scholarly journals MODERN LAMINATE COMPOSITE DESIGNED FOR AIRCRAFT CONSTRUCTION

2019 ◽  
Vol 5 (1) ◽  
Author(s):  
Izabela Korzec ◽  
Jacek Czarnigowski ◽  
Tomasz Łusiak ◽  
Daniel Rękas ◽  
Mateusz Marciniak ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Laminate Composite ◽  
Structural Elements ◽  
Propeller Blade ◽  
Strength Parameters ◽  
Laminate Composites ◽  
Strength Tests ◽  
Basic Strength

The article presents modern laminate composites designed for aircraft structural elements based on ECC e461 symmetric fabric and Interglas 02037 symmetric fabric with MGS L285/H285 resin. These composites differ in the weave used and the type of fabric. The article presents basic strength parameters of the composite obtained as a result of stand tests. The results of compressive strength tests of the material samples are presented. It was shown that the weave of the fabric significantly affects the strength parameters of the composite. The change of the weave caused the increase in strength by more than 65%. The possibilities of application of this material on selected structural elements of aircraft such as: propeller blade plating, masts, shavings, pylons.

scholarly journals Effect of Modifying Aggregates by Rap and the Simultaneous use of Adhesives for the Stabilization of a Sandy Pavement Subgrade

2021 ◽  
Vol 29 (2) ◽  
pp. 1-8
Author(s):  
Mohammad Mehdi Khabiri ◽  
Bahareh Ebrahimialavijeh
Keyword(s):  
Compressive Strength ◽  
Construction Projects ◽  
Cement Content ◽  
Road Construction ◽  
Environmental Issues ◽  
Dune Sand ◽  
Strength Parameters ◽  
Recycled Asphalt ◽  
Surface Method ◽  
Strength Tests

Abstract The improvement, reconstruction and repair of roads in recent years have increased the content of recycled asphalt in pavements. Using these materials in road construction projects because they reduce the costs, will also be of great help in improving environmental issues. In the present study, dune sand, which can be found in most desert area soil but does not have proper strength and loading capacity for a subgrade, was used. In order to increase the strength parameters of dune sand, various contents of cement and recycled asphalt were examined in California Bearing Ratio (CBR) and compressive strength tests. The results showed that the addition of cement and recycled asphalt can increase compressive strength and bearing capacity and reduce rupture deformations. In a stabilized sample with 27.5% recycled asphalt, increasing the cement from 7.5 to 12.5% increased the compressive strength by 1.045 times, which is the highest amount of change in the samples studied. The maximum CBR and minimum rupture deformations are related to 35% of the recycled asphalt and 12.5% of the cement. The predicted functions of the compressive strength, deformation and CBR depend on two variables of the cement content; the recycled asphalt was then calculated using the response surface method

scholarly journals Experimental Evaluation of the Effect of Silica Fume on Compressive, Tensile Strength, Abrasion Resistance, Slump and Impact Test and Water Permability Coefficient of Concrete

2018 ◽  
Vol 8 (1) ◽  
pp. 27-36
Author(s):  
M. Esmailpour ◽  
K. Rahmani ◽  
S. Piroti
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Silica Fume ◽  
Impact Test ◽  
Surface Cracks ◽  
Strength Parameters ◽  
Ordinary Concrete ◽  
Strength Tests ◽  
Compressive Strength Of Concrete ◽  
Positive Effect

Abstract The use of various additives (admixtures) in concrete and cement products has been considered by various researchers in recent years. Microsilica (Silica fume) can also be considered as one of the most widely used additives (admixtures) in this section. In this study, 120 concrete specimens were constructed using a mix design based on ACI in the laboratory with an overview of records and advantages of using microsilica in concrete. The microsilica used in concrete specimens has been considered 2%, 5.5% and 7.5% by weight of cement. Finally impact permeability, tension and uniaxial compressive strength tests were done on concrete specimens and their mechanical properties were evaluated. The results show that microsilica improves the mechanical properties of concrete. The results also show that the use of microsilica in ordinary concrete has a very positive effect in controlling the surface cracks and increasing some strength parameters such as tensile and compressive strength of concrete.

Temperature Control Responses of Structural Clay Masonry Blocks

2014 ◽  
Vol 805 ◽  
pp. 525-529 ◽  
Author(s):  
Neila Gondim Azeredo ◽  
Jonas Alexandre ◽  
Afonso Rangel Garcez Azevedo ◽  
Gustavo de Castro Xavier ◽  
Carlos Maurício Fontes Vieira ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Water Absorption ◽  
Temperature Control ◽  
Firing Condition ◽  
Structural Elements ◽  
Muffle Furnace ◽  
Laboratory Sample ◽  
Strength Tests ◽  
Control Response ◽  
Technical Properties

The compressive strength as well as other technical properties of structural clay masonry blocks are usually significantly affected by the firing temperature. The present work studied the temperature control response of structural clay masonry blocks when changing the firing condition from 700 to 800°C. Structural clay blocks fired at 700°C in an industrial furnace were compared with those fired in a laboratory electrical muffle furnace at 800°C. Both water absorption and compressive strength tests were carried out for the different brick samples. The block sample fired at 700°C failed to attend both the water absorption and the compressive strength requirements for structural elements. By contrast, after 800°C firing, the laboratory sample attended the water absorption specifications and showed higher compressive strength within the Brazilian standards.

Analysis of Regression for Strength Index of Concrete Performed Brick Masonry

2013 ◽  
Vol 639-640 ◽  
pp. 803-806
Author(s):  
Qi Fang Wang
Keyword(s):  
Compressive Strength ◽  
Bending Strength ◽  
Brick Masonry ◽  
Adjustment Coefficient ◽  
Masonry Structures ◽  
Strength Index ◽  
Strength Tests ◽  
Compressive Strength Of Concrete ◽  
Basic Strength ◽  
Regressive Analysis

Based on the data of the strength tests of concrete performed brick masonry，the basic strength formulas of concrete performed brick masonry are obtained. Through regressive analysis, it will be coherent to the compressive strength of concrete performed brick masonry to introduce the adjustment coefficient of mortar contrast to the Code for Design of Masonry Structures of China. The shear strength, bending strength along straight joint and bending strength along straight joint are uniform with the Code for Design of Masonry Structures of China.

scholarly journals Assessment of the early-age compressive strength of concrete

2021 ◽  
Vol 20 (2) ◽  
pp. 005-014
Author(s):  
Dorota Michałowska-Maziejuk ◽  
Barbara Goszczyńska
Keyword(s):  
Compressive Strength ◽  
Early Stage ◽  
Concrete Strength ◽  
Early Age ◽  
Concrete Compressive Strength ◽  
Strength Parameters ◽  
Eurocode 2 ◽  
Strength Tests ◽  
Compressive Strength Of Concrete

This paper analyses the results of concrete compressive strength tests on cubic samples with different w/c ratios during the early stage of hardening (at 7, 14, and 28 days). Statistical and strength parameters were assessed and the quality of the concrete was estimated. The expected concrete grade, C25/30, was confirmed against the formulation provided by the prefabrication plant. Then, the amount of individual constituents was adjusted to obtain the target grade of concrete, i.e., C20/25. The concrete grade was estimated based on concrete strength parameters measured at three time points and compared with the expected 28-day strength values determined as per Eurocode 2 and with the concrete grade defined by these values. The paper also provides an overview of the most widely used methods of testing concrete compressive strength.

Evaluation of concrete self-healing with different fly ash contents and cracking ages by means of ultrasonic pulse velocity and compressive strength tests

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Mayara Wons ◽  
Letícia Camara ◽  
Ian Esteves ◽  
Priscila O. Trentin ◽  
Ronaldo A. Medeiros-Junior
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Self Healing ◽  
Strength Tests

scholarly journals Material-removing machining wastes as a filler of a polymer concrete (industrial chips as a filler of a polymer concrete)

2021 ◽  
Vol 28 (1) ◽  
pp. 343-351
Author(s):  
Norbert Kępczak ◽  
Radosław Rosik ◽  
Mariusz Urbaniak
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Young’S Modulus ◽  
Industrial Waste ◽  
Splitting Tensile Strength ◽  
Polymer Concrete ◽  
Strength Parameters ◽  
Basic Parameters ◽  
Natural Fillers

Abstract The paper presents an impact of the addition of industrial machining chips on the mechanical properties of polymer concrete. As an additional filler, six types of industrial waste machining chips were used: steel fine chips, steel medium chips, steel thick chips, aluminium fine chips, aluminium medium chips, and titanium fine chips. During the research, the influence of the addition of chips on the basic parameters of mechanical properties, i.e., tensile strength, compressive strength, splitting tensile strength, and Young’s modulus, was analyzed. On the basis of the obtained results, conclusions were drawn that the addition of chips from machining causes a decrease in the value of the mechanical properties parameters of the polymer concrete even by 30%. The mechanism of cracking of samples, which were subjected to durability tests, was also explored. In addition, it was found that some chip waste can be used as a substitute for natural fillers during preparation of a mineral cast composition without losing much of the strength parameters.

scholarly journals Determination of Mechanical Properties of Altered Dacite by Laboratory Methods

Minerals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 813
Author(s):  
Veljko Rupar ◽  
Vladimir Čebašek ◽  
Vladimir Milisavljević ◽  
Dejan Stevanović ◽  
Nikola Živanović
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Rock Mass ◽  
Uniaxial Compressive Strength ◽  
Rock Material ◽  
Strength Parameter ◽  
Gradual Transition ◽  
Strength Parameters ◽  
Triaxial Compressive Strength ◽  
Heterogeneous Rock

This paper presents a methodology for determining the uniaxial and triaxial compressive strength of heterogeneous material composed of dacite (D) and altered dacite (AD). A zone of gradual transition from altered dacite to dacite was observed in the rock mass. The mechanical properties of the rock material in that zone were determined by laboratory tests of composite samples that consisted of rock material discs. However, the functional dependence on the strength parameter alteration of the rock material (UCS, intact UCS of the rock material, and mi) with an increase in the participation of “weaker” rock material was determined based on the test results of uniaxial and triaxial compressive strength. The participation of altered dacite directly affects the mode and mechanism of failure during testing. Uniaxial compressive strength (σciUCS) and intact uniaxial compressive strength (σciTX) decrease exponentially with increased AD volumetric participation. The critical ratio at which the uniaxial compressive strength of the composite sample equals the strength of the uniform AD sample was at a percentage of 30% AD. Comparison of the obtained exponential equation with practical suggestions shows a good correspondence. The suggested methodology for determining heterogeneous rock mass strength parameters allows us to determine the influence of rock material heterogeneity on the values σciUCS, σciTX, and constant mi. Obtained σciTX and constant mi dependences define more reliable rock material strength parameter values, which can be used, along with rock mass classification systems, as a basis for assessing rock mass parameters. Therefore, it is possible to predict the strength parameters of the heterogeneous rock mass at the transition of hard (D) and weak rock (AD) based on all calculated strength parameters for different participation of AD.

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.

Experimental Assessment of Strength Parameters of River Sand for Sandcrete Block Production

2021 ◽  
Vol 53 ◽  
pp. 67-75
Author(s):  
Babatunde Ogunbayo ◽  
Clinton Aigbavboa ◽  
Opeoluwa Akinradewo
Keyword(s):  
Compressive Strength ◽  
Quality Standard ◽  
Sieve Analysis ◽  
Building Structures ◽  
Strength Parameters ◽  
River Sand ◽  
Sieve Analyses ◽  
Aggregate Material ◽  
Average Compressive Strength ◽  
Minimum Quality

Sandcrete block is a vital building material used in the construction of building structures. The sandcrete blocks are produced by different manufacturers using river sand obtained from different locations as aggregate material without recourse to the minimum quality standard for the blocks produced. The study assessed the strength parameters of river sand used as an aggregate material in block production to determine its quality and suitability in relation to the strength of block produced. Three (3) block manufacturing sites in Nigeria were visited and 27 (twenty-seven) blocks of size 450 mm x 225 mm x 225 mm were selected randomly from the sites. The properties of the river sand was analyzed through sieve analyses, bulk density, silt content and water absorption while the compressive strength of the blocks was also tested. The result of sieve analysis of the river sand used in block production for this study all satisfied the particle size requirements of BS EN 933-1:1997 for general construction work including block production. The result of the study also shows that blocks produced with the river sand after 28days have an average compressive strength of 1.23 N/mm2 (SW), 1.54 N/mm2 (SE) and 1.95N/mm2 (NE). The study, therefore, concluded and recommended that regulatory and professional bodies in partnership with relevant associations should organize seminars for producers of sandcrete blocks on the best practices involved in producing quality sandcrete blocks.

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