scholarly journals The Impact of the Acidic Environment on the Mechanical Properties of Epoxy Compounds in Different Conditions

Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 2957
Author(s):  
Anna Rudawska
Keyword(s):  
Mechanical Properties ◽  
Immersion Time ◽  
Acidic Solution ◽  
Tap Water ◽  
Epoxy Compound ◽  
Acidic Environment ◽  
Similar Tendency ◽  
Strength Tests ◽  
Acidic Environments ◽  
The Impact

The aim of this work was to determine the impact of the acidic environment on the mechanical properties of two epoxy compounds in different conditions. The samples were made from the epoxy compounds composed of the epoxy resin (based on Bisphenol A), triethylenetetramine curing agent (unmodified compound), and calcium carbonate (CaCO3) (modified compound). The epoxy compound samples were seasoned for the following period of time (i.e., one week, one month, and three months). The environment was tap water and the acidic environment had three different concentrations of acetic acid (3%, 6%, and 9%). Strength tests of the epoxy compound samples were carried out in accordance with the ISO 604 standard. In the case of the modified composition, it is noted that the samples immersed in tap water were characterized by a higher strength than in acidic environments. A similar tendency was observed for unmodified compositions, although the differences were smaller than for the modified compositions. It was also noticed that the increase in the pH of the acidic solution in many analyzed cases contributed to the decrease in mechanical properties, although the immersion time in the acidic solution is important.

scholarly journals Analysis of the Impact on the Mechanical Properties of Modification of Oligohydroxyethers in Organic Solvent Solution with Rubbers

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 519
Author(s):  
Vitalii Bezgin ◽  
Agata Dudek ◽  
Adam Gnatowski
Keyword(s):  
Mechanical Properties ◽  
Scientific Paper ◽  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Molecular Weights ◽  
Wide Range ◽  
Strength Tests ◽  
Materials Used ◽  
Styrene Butadiene ◽  
The Impact

This paper proposes and presents the chemical modification of linear hydroxyethers (LHE) with different molecular weights (380, 640, and 1830 g/mol) with the addition of three types of rubbers (polysulfide rubber (PSR), polychloroprene rubber (PCR), and styrene-butadiene rubber (SBR)). The main purpose of choosing this type of modification and the materials used was the possibility to use it in industrial settings. The modification process was conducted for a very wide range of modifier additions (rubber) per 100 g LHE. The materials obtained in the study were subjected to strength tests in order to determine the effect of the modification on functional properties. Mechanical properties of the modified materials were improved after the application of the modifier (rubber) to polyhydroxyether (up to certain modifier content). The most favorable changes in the tested materials were registered in the modification of LHE-1830 with PSR. In the case of LHE-380 and LHE-640 modified in cyclohexanol (CH) and chloroform (CF) solutions, an increase in the values of the tested properties was also obtained, but to a lesser extent than for LHE-1830. The largest changes were registered for LHE-1830 with PSR in CH solution: from 12.1 to 15.3 MPa for compressive strength tests, from 0.8 to 1.5 MPa for tensile testing, from 0.8 to 14.7 MPa for shear strength, and from 1% to 6.5% for the maximum elongation. The analysis of the available literature showed that the modification proposed by the authors has not yet been presented in any previous scientific paper.

scholarly journals The impact of the health condition of oaks from the Krotoszyn Plateau on the mechanical properties of timber structures

2015 ◽  
Vol 57 (4) ◽  
pp. 224-232
Author(s):  
Jarosław Siwiński ◽  
Katarzyna Kubiak ◽  
Miłosz Tkaczyk ◽  
Anna Mazur ◽  
Ryszard Rekucki
Keyword(s):  
Mechanical Properties ◽  
Health Condition ◽  
Health State ◽  
Timber Structures ◽  
Strength Parameters ◽  
Modified Method ◽  
Strength Tests ◽  
Prior Selection ◽  
The Impact ◽  
Selection Of

Abstract The study was conducted to perform a comparative analysis of the mechanical properties of wood samples derived from oaks in the Krotoszyn Plateau, which depend on the health state of the trees. Strength parameters of oak wood were calculated for selected diseased and healthy trees (according to the Roloff classification). The study was conducted by a modified method described in the standard Polish Norm PN EN 408+ A1: 2012. For testing, prior selection of wood samples showed that more wood samples of diseased trees compared with those of healthy oaks did not fulfil the Polish standard requirements. According to the method used, the average results of strength tests of timber structures from healthy oaks exhibited higher strength parameters than those of the diseased trees.

An experimental study on the performance of fine-grained concrete incorporating recycled steel spring exposed to acidic conditions

2020 ◽  
Vol 23 (11) ◽  
pp. 2458-2470
Author(s):  
Ghasem Pachideh ◽  
Majid Gholhaki
Keyword(s):  
Tensile Strength ◽  
Magnesium Sulfate ◽  
Steel Fibers ◽  
Acidic Environment ◽  
Fine Grained ◽  
Strength Tests ◽  
Acidic Conditions ◽  
Acidic Environments ◽  
Recycled Steel ◽  
Standard Steel

This article aims to study the effects of adding steel fibers and galvanized recycled spring on mechanical properties and crack development in the fine-grained concrete exposed to the acidic environment containing magnesium sulfate. To this end, specimens containing 0.3% and 0.6% of steel fibers and springs, respectively, by concrete volume, were built in normal temperature using 10 cm × 20 cm standard steel formworks so as to conduct the compressive and tensile strength tests. All specimens were cured in 28 days exposed to the environment containing 0%, 5%, and 10% of magnesium sulfate. Based on the results, addition of steel fibers and recycled spring improves the compressive and tensile strength by 50% and 60%, respectively. Moreover, the specimens containing recycled spring better withstood against the acidic environments in comparison with the specimens including steel fibers. In general, it was found that due to the negligible difference between the strength of the specimens, the application of metal-recycled spring in the fine-grained concrete is technically and economically justifiable.

Effects of Modification on Structure and Properties of Ramie Fiber/Polypropylene Composites

2010 ◽  
Vol 146-147 ◽  
pp. 441-444
Author(s):  
Wen Lei ◽  
Xiao Ming Jin
Keyword(s):  
Mechanical Properties ◽  
Coupling Agent ◽  
Immersion Time ◽  
Raw Materials ◽  
Ramie Fiber ◽  
Structure And Properties ◽  
Molding Process ◽  
Polypropylene Composites ◽  
The Impact ◽  
Compatibilizing Agent

Ramie fiber and polypropylene were used as raw materials,ramie fiber/polypropylene composites were prepared by compression molding process,the effects of treating the ramie fiber with silane coupling agent and compatibilizing the composite with maleic anhydride gafted polypropylene(MAPP) on the structure, melting and mechanical properties of the composites were studied，the effects of immersion time in water on the mechanical properties of the composites were also investigated.The results show that,both the modification with coupling agent and by means of compatibilizing agent can strengthen the interfacial bonding between the fiber and matrix in the composite,and also improve its thermal stability.All the modified composites have greater strengths and moduli than the unmodified ones when immersed in water for any periods,especially the impact strength of the MAPP compatibilized composite not only increases with immersion time in water dramatically,but also is improved from that of the unmodified one by 104.84%,239.40%,294.48% and 320.01% respectively when immersed in water for 0,7,14 and 21d.

scholarly journals Analysis of Petro-Physico-Mechanical Properties of Coarse Aggregate and Its Implications on the Performance Characteristics of Concrete

2020 ◽  
pp. 45-60
Author(s):  
Larry Pax Chegbeleh ◽  
Lawrence Opanin Nkansah ◽  
Frank Siaw Ackah ◽  
Richard Adams Mejida
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Coarse Aggregate ◽  
Aggregate Size ◽  
Performance Characteristics ◽  
Rock Samples ◽  
Rock Types ◽  
Strength Tests ◽  
Compressive Strength Of Concrete ◽  
The Impact

The importance of concrete as one of the major materials in the building and construction industry cannot be over emphasized due to the myriad benefits and versatility to humankind. However, its performance characteristics on the stability of engineered structures have mostly been overlooked. In this paper, petrographic characteristics and physico-mechanical properties of ten (n=10) rock samples and some quantity of coarse aggregate representing one set of samples, each obtained from two quarry sites around Amasaman and Shai Hills in the Greater Accra Region of Ghana, have been investigated. This study aimed to determine the impact of aggregate size, content and type on the compressive strength of concrete. The study was conducted through petrographic and physico-mechanical properties analyses on the samples obtained. Petrographic studies were performed on the ten (n=10) rock samples from each quarry site, while the physico-mechanical property tests were conducted directly on the coarse aggregate. However, compressive strength tests were performed on cast concretes produced from aggregates with varying sizes and type obtained from the two quarry sites. Results of the petrographic analysis reveal two rock types: Quartzo-feldspathic gneiss and Granodiorites from Amasaman quarry and also two rock types: Gneiss and Meta-granite from Shai Hills quarry. Results of the physico-mechical properties tests are consistent with requirement of approved construction standards. Compressive strength tests show increasing compressive strength of concretes with increasing aggregate nominal sizes of classes A, B and C but show reduced compressive strength for aggregate nominal sizes of class D. It can therefore, be inferred that, aggregate size and content have profound impact on compressive strength of concrete. Also, aggregate type has influence on compressive strength of concrete, as observed in higher compressive strength of concretes produced from the quartzo-feldspathic gneiss and granodiorites than concretes produced from the gneiss and meta-granites.

scholarly journals The Effect of the Salt Water Aging on the Mechanical Properties of Epoxy Adhesives Compounds

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 843 ◽  
Author(s):  
Anna Rudawska
Keyword(s):  
Mechanical Properties ◽  
Calcium Carbonate ◽  
Salt Water ◽  
Tap Water ◽  
Testing Machine ◽  
Epoxy Adhesive ◽  
Curing Agent ◽  
Epoxy Adhesives ◽  
Adhesive Compound ◽  
Strength Tests

The objective of this study is to compare the effect of selected operating factors on the mechanical properties of epoxy adhesive compounds aged in salt water. Five different water environments were tested: tap water, normal seawater (reference salinity value), seawater with double reference salinity value, seawater with half of the reference salinity and seawater with a quarter of the reference salinity value. Samples of two different adhesive compounds were prepared using the epoxy resin and triethylenetetramine curing agent. One of the compounds was filled with calcium carbonate. The samples were aged in five different water environments for three months, one month and one week, respectively. Mechanical properties of the cured adhesive compound samples were determined via strength tests performed on the Zwick/Roell Z150 testing machine in compliance with the EN ISO 604 standard. The objective of the experiments was to determine the effect of different seawater environments on selected mechanical properties (including strength) of the fabricated adhesive compounds.

scholarly journals Influence of fineness level and applied agglomeration pressure of peppermint herb (Mentha piperita L.) on the mechanical properties of the obtained product

2018 ◽  
Vol 10 ◽  
pp. 02028
Author(s):  
Urszula Sadowskaʼ ◽  
Andrzej Żabiński ◽  
Krzysztof Mudryk
Keyword(s):  
Mechanical Properties ◽  
Testing Machine ◽  
Hydraulic Press ◽  
Brazilian Test ◽  
Mentha Piperita ◽  
Agglomeration Process ◽  
Strength Tests ◽  
The Matrix ◽  
The Impact ◽  
Chamber Diameter

The objective of the conducted study was to evaluate the impact of the pressure agglomeration process of peppermint herb on the mechanical properties of the obtained product. The separated fractions of peppermint with 0.5-2.5 and 2.5-5 mm particles were compacted using a hydraulic press Fritz Heckert EU 20, with pressure 50, 100, 150 and 200 MPa. A closed matrix with the compression chamber diameter of 15.6 mm was used. Every time, a 2-g herb sample (corresponding to the weight of tea used for the production of tea bags) was poured into the matrix. Thus, compacted herb in the form of a straight cylinder was obtained. When producing the agglomerate compaction work was determined. Strength tests of the obtained agglomerate were conducted using the MTS Insight 2 testing machine. The density of the produced agglomerate, its compaction level and strength in the Brazilian test was calculated. The obtained results indicate that the values of the tested parameters increase with the increase of pressure in the tested range, yet differences occur between the tested herb fractions. Typically, the agglomerate produced from 0.5-2.5 mm fraction is characterized by a greater density, and the higher level of agglomerate compaction is obtained using 2.5-5 mm herb fraction. The highest strength determined using Brazilian test was determined for agglomerate produced from 0.5-5 mm peppermint herb fraction at 200 MPa pressure and 0.5-2.5 mm fraction using 150 and 200 MPa pressure.

scholarly journals The Impact of the Seasoning Conditions on Mechanical Properties of Modified and Unmodified Epoxy Adhesive Compounds

Polymers ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 804 ◽  
Author(s):  
Anna Rudawska
Keyword(s):  
Mechanical Properties ◽  
Ambient Temperature ◽  
Testing Machine ◽  
Negative Temperature ◽  
Epoxy Adhesive ◽  
Adhesive Compound ◽  
Strength Tests ◽  
Curing Agents ◽  
Amine Curing ◽  
The Impact

The aim of this study was to analyse the impact of the adhesive samples seasoning conditions (temperature and time) on selected mechanical properties of four epoxy adhesive compounds (two unmodified and two modified ones). The samples were made of Epidian 53 epoxy resin mixed with the two different amine curing agents in appropriate stoichiometric proportions. A filler in the form of calcium carbonate (CaCO3) powder was used as a modifier. The adhesive compound samples were cured for seven days. Six seasoning variants were used. Four of them were related with the seasoning time at ambient temperature of 24 ± 2 °C for: one month, two months, five months and eight months, respectively. Two other variants were related with seasoning at negative temperature (−10 ± 2 °C) for one month. The last variant (F) also included seasoning at ambient temperature (24 ± 2 °C) for five months right after seasoning in negative temperature. Cured and cylinder-shaped adhesive compound samples were subjected to compressive strength tests (according to the ISO 604 standard). The strength tests were performed using a Zwick/Roell Z150 testing machine. Based on the tests, it was observed that both temperature and time of seasoning influenced the adhesive’s mechanical properties. In the perspective of eight months, these changes were relatively minor for the samples seasoned at ambient temperature. The adhesive samples prepared for the tests were especially sensitive to negative temperature.

scholarly journals Investigation on Properties of Cement Bitumen Emulsion Mortars (CBEM) in Consideration of Emulsifier Types

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Zhuoran Liu ◽  
Jinyang Huo ◽  
Zhenjun Wang
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Viscoelastic Property ◽  
Low Frequency ◽  
Dynamic Mechanical Analyzer ◽  
Bitumen Emulsion ◽  
Strength Tests ◽  
Before And After ◽  
The Impact ◽  
Better Than

In order to investigate the influences of emulsifier types on properties of cement bitumen emulsion mortars (CBEM), anionic and cationic emulsifiers were used to prepare CBEM in this work. Influences of anionic and cationic bitumen emulsions on workability, mechanical properties, and viscoelastic property of CBEM were studied. The workability of CBEM was evaluated by fluidity and extensibility tests. The mechanical properties were assessed by compressive strength and flexural strength tests. XRD was used to analyze the phase before and after bitumen emulsion was added. The viscoelastic property was studied by a dynamic mechanical analyzer (DMA). The results show that CBEM prepared by cationic bitumen emulsion (CBE) has better workability. The mechanical properties of CBEM are negatively affected by bitumen emulsion. The impact on the compressive strength of CBEM prepared by CBE is higher. Bitumen emulsion can significantly improve the viscoelastic property of CBEM. With the increase of bitumen emulsion dosage, the loss factor of CBEM increases. The viscoelastic property at low frequency is better than that at high frequency. In contrast to CBEM prepared by CBE, CBEM prepared with anionic bitumen emulsion (ABE) possesses better viscoelastic property.

Effect of combined drink cans and steel fibers on the impact resistance and mechanical properties of concrete

2020 ◽  
Vol 14 (2) ◽  
pp. 6734-6742
Author(s):  
A. Syamsir ◽  
S. M. Mubin ◽  
N. M. Nor ◽  
V. Anggraini ◽  
S. Nagappan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Reinforced Concrete ◽  
Impact Resistance ◽  
Fiber Reinforced Concrete ◽  
Steel Fibers ◽  
Fiber Reinforced ◽  
Indirect Tensile ◽  
The Impact

This study investigated the combine effect of 0.2 % drink cans and steel fibers with volume fractions of 0%, 0.5%, 1%, 1.5%, 2%, 2.5% and 3% to the mechanical properties and impact resistance of concrete. Hooked-end steel fiber with 30 mm and 0.75 mm length and diameter, respectively was selected for this study.  The drinks cans fiber were twisted manually in order to increase friction between fiber and concrete. The results of the experiment showed that the combination of steel fibers and drink cans fibers improved the strength performance of concrete, especially the compressive strength, flexural strength and indirect tensile strength. The results of the experiment showed that the combination of steel fibers and drink cans fibers improved the compressive strength, flexural strength and indirect tensile strength by 2.3, 7, and 2 times as compare to batch 1, respectively. Moreover, the impact resistance of fiber reinforced concrete has increase by 7 times as compared to non-fiber concretes. Moreover, the impact resistance of fiber reinforced concrete consistently gave better results as compared to non-fiber concretes. The fiber reinforced concrete turned more ductile as the dosage of fibers was increased and ductility started to decrease slightly after optimum fiber dosage was reached. It was found that concrete with combination of 2% steel and 0.2% drink cans fibers showed the highest compressive, split tensile, flexural as well as impact strength.    

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