scholarly journals Investigation of the integral strength and deformation characteristics of centrifuged and vibrocentrifuged concretes on activated Portland cement

2021 ◽  
Vol 9 (3) ◽  
pp. 46-50
Author(s):  
Levon Mailyan ◽  
Elena Vinogradova ◽  
D. El'shaeva ◽  
Y. Zherebtsov ◽  
N. Dotsenko ◽  
...  
Keyword(s):  
Portland Cement ◽  
Hole Diameter ◽  
Outer Diameter ◽  
Deformation Characteristics ◽  
Technological Parameters ◽  
Annular Section ◽  
Experimental Laboratory ◽  
Strength And Deformation ◽  
Optimal Values ◽  
Laboratory Centrifuge

In this work, a study of the integral strength and deformation characteristics of centrifuged and vibrocentrifuged concretes on activated Portland cement is carried out. Mechanical activation of cement was carried out using a specialized grinding unit. The manufacture of centrifuged and vibrocentrifuged samples was carried out on an experimental laboratory centrifuge. All samples were made from concrete of the same composition. In total, four basic samples of annular cross-section were manufactured and tested with the following dimensions: outer diameter D = 450 mm; inner hole diameter d = 150 mm; total height H = 1200 mm. The optimal values ​​of technological parameters of centrifugation and vibrocentrifugation are given. A scheme has been developed for obtaining small-sized samples from a common annular section to determine the strength and deformation characteristics. According to the results of the study, it was found that an improvement in the values ​​of integral strength and deformation characteristics when using activated Portland cement is observed in both centrifuged and vibrocentrifuged samples. It was found that samples made by vibrocentrifugation technology have the best strength and deformation characteristics than samples made by centrifugation. The conclusion is made about the technology of vibrocentrifugation as the most preferable for the manufacture of reinforced concrete products of annular section.

scholarly journals Investigation of differential strength and deformation characteristics of centrifuged and vibrocentrifuged concretes on activated Portland cement

2021 ◽  
Vol 9 (3) ◽  
pp. 1-5
Author(s):  
Levon Mailyan ◽  
Sergey Stel'makh ◽  
Evgeniy Shcherban' ◽  
Dmitrii Chernykh ◽  
Dmitrii Stroev ◽  
...  
Keyword(s):  
Portland Cement ◽  
Power Supplies ◽  
Outer Diameter ◽  
Deformation Characteristics ◽  
Technological Parameters ◽  
Annular Section ◽  
Experimental Laboratory ◽  
Strength And Deformation ◽  
Optimal Values ◽  
Laboratory Centrifuge

In this work, a study of the strength and deformation characteristics of the variatropic layers of centrifuged and vibrocentrifuged concretes on activated Portland cement was carried out. Mechanical activation of cement was carried out using a specialized grinding unit - a planetary ball mill "Aktivator-4M". The optimal mode of grinding Portland cement is proposed. For the manufacture of centrifuged and vibrocentrifuged samples, an experimental laboratory centrifuge TsSRL-1 with a DC electric motor with thyristor power supplies was used, and the form vibrations were carried out due to additional dowels (protrusions) put on the shafts. All samples were made from concrete of the same composition. In total, four basic samples of annular cross-section were manufactured and tested with the following dimensions: outer diameter D = 450 mm; inner hole diameter d = 150 mm; total height H = 1200 mm. The optimal values ​​of technological parameters of centrifugation and vibrocentrifugation are given. A scheme is proposed for obtaining small-sized samples to determine the strength and deformative characteristics of various layers of a sample by cutting them out of a common annular section. According to the results of the study, it was found that the activation of Portland cement at its rational values ​​is the optimal way to enhance variatropia.

scholarly journals Study of integral and differential strength and deformation characteristics of centrifuged and vibrating centrifuged concrete on activated Portland cement

2021 ◽  
Vol 2124 (1) ◽  
pp. 012005
Author(s):  
L R Mailyan ◽  
S A Stel’makh ◽  
E M Shcherban’ ◽  
D S Chernykh
Keyword(s):  
Portland Cement ◽  
Mechanical Activation ◽  
Deformation Characteristics ◽  
Technological Parameters ◽  
Annular Section ◽  
Experimental Laboratory ◽  
Strength And Deformation ◽  
Laboratory Centrifuge

Abstract In this work, the study of integral and differential strength and deformation characteristics of centrifuged and vibrating centrifuged concrete on activated Portland cement was carried out. Mechanical activation of cement was carried out using a specialized grinding unit. Manufacturing of centrifuged and vibrating centrifuged samples was carried out on an experimental laboratory centrifuge. All samples were made of concrete of the same composition. The optimum values of technological parameters of centrifugation and vibrating centrifugation are given. The scheme of obtaining small-size specimens from a common annular section to determine the strength and strain characteristics was developed. According to the results of the study it was found that the improvement of integral and differential strength and strain characteristics when using activated Portland cement is observed for both centrifuged and vibrating centrifuged specimens. However, the samples made by vibrating centrifugation technology have better strength and strain characteristics than the samples made by centrifugation. According to the results of the study, it was found that the activation of Portland cement at its rational values is the best way to enhance variatropy.

scholarly journals Strength and Deformation Characteristics of the Neogene Siltstone, exampled from Middle Formation of Kazusa Group.

1993 ◽  
Vol 34 (5) ◽  
pp. 233-244 ◽  
Author(s):  
Takayasu HOSONO ◽  
Masayuki NAKAJIMA ◽  
Kazuhiro KOIZUMI ◽  
Nobutaka SUGITA ◽  
Shohji OGAWA
Keyword(s):  
Deformation Characteristics ◽  
Strength And Deformation

Effect of Process Parameters on Hole Diameter Accuracy in High Pressure Through Coolant Peck Drilling Using Taguchi Technique

2018 ◽  
Vol 5 (1) ◽  
pp. 12-31 ◽  
Author(s):  
Hanmant V. Shete ◽  
Madhav S. Sohani
Keyword(s):  
Feed Rate ◽  
High Performance ◽  
Manufacturing Industry ◽  
Spindle Speed ◽  
Hole Diameter ◽  
Taguchi Technique ◽  
Machining Center ◽  
Analysis Of Results ◽  
Optimal Values ◽  
Peck Drilling

Machining with pressurized coolant is nowadays widely accepted technique in the manufacturing industry, especially in high performance machining conditions. The data on the effects of variation of high coolant pressure in drilling operation is limited. This paper presents the effect of high coolant pressures along with spindle speed, feed rate and peck depth on hole diameter accuracy. Experiments were performed on EN9 steel with TiAIN coated through coolant drill on CNC vertical machining center. Taguchi technique was employed for design of experiments and analysis of results. Results showed that the higher values of optimal coolant pressure and spindle speed were demanded for drilling at bottom of hole as compared to that for drilling at top of hole. The optimal values of feed rate and peck depth were same for both the cases of drilling at top and bottom of hole. Use of high coolant pressure in drilling permits higher peck depth for better hole diameter control which results in reduced cycle time and hence production cost.

scholarly journals Effects of loading rate on strength and deformation characteristics of gypsum mixed sand

2019 ◽  
Vol 92 ◽  
pp. 05008
Author(s):  
Zain Maqsood ◽  
Junichi Koseki ◽  
Hiroyuki Kyokawa
Keyword(s):  
Strain Rate ◽  
Axial Strain ◽  
Constitutive Modelling ◽  
Strain Rates ◽  
Deformation Characteristics ◽  
Wide Range ◽  
Strength And Deformation ◽  
Loading Tests ◽  
Rational Evaluation ◽  
Strain Responses

It has been unanimously acknowledged that the strength and deformation characteristics of bounded geomaterials, viz. cemented soils and natural rocks, are predominantly governed by the rate of loading/deformation. Rational evaluation of these time-dependent characteristics due to viscosity and ageing are vital for the reliable constitutive modelling. In order to study the effects of ageing and loading/strain rate (viscosity) on the behaviour of bounded geomaterials, a number of unconfined monotonic loading tests were performed on Gypsum Mixed Sand (GMS) specimens at a wide range of axial strain rates; ranging from 1.9E-05 to 5.3E+00 %/min (27,000 folds), and at different curing periods. The results indicate shifts in the viscous behaviour of GMS at critical strain rates of 2.0E-03 and 5.0E-01 %/min. In the light of this finding, the results are categorized into three discrete zones of strain rates, and the behaviour of GMS in each of these zones is discussed. A significant dependency of peak strength and stress-strain responses on strain rate was witnessed for specimens subjected to strain rates lesser than 2.0E-03 %/min, and the effects of viscosity/strain rate was found to be insignificant at strain rate higher than 5.0E-01%/min.

scholarly journals The effect of the type of fixators reinforcement on strength and deformation characteristics of reinforced concrete

2019 ◽  
Vol 97 ◽  
pp. 02034
Author(s):  
Evgenij Borisyuk
Keyword(s):  
Reinforced Concrete ◽  
Crack Resistance ◽  
Steel Reinforcement ◽  
Low Grade ◽  
High Grade ◽  
Building Structures ◽  
Deformation Characteristics ◽  
Reliable Operation ◽  
Different Types ◽  
Strength And Deformation

Rebar fixators of various types (plastic and concrete) became widespread with manufacturing of building structures of precast and monolithic reinforced concrete in order to fix steel reinforcement cage in strictly design position and to exclude the probability of its displacement during concreting. Such sufficiently rigid fixing is necessary for the following reliable operation of the structure in the building, as well as for the preservation of steel reinforcement which protected by a necessary layer of concrete from corrosion. Information available in the literature does not allow us to judge about the effects that different types of fixators apply to exploitative properties (such as strength and crack resistance) of reinforced concrete. The experiments, according to the accepted method, showed that these characteristics are slightly worse for the samples with plastic fixators and fixators made of low grade concrete than for the samples without fixators or fixators made of high grade concrete. On the base on the research results it becomes possible to substantiate the distinction between the areas of application of plastic and concrete fixatives

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