scholarly journals Behavior of Chinese Dahurian Larch Wood after High-Temperature Exposure: Degradation of Mechanical Properties and Damage Constitutive Model

2018 ◽  
Vol 2018 ◽  
pp. 1-10
Author(s):  
Qifang Xie ◽  
Lipeng Zhang ◽  
Zhenglei Yang ◽  
Long Wang ◽  
Yaopeng Wu
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Shear Strength ◽  
Constitutive Model ◽  
Elevated Temperatures ◽  
Dahurian Larch ◽  
Water Cooling ◽  
Residual Compressive Strength ◽  
Damage Constitutive Model

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.

scholarly journals Behavior of Steel Slag Concrete Subjected to Elevated Temperature

2020 ◽  
Vol 9 (4) ◽  
pp. 1165-1170
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
High Temperatures ◽  
Elevated Temperatures ◽  
Coarse Aggregate ◽  
Steel Slag ◽  
Partial Replacement ◽  
High Porosity ◽  
Residual Mechanical Properties

Recycling of materials has become a major interest for engineers. At present, the amount of slag deposited in storage yard adds up to millions of tons/year leading to the occupation of farm land and serious pollution to the environment, as a result of the rapid growth in the steel industry. Steel slag is made at 1500- 1650°C having a honey comp shape with high porosity. Using steel slag as the natural aggregate with a lower waste material cost can be considered as a good alternative for sustainable constructions. The objective of this study is to evaluate the performance of residual mechanical properties of concrete with steel slag as coarse aggregate partial replacement after exposing to high temperatures .This study investigates the behavior of using granulated slag as partial or fully coarse aggregate replacement with different percentages of 0%, 15%, 30%, 50% and 100% in concrete when subjected to elevated temperatures. Six groups of concrete mixes were prepared using various replacement percentages of slag exposed to different temperatures of 400 °C, 600 °C and 800 °C for different durations of 1hr, 1.5hr and 2hr. Evaluation tests were compressive strength, tensile strength, and bond strength. The steel slag concrete mixes showed week workability lower than control mix. A systematic increasing of almost up to 21.7% in compressive strength, and 66.2% in tensile strength with increasing the percentage of steel slag replacement to 50%. And the results showed improvement on concrete residual mechanical properties after subjected to elevated temperatures with the increase of steel slag content. The findings of this study give an overview of the effect of steel slag coarse aggregate replacement on concrete after exposed to high temperatures.

scholarly journals EXPERIMENTAL INVESTIGATION OF MECHANICAL PROPERTIES OF SOLID CONCRETE BLOCK MASONRY EMPLOYING DIFFERENT MORTAR RATIOS

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Muhammad Rizwan
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Shear Strength ◽  
Research Work ◽  
Concrete Block ◽  
Unit Weight ◽  
Three Samples ◽  
Individual Unit ◽  
Concrete Blocks

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.

Experimental Study on the Mechanical Properties of Metal Oxides Filled PA1010 Composites

2007 ◽  
Vol 353-358 ◽  
pp. 1346-1349
Author(s):  
Chuan Hui Huang ◽  
Shi Bo Wang ◽  
Li Guo Liu
Keyword(s):  
Mechanical Properties ◽  
Experimental Study ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Shear Strength ◽  
Metal Oxides ◽  
Experimental Results ◽  
Al2o3 Particles

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.

scholarly journals Effect of Quarry Rock Dust as a Binder on the Properties of Fly Ash and Slag-Based Geopolymer Concrete Exposed to Ambient and Elevated Temperatures

2021 ◽  
Vol 11 (19) ◽  
pp. 9192
Author(s):  
Khadim Hussain ◽  
Faheem Butt ◽  
Mamdooh Alwetaishi ◽  
Rana Muhammad Waqas ◽  
Fahid Aslam ◽  
...  
Keyword(s):  
Weight Loss ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Fly Ash ◽  
Elevated Temperatures ◽  
Geopolymer Concrete ◽  
Residual Compressive Strength ◽  
Hardened Properties ◽  
Mechanical Strengths ◽  
Rock Dust

This study presents the performance of quarry rock dust (QRD) incorporated fly ash (FA) and slag (SG) based geopolymer concretes (QFS-GPC) exposed to ambient and elevated temperatures. A total of five QFS-GPC mix types were prepared. The quantity of FA (50%) was kept constant in all the mixes, and SG was replaced by 5%, 10%, 15%, and 20% of QRD. The fresh, hardened properties of the QFS-GPC mixes, viz., workability, compressive strength, splitting tensile strength, and flexural strengths, and XRD for identification of reaction phases were evaluated. The prepared mixes were also heated up to 800 °C to evaluate the residual compressive strength and weight loss. The workability of the QFS-GPC mixes was observed to be reduced by increasing the dosage (0 to 20%) of QRD. Superplasticizer (SP) was used to maintain the medium standard of workability. The compressive, tensile, and flexural strengths were increased by replacing SG with QRD up to 15%, whereas a further higher dosage (20%) of QRD reduced the mechanical strengths of the QFS-GPC mixes. The strength of the QFS-GPC specimens, heated to elevated temperatures up to 800 °C, was reduced persistently with the increased contents of QRD from 0 to 20%. It was concluded from the study that QFS-GPC can be used to achieve 30 MPa strength of concrete.

scholarly journals Study on the Physical and Mechanical Properties of Granite After Multiple Thermal Shock Treatments

2020 ◽  
Author(s):  
Li Yu ◽  
Hai-wang PENG ◽  
Yu Zhang ◽  
GuoWei Li
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
High Temperature ◽  
Thermal Shock ◽  
Tensile Modulus ◽  
Physical And Mechanical Properties ◽  
P Wave ◽  
Water Cooling ◽  
Thermal Shocks

Abstract To study the influence of thermal shock caused by water cooling on the physical and mechanical properties of high-temperature granite, granite was subjected to an increasing number of high-temperature (300℃) water-cooling and thermal shock treatment cycles, and static mechanical experiments were carried out on the treated granite. The results support the following conclusions: (1) Thermal shock causes an increase in the number and size of the pores and cracks within the granite; thus, its volume expands, density decreases, water absorption rate increases, and P-wave velocity decreases. (2) With an increase in the number of thermal shocks, both the compressive strength and tensile strength of the granite decrease, and there is a linear relationship between the compressive strength and tensile strength. With the corresponding fitting formula, the change in the strength of the granite can be accurately predicted. (3) With an increase in the number of thermal shocks, the plasticity of the granite increases and its resistance to deformation weakens, which is manifested as a decrease in both the compressive modulus and tensile modulus of the granite. After 15 cycles of thermal shock, the compressive elastic modulus and tensile modulus of the granite decreased by 25.18% and 46.76%, respectively. (4) The m and s values of the damaged granite were calculated based on the Hoek-Brown empirical criterion, and it was found that both of these parameters decrease with the increase in the number of thermal shocks. The calculation results can provide a reference for engineering rock mass failure.Clinical trial registration

scholarly journals Effect of Steel Fibers and Temperature on the Mechanical Properties of Reactive Powder Concrete

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Mahmoud Ahmed Ali Abdelrahim ◽  
Aboelwafa Elthakeb ◽  
Usama Mohamed ◽  
Mohamed Taha Noaman
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Elevated Temperatures ◽  
Fine Sand ◽  
Splitting Tensile Strength ◽  
Steel Fibers ◽  
Reactive Powder Concrete ◽  
Strain Relationship ◽  
Reactive Powder

Abstract Reactive Powder Concrete (RPC) is a concrete of the modern generation it mainly contains a high percentage of cement and a small percentage of water For cement as well as the presence of fine sand, ground quartz and silica dust. This research aims Studying the behavior and mechanical characteristics of RPC exposed to elevated temperatures. The key variables in this study are steel fibers content and the high temperatures of different levels 25, 200, 300, 400 ºC. Mechanical properties of concrete behavior including compressive strength, splitting tensile strength, stress-strain relationship (modulus of elasticity), and flexural strength. The test findings indicated that the Output strength of RPC specimens decreased when the high temperature increases. At a temperature of 400 °C, all samples lost the compressive strength and splitting tensile strength.

scholarly journals Laminasi Kayu Sengon Sebagai Salah Satu Solusi Ketersediaan Kayu Untuk Bahan Bangunan

TAMAN VOKASI ◽  
2019 ◽  
Vol 7 (2) ◽  
pp. 182
Author(s):  
Agus Priyanto
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Shear Strength ◽  
Flexural Strength ◽  
Strength Test ◽  
Average Shear Strength ◽  
Compressive Strength Test ◽  
Average Shear ◽  
Shear Block

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.

Effect of Clay Dosage on Mechanical Properties of Plastic Concrete

2011 ◽  
Vol 250-253 ◽  
pp. 664-667 ◽  
Author(s):  
Qiao Yan Guan ◽  
Peng Zhang
Keyword(s):  
Mechanical Properties ◽  
Experimental Study ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Shear Strength ◽  
Elastic Modulus ◽  
Internal Friction ◽  
Friction Angle ◽  
Splitting Tensile Strength ◽  
Plastic Concrete

A designed experimental study has been conducted to investigate the effect of clay dosage on mechanical properties of plastic concrete. The mechanical properties include compressive strength, splitting tensile strength, shear strength and elastic modulus. On the basis of the experimental results of the specimens of eight sets of mix proportions, the mechanism of action of clay on these mechanical properties has been analyzed in details. The results indicate that there is a tendency of decrease in the compressive strength, splitting tensile strength, shear strength and elastic modulus of plastic concrete with the increase of clay dosage. However, the internal friction angle of the shear specimens is increasing gradually with the increase of clay dosage. Further, the clay appears can improve the ductility of plastic concrete and this can help plastic concrete to bear larger deformation before failure.

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.    

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.

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