scholarly journals Sustainable Mortars for Application in the Cultural Heritage Field

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 598
Author(s):  
Michelina Monaco ◽  
Marianna Aurilio ◽  
Anna Tafuro ◽  
Mariateresa Guadagnuolo
Keyword(s):  
Mechanical Properties ◽  
Cultural Heritage ◽  
Mechanical Test ◽  
Mechanical Tests ◽  
Historical Study ◽  
Test Results ◽  
Lime Mortars ◽  
Different Types ◽  
Heritage Buildings ◽  
Italian Territory

A large part of the world’s architectural heritage is composed of masonry buildings located in seismic areas, and its vulnerability has been shown by the damage caused by the last earthquakes. Meeting the safety demands of cultural heritage buildings according to the performance-based seismic codes requires a deep knowledge of the mechanical properties of material components. Traditional mortars are among these. However, significant samples of structural mortars cannot be taken from existing masonry walls to perform mechanical tests, but tests can, alternatively, be conducted on samples realized according to traditional instructions for composition. Based on a historical study of mix proportions, this paper presents the results of a mechanical test campaign of traditional mortars. The samples were obtained combining lime and pozzolan according to the proportions derived from ancient treatises. The laboratory tests were performed taking into account three different types of limes, and a discussion involving the results presented in the literature is provided. Besides the contribution to fulfilling the lack of knowledge about the mechanical properties of traditional lime mortars, the test results are good references for on-site preparation of mortars for use in restoration. There is a focus on natural pozzolanic lime mortars, widely used in the Neapolitan area and, in general, in the whole Italian territory.

Rheological Flow Study of Molten Weld Metal Using the Modified Casson Prediction Model

2011 ◽  
Vol 403-408 ◽  
pp. 491-495
Author(s):  
Joseph I Achebo
Keyword(s):  
Shear Stress ◽  
Weld Metal ◽  
Prediction Model ◽  
Mechanical Test ◽  
Mechanical Tests ◽  
Test Results ◽  
Upward Flow ◽  
Viscoplastic Flow ◽  
Flow Equations ◽  
Flow Study

This paper principally examines the flow pattern that occurs when molten weld metal droplets are detached from globule formations at the tip of an electrode and are thereafter transported to the weldpool. This viscoplastic flow study was done using the modified Casson prediction model which is based on the Newtonian Homogenous Flow equations. Both chemical and mechanical tests were done. The inclusions (Slag) were found to possess an upward flow of 3 ms-1. The mechanical test results show that the shear stress of 483.2 MPa, which exceeded a yield stress of 230 MPa, was responsible for the continuous slipping movement of the molten metal towards the center of the weld pool at a velocity of 1.2ms-1. The results obtained by the application of this model were validated by both computational and experimental results obtained by other researchers.

scholarly journals Structure and mechanical properties of GR/UHMWPE nanocomposite ropes

2019 ◽  
Vol 131 ◽  
pp. 01127
Author(s):  
Wen Wen Yu ◽  
Jian Gao Shi ◽  
Yong Li Liu ◽  
Lei Wang
Keyword(s):  
Mechanical Properties ◽  
Melt Spinning ◽  
Mechanical Test ◽  
Reactive Extrusion ◽  
Breaking Load ◽  
Hot Water ◽  
Test Results ◽  
Screw Extruder ◽  
Elongation At Break ◽  
Ultra High Molecular Weight

Ultra-high molecular weight polyethylene (UHMWPE) and graphene (GR) was melt compounded by reactive extrusion. Nanocomposite monofilaments were prepared by melt spinning through a co-rotating screw extruder and drawing at hot water. GR/UHMWPE nanocomposite ropes were twisted using nanocomposite monofilaments. A structure and mechanical properties of the GR/UHMWPE nanocomposite monofilaments and its ropes had been characterized by scanning electron microscopy (SEM), and mechanical test. Results showed that the monofilaments surface of monofilaments became rougher with introducing of GR nanosheets, which could be related to stacking of GR. The breaking load of GR/UHMWPE nanocomposite ropes was remarkably improved upon nanofiller addition, with the decrease of the elongation at break.

scholarly journals Mechanical Performance of Unstitched and Silk Fiber-Stitched Woven Kenaf Fiber-Reinforced Epoxy Composites

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4801
Author(s):  
Yasir Khaleel Kirmasha ◽  
Mohaiman J. Sharba ◽  
Zulkiflle Leman ◽  
Mohamed Thariq Hameed Sultan
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Mechanical Performance ◽  
Mechanical Test ◽  
Natural Fibers ◽  
Silk Fiber ◽  
Epoxy Composites ◽  
Test Results ◽  
The Impact ◽  
Woven Kenaf

Fiber composites are known to have poor through-thickness mechanical properties due to the absence of a Z-direction binder. This issue is more critical with the use of natural fibers due to their low strength compared to synthetic fibers. Stitching is a through-thickness toughening method that is used to introduce fibers in the Z-direction, which will result in better through-thickness mechanical properties. This research was carried out to determine the mechanical properties of unstitched and silk fiber-stitched woven kenaf-reinforced epoxy composites. The woven kenaf mat was stitched with silk fiber using a commercial sewing machine. The specimens were fabricated using a hand lay-up method. Three specimens were fabricated, one unstitched and two silk-stitched with deferent stitching orientations. The results show that the stitched specimens have comparable in-plane mechanical properties to the unstitched specimens. For the tensile mechanical test, stitched specimens show similar and 17.1% higher tensile strength compared to the unstitched specimens. The flexural mechanical test results show around a 9% decrease in the flexural strength for the stitched specimens. On the other hand, the Izod impact mechanical test results show a significant improvement of 33% for the stitched specimens, which means that stitching has successfully improved the out-of-plane mechanical properties. The outcome of this research indicates that the stitched specimens have better mechanical performance compared to the unstitched specimens and that the decrease in the flexural strength is insignificant in contrast with the remarkable enhancement in the impact strength.

scholarly journals Mechanical properties of highly porous PEEK bionanocomposites incorporated with carbon and hydroxyapatite nanoparticles for scaffold applications

2019 ◽  
Vol 8 (3) ◽  
pp. 211-221 ◽  
Author(s):  
Md. Nizam Uddin ◽  
Puttagounder S. Dhanasekaran ◽  
Ramazan Asmatulu
Keyword(s):  
Mechanical Properties ◽  
Bone Regeneration ◽  
Pore Size ◽  
Mechanical Tests ◽  
Bone Diseases ◽  
Filler Materials ◽  
Test Results ◽  
Micro Computed Tomography ◽  
Carbon Particles ◽  
Highly Porous

Abstract Bone regeneration is of great importance worldwide, because of various bone diseases, such as infections, tumors, and resultant fracture, birth defects, and bone loss due to trauma, explosion, or accident. Bone regeneration can be achieved by several materials and templates manufactured through various fabrication techniques. Uses of different materials and scaffold fabrication techniques have been explored over the past 20 years. In this research, polyetheretherketone (PEEK) was used to fabricate highly porous bionanocomposite foams for bone scaffolding. Melt casting and salt porogen (200–500 µm size) leaching methods were adapted to create an adequate pore size and the necessary percent of porosity, because pore size plays a vital role in cell implantation and growth. Porosity (75% and 85%) of the prepared scaffolds was adjusted by changing salt concentrations in the PEEK powder. Hydroxyapatite (HA) and carbon particles were used to improve cell attachments and interactions with the porous PEEK and to increase the mechanical properties of the scaffold materials. Carbon fiber (CF) and carbon nanotubes (CNTs) were uniformly dispersed into the PEEK powder before melt casting to enhance the mechanical properties and to observe the influence of the carbon particles on the properties of PEEK bionanocomposite foam. Compression test results of the fabricated bionanocomposites showed that HA and carbon particles are the potential filler materials for the enhancement of bionanocomposite mechanical properties. About 186% enhancement of compression modulus and 43% enhancement of yield strength were observed while incorporating only 0.5 wt% of CNTs into PEEK/HA bionanocomposites having 75% porosity, compared to PEEK/HA 20 wt% bionanocomposites. Micro-computed tomography (micro-CT) test results reveal that pore size and interconnectivity of the nanocomposite foams are in order and within the designed sizes. Mechanical tests proved that PEEK bionanocomposite foam has the potential for use in bone scaffolding and other biomedical applications.

Experimental Analysis of Interlocking Load Bearing Wall Brickool System

2013 ◽  
Vol 594-595 ◽  
pp. 439-443 ◽  
Author(s):  
S.A. Osman ◽  
Zawawi Samba Mohamed ◽  
A.R. Sulaiman ◽  
M. Fikri Ismail
Keyword(s):  
Experimental Analysis ◽  
Failure Load ◽  
Mechanical Test ◽  
Mechanical Tests ◽  
Structural Behavior ◽  
Test Results ◽  
Wall Panel ◽  
Load Bearing ◽  
Minimum Requirement ◽  
The Individual

This paper presents the results of investigation on structural behavior of the load bearing walls of interlocking bricks system called Brickcool. The model of Brickcool load bearing walls with and without reinforcement were tested in the laboratory until they failed. Both models were prepared with the same dimension of 1.3 m height, 1.0 m wide and 125 mm width. The influence of reinforcement on the deflection and strain of the load bearing walls were examined. Physical and mechanical tests of the individual brick were also been carried out. Results of this study proved that the model of load bearing wall with reinforcement have higher failure load with lower displacement at the top of the wall. The presence of reinforcement in strengthening the wall panel also increase the compression and tension strain compared to the wall panel without reinforcement. The physical and mechanical test results also found that the bricks have satisfied the minimum requirement values set by the British and American Standards.

scholarly journals Mechanical Properties of Fly Ash Polymer Concrete with Different Fibers

2018 ◽  
Vol 55 (3) ◽  
pp. 405-409 ◽  
Author(s):  
Marinela Barbuta ◽  
Alexandru Timu ◽  
Liliana Bejan ◽  
Roxana Dana Bucur
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Polymer Concrete ◽  
Test Results ◽  
Material Industry ◽  
Split Tensile Strength ◽  
Building Material Industry ◽  
Concrete Properties ◽  
Different Types ◽  
General Demand

The experimental results obtained by studying the influence of different types of fibers on the mechanical properties of fly ash polymer concrete are presented in the paper. The general demand of using wastes found applicability in building material industry because some of them are beneficial in improving concrete properties. The waste additions type fly ash and fibers were incorporated in polymer concrete. The study focused on fibers type glass, polyester, metallic and cellulose. The mechanical properties such as compressive strength, flexural strength and split tensile strength were investigated having in view the type, dosage and length of fibers. The results show that fibers improved mechanical properties in comparison with that of polymer concrete without fibers, the test results being differently influenced by the factors which were considered.

scholarly journals MECHANICAL CHARACTERISTICS FOR COMPOSITE MATERIALS USING COMMERCIAL EPOXY RESINS AND DIFFERENT FILLERS

2021 ◽  
Vol 56 (5) ◽  
pp. 179-185
Author(s):  
Omar A. Amin ◽  
S. A. Hassan ◽  
M. A. Sadek ◽  
M. A. Radwan ◽  
Hany A. Elazab
Keyword(s):  
Mechanical Properties ◽  
Epoxy Resin ◽  
Epoxy Resins ◽  
Three Dimensional ◽  
Mechanical Tests ◽  
Diglycidyl Ether ◽  
Dimensional Structure ◽  
Polymeric Chain ◽  
Hydroxyl Groups ◽  
Different Types

Epoxy resins are thermoset polymers that consist of epoxide groups in their molecular structure. It shows many attractive characteristics like strong adhesion, excellent mechanical strength, low shrinkage, excellent insulator, excellent chemical stability for acidic and basic environments, and microbial resistance due to the presence of hydroxyl groups and ether bonds and its three-dimensional structure. Many of these characteristics can be modified by adding strong bindings in the polymeric chain to give more improved characteristics. This research aims to prepare a composite material using epoxy resin and different types of fillers to achieve resistance to high kinetic energy impact. Experimental work is focused on preparing cured epoxy resin samples by using diglycidyl ether of bisphenol A (DGEBA) resin with tertiary amine as a hardener. In order to obtain different samples with different properties, we add different types of fillers, then mechanical tests are used to measure the mechanical properties of the samples. The results have proved that fiberglass is the best filler added to epoxy resins to improve its mechanical properties.

scholarly journals Evaluation of the mechanical characteristics of hygrothermally aged 2-D basalt-aramid/epoxy hybrid interply composites

2021 ◽  
Vol 2070 (1) ◽  
pp. 012234
Author(s):  
Yogeesha Pai ◽  
Dayananda Pai K ◽  
M Vijaya Kini
Keyword(s):  
Mechanical Properties ◽  
Moisture Absorption ◽  
Mechanical Performance ◽  
Mechanical Tests ◽  
Moisture Uptake ◽  
Molding Process ◽  
Micro Cracks ◽  
Different Types ◽  
Temperature Ageing ◽  
Saturation Absorption

Abstract Polymer composites used in outdoor applications are exposed to environmental factors such as temperature and moisture which may affect the mechanical performance of the composites. In this study, the influence of moisture absorption on the mechanical properties of basalt-aramid/epoxy hybrid interply composites were evaluated. Two different types hybrid interply composites were taken for the investigation namely (301 A/03 B/301 A) and (451 A/03B/451 A). Composites were prepared using compression molding process and cut specimens were subjected to three different ageing environments for 180 days. Selected ageing conditions are, (i) ambient temperature ageing (ii) Sub-zero temperature ageing (−10°C) and (iii) Humid temperature ageing (40°C and 60% Relative humidity). Mechanical tests of the aged composites were carried out to analyse the behaviour of the composites. Moisture uptake of the specimens follow Fick’s law of diffusion with saturation absorption of 5.44%, 3.12% and 1.80% for ambient, sub-zero and humid specimens respectively. Results revealed that (301 a/03 B/301 a) aged composites possess higher mechanical properties compared to (451 a/03 B/451 a) aged composites. Highest reduction in properties were observed in ambient aged specimens followed by humid and sub-zero specimens. Scanning electron microscopy (SEM) was employed to observe the damage modes of the fractured specimens. Matrix deterioration, micro cracks and fibre fracture were the major types of failures observed in aged laminates.

scholarly journals Nanoclay and Water Uptake Effects on Mechanical Properties of Unsaturated Polyester

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Necar Merah ◽  
Omer Mohamed
Keyword(s):  
Mechanical Properties ◽  
Water Uptake ◽  
Unsaturated Polyester ◽  
Flexural Properties ◽  
Test Results ◽  
Flexural Testing ◽  
Organically Modified ◽  
Different Types ◽  
Shear Mixing ◽  
Maximum Improvement

Unsaturated polyester/nanoclay (UP/NC) composites were developed using an optimized process, which combines high shear mixing (HSM) and ultrasonication. Different types of organically modified nanoclays (Cloisites 10A and 20A and Nanomer I.30E) were considered with I.30E resulting in the best morphology with an exfoliated structure. This and the higher aspect ratio of I.30E lead to its better performance under tensile and flexural testing. Different loadings of I.30E (0, 1, 2, 3, and 4 wt%) were thus used to manufacture UP/NC nanocomposites and test their resistance to water uptake as well as the moisture ingress effects on their mechanical properties. The results showed that the addition of I.30E nanoclay enhanced the hydrophobicity of the nanocomposite with a maximum improvement of about 40% at 4 wt% of NC loading. Flexural test results revealed relative degradation in the flexural properties of neat UP and UP/NC, due to moisture uptake. However, the reduction in flexural properties was found to be minimal at the optimum nanoclay loading of 3 wt%.

Experimental Study on Mechanical Properties of Jurassic Soft Rock in Shajihai Mining Area of Xinjiang

2013 ◽  
Vol 353-356 ◽  
pp. 20-23
Author(s):  
Xiao Lei Wang ◽  
Shun Xi Yan ◽  
Guang Can Zhang
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Compression Test ◽  
Mechanical Test ◽  
Triaxial Compression ◽  
Soft Rock ◽  
Mining Area ◽  
Surrounding Rock ◽  
Test Results ◽  
Support Design

According to the problemsof serious deformation of soft rock roadways and lack of system andcomprehensive study on surrounding rock characteristics and failure mechanismin Shajihai mining area, this paper carried out a series of mechanicalexperiments on the characteristics of surrounding rock in this area includinguniaxial compression test, triaxial compression test and water absorption propertiestest. Mechanical test results show that the compressive strength of surroundingrock of roadway is generally low, and mudstone compressive strength is thelargest which is 19.23 MPa, and compressive strength of the minimum is coalwhich is 11.32 MPa under natural condition. However sandstone and mudstone’sability of water absorbing is strong, and coal saturation strength issignificantly greater than that of mudstone and sandstone. Therefore, we shouldmake full use of the strength of coal in roadway layout and support design.

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