scholarly journals Strengthening the pavement bases through the use of stabilizing additives

2018 ◽  
Vol 5 (4) ◽  
Author(s):  
Dmitry Stroev ◽  
Sergey Sizonets ◽  
Vanik Kazaryan
Keyword(s):  
Road Construction ◽  
Mineralogical Composition ◽  
High Water ◽  
Base Layer ◽  
Cement Stone ◽  
Structure And Properties ◽  
Residual Deformations ◽  
Positive Properties ◽  
Mineral Binder ◽  
Structural Base

The experience of recent years of road operation shows that one of the ways to reduce the accumulation of residual deformations in the layers of road construction, expressed in rutting, the appearance of a grid of cracks and other types of transverse and longitudinal irregularities, is used in the base layers of pavements reinforced with mineral binders of crushed-stone-gravel-sandy mixtures (HGPS). The strength and deformability of hardened HGPS is determined mainly by the structure and properties of the cement stone, which holds the aggregate grains in place. The structure and properties of reinforced HGHPs depend on: the mineralogical composition, the water-cement ratio, the fineness of the cement, the age, the preparation and hardening conditions, or the addition of additives. With the introduction of additives, you can significantly change the strength and deformability of reinforced HGPS. Currently, stabilizing additives are widely used, the introduction of which allows to provide high water resistance, crack resistance and durability of the structural base layer. At the same time, a reinforced mixture with the use of additives has not only all the positive properties of HGPS on portland cement, but also eliminates its negative sides: low values of compressive strength, tensile strength in bending, and large shrinkage deformations. Based on the above, the introduction of stabilizing additives in fortified HGPS seems to be fruitful. As an additive, the stabilizer «ARMADOR» was used. The additive is a dry bulk mixture based on polymers, salts of alkali and alkaline earth metals. With the introduction of the stabilizer «ARMADOR», the physico-mechanical parameters increase in the composition of the reinforced material. This stabilizer creates strong crystallization and coagulation bonds, the use of which is recommended in conjunction with a mineral binder.

scholarly journals Application of Ceramsite Dust as an Active Pozzolan Additive in the Cement-Based Compositions

2021 ◽  
Vol 1203 (3) ◽  
pp. 032022
Author(s):  
Grigory Yakovlev ◽  
Zarina Saidova ◽  
Anastasiya Gordina ◽  
Natalia Kuzmina ◽  
Yulia Ginchitskaya ◽  
...  
Keyword(s):  
Microstructural Analysis ◽  
Mineralogical Composition ◽  
Waste Recycling ◽  
Mechanical Tests ◽  
Cement Matrix ◽  
Cement Stone ◽  
Structure And Properties ◽  
New Production ◽  
Mineral Additive ◽  
Calcium Aluminosilicate

Abstract Ceramsite (expanded clay) dust is a waste material, obtained in large volumes all over the world as a by-product of ceramsite gravel production. With the development of the construction industry and the ever-growing amount of ceramsite dust disposed in the landfills, the recycling and rational use of this material is becoming a relevant issue. The currently available technologies for the ceramsite waste recycling are very limited, this is why it is necessary to develop a new effective way to involve this waste into the new production. The present research is based on the assumption that ceramsite dust can be applied effectively as an active pozzolanic mineral additive in the cement-based materials. In order to study the composition, structure and properties of the original clay used for the production of ceramsite, as well as the dehydrated clay dust, captured in the dust removing systems of kilns at ceramsite gravel plants, physical and chemical analysis methods were used. Based on the experimental data, the influence of ceramsite dust on the structure and properties of cement compositions was evaluated. Mechanical tests of the samples showed that the introduction of ceramsite dust as an additive in the amount of 3% by the cement weight leads to an increase in compressive strength by 23% in comparison with the reference composition. The paper also presents the results of microstructural analysis, IR spectral analysis and differential thermal analysis of samples modified with the optimal amount of this microadditive. The study of the microstructure of the modified samples shows that the introduction of ceramsite dust into the composition of the cement stone does not only change the morphology of new formations, thus increasing the density of the structure, but also varies the mineralogical composition of the cement matrix with the formation of stronger and more water-resistant minerals in the form of calcium silicate hydrates and calcium aluminosilicate hydrates. This technology allows the recycling of waste from the production of ceramsite stone, thus improving the environmental situation and contributing to the creation of a circular economy.

scholarly journals Research on the Properties of Mineral–Cement Emulsion Mixtures Using Recycled Road Pavement Materials

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 563
Author(s):  
Łukasz Skotnicki ◽  
Jarosław Kuźniewski ◽  
Antoni Szydło
Keyword(s):  
Road Construction ◽  
Base Layer ◽  
Asphalt Emulsion ◽  
Reclaimed Asphalt ◽  
Pavement Materials ◽  
Road Pavement ◽  
Road Surfaces ◽  
Cement Binder ◽  
Pavement Structures ◽  
By Products

The reduction in natural resources and aspects of environmental protection necessitate alternative uses of waste materials in the area of construction. Recycling is also observed in road construction where mineral–cement emulsion (MCE) mixtures are applied. The MCE mix is a conglomerate that can be used to make the base layer in road pavement structures. MCE mixes contain reclaimed asphalt from old, degraded road surfaces, aggregate improving the gradation, asphalt emulsion, and cement as a binder. The use of these ingredients, especially cement, can cause shrinkage and cracks in road layers. The article presents selected issues related to the problem of cracking in MCE mixtures. The authors of the study focused on reducing the cracking phenomenon in MCE mixes by using an innovative cement binder with recycled materials. The innovative cement binder based on dusty by-products from cement plants also contributes to the optimization of the recycling process in road surfaces. The research was carried out in the field of stiffness, fatigue life, crack resistance, and shrinkage analysis of mineral–cement emulsion mixes. It was found that it was possible to reduce the stiffness and the cracking in MCE mixes. The use of innovative binders will positively affect the durability of road pavements.

scholarly journals Modeling of structuring processes at hardening of expanding cements and concretes on their basis

2018 ◽  
Vol 196 ◽  
pp. 04035 ◽  
Author(s):  
Igor Kharchenko ◽  
Alexander Panchenko ◽  
Alexey Kharchenko ◽  
Vyacheslav Alekseev
Keyword(s):  
Theoretical Analysis ◽  
Rheological Model ◽  
Experimental Studies ◽  
High Strength ◽  
Cementitious Materials ◽  
Cement Stone ◽  
Formation Processes ◽  
Structure And Properties ◽  
Potential Index ◽  
Kinetics Of

This paper reports the results of experimental research of the effect of strain-restriction conditions on the structure and properties of sulfoaluminate expanding cementitious materials. Theoretical analysis of the development of pattern formation processes is performed by applying the developed rheological model, illustrating features of the kinetics of structure-forming processes according to the ratio of the potential index of extension with linear, flat and volumetric limitation of deformations of the extension. The results show that rheological model adequately correlates with the results of experimental studies and can be described mathematically. Found that with the volume limitation of deformations arising when mixing crystallographic phases with high density and strength, the pore structure of the cement stone contains mainly gel pores. This is the main prerequisite for obtaining a dense, high-strength and durable structure of cement stone and concrete on its basis.

scholarly journals Laboratory characterization of reclaimed asphalt pavement for road construction in Egypt

2017 ◽  
Vol 44 (6) ◽  
pp. 417-425 ◽  
Author(s):  
E. Mousa ◽  
A. Azam ◽  
M. El-Shabrawy ◽  
S.M. El-Badawy
Keyword(s):  
Resilient Modulus ◽  
Asphalt Pavement ◽  
Road Construction ◽  
California Bearing Ratio ◽  
Base Layer ◽  
Coefficient Of Determination ◽  
Reclaimed Asphalt Pavement ◽  
Reclaimed Asphalt ◽  
Load Duration ◽  
The Impact

This paper presents the engineering characteristics of reclaimed asphalt pavement (RAP), blended with virgin aggregate for unbound base and subbase layers. The proportions of RAP were 0%, 20%, 60%, 80%, and 100% by total mass of the blend. The experimental laboratory testing included index properties such as gradation, modified Proctor compaction, California Bearing Ratio, and hydraulic conductivity. Repeated load resilient modulus testing was conducted on the blends. The impact of load duration on resilient modulus was also investigated. A strong inverse trend was found between resilient modulus and California Bearing Ratio. An accurate model was proposed for the prediction of the resilient modulus as a function of stress state and reclaimed asphalt pavement percentage with coefficient of determination of 0.94. Finally, multilayer elastic analysis of typical pavement sections with the base layer constructed of virgin aggregate and reclaimed asphalt pavement blends showed good performance.

scholarly journals Influence of calcium sulphoaluminoferrite on the cement stone structure

2020 ◽  
Vol 164 ◽  
pp. 14002
Author(s):  
Svetlana Samchenko ◽  
Dmitriy Zorin
Keyword(s):  
Solid Solution ◽  
Hydration Product ◽  
Cement Stone ◽  
Structure And Properties ◽  
Partial Dissolution

Usually to obtain expansive cements sulphoaluminate clinker or mix aluminate clinker with calcium sulphates (gypsum, hemihydrate, anhydrate) are used. This paper deals with the composition and properties of solid solution of calcium sulphoaluminoferrite. It was studied an influence of calcium sulphoaluminoferrite on structure and properties cement phases. For these cements ettringite is an important hydration product. The investigation of hydration and properties of sulphomineral cements shows that ettringite are formed thus providing expansion of cement stone. Study of the hydration processes of the calcium sulfoaluminoferrite mineral in gypsum solution showed that the hydration of fine mineral fractions (less than 28 μm) occurs during partial dissolution with crystallization of small ettringite crystals from solution. Sulphoaluminoferrite mineral is characterized by the growth of large prismatic ettringite crystals with their subsequent cleavage in fractions of 45–63 μm. Research showed that for expanding additives based on calcium sulfoaluminoferrite, a polyfraction composition combining only small fractions is preferable.

scholarly journals About the influence of hardening conditions on the structure and properties of expansive concretes

2018 ◽  
Vol 193 ◽  
pp. 03025 ◽  
Author(s):  
Vyacheslav Alekseev ◽  
Igor Harchenko ◽  
Aleksey Harchenko ◽  
Sofia Bazhenova
Keyword(s):  
Research Methodology ◽  
Concrete Structures ◽  
Operating Conditions ◽  
Cement Stone ◽  
Structure And Properties ◽  
Technical Parameters ◽  
Material Change ◽  
Volumetric Deformation ◽  
Durability Of Concrete

The paper describes the effect of hardening conditions on the hydration of cement stone and methods of controlling the concrete formation on the basis of the above research methodology. It has been proved that when the humidity of the medium in which hardening takes place is regulated, the strength and the deformation of the material change. By adding an expand-ing component to concrete, it is possible to adjust the technical parameters of concrete and simulate the durability of concrete structures. Thus, the study of the mechanisms of volumetric deformation during hardening of cement stone with a different ratio of the expanding additive allows designing con-crete compositions for different operating conditions.

scholarly journals Preliminary Examination of the System Fly Ash-Bottom Ash-Flue Gas Desulphurization Gypsum-Portland Cement-Water for Road Construction

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
R. Tokalic ◽  
S. Marinkovic ◽  
P. Trifunovic ◽  
G. Devic ◽  
S. Zildzovic
Keyword(s):  
Fly Ash ◽  
Portland Cement ◽  
Flue Gas ◽  
Bottom Ash ◽  
Road Construction ◽  
Mineralogical Composition ◽  
Mass Ratio ◽  
Preliminary Examination ◽  
Potential Use ◽  
Flue Gas Desulphurization

This paper describes an investigation into the use of three power plant wastes: fly ash, flue gas desulphurization gypsum, and bottom ash for subbase layers in road construction. Two kinds of mixtures of these wastes with Portland cement and water were made: first with fly ash consisting of coarser particles (<1.651 mm) and second with fly ash consisting of smaller particles (<0.42 mm). The mass ratio of fly ash-Portland cement-flue gas desulphurization gypsum-bottom ash was the same (3 : 1 : 1 : 5) in both mixtures. For both mixtures, the compressive strength, the mineralogical composition, and the leaching characteristics were determined at different times, 7 and 28 days, after preparation. The obtained results showed that both mixtures could find a potential use for subbase layers in road construction.

scholarly journals DEVELOPMENT OF ELECTROTHERMAL GEOTECHNOLOGY OF SOIL TRANSFORMATION IN ROAD CONSTRUCTION

2018 ◽  
pp. 197-207
Author(s):  
V. N. Efimenko ◽  
Yu. M. Charykov
Keyword(s):  
Energy Consumption ◽  
Road Construction ◽  
Raw Material ◽  
Flow Chart ◽  
Clay Soils ◽  
Material Base ◽  
Structure And Properties ◽  
The Road ◽  
Road Pavement ◽  
Pavement Engineering

The paper presents of research results on the development of the raw material base due to the use of clay soils widespread in the territory of Russia. The structure and properties of soils are processed by the nonconventional electrothermal technology. The flow chart is proposed for the rock material production. The data on energy consumption is suggested herein for the use of artificial rock materials in the road pavement engineering.

Sign in / Sign up

Export Citation Format

Share Document