scholarly journals Methods for determining mechanical properties of walls

2021 ◽  
Vol 73 (02) ◽  
pp. 127-140

Masonry buildings with wooden floor structures, not equipped with vertical and horizontal tie beams, suffered the greatest damage in the earthquake that hit Zagreb on 22 March 2020. It is very significant to know mechanical properties of walls during preparation of the masonry buildings renovation design and, consequently, methods for determining such properties are presented in detailed in this paper. In addition to description of these methods, results obtained by testing shear strength of walls of twenty masonry buildings in Zagreb (149 measuring points in total) are also presented, as well as the results obtained by testing compressive strength of bricks on 14 buildings, using a total of 62 samples.

2011 ◽  
Vol 250-253 ◽  
pp. 788-794
Author(s):  
Shu Lin Zhan ◽  
Shu Sen Gao ◽  
Jun Ying Lai

In order to study the influence of modified polypropylene (PP) fiber on the physical and mechanical properties of curing sludge, the same amount of cement and different content of polypropylene fiber were mixed into the sludge. Unconfined compressive strength tests, water content tests and shear strength tests were carried out on different specimens with different curing time. The results show that the sludge curing effect is markedly improved by the addition of the polypropylene fiber. As to the curing sludge with the same curing time, when the content of the polypropylene fiber increases, the unconfined compressive strength and the cohesive strength greatly increase, and the internal frictional angle decreases.


2021 ◽  
pp. 168-173
Author(s):  
I Wayan Sugiartha ◽  
Aryani Rofaida ◽  
Rini Srikus Saptaningtyas ◽  
Teti Handayani

This study aims to determine the mechanical properties (compressive strength and shear strength) of bamboo filled with PET plastic and wood sawdust. Five variations of test objects were made, namely BK-0 (bamboo without filler as a control), BK-1 (bamboo filled with PET plastic), BK-2 (bamboo filled with PET plastic + adhesive coated), BK-3 (bamboo filled with PET plastic + powder wood saw), BK-4 (bamboo filled with PET plastic + wood sawdust and coated with adhesive). The test results give the value of the compressive strength of bamboo from BK-0 to BK-4 in a row of 22.7 MPa, 29.4 MPa, 32.7 MPa, 33.2 MPa, 35.7 MPa or an increase in the compressive strength of BK-0 in a row by 30%, 44%, 46%, and 57%. Meanwhile, the shear strength of bamboo from BK-0 to BK-4 is 4.55 MPa, 5.00 MPa, 5.05 MPa, 5.40 MPa, 5.50 MPa or an increase in shear strength to BK-0 is 10%, 11%, respectively. , 19%, and 21%.


Author(s):  
Muhammad Rizwan

This research work aims to investigate experimentally the mechanical properties of solid concrete blocks as an individual unit and assembly (block masonry) employing different mortar mix ratios. The material properties of the concrete block unit, such as compressive strength and unit weight were explored by taking three samples from the four local factories. The block masonry assemblages were subjected to various load patterns for the evaluation of compressive strength, diagonal tensile strength and shear strength. For the bond, four types of mortars i.e., cement – sand (1:4), cement – sand (1:8), cement – sand – khaka (1:2:2) and cement – sand – khaka (1:4:4) were used in the joints of concrete block masonry assemblages. (Khaka is a by-product formed in the stone crushing process). For each type of mortar, three samples of block masonry were fabricated for compressive strength, shear strength and diagonal tensile strength, and tested in the laboratory. It is observed that the replacement of sand by khaka enhanced the mechanical properties of masonry.


2018 ◽  
Vol 2018 ◽  
pp. 1-10
Author(s):  
Qifang Xie ◽  
Lipeng Zhang ◽  
Zhenglei Yang ◽  
Long Wang ◽  
Yaopeng Wu

Wood has been extensively used in Chinese ancient buildings, and it is important to clearly understand the mechanical properties of wood after exposure to elevated temperatures. In this paper, three kinds of tests with 102 clear wood specimens fabricated with Chinese Dahurian larch for each kind of test were conducted. The residual compressive strength, tensile strength, and shear strength parallel to grain of specimens after exposure to different temperatures (100°C, 150°C, 200°C, and 250°C) with various exposure times (15 min, 30 min, and 45 min) and different cooling methods (natural cooling and water cooling) were obtained. Results indicate that exposure to elevated temperatures causes great degradation of compressive strength, tensile strength, and shear strength parallel to grain. When the exposure temperatures exceed 200°C, the relative compressive strength, tensile strength, and shear strength parallel to grain decrease greatly with the increase of exposure time. The residual compressive strength, tensile strength, and shear strength of specimens after water cooling are lower than that after natural cooling. Exposure temperatures also have a great impact on the weight loss and color change of wood. Based on the test data, degradation models for the residual compressive strength, tensile strength, and shear strength of wood were developed. Furthermore, the damage constitutive model of compressive (CDMC) and tensile (CDMT) parallel to grain was established and validated reasonably by tests.


2019 ◽  
Vol 10 (1) ◽  
pp. 15-21 ◽  
Author(s):  
Markéta Hošťálková ◽  
Nikola Vavřínová ◽  
Veronika Longauerová

The gypsum is one of the most often used materials in the civil engineering. Very often it is applied in the form of plasterboards without any reinforcement, for example, cladding boards are unusable as supporting construction. To improve the mechanical properties of plasterboards, fibrous materials such as cellulose or glass fiber are added. Reinforcement of gypsum with fibers improves in particular the flexural and shear strength. The main purpose of the research is to clarify whether natural wooden fibers could be used as the reinforced of composite gypsum building materials. Wooden fibers are used as a blown or board thermal insulation. This article presents the results of tests aimed at determining the mechanical and physical properties of gypsum composite reinforced with wooden fibers. The effect of the reinforcement on the strength properties as a compressive strength, flexural strength was verified on a series of test specimens. The results of the tests have shown that the reinforcing of gypsum composite has an impact on the mechanical-physical parameters.


2007 ◽  
Vol 353-358 ◽  
pp. 1346-1349
Author(s):  
Chuan Hui Huang ◽  
Shi Bo Wang ◽  
Li Guo Liu

This paper focuses on the effect of metal oxides on the mechanical properties of PA1010 composites, such as the tensile strength, compressive strength, shear strength and hardness. The experimental results show that the tensile strength of PA1010 composites filled with CuO and Al2O3 particles slightly decreases with the oxide contents increasing. However, the tensile strength of PA1010 composites filled with Fe3O4 particles increases, which has the average increment in tensile strength of 23.7% than the pure PA1010 materials. The results indicate that the compressive strength can be increased by adding CuO, Al2O3 and Fe3O4 particles into PA1010 polymer. The results exhibit that Fe3O4 particles have significant effects to increase the shear strength of PA1010 composites. However, Al2O3 particles filling reduce the shear strength of the composites.


2011 ◽  
Vol 368-373 ◽  
pp. 436-440
Author(s):  
Chun Ming Song ◽  
Ming Yang Wang ◽  
De Rong Wang

In order to get mechanical properties and anti-explosion capability parameters, some RPC samples with 5% steel fiber are tested, many groups data were obtained such as compressive strength, shear strength and fracture toughness. The model tests are also carried out on RPC shelter plate under contact explosion, the most important parameter to express anti-explosion capability,i.e. compression coefficient of the material, is obtained by above experiments and theory study, the results of tests show RPC with steel fiber has very high strength and anti-explosion capability, its compressive strength and anti-explosion capability are about six and three times higher than those of C30 concrete respectively.


2021 ◽  
Vol 13 (2) ◽  
pp. 745
Author(s):  
Jie Li ◽  
Hao Zhou ◽  
Wenwen Chen ◽  
Zhongfan Chen

Considering the advantages of energy conservation and reducing the construction skill requirement of the workers, a new type of interlocking hollow block using recycled aggregates concrete (IHB-RAC) with the compressive strength up to 10 Mpa was proposed, which could help improve more than 56% of the construction efficiency compared to commonly used concrete hollow blocks. In order to study the mechanical properties and promote the application of this new type block in building engineering, the masonries considering different strengths of mortar and the concrete used in the grouting holes were designed, and the corresponding compressive and shear strength, as well as the failure mode of the masonries were studied according to the test results. Then, experimental results were compared with the calculated values obtained from Chinese code GB50003-2011 to check the suitability of the standards. In order to make an accurate prediction of the compressive strength of the masonry, modifying coefficients were suggested considering the positive contributions of the connecting keys. In addition, according to the test results, an appropriate calculation method for accurately predicting the shear strength of the grouted IHB-RAC masonry was proposed by separately considering the effort of the mortar and the grouting hole concrete.


2017 ◽  
Vol 3 (1) ◽  
pp. 6-10
Author(s):  
Ali Awaludin ◽  
J.P. Gentur Sutapa

This study presented test results of mechanical properties of Cocos nucifera wood that were planted around Mt. Merapi, Yogyakarta. The test specimens were obtained from trees that had been exposed to pyroclastic flow during the 2010 volcanic eruption as indicated by dark colour of the outer bark. Test set-up was designed according to ASTM D143-94 and the mechanical properties, which are determined based on the lower 5% exclusion limit, were bending strength, shear strength, dowel bearing strength and compressive strength. Results of the specific gravity measurement showed significant variation of specific gravity between the inner part (close to the pith) and the outer part (far from the pith) in a cross-section. Since mechanical properties generally depend upon specific gravity, it was decided to divide the wood specimens into two groups: specimens from the inner part and specimens from the outer part. Most of the mechanical properties of wood specimens from the inner part, except for bending strength, were found to be much lower than E10 grade of the Indonesian National Standard (SNI). Hence it is not recommended for any structural use. In the case of wood specimens from the outer part, their mechanical properties were as follows: bending strength 83.66 MPa; shear strength parallel to grain 4.41 MPa; dowel bearing strength parallel to grain 40.65 MPa; dowel bearing strength perpendicular to grain 25.88 MPa, compressive strength parallel to grain 37.89 MPa; and compressive strength perpendicular to grain 7.48 MPa. It seemed that the wood specimens from the outer part had excellent mechanical properties especially in bending, but their shear strength is extremely low.


TAMAN VOKASI ◽  
2019 ◽  
Vol 7 (2) ◽  
pp. 182
Author(s):  
Agus Priyanto

Abstracts. The supply of wood that is quite durable and of high quality has not been able to meet the needs of building construction at the present time, especially in the future. Sengon wood (Paraserianthes falcataria) is a fast-growing type of plant that has a large increase (volume of wood per hectare per year) which is around 28 - 48 m3 / ha / year. To fulfill various human objectives, the majority of Sengon wood can be collected from the age of 6 years. With the use of lamination technology, wood remnants can be utilized to be made into wooden blocks of various sizes and various shapes. Lamination can make the strength of Sengon wood higher than solid wood beams.The test is carried out by physical and mechanical tests as well as the Sengon wood laminated sliding block test. In testing physical and mechanical properties based on ISO 1975 regulations. Testing of physical properties of Sengon wood includes wood density test and moisture content test. Testing the mechanical properties of Sengon wood includes fiber parallel compressive strength test, fiber perpendicular compressive strength test, tensile strength test, shear strength test and flexural strength test. Testing of Sengon wood laminated sliding blocks to determine the strength of lamination has a variation of 30 MDGL, 40 MDGL and 50 MDGL slurry adhesives with 3 replications of each shear test.The average density of Sengon wood is 0.315 t / m3 and the average moisture content of Sengon wood is 13.539%. The average compressive strength of fibers is 26.85 MPa and the compressive strength of fibers is 9.62 MPa. The average tensile strength of Sengon wood is 61.48 MPa and the average shear strength of Sengon wood is 5.31 MPa. In testing the flexural strength of Sengon wood an average of 43.18 MPa. Testing of Sengon wood laminate sliding block for 30 / MDGL obtained an average of 0.05 kg / mm2. In the shear block 40 / MDGL obtained an average shear strength of 0.02 kg / mm2. For the 50 / MDGL laminate shear block an average shear strength of 0.08 kg / mm2 was obtained.


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