scholarly journals Properties of Mortars with Recycled Stone Aggregate for the Reconstruction of Sandstone in Historic Buildings

2021 ◽  
Vol 13 (3) ◽  
pp. 1386
Author(s):  
Beata Klimek ◽  
Małgorzata Grzegorczyk-Frańczak
Keyword(s):  
Mechanical Properties ◽  
Weight Loss ◽  
Physical And Mechanical Properties ◽  
Historic Buildings ◽  
Biological Factors ◽  
Destructive Effect ◽  
External Appearance ◽  
No Weight Loss ◽  
The Face ◽  
Stone Walls

The research concerned the mortars with recycled stone aggregate used for the reconstruction of historic objects. The face of stone walls is exposed to atmospheric, chemical, and biological factors, causing its destruction. The aim of the research was to develop a mortar that would be compatible with the stone both in terms of its external appearance as well as its physical and mechanical properties. For this purpose, three mortars based on recycled sandstone aggregate with three different gradations were prepared. The compatibility of stone and mortar was tested in terms of the physical and mechanical properties as well as the resistance to salt and frost corrosion. The mortars reflect the properties of sandstone and offer great opportunities to adjust them as desired. The frost resistance of the mortars was consistent, with practically no weight loss after 25 test cycles. They achieved lower compression strength than stone, which is an important feature in avoiding destruction by using an excessively strong mortar. Moreover, the absorbability of the mortars turned out to be favorable (max. 25%). Mortars were resistant to the destructive effect of salt and did not show the ability to whitewash and desalinate.

scholarly journals Effects of High Temperatures on the Physical and Mechanical Properties of Carbonated Ordinary Concrete

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Qifang Xie ◽  
Lipeng Zhang ◽  
Shenghua Yin ◽  
Baozhuang Zhang ◽  
Yaopeng Wu
Keyword(s):  
Mechanical Properties ◽  
Weight Loss ◽  
Elastic Modulus ◽  
High Temperatures ◽  
Elevated Temperatures ◽  
Physical And Mechanical Properties ◽  
Surface Characteristics ◽  
Time Service ◽  
Different Temperatures ◽  
Cooling Methods

Fires are always known for seriously deteriorating concrete in structures, especially for those with certain carbonation due to long-time service. In this paper, 75 prism specimens were prepared and divided into four groups (three carbonated groups and one uncarbonated group). Specimens were tested under different temperatures (20, 300, 400, 500, 600, and 700°C), exposure times (3, 4, and 6 hours), and cooling methods (water and natural cooling). Surface characteristics, weight loss rate, and residual mechanical properties (strength, initial elastic modulus, peak, and ultimate compressive strains) of carbonated concrete specimens after elevated temperatures were investigated and compared with that of the uncarbonated ones. Results show that the weight loss rates of the carbonated concrete specimens are slightly lower than that of the uncarbonated ones and that the cracks are increased with raising of temperatures. Surface colors of carbonated concrete are significantly changed, but they are not sensitive to cooling methods. Surface cracks can be evidently observed on carbonated specimens when temperature reaches 400°C. Residual compressive strength and initial elastic modulus of carbonated concrete after natural cooling are generally larger than those cooled by water. The peak and ultimate compressive strains of both carbonated and uncarbonated concrete specimens increase after heating, but the values of the latter are greater than that of the former. Finally, the constitutive equation to predict the compressive behaviors of carbonated concrete after high temperatures was established and validated by tests.

scholarly journals Relationships between Thermoplastic Type and Properties of Polymer-Triticale Boards

Polymers ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1750 ◽  
Author(s):  
Radosław Mirski ◽  
Pavlo Bekhta ◽  
Dorota Dziurka
Keyword(s):  
Mechanical Properties ◽  
Modulus Of Elasticity ◽  
Bending Strength ◽  
Physical And Mechanical Properties ◽  
Thickness Swelling ◽  
Hydrophobic Properties ◽  
Pine Wood ◽  
Moisture Contents ◽  
The Face

This study examined the effects of selected types of thermoplastics on the physical and mechanical properties of polymer-triticale boards. The investigated thermoplastics differed in their type (polypropylene (PP), polyethylene (PE), polystyrene (PS)), form (granulate, agglomerate) and origin (native, recycled). The resulting five-ply boards contained layers made from different materials (straw or pine wood) and featured different moisture contents (2%, 25%, and 7% for the face, middle, and core layers, respectively). Thermoplastics were added only to two external layers, where they substituted 30% of straw particles. This study demonstrated that, irrespective of their type, thermoplastics added to the face layers most favorably reduced the hydrophobic properties of the boards, i.e., thickness, swelling, and V100, by nearly 20%. The bending strength and modulus of elasticity were about 10% lower in the experimental boards than in the reference ones, but still within the limits set out in standard for P7 boards (20 N/mm2 according to EN 312).

scholarly journals Effect of Soaking/Oven- Drying on Mechanical and Physical Properties of Birch (Betula spp.) Plywood

2021 ◽  
Vol 72 (2) ◽  
pp. 121-129
Author(s):  
Regino Kask ◽  
Harri Lille ◽  
Mihkel Kiviste ◽  
Silver Kruus ◽  
Johann Olaf Lääne
Keyword(s):  
Mechanical Properties ◽  
Bending Strength ◽  
Phenol Formaldehyde ◽  
Physical And Mechanical Properties ◽  
Thickness Swelling ◽  
Oven Drying ◽  
Mechanical And Physical Properties ◽  
The Face ◽  
European Standards ◽  
Fractional Equation

The objective of this study was to explore some of the physical and mechanical properties of 9-layer birch (Betula spp.) plywood with the addition of phenol-formaldehyde glue, in cases in which the cutting edges of the samples are coated with the damp-proof mastic Fibergum, and in case in which they remain unprocessed (uncoated), following a total of ten cycles of soaking/oven-drying. The properties to be determined were the bending strength (BS), modulus of elasticity in bending (MOE), thickness swelling (TS) and restore dimensions (RD), which were tested according to the European standards (EN). A linear-fractional equation and linear relationship were used for the approximation of any change in the physical and mechanical properties of the samples depending upon the number of soaking/oven-drying cycles. It was shown that the values of the properties investigated were most affected by the first soaking and drying cycle. Thereafter, BS and MOE levels decreased smoothly at a low rate, but the values of TS became stabilised. The BS and MOE values for the wet samples with coated cutting edges were higher than when they were uncoated, as the moisture levels in the former case were lower. After the first soaking of the samples with coated cutting edges, the retention values were as follows: BS at 52.8 % and 66.7 % for the major and minor axes, respectively, with the same applying to MOE at 61.9 % and 64.2 %, while TS was at 105.2 %. To clarify the phenomenon that causes a decrease of the properties, the face plies and edge structures of the initial dry samples and of the samples after the first, second and ninth soaking/oven-drying cycles were studied using the X-Ray technique.Ključne riječi

scholarly journals Effect of Variable Conditions of Exposure on the Physical and Mechanical Properties of Blockboards

2022 ◽  
Vol 12 (2) ◽  
pp. 609
Author(s):  
Octavia Zeleniuc ◽  
Camelia Coșereanu
Keyword(s):  
Mechanical Properties ◽  
Interior Design ◽  
Environmental Conditions ◽  
Physical And Mechanical Properties ◽  
Solid Wood ◽  
Raw Material ◽  
Climatic Chamber ◽  
Parameter Variations ◽  
The Face ◽  
Cyclic Changes

The growing demand for wood and the continued increase of the raw material price have resulted in companies using more efficient wood resources in wood-based products such as blockboard. These boards are used in the field of interior design, especially. The aim of this research was to evaluate the effect of variable environmental conditions on the physical and mechanical properties of blockboard (BK). Two types of commercial BK were exposed in variable environmental conditions (kitchen, bathroom and climatic chamber) for three months. The BK structures were composed of veneer (V) and high-density fibreboards (HDF) for the face sheets and glued, solid wood, resinous strips for the core. The temperature and relative humidity of the air (RH) ranged from 18 °C to 25 °C and from 25% to 90%, respectively. In the climatic chamber (CC), the dynamics of the parameter variations were different than in the other two exposure climates, being determined by the programmed cyclic changes in RH. The changes observed on physical and mechanical properties were more extreme for the blockboards tested in the CC than in the kitchen (K) and bathroom (Ba). After 3 months of exposure in the CC, the thickness and weight of the boards increased by 1.8 and 1.1 times, respectively, for veneered BK, and by 4.4 and 0.4 times, for BK with HDF faces, compared to values recorded in the kitchen. The panels exposed in the CC exhibited the highest increase in moisture content (MC): 41% for veneered BK and 82% for BK with HDF faces after three months of exposure, followed by those exposed in the bathroom and kitchen. Increases in MC determined decreases of flexural properties and soundness surfaces, more evident for HDF face structures compared to V ones.

scholarly journals The physical and mechanical properties of magnesium oxychloride cement-based materials

2015 ◽  
Vol 14 (4) ◽  
pp. 089-098 ◽  
Author(s):  
Szymon Malinowski ◽  
Justyna Jaroszyńska-Wolińska
Keyword(s):  
Mechanical Properties ◽  
Weight Loss ◽  
Compressive Strength ◽  
Physical And Mechanical Properties ◽  
Polypropylene Fibers ◽  
Experimental Part ◽  
Cement Based Materials ◽  
Magnesium Oxychloride ◽  
Magnesium Oxychloride Cement ◽  
Micro Silica

The aim of this paper was the examination of the physical-mechanical properties of Sorel cement-based material. In the experimental part the effect of polypropylene fibers (PP) and micro-silica on properties of composite materials were studied. The results show that addition of these modifiers increases compressive strength, waterproofing and resistance against corrosion. Increase of compressive strength was observed from both addition of PP and micro-silica. PP resulted in an increase in compressive strength of 0,72 MPa, whereas addition of micro-silica caused an increase of 17,5 % compared to pure Sorel’s cement. Improvement of water-tightness was observed in both additions of PP and micro-silica. Weight loss of samples with PP addition to the concrete after a 7-day bath in an aggressive solution of 5% HCl was less than about 20%.

scholarly journals Pengaruh Konsentrasi Alginat Dengan Gliserol Sebagai Plasticizer Terhadap Sifat Fisik Dan Mekanik Bioplastik

2019 ◽  
Vol 8 (3) ◽  
pp. 314-321
Author(s):  
Novita Thea Puspita Langit ◽  
Ali Ridlo ◽  
Subagiyo Subagiyo
Keyword(s):  
Mechanical Properties ◽  
Weight Loss ◽  
Tensile Strength ◽  
Physical Properties ◽  
Water Resistance ◽  
Physical And Mechanical Properties ◽  
Packaging Materials ◽  
Biodegradable Packaging ◽  
Japanese Industrial Standard ◽  
Alginate Concentration

Munculnya permasalahan lingkungan akibat plastik sintetik mendorong perlunya penelitian bahan kemasan mudah terurai (bioplastik). Salah satu bahan yang tersedia di alam dan berpotensi sebagai pembentuk bioplastik adalah alginat karena mampu membentuk gel. Bioplastik dari alginat memiliki sifat yang tidak fleksibel sehingga perlu ditambah gliserol sebagai plasticizer. Penelitian ini bertujuan untuk mengetahui pengaruh konsentrasi alginat dari Sargassum sp. terhadap sifat fisik dan mekanik bioplastik dengan penambahan gliserol dan CaCl2. Materi penelitian ini adalah alginat hasil ekstraksi Sargassum sp. yang diambil dari Perairan Pantai Sundak, Gunung Kidul. Penelitian ini menggunakan metode eksperimental laboratoris yang terdiri dari empat perlakuan konsentrasi alginat (0,5%, 1%, 3% dan 5%)  dengan tiga pengulangan.  Sifat bioplastik yang diuji meliputi sifat fisik (ketebalan, ketahanan air, kehilangan berat) dan sifat mekanik (kuat tarik dan elongasi). Data yang diperoleh dianalisis menggunakan analisis sidik ragam (ANOVA). Hasil penelitian menunjukkan semakin tinggi konsentrasi alginat akan meningkatkan  ketebalan, ketahanan air dan kuat tarik bioplastik namun menurunkan elongasi dan kehilangan berat bioplastik. Konsentrasi alginat berpengaruh terhadap sifat fisik (ketebalan, ketahanan air, kehilangan berat) dan sifat mekanik (kuat tarik  kecuali elongasi), konsentrasi alginat terbaik yang memenuhi Japanese Industrial Standard dan standar SNI 7188.7:2016 adalah 0,5% The emergence of environmental problems due to synthetic plastics has led to the need to research biodegradable packaging materials (bioplastics). One of the ingredients available in nature and has the potential to form bioplastics is alginate because it is capable of forming gel. Bioplastic from alginate has inflexible properties so it needs to be added by glycerol as a plasticizer. This research aims to determine the effect of alginate concentration from Sargassum sp. on the physical and mechanical properties of bioplastics with the addition of glycerol and CaCl2. The method of this research is alginate from Sargassum sp. taken from Sundak Beach Waters, Gunung Kidul. This research used a laboratory experimental method consisting of four treatments of alginate concentration (0.5%, 1%, 3% and 5%) with three repetitions. The properties of the bioplastics tested included physical properties (thickness, water resistance, weight loss) and mechanical properties (tensile strength and elongation). Data obtained were analyzed using variance analysis (ANOVA). The results showed that the higher the concentration of alginate would increased thickness, water resistance and tensile strength of bioplastics but decreased the elongation and weight loss of bioplastics. The alginate concentration affects the physical properties (thickness, water resistance, weight loss) and mechanical properties (tensile strength and except elongation), the best alginate concentrations that meet the Japanese Industrial Standard and SNI 7188.7: 2016 are 0.5%

Producing Particleboard Using of Mixture of Bagasse and Industrial Wood Particles

2011 ◽  
Vol 471-472 ◽  
pp. 31-36 ◽  
Author(s):  
Taghi Tabarsa
Keyword(s):  
Mechanical Properties ◽  
Single Layer ◽  
Physical And Mechanical Properties ◽  
Raw Material ◽  
Press Temperature ◽  
The Core ◽  
Wood Particles ◽  
The Face ◽  
Particleboard Properties ◽  
Better Than

In this study feasibility of using of mixture of bagasse and industrial wood particles for producing single and three layer particleboard . The aim of this study was to consider bagasse as partially substitute particleboard industry raw material. Variables were type of board at two levels (single and three layer), percentage of added bagasse to industrial particles at 4 levels (20%,30%, 40% and 50%) , and press temp. at two levels (165OC and 180 OC ). In producing three layer particleboard wood and bagasse particles were separated and placed in different layers so that bagasse particles were located in the face layers and wood particles were placed in the core of board. But in one layer particleboard bagasse and wood particles were used in the form of mixture. Effect of variables on physical and mechanical properties of particleboard were determined. Results showed that in three layer particleboard physical and mechanical properties were better than single layer particleboard. Increasing press temperature caused improvement in particleboard properties in most cases due to intermeshing and increasing softening wood and bagasse particles. The optimum treatment in this study was found to be adding 50% bagasse and press temperature of 180 OC.

scholarly journals Size Effect of Core Strands on the Major Physical and Mechanical Properties of Oriented Strand Boards from Fast Growing Tropical Species

2021 ◽  
Author(s):  
Wan Mohd Nazri Wan Abdul Rahman ◽  
Nur Sakinah Mohamed Tamat ◽  
Nor Yuziah Mohd Yunus ◽  
Jamaludin Kasim
Keyword(s):  
Mechanical Properties ◽  
Physical And Mechanical Properties ◽  
Major Axis ◽  
Resin Content ◽  
Tropical Species ◽  
Thickness Swelling ◽  
Bending Properties ◽  
Board Density ◽  
Fast Growing ◽  
The Face

Oriented strand board (OSB) is generally used for sheathing in residential walls, floors, and roofs. Because of its low pricing and utilisation of tiny diameter logs from fast-growing trees and thinning logs as raw materials, OSB is anticipated to gain popularity. In chapter, board properties of OSB using smaller strand size of Leucaena leucocephala as core layer had been studied. Small strand size of S3 (length = 75 mm, width = 3.2 to 6.3 mm) was located in the middle layer of the board while bigger strand sizes of S1 (length = 75 mm, width = 12.7 to 19.0 mm) and S2 (length = 75 mm, width = 6.3 to 12.7 mm) were located at the face and back layers. Utilization of smaller strands (S3) in the middle layers may yield boards that have better physical and mechanical properties. Except for MOR in the minor axis, board density and resin content were shown to have a substantial impact on physical and mechanical properties. Except for MOR in the major axis, strand size had little affected on physical and mechanical properties. The effects of board density on mechanical properties were discovered to affect significantly different. With a positive correlation, board density had a significant effect on thickness swelling. Between S1+S3 and S2+S3 strand size, there is no significant effect on bending properties, internal bond strength and thickness swelling. The effect of resin content on bending properties revealed a significant difference of MOR in major axis, as well as MOE values in both major and minor axes. Even when the resin content was as low as 5%, all treatments of OSB passed the general requirement of general purpose OSB.

Functionally Graded MDP Panels Using Bamboo Particles

2015 ◽  
Vol 668 ◽  
pp. 39-47 ◽  
Author(s):  
Raquel Teodoro ◽  
Joabel Raabe ◽  
Danillo Wisky Silva ◽  
Rafael Farinassi Mendes ◽  
Lourival Marin Mendes ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Urea Formaldehyde ◽  
Physical And Mechanical Properties ◽  
Functionally Graded ◽  
Modulus Of Rupture ◽  
High Concentration ◽  
The Core ◽  
Pressing Time ◽  
The Face ◽  
The Impact

MDP (medium density particleboard) panels are normally graded in composition along their cross-section, using low-size particles and high concentration of adhesive on the particleboard surface (leading to improved physical and mechanical properties), and high-size particles in the particleboard core (interior), which provide higher porosity. Then, the aim of this study was to evaluate the impact of using different contents of bamboo particles in the particleboard core, on their physical and mechanical properties. The production of the panels was carried out using Pinusoocarpa (P) and Bambusavulgaris var. Vittata (B) particles in different contents (100% P, 100% B, 50% de B e 50% de P, 25% de B e 75% de P, 75% de B e 25% de P) in the core of the particleboards. The face of the particleboards were composed of P particles. The panels were produced with nominal density of 0.70 g/cm3, 40:60 face:core relation, 11% urea-formaldehyde adhesive in the faces and 8% adhesive for the core, specific pressure of 3.92 MPa, 160 °C temperature and pressing time of 8 min. After seasoning, the panels were submitted to evaluation of the thickness swelling (TS) and water absorption (WA) after 2 and 24 h of immersion, apparent density (AD), internal bonding (IB), modulus of rupture (MOR) and modulus of elasticity (MOE) under static bending. There was no statistical difference between the treatments for AD, IB, MOR and MOE values. Panels produced with high contents of bamboo particles (100% B, 75% B e 50% B) in the core, presented the lower WA and TS values, leading to improved dimensional stability than panels with only pinus particles. The present results show the important impact of using functionally gradation and bamboo particles on the physical properties of the MDP panels produced.

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