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The characteristics of organic soil are low permeability, low shear strength, and high compressibility, therefore organic soil has to be improved before any engineering works can commence. In this study, dry kaolinite is used as a clay mineral and fresh reed as an organic material for different percentages (0%, 2%, 5%, 8%, 12%, and 20%) by dry weight. Lime is used as a treatment material for different percentages (0%, 3%, 6%, and 9%) by dry weight. The experimental work includes a series of compaction and direct shear tests conducted on 48 samples. The effect of the addition of lime on shear strength parameters of non-decomposed and decomposed model organic soil was studied. The results showed that the cohesion values (c) increase with increasing organic content up to 5% for non-decomposed samples and up to 7.0% for decomposed samples while the angle of internal friction (φ) increases with the increase in organic content for both decomposed and non-decomposed samples. Also use of lime has increased the angle of internal friction of soil, especially when used within the range of (0-3) % lime content.

Evaluation of mechanical behavior of the soil-structure interface has been the focus of many researchers as an effective factor on the strength performance and deformation of the structure. Since the interaction of the structure and the soils around it will have a great impact on the soil bearing capacity, it is important to study the physical conditions. In this study, taking into account the curing time, effect of using Persian gum and the roughness of the steel on the behavior of the soil-structure interface using large-scale direct shear test have been investigated. The Persian gum was used in three amounts of 0.3, 0.6 and 0.9% on three smooth, rough and geotextile covered surfaces. Based on the results, by injecting Persian gum into the soil-candle interface, the adhesion between soil and contact surface increases by about 20 times and the internal friction angle increases by one degree. The rate of increase of strength parameters decreases with increasing curing time. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Engineering Sciences & Information Technology is the property of Arab Journal of Sciences & Research Publishing (AJSRP) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of International Journal of Sports Science & Arts - Arabic is the property of Helwan University, Faculty of Physical Education for Girls and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract The interaction between soil and geosynthetic reinforcement is important for the design and performance of reinforced soil structures. This interaction can be very complex depending on the type, properties of the reinforcement and orientation for these geosynthetic into a reinforced soil. The interaction mechanism for different orientation of these geosynthetic still doesn’t study accurately. This paper investigates the interaction mechanism for reinforced sand with different geosynthetics types at different inclination angles. The strength parameters of soil geogrid interface were obtained from direct shear tests. Two types of geosynthetic, Woven geotextile and Biaxial geogrid were selected to insert into sand. Laboratory testing program were performed in shear box device, square box with 100 mm in length was used and the reinforcement layer was placed in different inclination angles. The first angle is perpendicular to the failure surface 90. the second angle of reinforced was inclined with 45. to the failure surface and the third angle of reinforced was horizontally parallel to the failure surface. All tests were conducted with three vertical load 17.95, 27.95 and 37.95 kg. Three parameters were studied according to the relative density of sand, inclination angle of geosynthetics in shear box and type of geosynthetics reinforcement layer. The test results reveal that the sand reinforced with biaxial geogrid achieved the highest value of shear strength enhancement. The maximum shear strength improvement occurred at inclination angle 90 to the failure plan when reinforced by biaxial geogrid and Woven geotextile.

Copyright of Ferdowsi Civil Engineering is the property of Ferdowsi University of Mashhad Press and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Numerical modeling of unsaturated soils has become increasingly popular in recent years. The Discrete Element Method (DEM) is a powerful tool for modeling granular materials by focusing on particle interactions. In this study, the behavior of unsaturated granular soil was investigated using two-dimensional DEM by considering meniscus formation among particles. Unlike previous studies that simply considered particle shapes as circular or spherical, this study used more realistic polygonal particles shape that forming meniscus can be examined in different pores with respect to the geometry and arrangement of the particles. However, because of symmetry in circular and spherical particles, the shape of the meniscus among these particles depends only to the size of the particles. To this end, using a program based on the DEM was developed and a soil sample were simulated under different suction values and confining pressures. The results showed that the shear strength of the sample augments by increasing suction until a specific value and then, decreased with further suction increases. It was also observed that the effect of meniscus force on increasing shear strength decreased with increasing confining pressures. Modeling particles of different sizes also showed that the effect of meniscus force is greater for smaller particles and decreases with particle size. [ABSTRACT FROM AUTHOR]

This research aims to improve the engineering properties of expansive soil by using locally low-cost materials such as crushed glass wastes and lime. The studied expansive soil is considered unsuitable soil for civil engineering projects such as roads and buildings, as it was classified according to the AASHTO classification A-7-6. This soil was treated only with different ratios of crushed glass wastes (0%, 5%, 10%, 15%, and 20% by weight of dry soil), as well as the soil was treated only with different ratios of lime (0%, 2%, 4%, 6%, and 8% by weight of dry soil). Experiments of Atterberg limits, standard Procter, direct shear, free swell, swelling pressure, and both un-soaked and soaked California Bearing Ratio tests were carried out on the untreated and treated soil. The results showed that by increasing added percentage of crushed glass wastes and lime separately, the consistency properties (Atterberg limits), the shear strength parameters (direct shear test), free swell, swelling pressure, and both un-soaked and soaked California Bearing Ratio of the studied expansive soil were improved; except for compaction characteristics, by adding crushed glass wastes the M.D.D was increased and O.M.C was decreased while by adding lime, the M.D.D was decreased and O.M.C was increased. This helps to make use of low-cost local materials, clean the environment of glass wastes, and recycle these wastes so that they can be used on an environmental, economic, and engineering level. This aligns with Egypt's Vision 2030 sustainable development approach in both the environmental and economic dimensions.

Copyright of International Journal of Sports Science & Arts - Arabic is the property of Helwan University, Faculty of Physical Education for Girls and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

At the present time the disposal of industrial wastes has become a challenge for most countries. This research aims to study the effect of mixing the industrial textile sludge on geotechnical properties of collapsible soil. The experimental program studies the effect of textile wastes on Atterberg limits, collapse potential, compaction, CBR, and shear strength parameters. The percentages of textile wastes mixed with soil are 4, 8, 12, 16, 20, and 24 %. The results indicated that the collapse potential of untreated soil is significantly decreased from about 11% to 2.6% at 24% of textile sludge. Shear test results show an increase in cohesion and decrease in the internal friction angle. For Atterberg limits there was an increase in liquid limit. For Compaction results, it is noticed a decrease in maximum dry density and an increase in optimum moisture content. CBR values for all samples indicates the suitability of using soil and soil-sludge mixtures only in subgrade layer of pavement. It was found that the reuse of textile sludge with collapsible soils considers an economic method to improve the physical and mechanical properties of the soil, in addition, it could be considered as sustainable management of textile sludge which leads to a reduction in the consumption of natural resources and preserves the surrounding environment through decreasing the retention of these wastes to a minimum

Using of Reclaimed Asphalt Pavement (RAP) has been become indispensable in most of the world nations as for its many benefits as significant cost savings and provide environmental benefits. Many factors such as virgin materials, binder content, availability of RAP, viscosity of binder and extent of deterioration had important role in effecting on Optimum percentage of RAP. In this study, effect of using RAP on the asphalt mixture properties and the its optimum ratio was determined to achieve the objective of the study. The glass fiber (GS) was used as additives to improve the asphalt mixture. It has been observed from the previous researches that the optimum percentage of reclaimed asphalt use is not determiner and is disagreed from project to project. So, different percentages of RAP was (25%, 50%, 75%, 100%) by weight of aggregate were added as well as using the additive GS at optimum bitumen content. The study is revealed that untreated 100% RAP materials are not good as a bituminous mix. and was showed that mix prepared with 25% RAP gave nearly the same physical and strength parameters as virgin bituminous mix. From results of study, the use of RAP until (%50) as a maximum percentage in unmodified asphalt mixture course sustained good results. To achieve better performance, the percentage of 25% RAP was used with percentage of 0.26% GS. This mix achieved the specification requirements and ensured the degree of better performance for paving. The economical evaluation of using percentage of 25% RAP with percentage of 0.26% GS was also studied. The results indicated that, about 21% of the cost was saved. Keywords: Reclaimed Asphalt Pavement (RAP), Marshall Mix Design, Material Testing, Stability, Glass fiber, Optimum Bitumen Content, Cost effectiveness.

The amount of wastes has increased year by year and the disposal becomes a serious problem. Particularly, recycling ratio of the plastic wastes in life and industry is low and many of them have been reclaimed for the reason of unsuitable ones for incineration. It is necessary to utilize the wastes effectively with technical development in each field. This study presents a simple way of recycling plastic waste in the field of civil engineering as reinforcing material. Reinforced soil construction is an efficient and reliable technique for improving the strength and stability of soils. The technique is used in a variety of applications, ranging from retaining structures and embankments to subgrade stabilization beneath footings and pavements. This paper describes an experimental study on mixing plastic waste pieces with two types of soil (clayey soil and sandy soil) at different mixing ratios (0,2,4,6,8 )% by weight respectively. For the two types of soils, the shear strength parameters (cohesion value and angle of internal friction) of reinforced and unreinforced samples were investigated by the direct shear test. In addition, a series of compaction tests were performed on clayey soil mixed with different percentages of waste pieces.

This paper investigated the effect of fly ash addition on geotechnical properties of expansive soil. Classification tests, consistency limits test, specific gravity test, compaction test, direct shear test, swell percentage, and swell pressure tests, were conducted on specimen of expansive soil. Results of tests showed that soil was a clay high plasticity (CH) soil, according to the Unified Classification System (USCS) classification system. Liquid limit reduced from 74 % at 0 % fly ash to 56 % at 20 % fly ash content by dry weight of soil, the plastic limit reduced from 31 % at 0 % fly ash to 25 % at 20 % fly ash content, the plasticity index reduced from 44% at 0% fly ash to 31 % at 20% fly ash. The maximum dry density reduced from17.3 kN/mᵌ at 0% fly ash to13 kN/mᵌ at 20 % fly ash and optimum moisture content increased from 19.2% at 0% fly ash to 29.3% at 20% fly ash. Shear strength parameters c and Ø were measured after the addition of various contents of fly ash on curing days (7, 14 & 21). The value of cohesion (c) increased with increasing the amount of fly ash added to 15% then decreases. The effect of curing time on cohesion increased until 14 days. While c is decreased at various contents of added fly ash at 0 time (no curing or immediately tested). The increased internal friction angles (Ø) with added fly ash in all samples are independent ....

This research presents a laboratory study on the influence of different compactive efforts, curing and soaking periods at no-delayed and up to 4-hrs compaction delay periods on compaction, strength and swelling characteristics of untreated and 3%, 5% and 8% by dry weight of lime-treated Semeel soil. The results of the tests without and with compaction delay of lime-treated soil show that for both of standard and modified compactive efforts, as the lime content % increases the Maximum Dry Density (MDD) decreases while the Optimum Moisture Content (OMC) increases. The decrease in MDD is occurred due to alteration of the material's gradation as a result of the flocculation and agglomeration of the soil particles upon lime addition. Whereas the increase in OMC is mainly referred to the more water required for the hydration of lime and cation exchange. It has been found that as the compaction delay period increases, the strength properties of lime-treated soil decrease for unsoaked and soaked conditions. This loss in strength therefore needs to be considered in design and construction and the durability of the UCS specimens should be assessed by evaluating their resistance to strength loss after 7-days curing followed by 4-days soaking. The swelling characteristics measured on remolded soil samples at no compaction delay show that Semeel soil is classified as highly expansive soil. While, at small lime contents %, as the compaction delay increases, swell percent and swelling pressure values are slightly increased from that at no compaction delay. [ABSTRACT FROM AUTHOR]