CLASSIFICATION AND APPLICATION OF SOILS STABILIZED WITH HYDRAULIC BINDER IN ACCORDANCE WITH EUROPEAN STANDARDS

2020 ◽  
pp. 40-48
Author(s):  
Tatiana Tereshchenko ◽  
Serhii Illiash
Keyword(s):  
Compressive Strength ◽  
Building Industry ◽  
Road Building ◽  
Optimum Water Content ◽  
Hydraulic Binder ◽  
European Standards ◽  
Wide Experience ◽  
Optimum Water

Soils being the most widely used materials for road building industry predominantly contribute the improvement of their mechanical and/or technological properties. Relating to the world-wide experience in road building industry, the most effective method for such improvement is treatment of soils with hydraulic binder under optimum water content. Those mixtures being properly compacted set and harden by hydraulic reaction and give stabilized soils. Requirements and classification of hydraulically stabilized soils established by European standards provide wide possibilities for soils application considering their performance in pavement layers. The elaboration of Ukrainian standards identical to the European standards relating hydraulically stabilized soils should permit the elongated life cycle of pavement and also decrease expenses on repairs of road pavements caused by deformation of sub-grade. This article reviews classification and application of hydraulically stabilized soils according to the requirements of European standards. In accordance with European standards, stabilized soils are classified as hydraulically bound mixtures which properties are covered by Specifications on Hydraulically Bound Mixtures (European Standard EN 14227, Part 15). To conform the standard requirements soils should be treated by standard hydraulic binder (or a combination thereof): cement, slag, fly ash, lime, or a standard hydraulic road binder should be applied. Composition and methods of manufacturing (compaction) of specimens of hydraulically stabilized soils give several strength classes of stabilized materials with the highest category characterized by the cubes compressive strength not less than 12 MPa. European standards establish also classification of hydraulically stabilized soils by tensile strength Rt in combination with elastic modulus E; according to that classification the stabilized materials are divided into five categories from T1 to T5. European standards establish also classification of fresh mixtures by immediate bearing index. This value determines the suitability of a compacted layer to support the immediate trafficking. Nevertheless, that requirement may not cover cement-stabilized mixtures for construction of layers which are not intended to be trafficked for 7 days. The in-situ manufacture of stabilized mixtures needs some measures to minimize the inadequacy of properties of a material, or geometry of a layer such as an increased proportion of a binder or an increased layer thickness. Keywords: hydraulically stabilized soils, classification, compressive strength, immediate bearing index, construction of a layer.

EXPERIENCE ON DESIGN AND CONSTRUCTION OF ROAD PAVEMENTS USING THE CLAUSES OF EUROPEAN STANDARDS ON HYDRAULICALLY BOUND MATERIALS

2019 ◽  
pp. 42-50
Author(s):  
Tatiana Tereshchenko ◽  
Serhii Illiash
Keyword(s):  
Compressive Strength ◽  
Strength Properties ◽  
Road Pavement ◽  
Rigid Pavements ◽  
State Classification ◽  
Hydraulic Binder ◽  
European Standards ◽  
Pavement Construction ◽  
Design And Construction

Hydraulically bound mixtures (HBM) are most effectively applied in the base layers of flexible road pavements to enhance their load bearing capacity and also in the base layers of rigid road pavements in the case of weak soils of the sub-grade. The evaluation of Ukrainian standards which are identical to European standards relating HBM leads to the point of subsequent implementation of new requirements trough design and construction of motor roads in Ukraine. The by European standards stated requirements and classification of HBM provide a modelling regime closer to the performance of bound pavement layer and give the wider range of HBM designations with different strength properties. Thus, this article reviews such aspects of design and construction of road pavements with HBM layers which are distinguished from the conception approved now in Ukraine. The reviewed clauses on design and construction concern road pavements which, in accordance with the European practice, are classified as flexible pavements or semi-rigid pavements and are comprised of flexible (bitumen-bound) upper layers laid on a HBM base. The reviewed types of road pavement constructions are most eligible to emphasize the possibilities of implementation of new standard requirements in the Ukrainian road building industry. As it was concluded, the European standards state classification of HBM by compressive strength RC and classification by tensile strength in combination with elastic modulus Rt, E. These methods of classification are equivalent with no correlation intended between them and have been successfully used during design and construction of road pavement constructions comprised of bitumen-bound layers laid on a HBM base. When designing the motor roads with the above mentioned pavement construction to be loaded with high traffic, HBM of strength classes RС from С8/10 to С9/12 shall be contributed where classes of strength are determined by the type of a hydraulic binder and can be accorded to the categories by ”Rt, E” values not less than T3 (from T3 to T5). Keywords: hydraulically bound mixtures, classification by values of mechanical properties, compressive strength, base layers from hydraulically bound mixtures.

scholarly journals Study on the Compaction Effect Factors of Lime-treated Loess Highway Embankments

2017 ◽  
Vol 3 (11) ◽  
pp. 1008 ◽  
Author(s):  
Yuyu Zhang ◽  
Wanjun Ye ◽  
Zuoren Wang
Keyword(s):  
Water Content ◽  
Dry Density ◽  
In Situ Tests ◽  
Maximum Dry Density ◽  
Lime Content ◽  
Optimum Water Content ◽  
Compaction Energy ◽  
Highway Embankments ◽  
Optimum Water

This paper presents a study to investigate the effects of water content, lime content and compaction energy on the compaction characteristics of lime-treated loess highway embankments. Laboratory compaction tests were conducted to determine the maximum dry density  and optimum water content  of loess with different lime Contents (0, 3, 5 and 8%), and to examine the effects of water content, lime content and compaction energy on the value of  and . In situ compaction tests were performed to obtain the in situ dry density  and the degree of compaction  of different lime-treated loess. Experimental embankments with different fill materials (0, 3, 5 and 8% lime treated loess) were compacted by different rollers during in situ tests. The results indicate that  increases due to the increase of water content . Once water content exceeds , dry density  decreases dramatically. The addition of lime induced the increase of  and the decrease of . A higher compaction energy results in a higher value of  and a lower value of . The value of  achieves it’s maximum value when in situ water content  was larger than the value of  (+1-2%). The degree of compaction  can hardly be achieved to 100% in the field construction of embankments. Higher water content and compaction energy is needed for optimum compaction.

Effects of Using Fine Quarry Waste as Cement Replacement Material on the Compressive Strength of the Mixture of Interlocking Block

2014 ◽  
Vol 1030-1032 ◽  
pp. 2348-2353 ◽  
Author(s):  
Wasan Teerajetgul ◽  
Suppachai Sinthaworn
Keyword(s):  
Compressive Strength ◽  
Water Content ◽  
Average Density ◽  
Strength Ratio ◽  
Cement Replacement ◽  
Compaction Test ◽  
Optimum Water Content ◽  
Close Relationship ◽  
Optimum Water

The compressive strength of the sand-cement interlocking block mixtures were investigated by the method adapt from ASTM C 109. The cementitious to sand ratio of all mixtures were set at 1:2.75. Amount of water in the mixtures were 8% by weight of the solid as determined from optimum water content according to the compaction test (ASTM D698). In the mixtures, cement was replaced by fine quarry waste at the rate of 0, 10, 20, 30, 40 and 50% by weight of the binder. The results show that the average density of the mixture is 2.30 ton/m3 while increasing percentage of fine quarry wastes to replace cement decreases the compressive strength of the mixture at all tested ages (i.e. 1, 3, 7, 14, 28, 56 and 90 days). Moreover, the compressive strength ratio, the proposed parameter in this paper, shows a close relationship between percentages replacement of fine quarry wastes and compressive strength at later age.

scholarly journals Significance of Stone Waste in Strength Improvement of Soil

2020 ◽  
Vol 1 (1) ◽  
pp. 32
Author(s):  
Amit Kumar ◽  
Kiran Devi ◽  
Maninder Singh ◽  
Dharmender Kumar Soni
Keyword(s):  
Compressive Strength ◽  
Water Content ◽  
Fine Particles ◽  
Industrial Wastes ◽  
Dry Density ◽  
Regression Equations ◽  
Human Beings ◽  
Maximum Dry Density ◽  
Optimum Water Content ◽  
Optimum Water

The evolution of industries is essential for the economic growth of any country; however, this growth often comes with exploitation of natural resources and generation of wastes. The safe disposal and utilisation of industrial wastes has become essential for sustainable development. A possible approach would be to utilize these wastes in construction industries. The stone industry is one such flawed industries that generates waste in dust or slurry form; this leads harmful impacts on human beings, animals, and surrounding areas which, in turn, can lead to soil infertility. In the present study, stone waste was examined for its influence on maximum dry density (MDD), optimum water content (OMC) and unconfined compressive strength (UCS) of soil experimentally. Stone waste was used at 0%, 4%, 8%, 12%, 16% and 20% by weight of soil and UCS tests were conducted at maturing periods of 7, 14 and 21 days. Test results reported that the incorporation of stone waste improved the compressive strength value significantly. Maximum dry density was enhanced; however, optimum water content was reduced with the use of stone waste in soil due to its fine particles. Linear regression equations were also derived for various properties.

scholarly journals Measuring Compressive Strength Characteristics of Soil-Dobak-Glue Mixtures over Curing Time

2022 ◽  
Vol 2022 ◽  
pp. 1-10
Author(s):  
Myeonghwan Kim ◽  
Seongjun Eom
Keyword(s):  
Compressive Strength ◽  
Water Content ◽  
Building Materials ◽  
Standard Specimen ◽  
Dry Density ◽  
Curing Time ◽  
Soil Mixing ◽  
Optimum Water Content ◽  
Significant Difference ◽  
Optimum Water

The building materials used by mankind in the past, such as stone, soil, and wood, have been environment-friendly. However, the various building materials invented over time with the development of the industrial age pose problems such as environmental hormone generation and waste generation/disposal. To overcome these problems, building materials based on soil, a traditional building material, are being developed by researchers. However, the improvement in soil’s structural characteristics is insufficient as it excessively emphasizes efficacy and function only. In this study, lime and Dobak-glue were mixed with soil to solve the structural problems and improve the strength of soil, and water content and change in strength in accordance with curing time were tested. In order to understand the change in strength, a compaction test was performed by preparing a standard specimen based on the optimum water content and maximum dry density. The lime mix required optimum water content and quantity of lime equal to 3% of soil weight, while the Dobak-glue mix was prepared by soil mixing in the same weight ratio as optimum water content. Changes in water content and compressive strength were measured over curing time of 3, 7, and 28 days. Three specimens, lime mixed specimen, Dobak-glue mixed specimen, and standard specimen, were prepared, and their water content and compressive strength values were averaged. Although the change in water content according to the curing period differed depending on the material mixed with soil, there was no significant difference between 7.12% and 2.82% after 7 days. As for the change in compressive strength, the initial compressive strength in lime mixed specimen was excellent, but the Dobak-glue mixed specimen displayed the greatest strength after 7 days. To conclude, Dobak-glue is an eco-friendly material, and it can be very useful in compensating for the structural shortcomings of soil.

scholarly journals Significance of Stone Waste in Strength Improvement of Soil

2020 ◽  
Vol 1 (1) ◽  
pp. 32
Author(s):  
Amit Kumar ◽  
Kiran Devi ◽  
Maninder Singh ◽  
Dharmender Kumar Soni
Keyword(s):  
Compressive Strength ◽  
Water Content ◽  
Fine Particles ◽  
Industrial Wastes ◽  
Dry Density ◽  
Regression Equations ◽  
Human Beings ◽  
Maximum Dry Density ◽  
Optimum Water Content ◽  
Optimum Water

The evolution of industries is essential for the economic growth of any country; however, this growth often comes with exploitation of natural resources and generation of wastes. The safe disposal and utilisation of industrial wastes has become essential for sustainable development. A possible approach would be to utilize these wastes in construction industries. The stone industry is one such flawed industries that generates waste in dust or slurry form; this leads harmful impacts on human beings, animals, and surrounding areas which, in turn, can lead to soil infertility. In the present study, stone waste was examined for its influence on maximum dry density (MDD), optimum water content (OMC) and unconfined compressive strength (UCS) of soil experimentally. Stone waste was used at 0%, 4%, 8%, 12%, 16% and 20% by weight of soil and UCS tests were conducted at maturing periods of 7, 14 and 21 days. Test results reported that the incorporation of stone waste improved the compressive strength value significantly. Maximum dry density was enhanced; however, optimum water content was reduced with the use of stone waste in soil due to its fine particles. Linear regression equations were also derived for various properties.

Strategies of In Situ Generated Magnesium Catalysis in Asymmetric Reactions

Synlett ◽  
2021 ◽  
Author(s):  
Dongxu Yang ◽  
Linqing Wang
Keyword(s):  
Asymmetric Synthesis ◽  
Alkaline Earth ◽  
Earth Metal ◽  
Asymmetric Reactions ◽  
Chiral Ligands ◽  
Alkaline Earth Metal ◽  
Enantioselective Reactions ◽  
Earth's Crust

AbstractMagnesium (Mg) is a cheap, non-toxic, and recyclable alkaline earth metal that constitutes about 2% weight in the Earth’s crust. The use of magnesium catalysts to forge chiral moieties in molecules is highly attractive. Based on our work in recent years, we describe the current progress in the development of in situ generated magnesium catalysts and their application in asymmetric synthesis. In this perspective, a critically concise classification of in situ generated magnesium catalytic modes, with relevant examples, is presented, and representative mechanisms of each category are discussed. Building on the established diverse strategies, one can foresee that more innovative and structurally creative magnesium catalysts that are generated in situ will be developed to overcome more formidable challenges of catalytic enantioselective reactions.1 Introduction2 Magnesium Catalysts Generated in Situ from Chiral Ligands Containing Dual Reactive Hydrogens3 Magnesium Catalysts Generated in Situ from Monoanionic Chiral Ligands4 Bimetallic and Polymetallic Magnesium Catalysts Assembled in Situ5 Summary and Outlook

scholarly journals Underwater Holographic Sensor for Plankton Studies In Situ Including Accompanying Measurements

Sensors ◽  
2021 ◽  
Vol 21 (14) ◽  
pp. 4863
Author(s):  
Victor Dyomin ◽  
Alexandra Davydova ◽  
Igor Polovtsev ◽  
Alexey Olshukov ◽  
Nikolay Kirillov ◽  
...  
Keyword(s):  
World Ocean ◽  
Field Tests ◽  
Field Measurements ◽  
Measuring Systems ◽  
Water Turbidity ◽  
Background Data ◽  
Average Size ◽  
Size Dispersion

The paper presents an underwater holographic sensor to study marine particles—a miniDHC digital holographic camera, which may be used as part of a hydrobiological probe for accompanying (background) measurements. The results of field measurements of plankton are given and interpreted, their verification is performed. Errors of measurements and classification of plankton particles are estimated. MiniDHC allows measurement of the following set of background data, which is confirmed by field tests: plankton concentration, average size and size dispersion of individuals, particle size distribution, including on major taxa, as well as water turbidity and suspension statistics. Version of constructing measuring systems based on modern carriers of operational oceanography for the purpose of ecological diagnostics of the world ocean using autochthonous plankton are discussed. The results of field measurements of plankton using miniDHC as part of a hydrobiological probe are presented and interpreted, and their verification is carried out. The results of comparing the data on the concentration of individual taxa obtained using miniDHC with the data obtained by the traditional method using plankton catching with a net showed a difference of no more than 23%. The article also contains recommendations for expanding the potential of miniDHC, its purpose indicators, and improving metrological characteristics.

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