Influence of adhesive and layer composition on compressive strength of mixed cross-laminated timber

BioResources ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. 7461-7473
Author(s):  
In-Hwan Lee ◽  
Keon-Ho Kim
Keyword(s):  
Compressive Strength ◽  
Testing Machine ◽  
Fem Simulation ◽  
Limit Load ◽  
Red Pine ◽  
Japanese Larch ◽  
Yellow Poplar ◽  
Cross Laminated Timber ◽  
Polyurethane Adhesives ◽  
Average Compressive Strength

Different types of wood can be used for making cross-laminated timber (CLT), which is useful as a structural material. Therefore, to assess the viability of mixed cross-laminated timbers prepared with different adhesives, their compressive strength performances were evaluated. Laminae of Japanese larch, red pine, and yellow poplar were used to manufacture eight types of mixed CLTs, which were then tested in a universal testing machine for obtaining the compressive strength. The results were then compared to those obtained from the finite element (FEM) simulation of the CLTs at proportional limit load. The compressive strength of CLTs consisting of Japanese larch laminae, with a high modulus of elasticity, tended to increase. Mixed CLT with polyurethane adhesives showed an average compressive strength that was 14% lower than that of larch CLT, while mixed CLT consisting of red pine and yellow poplar showed an average compressive strength that was 18% lower than that of the larch CLT. The CLT prepared with phenol-resorcinol-formaldehyde adhesive yielded the highest compressive strength among the three adhesives. The FEM-predicted strengths were found to be close to the actual values in all specimens. The obtained results will be useful for selecting material and adhesive for future endeavors.

scholarly journals Influence of Water Binder Ratio on High Performance Concrete

2014 ◽  
Vol 8 (1) ◽  
pp. 18-21 ◽  
Author(s):  
N. Seshadri Sekhar ◽  
P.N. Raghunath
Keyword(s):  
Compressive Strength ◽  
Modulus Of Elasticity ◽  
Static Loading ◽  
High Performance ◽  
High Performance Concrete ◽  
Testing Machine ◽  
Influence Of Water ◽  
Binder Ratio ◽  
Average Compressive Strength ◽  
Water Binder Ratio

High performance concrete M60 cubes of 150 mm X 150 mm X 150 mm were tested experimentally under static loading. With the variation in the water binder ratios of 0.25, 0.28, 0.33, 0.39 and hyper plasticizer of 0.6%. 0.8%. 1.0%, 1.2% the cubes were cast and accordingly the cylinders were cast. For each ratio of water binder, 12 cubes and 2 cylinders were cast. Out of 12 cubes, 3 cubes were cured for 7 days, 3cubes for 15 days, 3 cubes for 21 days and the balance 3 cubes for 28 days. All the cubes were tested in a 2000kn compression testing machine. The load deflection curves, stress- strain curves were drawn for each cube and cylinder. The average compressive strength of each mix for different number of days of curing were calculated. The modulus of elasticity was calculated for each design mix.

scholarly journals Predicting nail withdrawal resistance and bearing strength of cross-laminated timbers from mixed species

BioResources ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. 4027-4038
Author(s):  
Keonho Kim
Keyword(s):  
Structural Stability ◽  
Japanese Larch ◽  
Mixed Species ◽  
Yellow Poplar ◽  
Sustainable Architecture ◽  
Wood Structures ◽  
Strength Performance ◽  
Cross Laminated Timber ◽  
Bearing Strength ◽  
Increasing Demand

The increasing demand for sustainable architecture has led to a growing interest in wood structures. Hence, ensuring their structural stability and strength performance is an imperative. This study investigated the nail bearing strength and withdrawal resistance of mixed cross-laminated timber (CLT) using Japanese larch and yellow poplar layers. The mixed CLT was composed of three larch laminas (major) and two yellow poplar laminas (minor). The bearing strength of the mixed CLT decreased as the ratio of the thickness of the minor lamina to nail depth increased. The nail withdrawal resistance differed in the penetration and axial directions of the laminas. In the direction perpendicular to the grain, the withdrawal resistance load of the yellow poplar lamina was measured to be 1.45-times that of the larch lamina. The withdrawal resistance of the mixed CLT with the yellow poplar layer was 17% higher than that with larch. Therefore, the length of the nail used for the mixed CLT should be selected based on the thickness of the minor lamina to achieve efficient bearing and withdrawal resistance of the nail connection.

scholarly journals Pengaruh Limbah Logam Pada Kuat Tekan Beton

2021 ◽  
Vol 3 (1) ◽  
pp. 58-63
Author(s):  
Dewi Setiawati ◽  
Bambang Jatmika ◽  
Muhammad Rizal Aditya
Keyword(s):  
Compressive Strength ◽  
Coarse Aggregate ◽  
Cylindrical Specimen ◽  
Testing Machine ◽  
Weight Ratio ◽  
Mean Value ◽  
Concrete Mixture ◽  
Test Results ◽  
The Mean ◽  
Average Compressive Strength

This study aims to determine the effects of nickel slag in the concrete mixture and on its compressive strength value. In this study, cylindrical specimen having 15cm diameter and 30cm height is used. We have used nickel slag as substitute of coarse aggregate in weight ratio of 25%, 50% & 100% respectively of coarse aggregate in sample. The ratio of concrete mixture used in this study is comprised of ratio 1:2:3 of cement, sand & gravel respectively. Compressive strength was used as a parameter for testing the samples in this study.             Test was performed using compression Testing machine, from the test results, the mean value of the average compressive strength of cylindrical concrete at the age of 3 days with a 25% variant nickel slag is 134.02 kg / cm2, 50% variant nickel slag is 165.76 kg / cm2, and 70% variant nickel slag is 148.92 kg / cm2, at age 7 days for the 25% is 219.61 kg / cm2, the 50% variant is 191.27 kg / cm2, and the 70% is 181.57 kg / cm2, while at the age of 28 days the 25% is 275.09 kg / cm2, the 50% iis equal to 296.28 kg / cm2, and the 70% is 225.37kg / cm2  

scholarly journals Withdrawal Properties of Self-Tapping Screws in Japanese larch (Larix kaempferi (Lamb.) Carr.) Cross Laminated Timber

Forests ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 524
Author(s):  
Junhua Xu ◽  
Shuangbao Zhang ◽  
Guofang Wu ◽  
Yingchun Gong ◽  
Haiqing Ren
Keyword(s):  
Regression Model ◽  
Engineering Design ◽  
Wood Species ◽  
Japanese Larch ◽  
Effective Length ◽  
Larix Kaempferi ◽  
Cross Laminated Timber ◽  
The World ◽  
Different Types ◽  
Length Increment

With the increasing popularity of cross-laminated timber (CLT) constructions around the world, there have been attempts to produce CLT using local wood species in different countries, such as Japanese larch (Larix kaempferi (Lamb.) Carr.) in China. Thus, the need to investigate the connection performance also increases to support the design and construction of CLT buildings using local wood species. In this study, the withdrawal properties of three different types of self-tapping screws (STS), with a diameter of 6 mm, 8 mm, and 11 mm, were tested with Japanese larch CLT. The results revealed that the withdrawal strength of STS increased with increasing density and effective length, but decreased with an increasing diameter. With a density increment of 0.05 g/cm3, the withdrawal strength increased by an average of 9.4%. With an effective length increment of 24 mm, the withdrawal strength increased by an average of 1.4%. An empirical regression model was adopted to predict the withdrawal strength of Japanese larch CLT based on the results, which can be used for potential engineering design of CLT connections using STS.

scholarly journals Mechanical Properties of the Composite Material consisting of β-TCP and Alginate-Di-Aldehyde-Gelatin Hydrogel and Its Degradation Behavior

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1303
Author(s):  
Michael Seidenstuecker ◽  
Thomas Schmeichel ◽  
Lucas Ritschl ◽  
Johannes Vinke ◽  
Pia Schilling ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Protein Concentration ◽  
Failure Load ◽  
Testing Machine ◽  
Experimental Period ◽  
Flow Chamber ◽  
Degradation Behavior ◽  
Gelatin Hydrogel ◽  
Universal Testing

This work aimed to determine the influence of two hydrogels (alginate, alginate-di-aldehyde (ADA)/gelatin) on the mechanical strength of microporous ceramics, which have been loaded with these hydrogels. For this purpose, the compressive strength was determined using a Zwick Z005 universal testing machine. In addition, the degradation behavior according to ISO EN 10993-14 in TRIS buffer pH 5.0 and pH 7.4 over 60 days was determined, and its effects on the compressive strength were investigated. The loading was carried out by means of a flow-chamber. The weight of the samples (manufacturer: Robert Mathys Foundation (RMS) and Curasan) in TRIS solutions pH 5 and pH 7 increased within 4 h (mean 48 ± 32 mg) and then remained constant over the experimental period of 60 days. The determination surface roughness showed a decrease in the value for the ceramics incubated in TRIS compared to the untreated ceramics. In addition, an increase in protein concentration in solution was determined for ADA gelatin-loaded ceramics. The macroporous Curasan ceramic exhibited a maximum failure load of 29 ± 9.0 N, whereas the value for the microporous RMS ceramic was 931 ± 223 N. Filling the RMS ceramic with ADA gelatin increased the maximum failure load to 1114 ± 300 N. The Curasan ceramics were too fragile for loading. The maximum failure load decreased for the RMS ceramics to 686.55 ± 170 N by incubation in TRIS pH 7.4 and 651 ± 287 N at pH 5.0.

Preparation of Porous HA Bioceramics by Gelcasting and Pressureless Sintering

2011 ◽  
Vol 335-336 ◽  
pp. 1454-1458
Author(s):  
Jing Xian Zhang ◽  
Bi Qin Chen ◽  
Dong Liang Jiang ◽  
Qing Ling Lin ◽  
Zhong Ming Chen ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Pore Size ◽  
Pressureless Sintering ◽  
High Compressive Strength ◽  
Microstructure And Properties ◽  
Pmma Beads ◽  
Average Compressive Strength

In the present work, porous HA scaffolds with well controlled pore size, porosity and high compressive strength were prepared by aqueous gelcasting. PMMA beads with different size were used as the pore forming agent. The compositions, microstructure and properties of porous HA bioceramics were analyzed by XRD, SEM, Hg porosimetry etc. The mechanical properties were also tested. For scaffolds with the porosity as 70%, the average compressive strength was 11.9±1.7 MPa. Results showed that glecasting process can be used for the preparation of porous HA biomaterials with well controlled pore size and improved mechanical properties.

Selected Properties of Parallel Strand Lumber Made from Southern Pine and Yellow-Poplar

Holzforschung ◽  
2003 ◽  
Vol 57 (2) ◽  
pp. 207-212 ◽  
Author(s):  
Y. Liu ◽  
A.W.C. Lee
Keyword(s):  
Compressive Strength ◽  
Shear Strength ◽  
Specific Gravity ◽  
Moisture Content ◽  
Dimensional Stability ◽  
Modulus Of Rupture ◽  
Southern Pine ◽  
Yellow Poplar ◽  
Average Modulus ◽  
Parallel Strand Lumber

Summary This study was conducted to explore basic physical and mechanical properties of parallel strand lumber (PSL) made exclusively from southern pine and yellow-poplar, respectively, and to examine their relationships using statistical analysis. Small specimens were prepared from commercial southern pine PSL and yellow-poplar PSL billets and tested for specific gravity, moisture content, dimensional stability, bending properties, shear strength and compressive strength. Results indicate average specific gravity of southern pine PSL is higher than that of yellow-poplar PSL, while their average moisture content and dimensional stability are very similar. Southern pine PSL has higher average modulus of elasticity but lower average modulus of rupture than yellow-poplar PSL. While average longitudinal shear strength does not exhibit differences between southern pine PSL and yellow-poplar PSL, average compressive strength of southern pine PSL is higher than that of yellow-poplar PSL. There are positive correlations among modulus of elasticity, modulus of rupture and specific gravity. PSL improves some properties of solid wood from which PSL is made.

Assessment of Residual Ultimate Strength of VLCC According to Damage Extents and Average Compressive Strength of Stiffened Panel

2014 ◽  
Author(s):  
Ji-Myung Nam ◽  
Joonmo Choung ◽  
Se-Yung Park ◽  
Sung-Won Yoon
Keyword(s):  
Compressive Strength ◽  
Ultimate Strength ◽  
Probabilistic Approach ◽  
Stiffened Panel ◽  
Moment Capacity ◽  
Hull Girder ◽  
Damage Area ◽  
Damage Indices ◽  
Smith Method ◽  
Average Compressive Strength

This paper presents the prediction of residual ultimate strength of a very large crude oil carrier considering damage extents due to collision and grounding accidents. In order to determine extents of damage, two types of probabilistic approaches are employed: deterministic approach based on regulations based on ABS [1], DNV [2], and MARPOL [3] and probabilistic approach based on IMO probability density functions (PDFs) (IMO guidelines [4]). Hull girder ultimate strength is calculated using Smith method which is dependent on how much average compressive strength of stiffened panel is accurate. For this reason, this paper uses two different methods to predict average compressive strength of stiffened panel composing hull girder section: CSR formulas and nonlinear FEA. Calculated average compressive strength curves using CSR formulas (IACS [5, 6]) and nonlinear FEA are imported by an in-house software UMADS. Residual ultimate moment capacities are presented for various heeling angles from 0° (sagging) to 180° (hogging) by 15° increments considering possible flooding scenarios. Three regulations and IMO guidelines yield minimum of reduction ratios of hull girder moment capacity (minimum of damage indices) approximately at heeling angles 90° (angle of horizontal moment) and 180° (angle of hogging moment), respectively, because damage area is located farthest from neutral axis.

Dynamic and Quasi-Static Compressive Deformation Behaviour of Polyimide Foam at Various Elevated Temperature

2014 ◽  
Vol 566 ◽  
pp. 158-163 ◽  
Author(s):  
A. Yosimoto ◽  
Hidetoshi Kobayashi ◽  
Keitaro Horikawa ◽  
Keiko Watanabe ◽  
Kinya Ogawa
Keyword(s):  
Compressive Strength ◽  
Room Temperature ◽  
Deformation Behaviour ◽  
Testing Machine ◽  
Negative Temperature ◽  
Strain Rates ◽  
Compression Tests ◽  
Hopkinson Pressure Bar ◽  
Universal Testing ◽  
Pressure Bar

In order to clarify the effect of strain rate and test temperature on the compressive strength and energy absorption of polyimide foam, a series of compression tests for the polyimide foam with two different densities were carried out. By using three testing devices, i.e. universal testing machine, dropping weight machine and sprit Hopkinson pressure bar apparatus, we performed a series of compression tests at various strain rates (10-3~103s-1) and at several test temperatures in the range of room temperature to 280 ̊C. At over 100 s-1, the remarkable increase of flow stress was observed. The negative temperature dependence of strength was also observed.

PEMANFAATAN LIMBAH KOTORAN SAPI SEBAGAI PENGGANTI SEBAGIAN SEMEN DALAM PEMBUATAN BATAKO

2020 ◽  
Vol 15 (2) ◽  
pp. 53-57
Author(s):  
Kiki Kurniawan ◽  
Prihantono Prihantono ◽  
Rosmawita Saleh
Keyword(s):  
Compressive Strength ◽  
Water Absorption ◽  
Mean Value ◽  
Cow Dung ◽  
A Value ◽  
Average Water ◽  
Hollow Brick ◽  
Average Compressive Strength

The results showed the use of cow dung waste can increase the compressive strength of hollow brick from any composition of waste. Hollow brick with cow dung substitution of 0% has an average compressive strength value 44.75 Kg/Cm2 has an average water absorption of 14.31%, hollow brick with cow dung substitution of 5% has a value of compressive strength average 47.47 Kg/Cm2 has an average water absorption of 15.67%, Batako perforation with cow dung substitution of 7.5% has an average compressive strength value of 51.83 Kg/Cm2 has the absorption water averaging 13.71%, batako perforated with substitution of cow dung waste of 10% has an average compressive strength value 53.81 Kg/Cm2 has an average water absorption of 10.04%, hollow brick with substitution cow dung waste of 12.5% has an average compressive strength value of 50.66 Kg/Cm2 has an average water absorption of 23.6%, hollow brick with cow dung substitution of 15% average 48.84 Kg/Cm2 has an average water absorption of 19.72%. The optimum compressive strength value was obtained from percentage substitution of cow dung waste at 10% with mean value of compressive strength 53,81 Kg/Cm2 with average water absorption 10,04%.

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