Development of Cement Compositions with a Finely Dispersed Additive for Consolidation of Soil by the Injection

2019 ◽  
Vol 974 ◽  
pp. 149-155
Author(s):  
Irina V. Kozlova ◽  
Alexey E. Bespalov ◽  
Alexandra V. Bespalova
Keyword(s):  
Compressive Strength ◽  
Portland Cement ◽  
Mechanical Characteristics ◽  
Cement Stone ◽  
Soil Consolidation ◽  
Injection Solution ◽  
Concentrated Load ◽  
Reduced Viscosity ◽  
Injection Technology ◽  
Physical And Mechanical Characteristics

Cement compositions prepared by mixing cement with a stabilized finely dispersed slag suspension, which allow improving the structural, physical and mechanical characteristics of the cement stone are considered. On the first day of hardening, the strength of modified specimens increased by 54%, at the grade age - by 43%, and the porosity decreased by 13.8 and 17.3%, respectively. The possibility of obtaining an injection solution for soil consolidation on the basis of Portland cement and a stabilized slag suspension with the concentration of a finely dispersed slag of 50 g/l is considered. Studies have shown that the injection solution under study has reduced viscosity and sedimentation, increased compressive strength. After 28 days of hardening, the strength was 14.2 MPa, which is higher than the recommended values ​​for consolidation of soil under the foundations (4-6 MPa), and at a concentrated load, for the base under the foundations of the columns (9-10 MPa). The data obtained allows considering an injection solution based on Portland cement and slag suspension for the use in the injection technology of soil consolidation.

scholarly journals Amorphous fiber based on the Fe-B-C molten system for bulk reinforcement of concrete

2018 ◽  
Vol 245 ◽  
pp. 03019 ◽  
Author(s):  
Artemiy Cherkashin ◽  
Yasmin Begich ◽  
Polina Sherstobitova ◽  
Oleg Tolochko
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Mechanical Characteristics ◽  
Test Material ◽  
Comparative Tests ◽  
Physical And Mechanical Characteristics

The article deals with the use of amorphous fiber of the Fe-B-C system, which was obtained by spinning the melt. Comparative tests of the samples made on the basis of the test material on the compressive strength and tensile strength of the traditional destructive method were made. The conductivity of the samples was also tested. Physical and mechanical characteristics of the material are obtained.

scholarly journals Thermal and mechanical properties of PCM-incorporated normal and lightweight concretes containing silica fume

2019 ◽  
Vol 46 (7) ◽  
pp. 643-656 ◽  
Author(s):  
Amin Moshtaghi Jafarabad ◽  
Morteza Madhkhan ◽  
Naser P. Sharifi
Keyword(s):  
Compressive Strength ◽  
Silica Fume ◽  
Thermal Performance ◽  
Phase Change Materials ◽  
Mechanical Characteristics ◽  
Lightweight Aggregate ◽  
Salt Hydrate ◽  
Promising Strategy ◽  
Compressive Strength Of Concrete ◽  
Physical And Mechanical Characteristics

Improving the thermal performance of concrete, as an important construction and pavement material, by incorporating phase change materials (PCMs) has been the topic of much research. Also, various carrier agents such as lightweight aggregate (LWA) have been introduced to incorporate PCMs into concrete. However, incorporation of PCM-impregnated LWA reduces the compressive strength of concrete. In this study, the application of silica fume to improve the compressive strength of PCM-incorporated concrete is investigated. Two types of PCMs, salt hydrate PCM and polyethylene glycol PCM, were incorporated into concrete via scoria LWA, and different physical and mechanical characteristics of the concrete were studied when silica fume was incorporated into the mix. The results show that incorporation of silica fume increases the compressive strength of PCM-incorporated concrete, and at the same time does not diminish the thermal performance of the incorporated PCM. Therefore, incorporation of silica fume was found to be a promising strategy to improve the compressive strength of PCM-incorporated concrete.

Physical and mechanical characteristics of cement mortars and concretes with addition of clinoptilolite from Beli Plast deposit (Bulgaria), silica fume and fly ash

Clay Minerals ◽  
2011 ◽  
Vol 46 (2) ◽  
pp. 213-223 ◽  
Author(s):  
V. Lilkov ◽  
I. Rostovsky ◽  
O. Petrov
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Fly Ash ◽  
Silica Fume ◽  
Mechanical Characteristics ◽  
Physical And Mechanical Properties ◽  
Specific Pore Volume ◽  
Cement Mortars ◽  
Physical And Mechanical Characteristics

AbstractCement mortars and concretes incorporating clinoptilolite, silica fume and fly ash were investigated for changes in their physical and mechanical properties. It was found that additions of 10% clinoptilolite and 10% Pozzolite (1:1 mixture of silica fume and fly ash) were optimal for improvement of the quality of the hardened products, giving 8% and 13% increases in flexural and compressive strength respectively. The specific pore volume of the mortars incorporating zeolite decreased between the 28th and 180th day to levels below the values for the control composition due to the fact that clinoptilolite exhibits its pozzolanic activity later in the hydration. In these later stages, pores with radii below 500 nm increased at the expense of larger pores. The change in the pore-size distribution between the first and sixth months of hydration occurs mostly in the mortars with added zeolite.

Усиление внутреннего слоя многослойного композита базальтопластиком в виде сотовой структуры

2021 ◽  
Vol 27 (2) ◽  
pp. 205-216
Author(s):  
Г. П. Пономарева ◽  
◽  
И. М. Попова ◽  
О. М. Сладков ◽  
М. В. Пономарев ◽  
...  
Keyword(s):  
Mechanical Characteristics ◽  
Laminated Composite ◽  
Middle Layer ◽  
Epoxy Compound ◽  
Reaction Mass ◽  
Relative Deformation ◽  
Concentrated Load ◽  
Liquid Reaction ◽  
Constant Rate ◽  
Physical And Mechanical Characteristics

In our studies we present a multilayer structure consisting of outer layers of two-ply basalt composed of basalt fabric impregnated with an epoxy compound and an inner layer of polyurethane reinforced with basalt, having the same composition, formed in conjugate hexagonal prisms, and forming a cellular framework. The main part describes the technological sequence of obtaining basalt face layers, basalt hexagonal cellular frame, and filling it with a liquid reaction mass of rigid polyurethane system. The formation of a single multilayer composite structure is shown. We also present the results of the experimental research of strength of a laminated composite and its inner layer without facing layers when tested for static bending with concentrated load increasing at a constant rate and compression testing up to 10% of relative deformation. It describes the effect of the size of hexagonal prismatic cells of the frame on the physical and mechanical characteristics of the middle layer. The reduction of the cell size results in the increase of the composite strength. The dependence of the composite density on the size of the cells of the basalt frame has been studied.

scholarly journals STRUCTURAL CONCRETE MODIFIED WITH SCALLOP SHELL LIME

2021 ◽  
Vol 36 (3) ◽  
Author(s):  
Ronal Alex Mauricio Villarrial ◽  
◽  
Marlon Gaston Farfan Cordova ◽  
Keyword(s):  
Compressive Strength ◽  
Mechanical Characteristics ◽  
Concrete Strength ◽  
Calcium Content ◽  
Cement Type ◽  
Scallop Shell ◽  
High Calcium ◽  
Compressive Strength Of Concrete ◽  
Natural Aggregates ◽  
Physical And Mechanical Characteristics

This research was conducted to determine the effect of the scallop shell lime (SSL) on the compressive strength of concrete made with Portland cement type Ico and natural aggregates from a quarry, where SSL was added at 3%, 4% and 5%. The physical and mechanical characteristics of the aggregates were determined based on the N.T.P. 400.037/ASTM C22 standard, and the mix design was carried out through the ACI method. The SSL was used due to the high calcium content present in the valve. Standard concrete controls were prepared and cured by adding 3%, 4% and 5% SSL (339.0183/ASTM C192M), which were analyzed at 7, 14 and 28 days of curing. The results showed that the compressive strength at 28 days was 242.63 kg/cm2 when 3% SSL was added, increasing with respect to the standard control by 16%. With the addition of 4% SSL, the maximum strength reached was 245.25 kg/cm2, and with 5%, the compressive strength reached was 261.17 kg/cm2, increasing by 24%. In conclusion, the SSL positively affects the increase of concrete strength, and the percentage with the highest incidence is 5%.

scholarly journals CHANGES IN THE STRUCTURAL AND PHASE COMPOSITION OF CEMENT CONCRETE DURING MICROBIOLOGICAL CORROSION

2021 ◽  
Vol 6 (11) ◽  
pp. 106-113
Author(s):  
K. Strokin ◽  
D. Novikov ◽  
V. Konovalova ◽  
N. Kasiyanenko
Keyword(s):  
Compressive Strength ◽  
Phase Composition ◽  
Portland Cement ◽  
Cement Stone ◽  
Cement Concrete ◽  
Microbiological Corrosion ◽  
Crystalline Phases ◽  
X Ray ◽  
Calcium Hydrosilicates ◽  
Black Mold

The article considers the change in the structural and phase composition of cement stone made of Portland cement of the CEM I 42.5 N brand in the process of bacterial and fungal corrosion during 6 months when humidified. The X-ray images of cement stone show peaks that characterize the non-hydrated components of Portland cement alite, belite, tricalcium aluminate, four-calcium aluminoferrite and gypsum. By the method of X-ray phase analysis, it is found that during microbiological corrosion, the content of all phases of cement stone decreases. The aspergillus niger van Tieghem fungi have a stronger effect on the structural and phase composition of cement stone. Fungal microorganisms destroy the crystalline phases and absorb amorphous phases – calcium hydrosilicates C-S-H (I) and C-S-H (II) and tobermorite. When bacteria Bacillus subtilis affects the cement stone, the content of the calcite phase increases, which is a product of corrosion, while the action of black mold reduces the intensity of CaCO3 peaks. A decrease in the content of low-base calcium hydrosilicates and ettringite, as well as other crystalline phases, leads to a decrease in the compressive strength of the cement stone. During 6 months of microbiological corrosion of cement concrete under conditions of constant wetting, the compressive strength decreases by about 35 %.

scholarly journals Управление физико-механическими характеристиками бетона за счет варьирования высоты и шага технологических выступов хомутов виброцентрифугирующих устройств

2021 ◽  
Vol 46 (1) ◽  
Author(s):  
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Cross Section ◽  
Mechanical Characteristics ◽  
Experimental Studies ◽  
Strength Analysis ◽  
Technological Parameters ◽  
Axial Tensile ◽  
Concrete Mix ◽  
Physical And Mechanical Characteristics

Для регулирования вариатропной структуры центрифугированных изделий авторы данной статьи совместили процесс центрифугирования с вибрированием. Во время эксперимента вибрации формы обеспечивались за счет надетых на валы установки хомутов. Представлена авторская экспериментальная установка для создания виброцентрифугированных образцов кольцевого сечения с вариатропной структурой, а также способ их изготовления. Выделены технологические параметры вибрирования, которые оказывали наиболее значимое влияние на характеристики виброцентрифугированного бетона, конструкций и изделий из него. В опытах варьировались высота технологических выступов хомутов и шаг между ними. Исследовалось влияние этих факторов на физико-механические характеристики бетона: плотность; кубиковая прочность на сжатие; призменная прочность на сжатие; прочность на растяжение при изгибе; прочность на осевое растяжение. Приведен анализ результатов экспериментальных исследований и получены следующие физико-механические характеристики виброцентрифугированных бетонов, изготовленных с использованием хомутов: лучшие – с высотой технологических выступов 5 мм и шагом между ними 30 мм, самый низкий показатель – соответственно 2,5 мм при любом шаге. Ключевые слова: виброцентрифугированный бетон, физико-механические характеристики, прочность при сжатии, плотность, бетонная смесь, центрифугирование, прочность при изгибе To regulate the variatropic structure of centrifuged products, the authors of this article combined the process of centrifugation with vibration. During the experiment, vibrations of the mold were provided with clamps set on the shafts of the installation. The author's experimental setup for creating vibrocentrifuged samples of annular cross-section with a variatropic structure, as well as a method for their manufacture is presented. The technological parameters of vibration, which had the most significant effect on the characteristics of vibrocentrifuged concrete, structures and products made of it, were identified. In the experiments, the height of the technological protrusions of the clamps and the pitch between them were varied. The influence of these factors on the physical and mechanical characteristics of concrete was investigated: density; cube compressive strength; prismatic compressive strength; bending tensile strength; axial tensile strength. Analysis of the results of experimental studies is given and the following physical and mechanical characteristics of vibrocentrifuged concretes made using clamps have been obtained: the best ones with a height of technological protrusions of 5 mm and a step between them of 30 mm, the lowest indicator is, respectively, 2.5 mm at any step. Keywords: vibrocentrifuged concrete, physical and mechanical characteristics, compressive strength, density, concrete mix, centrifugation, flexural strength

scholarly journals The influence of clay additives in Portland cement on the compressive strength of the cement stone

2015 ◽  
Vol 59 (07) ◽  
pp. 66-73 ◽  
Author(s):  
A.R. Gaifullin ◽  
R.Z. Rakhimov ◽  
N.R. Rakhimova
Keyword(s):  
Compressive Strength ◽  
Portland Cement ◽  
Cement Stone

scholarly journals Relationship between Density and Early Compressive Strength of Slurry Infiltrated Fiber Reinforced Concrete (SIFCON)

2021 ◽  
Vol 2129 (1) ◽  
pp. 012062
Author(s):  
Mustaqqim Abdul Rahim ◽  
Lim Jiann Jonq ◽  
Afizah Ayob ◽  
Shamilah Anudai Anuar ◽  
Nor Faizah Bawadi ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Reinforced Concrete ◽  
Mechanical Characteristics ◽  
Steel Fiber ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Concrete Compressive Strength ◽  
Ordinary Concrete ◽  
Percentage Volume ◽  
Physical And Mechanical Characteristics

Abstract The aim of the study is to study the physical and mechanical characteristics of Slurry Infiltrated Fiber Reinforced Concrete with fiber percentage volume of 5% and lower. For the testing of physical characteristics of the concrete, density test been conducted. For the testing of mechanical characteristics, compression test used to determine strength of concrete sample. The density of Slurry Infiltrated Fiber Reinforced Concrete increased when the usage of steel fiber percentage volume increases from 1% to 5%, nevertheless when compared to density of ordinary concrete, ordinary concrete is denser. For the significant of study, the mechanical properties of Slurry Infiltrated Fiber Reinforced Concrete, compressive strength increased when the fiber content increases from 1% to 5% percentage volume.

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