scholarly journals INFLUENCE OF COMPOSITION OF MORTAR MIXTURE ON STRENGTH AND DEFORMABILITY OF EXTERNAL WALLS/SKIEDINIO SUDĖTIES ĮTAKA IŠORINIŲ SIENOS SLUOKSNIŲ STIPRUMUI IR DEFORMA VIMUISI

2000 ◽  
Vol 6 (2) ◽  
pp. 76-81
Author(s):  
Gediminas Marčiukaitis ◽  
Darius Zabulionis

The basic element of building, wall, must satisfty not only requirements for strength, stability, but also for cracking. Experiments and practice show that in many cases external decoration layers of external walls are cracked. It is because designers and builders do not take into consideration one of the basic conditions of the theory of layers—to satisfy compatibility of deformations of layers. Therefore it is necessary to know physical and mechanical properties of plasters such as strength limits of compressive and tensile strains and modulus of elasticity. In this paper, data and recommendations about strength and deformation properties of plaster are given, as well as regressive equations by which it is possible to choose the composition of composite cement-lime-sand mortar recording the following parameters: compressive and tensile strength, limit strain, modulus of elasticity. Analysis of experimental data shows that the compressive and tensile strength of mortar and modulus of elasticity mainly depend on the ratio cement/sand. Limit deformations depend on all 3 factors: cement, lime and sand.

2020 ◽  
Vol 10 (11) ◽  
pp. 3918
Author(s):  
Jacek Góra ◽  
Małgorzata Szafraniec

Depending on the dimensions of concrete elements, aggregates of different grain sizes are used for the building structures. Taking this fact into account, the authors of the paper have undertaken in their work an issue concerning the analysis of the influence of maximum aggregate grain size on the strength properties and modulus of elasticity of concrete. This is also due to the fact that few published research results are available in this area. In this paper, the influence of the maximum grain size on the basic strength and deformation properties of concrete is discussed. The research concerns both concretes and gravel aggregates used for their construction with maximum grain sizes of 8 mm, 16 mm and 31.5 mm. The values of the compressive and splitting tensile strength, brittleness and modulus of elasticity of concretes with w/c = 0.45 were analysed. The analysis showed that the strength properties are proportional not only to the maximum size of aggregate grain, but also to the crushing strength of the aggregate. There were no analogous relations found with respect to the modulus of elasticity of the tested concretes. Tensile strength was particularly susceptible to the observed changes.


2021 ◽  
Vol 83 (1) ◽  
pp. 5-21
Author(s):  
A.M. Bragov ◽  
A.Yu. Konstantinov ◽  
A.K. Lomunov ◽  
T.N. Yuzhina

As a damping material in the structures of containers for the transportation of hazardous materials, along with plastic metals, fiber-claydite concrete and synthetic foams, it is proposed to use wood of different species. Since containers are transported in different climate regimes, there is an urgent need to study the properties of wood at elevated temperatures. The paper presents the results of dynamic tests of aspen under uniaxial compression under conditions of temperature increased to +60°C. The tests were carried out according to the Kolsky method on a Hopkinson split-bar setup. To study the anisotropy of properties, aspen samples were made and tested by cutting samples along and across the direction of the grains. As a result of processing the experimental data, dynamic stress-strain curves were obtained. According to the experimental data, there are determined the stresses at which the integrity of the samples were violated. The mean values of the moduli of deformation in the active loading regions of stress-strain curves are also presented. The highest slope of the load sections and the highest breaking stresses were observed for the specimens when loaded along the grains, and the smallest values of these parameters were noted when loaded across the grains. For specimens loaded along grains at strain rates above 1500 s–1, after reaching the limiting stress values, a decrease (relaxation) of stresses is observed with increasing deformations. For specimens loaded across the grains, an almost horizontal section the diagrams of deforming or even with some strengthening is more typical. The effect of elevated temperature on the strength and deformation properties of aspen is estimated. There is a tendency towards some decrease in the diagrams at a temperature of +60 °C in comparison with the diagrams at room temperature. In this case, both the moduli in the loading and unloading sections and the limiting (breaking) stresses decrease. The obtained features of the behavior of aspen specimens at elevated temperatures should be taken into account when modeling deforming wood.


2016 ◽  
Vol 1 (1) ◽  
pp. 78
Author(s):  
S.V. Koshkin ◽  
N.A. Taranukha

<p>The work presents the study of changes in the physical and mechanical properties of sea ice in bending. Strength limit σ<sub>в</sub> and deformation module Е<sub>в</sub> of ice under bending are conditional mechanical characteristics of sea ice. These characteristics do not reflect the actual stress state of ice destruction at the time. The ratio of the module to the strength limit Е<sub>в</sub>/σ<sub>в</sub> determines the relative radius of curvature of neutral layer in the place of ice destruction. It is shown that this ratio increases with the increase of ice temperature. Dependencies for determining of Е<sub>в</sub> and σ<sub>в</sub> of sea ice that generalize the experimental data are obtained.</p>


2014 ◽  
Vol 6 (1) ◽  
pp. 15 ◽  
Author(s):  
Budi Tri Cahyana

This research aimed to get the physical and mechanical properties of non adhesive-particle board from oil palm empty fruit bunches. The oil palm empty fruit bunches were degradated to fibre and boiled in boiling water during 60 minute then dried in ± 2 weeks. The dried raw material was chopped to be fibre in 5 mesh, 10 mesh, and 16 mesh. It were complied into a mold and then hot pressed in 35 kgf/cm2 pressure during 10 minute with 3 of temperature variety, 160°C, 180°C and 200°C. The result showed that the average of particle board water content was 7,11 -  9,85 % and the density was 0,63 – 0,76 gr/cm3. The highest thickness swelling was 22,59 % in 10 mesh and 160 0C (a2b1) temperature of oil palm empty fruit bunches. The modulus of rupture was 211,67 kg/cm2  in 10 mesh and 180 0C (a2b2) temperature. The modulus of elasticity was 490,85 kg/cm2 in 10 mesh and 160 0C (a2b1) temperature. The tensile strength was 7,49 kg/cm2 in 5 mesh and 200 0C (a1b3) temperature. The average of physical and mechanical properties such as water content, density, modulus of rupture, tensile strength were fulfill the SNI requirement, while the average of thickness swelling and modulus of elasticity were not fulfill the SNI requirement.Keywords: oil palm empty fruit bunches, particle board


2014 ◽  
Vol 574 ◽  
pp. 411-415
Author(s):  
Ming Chen ◽  
Jian Hua Lyu

The mechanical and physical properties of Alnus formosana wood from Sichuan, China were studied. Air-dry density, oven-dry density, basic density, shrinkage, swelling, parallel-to-grain compressive strength, parallel-to-grain tensile strength, modulus of rupture (MOR),modulus of elasticity (MOE) ,impact toughness were analyzed. Results from this study show that air-dry density, oven-dry density and basic density were respectively 0.52, 0.49 and 0.43g/cm3. The average value of volumetric shrinkage was 7.111% and the average value of volumetric swelling was 7.06%. The average values of modulus of elasticity (MOE) ,modulus of rupture (MOR), parallel-to-grain compressive strength, parallel-to-grain tensile strength and impact toughness were 8102.429 Mpa, 80.429 Mpa, 41.575Mpa, 81.542 Mpa and 47.406 Kj/m2 , respectively. This study solved a basic problem about the planting and utilization of Alnus formosana wood in Sichuan, China.


2021 ◽  
Vol 3 (1) ◽  
pp. 33-40
Author(s):  
Lantif Anggrahita Pratama ◽  
Ahmad Hakam Rifqi ◽  
Muhtarom Riyadi

Concrete is the most important part of a construction building. The purpose of this study was to examine how the comparison of physical and mechanical properties and optimum levels of the addition of straight tie wire as an added material with a water-cement ratio of 0.4. The percentage of addition of straight tie wire: 0%, 0.5%, 0.75%, 1.0%, of the total weight of the specimen with a tie-wire length of 8 cm. The test specimens for compressive strength, modulus of elasticity, and split tensile are in the form of a cylinder with a diameter of 15 cm and a height of 30 cm, and the specimen for flexural strength is a block with a length of 50 cm, a width of 10 cm and a height of 10 cm. The results show that the maximum compressive strength test on tie wire occurred at a percentage of 0.75% of 16.56 MPa. The maximum modulus of elasticity in tie wire occurred at a percentage of 0.75% of 15184.56 MPa. The maximum split tensile strength of tie wire occurred in a percentage of 0.75% of 1.165 MPa, and the maximum flexural strength of tie wire occurs at a percentage of 0.75% of 1.950 MPa. The research results concluded that the addition of a straight tie-wire to the concrete mixture could increase the compressive strength, split tensile strength, tensile strength, and elastic modulus of concrete.


Fibers ◽  
2018 ◽  
Vol 6 (3) ◽  
pp. 53 ◽  
Author(s):  
Abass Okeola ◽  
Silvester Abuodha ◽  
John Mwero

Concrete is a very popular material in the construction industry—it is, however, susceptible to quasi-brittle failure and restricted energy absorption after yielding. The incorporation of short discrete fibers has shown great promise in addressing these shortfalls. A natural fiber such as sisal is renewable, cheap, and easily available. It has also exhibited good tensile strength and can significantly improve the performance of concrete. In this study, the physical and mechanical properties of sisal fiber-reinforced concrete were reported. Sisal fibers were added in the mix at percentages of 0.5%, 1.0%, 1.5%, and 2.0% by weight of cement. Physical properties measured are workability, water absorption, and density while mechanical properties reported are compression strength, split tensile strength, and static modulus of elasticity. The computed modulus of elasticity of sisal fiber-reinforced concrete was compared with predicted values in some common design codes. From the study, it was concluded that sisal fiber can enhance the split tensile strength and Young’s modulus of concrete but cannot improve its workability, water absorption, and compressive strength.


2012 ◽  
Vol 535-537 ◽  
pp. 1868-1876
Author(s):  
Wai Ching Tang ◽  
Hong Zhi Cui

This paper proposes a method for evaluating the linear stress-strain curve and bilinear stress-COD curve, suggested by Petersson, which can describe the tensile fracture behaviour of ordinary concrete satisfactorily. The two curves can be evaluated once modulus of elasticity (E), tensile strength (ft) and fracture energy (GF) are determined. It is proposed that the same fracture energy test suggested in the RILEM Recommendation be used to evaluate E, ftand GF. Firstly, the fracture energy was as usual evaluated from the area under the load-deflection curve. Secondly, the modulus of elasticity was calculated from the initial compliance in the same curve. Finally, the tensile strength was derived from the peak load. The proposed method was verified using some experimental data available in literature. The calculated values of the modulus of elasticity and the tensile strength were in good agreement with the corresponding experimental data. The method seems to provide a simple and practical way of evaluating the stress-strain and strain-softening curves of ordinary concrete, though further assessment is needed.


2021 ◽  
Vol 3 (1) ◽  
pp. 65-72
Author(s):  
Danindra Pramudya Wardana ◽  
Gilang Fadhlurrahman Evriantama ◽  
Muhtarom Riyadi

Concrete is a material commonly used for structural work. However, concrete has one disadvantage, namely that its specific gravity is high enough so that the dead load on a structure becomes large. One way to deal with high concrete density is to use Styrofoam waste as a substitute for some of the fine aggregate. This research was conducted to examine the physical and mechanical properties as well as the optimum value of compressive strength, split tensile strength and modulus of elasticity of concrete with a 0.4 fas using Styrofoam as a partial substitute for fine aggregate. The research method used is an experimental method by making the test object in the form of a concrete cylinder with a diameter of 15 cm and a height of 30 cm. The composition of the concrete mixture used is a volume ratio of 1 Pc: 2 Ps: 2 Kr with a fas 0.4. The styrofoam variations used are 10%, 20%, and 30% of the ratio to the volume of fine aggregate in normal concrete mixtures. Testing of the mechanical properties of concrete was carried out at the age of 7, 14, 21, and 28 days for the concrete compressive strength test, and 28 days for the split tensile strength of the concrete, and the modulus of elasticity. The results showed that the compressive strength of the concrete increased with the age of the concrete and the addition of the styrofoam variations with the exception of the 10% variation. For the split tensile strength test, there was an increase in line with the increase in the styrofoam variation, while the modulus of elasticity decreased at 10% variation against 0% variation and increased at 20% and 30% variation with 0% variation.


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