Analysis of the Effectiveness of the New Generation of Additives in Improving Physical and Mechanical Properties of Highway Subgrades

2021 ◽  
Vol 1017 ◽  
pp. 101-110
Author(s):  
Anna I. Trautvain ◽  
Evgeniy A. Yakovlev ◽  
Anatoly M. Gridchin
Keyword(s):  
Tensile Strength ◽  
Frost Resistance ◽  
Water Saturation ◽  
Physical And Mechanical Properties ◽  
High Strength ◽  
Average Density ◽  
Soil Composition ◽  
Practical Application ◽  
New Generation ◽  
Loss Of Strength

At present, the introduction of only organic or inorganic binder is not always sufficient for the practical application of stabilized soils. The research investigated the effect of the stabilizing additives Chimston, Baustab and Dorstab on changing a number of parameters over time, such as: average density, water saturation, ultimate compression and tensile strength, and frost resistance. All the researched parameters were determined at intermediate and target age — 7, 14 and 28 days respectively. Tests to assess the effectiveness of various stabilizing additives in strengthening loamy soil have shown the feasibility of using Baustab and Chimston-3 additives (in the dosage of 2%). Introduction of additives into the soil composition allowed obtaining soil with high strength characteristics and higher frost resistance as compared to the control composition. Composition No.2 has the compressive strength of 5.1 MPa and the tensile strength of 1.6 MPa. Composition No.7 has the limit of compression strength of 5.4 MPa, and the limit of tensile strength of 1.27 MPa. Thus, both compositions have the strength grade M40. Such soil will be subject to minimal subsidence and loss of strength.

scholarly journals Concrete based on sulfur binder being modified with inorganic additives

2018 ◽  
Vol 212 ◽  
pp. 01013
Author(s):  
Vadim Balabanov ◽  
Victor Baryshok ◽  
Nikita Epishkin
Keyword(s):  
Frost Resistance ◽  
Building Materials ◽  
Physical And Mechanical Properties ◽  
High Strength ◽  
Strength Properties ◽  
Climatic Conditions ◽  
Freezing And Thawing ◽  
Concrete Mixtures ◽  
Irkutsk Region ◽  
Water Saturated

The sharply continental climate of the Irkutsk region is characterized by wide temperature intervals throughout the year. The repeated cyclicity of freezing and thawing of building materials in the water-saturated state influences the change in technical characteristics and the durability of concrete products and structures. The concrete products’ features in such climatic conditions create the need for the production of concretes with improved indicators of physical and mechanical properties. The effect of modifying additives on the technological characteristics of sulfur concrete is established. The effect of all elements of sulfur concrete on its strength and frost resistance. The composition of sulfuric concrete is obtained, which meets all the requirements and also has high strength and increased frost resistance. Formulations with a certain ratio of structural sulfuric concrete mixtures were developed. As a result of the use of technical sulfur in the composition of concrete products, the problem of utilizing annually accumulating reserves of technical sulfur is partially solved. The strength properties of sulfuric concretes easily compete with high-quality brands of concrete, special types of concretes that have in their composition additives.

Damaging effect of salt crystallization on highly porous limestone from Hungary

2020 ◽  
Author(s):  
Nikoletta Rozgonyi-Boissinot ◽  
Mohammad Ali Khodabandeh
Keyword(s):  
Tensile Strength ◽  
Sea Water ◽  
Water Saturation ◽  
Salt Content ◽  
Physical And Mechanical Properties ◽  
Optical Microscope ◽  
Sodium Sulphate ◽  
Capital City ◽  
Salt Crystallization ◽  
Petrophysical Properties

<p>One of the most important weathering processes on stone-built monuments is the crystallization of salts. Since the transport material of these substances is water, the porous rock types are particularly affected. In Hungary many monuments and historic buildings have been constructed from oolithic Miocene limestone. So in this study, the effect of salt crystallization on the physical and mechanical properties of high porous limestone has been investigated. Samples were obtained from Sóskút (near to Budapest, the capital city of Hungary).</p><p>At first the petrophysical properties of the stone were determined. The porosity of the investigated stone type was 26-34 V/V%, the uniaxial compressive strength (4-5 MPa) and the Brazilian tensile strength (0,4-0,5 MPa) were very low. A special proper of this rock type is the large-pore system (2-3mm) between the ooid fragments.</p><p>Sodium chloride (NaCl) and sodium sulphate (Na<sub>2</sub>SO<sub>4</sub>) were used to investigate the effect of salt crystallization. Cylindrical rock samples were exposed to salt solutions of 14 m/m% Na<sub>2</sub>SO<sub>4</sub> (MSZ EN 12370) and 5% NaCl solution (sea water salt content). After 15 salted water saturation- drying cycles the changes of mineralogical and petrophysical properties and indirect tensile strength of the samples were investigated. The damages on the pore walls were determined with scanning electron microscope (SEM) and the building of scaling layers on the stone surfaces were investigated with optical microscope.</p>

scholarly journals The Mechanism of Reinforced Backfill Body with Flexible Mesh

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Xiaosheng Liu ◽  
Weijun Wang ◽  
Quan Liu ◽  
Chao Yuan
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Laboratory Experiments ◽  
Physical And Mechanical Properties ◽  
High Strength ◽  
Strengthening Effect ◽  
Passive Resistance ◽  
Metal Mines ◽  
Reinforcement Material

The backfill of metal mines is easily damaged by the disturbance due to their low strength. We proposed a method that uses flexible meshes as the backfill skeleton to enhance the strength of the backfill. The physical and mechanical properties of the flexible mesh-reinforced filling body are investigated by combining theoretical analysis and laboratory experiments. The strengthening effect is remarkable with the flexible meshes. With the friction-passive resistance between the high-strength reinforcement material and the filling body, the insufficient tensile strength of the filling body is compensated and the reinforcement is improved. The ultimate compressive strength is increased by 1.07 to 1.35 times, and the elastic modulus is increased by 1.08 to 4.42 times. We concluded that the essence of strengthening the flexible mesh-reinforced filling is to increase the cohesive force of the filling and increase the ability to resist external load damage.

scholarly journals A review on study of partial replacement of cement by metakaolin and glenium b233 in self- compacting concrete.

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Nazrin Fathima Fazil M ◽  
C.J. Chitra
Keyword(s):  
Tensile Strength ◽  
High Strength Concrete ◽  
High Strength ◽  
Partial Replacement ◽  
Kaolin Clay ◽  
Fresh Properties ◽  
Self Compacting Concrete ◽  
Durability Properties ◽  
Super Plasticizer ◽  
New Generation

        Self-compacting concrete (SCC) refers to high strength concrete which will compact under its own weight and does not require external vibration. This paper gives a review on the journals to study the effect of metakaoiln in SCC. The metakaolin is used as a replacement of cement and it is obtained from natural Kaolin clay. Metakaolin helps to increase the compressive strength, spilt tensile strength, flexural strength and also the fresh properties. The use super plasticizer greatly improves pump-ability and the slump value. GLENIUM B233 is a new generation based super plasticizer which is based on modified polycarboxylic ether. The fresh properties such as pump ability and workability and the durability properties of super plasticizer in SCC with metakaolin are discussed. Keywords: Self-Compacting Concrete, Metakaolin, GLENIUM B233, Superplasticizer, Polycarboxylic Ether

scholarly journals Improving the properties of composite materials for civil engineering

2019 ◽  
Vol 91 ◽  
pp. 02015
Author(s):  
Valentina Soloviova ◽  
Irina Stepanova ◽  
Nicholas Ershikov ◽  
Dmitry Soloviov
Keyword(s):  
Mechanical Properties ◽  
Chemical Activation ◽  
Physical And Mechanical Properties ◽  
High Strength ◽  
Deformation Characteristics ◽  
Energy Effect ◽  
Composite Mixture ◽  
Strength And Deformation ◽  
New Generation ◽  
Hardening System

It is shown that a highly-efficient chemical activation of the cement-containing composite mixture with the help of a new generation nanostructural additive makes it possible to develop high-strength finegrained and heavy-weight concretes with the improved strength and deformation characteristics. The recommended nanostructural additive has an increased triple effect: reactive, catalytic, and plasticizing. The use of the proposed additive many times increases the hydration activity of the hardening system, exerting a double energy effect on it, chemical and thermal, thus making it possible to develop the composite building material of a new level of physical and mechanical properties.

scholarly journals Влияние отжига и дополнительной деформации на механические свойства ультрамелкозернистого сплава Al-1.5Cu

2020 ◽  
Vol 46 (18) ◽  
pp. 30
Author(s):  
А.М. Мавлютов ◽  
Т.С. Орлова ◽  
Э.Х. Яппарова
Keyword(s):  
Mechanical Properties ◽  
High Pressure ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
High Pressure Torsion ◽  
High Strength ◽  
High Ductility ◽  
Practical Application ◽  
Short Term ◽  
Ultrafine Grained

The mechanical properties of the ultrafine-grained (UFG) Al–1.5Cu (wt.%) alloy were investigated. The UFG structure was obtained using high pressure torsion (HPT) technique. UFG alloy demonstrates high values of microhardness (1690 MPa), yield strength (515 MPa) and ultimate tensile strength (655 MPa), but low ductility (~3%). Subsequent short-term annealing at 150 °C and additional HPT deformation to 0.25 rotations resulted in some decrease in ultimate tensile strength to 450 MPa, which was ~70% of the value before annealing but provided high ductility (~22%). The results suggests a high potential for practical application of the material. The proposed approach can be an universal effective way to achieve combination of high strength and high ductility for various UFG materials.

scholarly journals THE EFFECT OF MODIFIED ADDITIVES ON STRENGTH AND FROST RESISTANCE IN FIBROUS CONCRETE OF RIGID ROAD PAVEMENTS

2020 ◽  
pp. 68-74
Author(s):  
A.V. Mishutin ◽  
◽  
L. Chintea ◽  
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Portland Cement ◽  
Frost Resistance ◽  
Polypropylene Fiber ◽  
High Strength ◽  
Fibrous Concrete ◽  
Fiber Concrete ◽  
Mineral Additive ◽  
Compressive Strength Of Concrete

Abstract. The research is devoted to the development of compositions of modified fiber concrete of rigid road pavements with high strength and frost resistance through the use of metakaolin and a polycarboxylate type superplasticizer. The compressive strength, tensile strength under bending and frost resistance of concrete and fiber concrete of rigid road pavements were investigated according to the 4-factor optimal plan. In the experiment the amount of concrete components varied: Portland cement, polypropylene fibers, metakaolin, the polycarboxylate type additives Coral ExpertSuid-5. All mixtures had equal mobility P2 and their W/C depended on the composition of concrete. The use of polypropylene fiber and metakaolin necessitates an increase of W/C to maintain the mobility of the mixture. Increasing the amount of Coral ExpertSuid-5 additive in concrete to 0.9-1% allows to reduce significantly W/C of the mixture. Metakaolin as an active mineral additive increases the compressive strength and tensile strength of concrete. Rational in terms of increasing strength is the amount of metakaolin at the level of 20..22 kg/m3. With an increase in the amount of Coral ExpertSuid-5 additive to 0.9..1% due to a decrease of W/C, the compressive strength of concrete increases by 5..7 MPa, and the tensile strength increases by about 0.5 MPa. Due to the introduction of polypropylene fiber, the tensile strength of concrete in bending increases by 0.6..0.9 MPa. But dispersed reinforcement does not affect the compressive strength of concrete. The developed fiber concrete using a rational amount of modifiers, depending on the amount of Portland cement in the composition, has a compressive strength from 55 MPa to 70 MPa and tensile strength from 8 MPa to 9.5 MPa. The high strength of fiber-reinforced concretes allows their use in road pavements with the highest load. Frost resistance of concrete increases by 50 cycles or more when using fiber in an amount of 1.5-2 kg/m3. Due to the use of a rational amount of modifiers (0.8-1% Coral ExpertSuid-5 additive and 15-20 kg/m3 metakaolin), frost resistance of concrete and fiber concrete increases by 50-100 cycles. The developed modified fiber concretes of rigid road pavements depending on the amount of Portland cement in the composition have frost resistance from F350 to F450, which ensures their sufficient durability.

scholarly journals Physical and Mechanical Properties of High Strength Concrete containing PVC Waste as a Sand Replacement

2020 ◽  
Vol 7 (3) ◽  
pp. 156-175
Author(s):  
Tavga Mohammad ◽  
◽  
Azad Mohammed
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
High Strength Concrete ◽  
Physical And Mechanical Properties ◽  
High Strength ◽  
Fine Aggregate ◽  
Appreciable Effect ◽  
Strength Concrete ◽  
Aggregate Content ◽  
Concrete Properties

In this research, physical and mechanical properties of high strength concrete containing PVC waste have been investigated. The fine aggregate was replaced with PVC waste with two different gradings (fine grading and coarse grading) at dosages of 0%, 5%, 10%, 20%, and 40% by the volume of aggregate. The properties include physical properties of density and water absorption, mechanical properties of compressive strength, splitting tensile strength and flexural strength. Results show that in general, using 5% PVC replacement in high strength concrete has no appreciable effect to damage the physical and mechanical properties of concrete. With increasing PVC aggregate content, the deterioration of the concrete properties was observed. The coarse graded PVC aggregate has some more effect on the deterioration of concrete properties compared to the fine graded PVC aggregate.

scholarly journals Structural Characterization and Analysis of High-Strength Laminated Composites from Recycled Newspaper and HDPE

Polymers ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1311 ◽  
Author(s):  
Binwei Zheng ◽  
Chuanshuang Hu ◽  
Litao Guan ◽  
Jin Gu ◽  
Huizhang Guo ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Water Absorption ◽  
High Density Polyethylene ◽  
Laminated Composites ◽  
Quantitative Description ◽  
Physical And Mechanical Properties ◽  
High Strength ◽  
Maximum Density ◽  
Pressing Time

Recycled newspaper (NP) shows excellent potential as a reinforcement for polymer composites. Herein, high-strength laminated composites were prepared by using NP laminas as reinforcement and high-density polyethylene (HDPE) films as matrix. Physical and mechanical properties of the laminated composites were measured. It was found that the flexural strength of the composites had a good linear relationship to its density, with R2 = 0.9853. The flexural and tensile strength of the composites at the maximum density (1.40 g/cm3) reached up to 95.6 ± 2.4 MPa and 99.4 ± 0.8 MPa, respectively. SEM results showed that NP layer inside the composite became compact at the hot pressing time of 40 min, because the melted HDPE permeated into the NP layers to bond the NP fibers. Quantitative description of the composite porosity was conducted according to the density of the composite. The 24-h water absorption of the composite was highly related to its porosity, with R2 = 0.8994. This study reveals that density of laminated composites is an important parameter, which could be used to forecast the mechanical strength, and its derived value, porosity of the composites, could be used to predict the water absorption behavior of the composite.

Disperse-Reinforced Polystyrene Concrete Modified by Silica-Containing Additive

2020 ◽  
Vol 992 ◽  
pp. 20-25
Author(s):  
A.A. Pykin ◽  
N.P. Lukuttsova ◽  
S.N. Golovin
Keyword(s):  
Mechanical Properties ◽  
Frost Resistance ◽  
Water Glass ◽  
Thermal Conductivity Coefficient ◽  
Physical And Mechanical Properties ◽  
Resistance Coefficient ◽  
Average Density ◽  
Cement Stone ◽  
Basalt Fibre ◽  
Tension Strength

The composition of disperse-reinforced polystyrene concrete for the manufacture of small-pieces load-bearing structural insulating wall products is developed. Its properties and microstructure are studied. It is composed of Portland cement, granular foamed polystyrene, basalt fibre, water and silica-containing modifier obtained by mixing condensed silica, superplasticizer S-3 and an aqueous solution of sodium water glass. The developed disperse-reinforced polystyrene concrete modified by silica-containing additive is characterized by higher values of adhesive strength (0.231 MPa), class by bending tension strength (Btb4), class by compressive strength (B5), cracking resistance coefficient (0.77), grade by frost-resistance (F1150) with a slight increase in the average density and thermal conductivity coefficient. The increase of physical and mechanical properties and frost resistance of polystyrene concrete of the developed composition is achieved by compaction and hardening of cement stone, improving its adhesion to granular foamed polystyrene due to the synergistic effect of a silica-containing modifier acting as an adhesive and structure-forming additive, and basalt fibre as a disperse-reinforcing component.

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