratory samples with a length of 20cm and a diameter of 10cm have been constructed. The result of mixing soil-cement and soil-lime was taken into account that cured in the temperature and humidity of both laboratory environments and field conditions and then subjected to unconfined uniaxial loading tests. Different weight mixtures of soil-adhesive materials with a minimum of 6% and a maximum of 14% by weight of adhesive materials have been used for this purpose. Also, in this study, the deep mixing of the soil in real and field scale has been implemented in a layer of thin clayey soil, CL, with low plasticity properties of CL-type clay. Mixing of deep field soil has been carried out by the designed digging-mixing machine. In addition to laboratory cylindrical samples, cylindrical samples were taken from bulk mixing columns in two linear (single) and clock-type (group) arrangements and were subjected to uniaxial loading in the laboratory until the moment of failure. The general result of this study is the proposal of conversion coefficients of strength of laboratory samples to field samples and vice versa, in the same conditions of construction geometry and the type of selected materials and different environmental conditions of samples curing.

Leakage of hydrocarbon organic fluids into the soil usually causes a reduction in its bearing capacity and performance. Cementation is one of the most effective and suitable solutions to improve the geotechnical parameters of contaminated clays. In this study, the effect of Portland cement (3, 6 and 9%) and lime (10, 20 and 30%) on improvement of kaolinite clay contaminated with anthracene (0. 06, 0. 09 and 0. 12%) was investigated by performing an experimental study. For this purpose, the samples were prepared as mixtures of clean or anthracene-contaminated clay with different cement and lime contents for a curing time of 7 days. Then, unconfined compressive strength (UCS) tests were conducted on the samples. The results showed the strength reduction of anthracene-contaminated kaolinite clay compared to the clean soil. The reduction in the unconfined strength was about 46% with an increase in degree of contamination up to 0. 12%. Adding Portland cement and lime to the clean and contaminated soil increased the compressive strength. As, the addition of 3% Portland cement or 10% lime to clay contaminated with 0. 12% anthracene increased UCS up to 4 times. Thus, according to the results of soil improvement, the strength of soil-cement mixture containing 3% Portland cement is approximately equal to that of soil-lime containing 10% lime. Both the Portland cement and lime were capable of improving the strength of anthracene-contaminated soil. However, the rate of improvement by cement was more than that of lime. The main reason was due to the reduction of double layer thickness which causes flocculation of particles and tendency of clay structure to behave like granular soils.

At present, managers are under increasing pressure to not only reduce operating costs, but also to minimize the environmental impact of their activities and increase environmental performance. The main objective of this study is to identify environmental factors at the corporate level. In order to achieve this, the research was carried out in two separate phases during the years 2018 and 2019. First, after studying the theoretical foundations of the research, a descriptive phenomenological baroque qualitative research method was used, based on the experiences of people involved in the field of research. Secondly, in order to confirm and meet the identified criteria, data analysis was performed by designing a questionnaire and conducting a survey of scientific experts. The result of the study is to identify 20 criteria and classify them into 4 general categories and in the second stage to confirm and fit the general structure of all instances using structural equation technique and factor analysis test. The research findings are effective in identifying and understanding environmental standards and adhering to them at the corporate level, developing environmental accounting standards across industries and encouraging organizations to implement green accounting and will have desirable consequences.

This paper examines the behavior of untreated and treated soil with cement and lime, as well as the relationship between the design parameters of the base layer such as uniaxial compressive strength (UCS), CBR with resilient modulus. The specimen selection for the triaxial test was based on the results of UCS, indirect tensile strength (INTS), wetting-drying, and freezing-thawing cycles tests. In general, the addition of lime along with cement causes the tensile strength to be halved compared to the addition of cement alone, but it eliminates the volume reduction problems caused by modification with cement. Also, a large-scale dynamic triaxial test was performed on the untreated base and C7L2 specimens. In all confining pressures, the values of elasticity modulus and damping ratio of C7L2 are higher and lower, respectively, compared to the untreated soil. The data points of the ratio of modulus of the elasticity-axial strain of specimen C7L2 are above the corresponding curves for sand and even higher than the rock ones, and its damping ratio data points are above the corresponding curve for rock specimens. The average values of the modulus of elasticity increase with the increase of confining pressure and initial axial stress. Increasing the loading frequency increases the Yang modulus, shear modulus, and damping ratio, but decreases the induced shear strain on the specimen.

Asphalt recycling has many benefits among which the preservation of natural resources, saving cost and energy can be mentioned. Although hot recycled mixtures are more durable and resistant compared to cold mixtures, using heat causes environmental pollution and toxic and hazardous gas emission and reduce workers safety. Therefore, there is a need to use additives in recycled asphalt mixtures for increasing durability and resistance of mixtures.

Little research has been carried out to characterize Iranian desert solis from highway Engineering point of view sofar. In such areas conventional paving materials are sometimes difficult and costly to provide. The research presented herein include studying the geotechnical properties of four soils sampled from eastern fringes of Kavir-e Namak, and determining their suitability as paving materials once stabilized with lime and cement. Selection and sampling of soils were accomplished so that they represent the general characteristics of soils in the area. Standard techniques were used to determine the physico-chemical and mineralogical properties of soils. The influence of lime-cement content and curing period on the properties of lime-cement-soil mixtures were investigated. The results show that loess soils are amenable to stabilization with lime and cement while sandy soils are amenable to stabilization with cement, and both might be used as paving materials. But, saline soils containing high proportions of salts do not respond to stabilization.