scholarly journals Laboratory tests and analysis of CIPP epoxy-resin internal liners used in pipelines – part I: comparison of tests and engineering calculations

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Tomasz Abel
Keyword(s):  
Epoxy Resin ◽  
Construction Site ◽  
Safe Operation ◽  
Strength Parameters ◽  
Design Work ◽  
Actual Load ◽  
Comparison Of Tests ◽  
Different Diameters ◽  
Investment Process ◽  
Acceptance Tests

Abstract Tests that were carried out in order to obtain knowledge of the actual values of strength parameters obtained by CIPP liners that are used to repair pipelines. Specimens of liners made of high quality polyester felt cured with epoxy resin were subjected to tests. The scope of the performed studies corresponded with the scope of acceptance tests, which are carried out in the investment process during quality control of renovation works. Specimens of liners taken from sewers with 3 different diameters, i.e. 200mm, 350mm and 500mm were selected as representative for underground sewage networks. The obtained results enabled the calculations carried out in the course of design work to be verified, and differences between the model values of the strength parameters obtained from the calculations, and real values that are burdened with irregularities resulting from the conditions prevailing at a construction site and which were obtained for specimens taken from their built-in locations to be compared. The tests confirmed that it is possible to renovate - using CIPP liners - sewers with a lot of structural and material damage that negatively affects a liner‘s geometry. The implementation of the reinforcing internal coating in a sewer enables its further safe operation. The direct application value of the research involves the enlargement and clarification of knowledge concerning the actual load-bearing capacity of CIPP liners.

scholarly journals Arrangement and safe operation of auto-roads on a construction site

2020 ◽  
Vol 164 ◽  
pp. 08003
Author(s):  
Ivan Doroshin ◽  
Boris Zhadanovskiy ◽  
Ruben Kazaryan
Keyword(s):  
Construction Materials ◽  
Great Influence ◽  
Construction Site ◽  
Railway Transport ◽  
Safe Operation ◽  
Construction Operations ◽  
Basic Principles ◽  
The Subject ◽  
Data Investigation ◽  
Working Out

Traditional and innovative ways of constructing temporary roads at a construction site are considered. The basic principles of the preparation of construction operations are given, which should be taken into account at this stage. Particular attention is paid to the preparation of the construction of the facility and preparation for the construction and installation works. The organization of designing construction roads, temporary and permanent, is considered. Methods for determining the parameters of construction roads are described. The main technical indicators of construction roads are given. Dangerous areas of the roads are indicated. The main purpose of the research is to generalize and systematize the modern ways of arrangement and operation of auto-roads on a construction site. For carrying out of the study the methodical and scientific literature on the subject was analyzed, and also the statistic methods of data investigation were used. The main results of the research is the accomplishment of estimation of expenses on arrangement of auto-roads, the indication of order of working out of design of the auto-roads, also the indication of necessity of use of permanent roads as temporary. The design of temporary and permanent construction roads is very important because of their greater use in comparison with railway transport and a great influence on the supply of construction materials.

Tensile Tests for Cast Stainless Steel: Evolution of the RCC-M Code

2018 ◽  
Author(s):  
Arnaud Blouin ◽  
Mathieu Couvrat ◽  
Félix Latourte ◽  
Julian Soulacroix
Keyword(s):  
Tensile Strength ◽  
Stainless Steel ◽  
Ultimate Tensile Strength ◽  
Tensile Tests ◽  
Pressurized Water Reactor ◽  
Pressurized Water ◽  
Different Diameters ◽  
Cast Stainless Steel ◽  
Acceptance Tests ◽  
Do So

In the framework of a pressurized water reactor primary loop replacement, elbows of different types were produced in cast austenitic stainless steel grade Z3CN 20-09 M. For that type of component, acceptance tests to check the sufficient mechanical properties include room and hot temperature tensile tests, following the RCC-M CMS – 1040 and EN 10002 specifications. A large test campaign on standard 10mm diameter specimens was performed and exhibited a high scattering in yield stress and ultimate tensile strength values. As a consequence, some acceptance tensile tests failed to meet the required minimal values, especially the ultimate tensile strength. Optical and electronic microscopy revealed that the low values were due to the presence of very large grain compared to the specimen gage diameter. However, tensile tests strongly rely on the hypothesis that the specimen gage part can be considered as a representative volume element containing a number of grains large enough so that their variation in size and orientation gives a homogeneous response. To confirm the origin of the scattering, a huge experimental tensile test campaign with specimens of different diameters was conducted. In parallel, FE calculations were also performed. From all those results, it was concluded that it was necessary to improve the RCC-M code for that type of test for cast stainless steel: to do so, a modification sheet was sent and is being investigated by AFCEN.

scholarly journals The Design of an Advanced Cooled First Stage for a Full-Scale Utility Combustion Turbine

1982 ◽  
Author(s):  
G. N. Levari ◽  
J. D. Sauer ◽  
A. Cohn
Keyword(s):  
Heat Transfer ◽  
Material Selection ◽  
Field Tests ◽  
Full Scale ◽  
Fabrication Process ◽  
Preliminary Design ◽  
Design Work ◽  
Detailed Design ◽  
Temperature Selection ◽  
Acceptance Tests

The design of an advanced cooled first stage for a full-scale utility size combustion turbine is discussed. The preliminary design work involved evaluating three candidate “skin/spar” concepts: the shell/spar, Lamilloy*/spar and hybrid configurations. A shell/spar concept at 1600°F (871°C) maximum metal temperature was selected for continued development because it ensures against transpiration hole plugging; temperature selection was based on performance and corrosion considerations. The detailed design of the shell/spar advanced cooled stage is featured in this presentation and includes heat transfer and mechanical designs, stress analyses and durability considerations, and material selection. The fabrication process and acceptance tests planned for the advanced cooling components are described along with the shop and field tests proposed for the demonstration engine.

scholarly journals Influence of source data on fatigue estimation of a fighter aircraft

2018 ◽  
Vol 48 (1) ◽  
pp. 301-322
Author(s):  
Piotr Reymer ◽  
Wojciech Zieliński ◽  
Artur Kurnyta
Keyword(s):  
Load Spectrum ◽  
Safe Operation ◽  
Fighter Aircraft ◽  
Aircraft Structures ◽  
Flight Data ◽  
Design Load ◽  
Source Data ◽  
Actual Load ◽  
Load Monitoring ◽  
Fatigue Estimation

Abstract Aircraft structures during operation are exposed to fluctuating loads caused both by aerodynamic and inertial loads. This fluctuation leads to the creation of fatigue cycles, which gradually diminish the residual durability of the structure. During the design process, the flight envelope is defined as well as the design load spectrum, which then defines the durability of the structure (often expressed in means of flight hours). However, during the operation of an individual aircraft the actual load cycles can be significantly lower or higher than the designed; therefore, load monitoring is essential for safe operation of aircraft structures. The following article shows the results of fatigue analysis based on flight data from different flight data recorders for the Su-22 fighter aircraft.

scholarly journals Inverse Proportionality of Thermal Conductivity and Complex Permittivity to Filler-Diameter in Epoxy Resin Composites with Silica

2021 ◽  
Vol 5 (10) ◽  
pp. 266
Author(s):  
Yoshimichi Ohki ◽  
Naoshi Hirai ◽  
Takahiro Umemoto ◽  
Hirotaka Muto
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Epoxy Resin ◽  
Silica Content ◽  
Resin Composites ◽  
Bulk Properties ◽  
Silica Filler ◽  
Epoxy Resin Composites ◽  
Different Diameters ◽  
Inverse Proportionality

We prepared six kinds of epoxy resin nanocomposites with silica and an epoxy resin with no silica. The nanocomposites contain silica with different diameters (10, 50, and 100 nm) while their silica contents are 1, 5, 10, and 20 vol%. At 25 and 100 °C, the thermal conductivity has a nearly proportional dependence on the silica content and exhibits an almost reciprocal proportionality to the diameter of the silica. The latter result indicates that the interaction at filler-resin interfaces plays a significant role in heat transfer. However, this view contradicts an easy-to-understand thought that the filler-resin interfaces should work as a barrier for heat transfer. This in turn indicates that the interaction at filler-resin interfaces controls the bulk properties of the resin when the filler is in a nm size. Although the dielectric constant increases with the addition of the silica filler, its increment from the resin with no silica is the smallest in the resin with the 10-nm silica. Therefore, the addition of the 10-nm silica is adequate for electrical insulation purposes.

scholarly journals Impact of epoxy resin modification on their strength parameters

2020 ◽  
Vol 18 (4) ◽  
pp. 041-050
Author(s):  
Andrzej Szewczak
Keyword(s):  
Epoxy Resin ◽  
Sem Analysis ◽  
Crosslinking Reaction ◽  
Inorganic Polymers ◽  
Strength Parameters ◽  
Structural Element ◽  
Element Carbon ◽  
Epoxy Resin Modification ◽  
Solid Form ◽  
Chemical Formulas

Modifications of polymer composites are one of the fastest developing fields of technology. Research is focused on two directions: obtaining new composites or modifying existing materials. The first group of tests uses methods for preparing new chemical formulas of polymers containing, as the main structural element: carbon (organic polymers) or silicon (inorganic polymers). In the second group, the research consists in seeking methods to modify the properties of polymers. In building construction, among the others types, the glues (adhesive polymers) are used. They are exerted to connect materials with different physical andmechanical properties. Under the influence of the factor initiating the crosslinking reaction (hardener or temperature), the polymers obtain a solid form. The strength of the glued joint depends on the initial parameters of the glue resin and the target substrate of its application.The glued surface is usually the weakest element in this connection in terms of the possibility of damage due to the effects of loads, therefore methods to improve the strength parameters of adhesives are sought. The study presents the results of own research on methods of modification of a selected epoxy resin used in the technique as a glue. In order to ensure effective mixing of the adhesive with the fillers, ultrasound energy was used. After the resin had hardened, tests were carried out to determine the hardness and tensile strength of the obtained composites. Based on the results, SEM analysis and observation of the effect of ultrasound, the phenomena affecting the changes in the above mechanical properties were explained.

scholarly journals The Service Life of the Repair Welded Joint of Cr-Mo / Cr-Mo-V

2016 ◽  
Vol 61 (3) ◽  
pp. 1315-1320 ◽  
Author(s):  
M. Sroka ◽  
A. Zieliński ◽  
J. Mikuła
Keyword(s):  
Service Life ◽  
Welded Joint ◽  
Residual Life ◽  
Creep Condition ◽  
Basic Material ◽  
Safe Operation ◽  
Creep Tests ◽  
Work Time ◽  
Design Work

Abstract This paper presents the evaluation of the service life of dissimilar repair welded joint from Cr-Mo/Cr-Mo-V steel after 200,000 h service under creep condition. The investigations of microstructure using scanning electron microscopy, investigations of mechanical properties at room and elevated temperature as well as creep tests of the basic material from Cr-Mo and Cr-Mo-V steel and welded joint from these steels were carried out. The investigations allowed the time of further safe operation of the repair welded joint in relation to the residual life of the materials to be determined. The evaluation of residual life and disposable residual life, and thus the estimation or determination of possible time of further safe operation, is crucial when the elements are operated much beyond the design work time.

scholarly journals Geotechnology of restoration of culverts in complex ground conditions without their decommissioning

2019 ◽  
Vol 265 ◽  
pp. 05003
Author(s):  
Nicolay Perminov ◽  
Andrey Perminov
Keyword(s):  
Experimental Design ◽  
Technical Condition ◽  
Operating Conditions ◽  
The Body ◽  
Construction Site ◽  
Engineering Structures ◽  
Design Work ◽  
Concrete Pipes ◽  
Ground Conditions ◽  
Water Disposal

In the article, on the basis of extensive theoretical and experimental research carried out, innovative geotechnology for repair of culverts is presented, which provides an improvement in the conditions for interaction between the body of the structure and the soil massif with increasing technogenic impacts. The analysis of the technical condition of the culvert transport and engineering structures under special operating conditions is given. Factors determining their premature emergency condition and interfering with stable functioning under increasing loads and impacts have been studied. On the basis of many years of experimental and theoretical and experimental design work, geotechnology «Saturn» has been proposed, suitable for repairing all types of culverts on railroads and highways, engineering infrastructure facilities, and especially for repair and reconstruction of pipes under conditions of a constant intensive watercourse with nonstandard (atypical) constructive solutions, as well as located in hard-to-reach and difficult for the organization of the construction site sections of the route. The experience of successful application of the developed technology "Saturn" on the railroad during the repair and reconstruction of long-maintained culverts of stone and concrete pipes under the conditions of a constant intensive watercourse and at water disposal facilities during repair of deep tunnels without their decommissioning is described.

Ultrastructural investigation of spontaneous pituitary gonadotroph cell adenomas in aging Sprague-Dawley rats

1983 ◽  
Vol 41 ◽  
pp. 702-703
Author(s):  
D. J. McComb ◽  
J. Beri ◽  
F. Zak ◽  
K. Kovacs
Keyword(s):  
Electron Microscopy ◽  
Animal Model ◽  
Epoxy Resin ◽  
Immunoelectron Microscopy ◽  
Tumor Type ◽  
Gonadal Function ◽  
Sprague Dawley ◽  
Male And Female ◽  
Reticulin Fibers ◽  
Sprague Dawley Rats

Gonadotroph cell adenomas of the pituitary are infrequent in human patients and are not invariably associated with altered gonadal function. To date, no animal model of this tumor type exists. Herein, we describe spontaneous gonadotroph cell adenomas in old male and female Sprague-Dawley rats by histology, immunocytology and electron microscopy.The material consisted of the pituitaries of 27 male and 38 female Sprague Dawley rats, all 26 months of age or older, removed at routine autopsy. Sections of formal in-fixed, paraffin-embedded tissue were stained with hematoxylin-phloxine-saffron (HPS), the PAS method and the Gordon-Sweet technique for the demonstration of reticulin fibers. For immunostaining, sections were exposed to anti-rat β-LH, anti-ratβ-TSH, anti-rat PRL, anti-rat GH and anti-rat ACTH 1-39. For electron microscopy, tissue was fixed in 2.5% glutaraldehyde, postfixed in 1% OsO4 and embedded in epoxy-resin. Tissue fixed in 10% formalin, embedded in epoxy resin without osmification, was used for immunoelectron microscopy.

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