Experimental behavior of injected geopolymer grout using styrene-butadiene latex for the repair and strengthening of masonry walls

2021 ◽  
pp. 136943322110015
Author(s):  
Muslum Murat Maras
Keyword(s):  
Failure Mode ◽  
High Viscosity ◽  
Masonry Wall ◽  
Alkali Activation ◽  
Compression Tests ◽  
Repair Materials ◽  
Bonding Failure ◽  
Structural Impacts ◽  
Styrene Butadiene ◽  
The Impact

Unreinforced masonry buildings in the historic centers of the world have often been overlooked for centuries without any protection. These buildings demonstrate low resistance under external effects, especially against earthquakes. Earthquakes cause serious damage to the buildings and even the collapse of structures as a result of seismic stimulation from the impact of pounding with structural impacts. For this reason, it is of great importance to repair and strengthen damaged masonry structures. This study investigated the testing of masonry wall specimens produced from different kinds of masonry units with various types of mortar. Then, geopolymer grouts with high mechanical properties were produced by using alkali activation and industrial products. The experimental performance of strengthened masonry wall samples was determined using the optimum geopolymer grout in vertical compression tests. The behavior, failure mode, and crack pattern of the masonry wall samples were determined under loading systems. Experimental results demonstrate that the use of additive styrene-butadiene (SB) latex geopolymer grouts on damaged walls increased the load-carrying capacity and ductility significantly compared to the corresponding values of samples before initial failure. All of the strengthened walls failed through the de-bonding failure mode, and no visible damage was observed on the samples. Consequently, geopolymer grouts displayed many advantages over conventional repair materials due to their high viscosity, compressive strength, eco-friendliness, and excellent resistance.

scholarly journals Lightweight Cement Conglomerates Based on End-of-Life Tire Rubber: Effect of the Grain Size, Dosage and Addition of Perlite on the Physical and Mechanical Properties

Materials ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 225
Author(s):  
Andrea Petrella ◽  
Michele Notarnicola
Keyword(s):  
Grain Size ◽  
End Of Life ◽  
Compression Tests ◽  
Tire Rubber ◽  
Impact Compression ◽  
Weight Percentage ◽  
Deep Groove ◽  
Mechanical Strengths ◽  
The Impact ◽  
Thermal Conductivities

Lightweight cement mortars containing end-of-life tire rubber (TR) as aggregate were prepared and characterized by rheological, thermal, mechanical, microstructural, and wetting tests. The mixtures were obtained after total replacement of the conventional sand aggregate with untreated TR with different grain sizes (0–2 mm and 2–4 mm) and distributions (25%, 32%, and 40% by weight). The mortars showed lower thermal conductivities (≈90%) with respect to the sand reference due to the differences in the conductivities of the two phases associated with the low density of the aggregates and, to a minor extent, to the lack of adhesion of tire to the cement paste (evidenced by microstructural detection). In this respect, a decrease of the thermal conductivities was observed with the increase of the TR weight percentage together with a decrease of fluidity of the fresh mixture and a decrease of the mechanical strengths. The addition of expanded perlite (P, 0–1 mm grain size) to the mixture allowed us to obtain mortars with an improvement of the mechanical strengths and negligible modification of the thermal properties. Moreover, in this case, a decrease of the thermal conductivities was observed with the increase of the P/TR dosage together with a decrease of fluidity and of the mechanical strengths. TR mortars showed discrete cracks after failure without separation of the two parts of the specimens, and similar results were observed in the case of the perlite/TR samples thanks to the rubber particles bridging the crack faces. The super-elastic properties of the specimens were also observed in the impact compression tests in which the best performances of the tire and P/TR composites were evidenced by a deep groove before complete failure. Moreover, these mortars showed very low water penetration through the surface and also through the bulk of the samples thanks to the hydrophobic nature of the end-of-life aggregate, which makes these environmentally sustainable materials suitable for indoor and outdoor elements.

scholarly journals Damage Evolution of Granodiorite after Heating and Cooling Treatments

Minerals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 779
Author(s):  
Mohamed Gomah ◽  
Guichen Li ◽  
Salah Bader ◽  
Mohamed Elkarmoty ◽  
Mohamed Ismael
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Failure Mode ◽  
Physical And Mechanical Properties ◽  
P Wave ◽  
Physical Parameters ◽  
Slow Cooling ◽  
Heating And Cooling ◽  
Natural Rock ◽  
The Impact

The awareness of the impact of high temperatures on rock properties is essential to the design of deep geotechnical applications. The purpose of this research is to assess the influence of heating and cooling treatments on the physical and mechanical properties of Egyptian granodiorite as a degrading factor. The samples were heated to various temperatures (200, 400, 600, and 800 °C) and then cooled at different rates, either slowly cooled in the oven and air or quickly cooled in water. The porosity, water absorption, P-wave velocity, tensile strength, failure mode, and associated microstructural alterations due to thermal effect have been studied. The study revealed that the granodiorite has a slight drop in tensile strength, up to 400 °C, for slow cooling routes and that most of the physical attributes are comparable to natural rock. Despite this, granodiorite thermal deterioration is substantially higher for quick cooling than for slow cooling. Between 400:600 °C is ‘the transitional stage’, where the physical and mechanical characteristics degraded exponentially for all cooling pathways. Independent of the cooling method, the granodiorite showed a ductile failure mode associated with reduced peak tensile strengths. Additionally, the microstructure altered from predominantly intergranular cracking to more trans-granular cracking at 600 °C. The integrity of the granodiorite structure was compromised at 800 °C, the physical parameters deteriorated, and the rock tensile strength was negligible. In this research, the temperatures of 400, 600, and 800 °C were remarked to be typical of three divergent phases of granodiorite mechanical and physical properties evolution. Furthermore, 400 °C could be considered as the threshold limit for Egyptian granodiorite physical and mechanical properties for typical thermal underground applications.

scholarly journals Analysis of the Impact on the Mechanical Properties of Modification of Oligohydroxyethers in Organic Solvent Solution with Rubbers

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 519
Author(s):  
Vitalii Bezgin ◽  
Agata Dudek ◽  
Adam Gnatowski
Keyword(s):  
Mechanical Properties ◽  
Scientific Paper ◽  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Molecular Weights ◽  
Wide Range ◽  
Strength Tests ◽  
Materials Used ◽  
Styrene Butadiene ◽  
The Impact

This paper proposes and presents the chemical modification of linear hydroxyethers (LHE) with different molecular weights (380, 640, and 1830 g/mol) with the addition of three types of rubbers (polysulfide rubber (PSR), polychloroprene rubber (PCR), and styrene-butadiene rubber (SBR)). The main purpose of choosing this type of modification and the materials used was the possibility to use it in industrial settings. The modification process was conducted for a very wide range of modifier additions (rubber) per 100 g LHE. The materials obtained in the study were subjected to strength tests in order to determine the effect of the modification on functional properties. Mechanical properties of the modified materials were improved after the application of the modifier (rubber) to polyhydroxyether (up to certain modifier content). The most favorable changes in the tested materials were registered in the modification of LHE-1830 with PSR. In the case of LHE-380 and LHE-640 modified in cyclohexanol (CH) and chloroform (CF) solutions, an increase in the values of the tested properties was also obtained, but to a lesser extent than for LHE-1830. The largest changes were registered for LHE-1830 with PSR in CH solution: from 12.1 to 15.3 MPa for compressive strength tests, from 0.8 to 1.5 MPa for tensile testing, from 0.8 to 14.7 MPa for shear strength, and from 1% to 6.5% for the maximum elongation. The analysis of the available literature showed that the modification proposed by the authors has not yet been presented in any previous scientific paper.

Toughening of Polypropylene-Ethylene Copolymer with Nanosized CaCO3 and Styrene-Butadiene-Styrene

2007 ◽  
Vol 121-123 ◽  
pp. 1451-1454
Author(s):  
Jian Feng Chen ◽  
Guo Quan Wang ◽  
Xiao Fei Zeng ◽  
Hong Ying Zhao
Keyword(s):  
Average Particle Size ◽  
Average Particle ◽  
Single Screw Extruder ◽  
Roll Mill ◽  
The Matrix ◽  
Ethylene Copolymer ◽  
Styrene Butadiene Styrene ◽  
Styrene Butadiene ◽  
The Impact ◽  
Butadiene Styrene

Nanocomposites of nanosized-CaCO3/polypropylene-ethylene copolymer (PPE) and nanosized CaCO3/ PPE/ styrene-butadiene-styrene (SBS) were prepared by using two-roll mill and single screw extruder. The average particle size of nanosized CaCO3 was determined to be about 30 nm. By adding nanosized CaCO3 into PPE matrix, the toughness of the matrix improves significantly. At nanosized CaCO3 content of 12 phr (parts per hundred PPE resin by weight), the impact strength of CaCO3/PPE at room temperature reaches 61.6 KJ/m2, which is 3.02 times that of unfilled PPE matrix. In addition, the synergistic toughening effect of nanosized CaCO3 and SBS particles on PPE matrix was investigated.

scholarly journals Axial compression behavior of concrete masonry wallettes strengthened with cement mortar overlays

2008 ◽  
Vol 1 (2) ◽  
pp. 158-170 ◽  
Author(s):  
F. L. De Oliveira ◽  
J. B. De Hanai
Keyword(s):  
Axial Compression ◽  
Cement Mortar ◽  
High Strength ◽  
Concrete Block ◽  
Masonry Wall ◽  
Compression Tests ◽  
Steel Mesh ◽  
Mortar Strength ◽  
Theoretical Approaches ◽  
Wall Strength

This paper presents the results of a series of axial compression tests on concrete block wallettes coated with cement mortar overlays. Different types of mortars and combinations with steel welded meshes and fibers were tested. The experimental results were discussed based on different theoretical approaches: analytical and Finite Element Method models. The main conclusions are: a) the application of mortar overlays increases the wall strength, but not in a uniform manner; b) the strengthening efficiency of wallettes loaded in axial compression is not proportional to the overlay mortar strength because it can be affected by the failure mechanisms of the wall; c) steel mesh reinforced overlays in combination with high strength mortar show better efficiency, because the steel mesh mitigates the damage effects in the block wall and in the overlays themselves; d) simplified theoretical methods of analysis as described in this paper can give satisfactory predictions of masonry wall behavior up to a certain level.

On the Impact of Liquid Drops on Immiscible Liquids

2016 ◽  
Author(s):  
Eduardo Castillo-Orozco ◽  
Ashkan Davanlou ◽  
Pretam K. Choudhury ◽  
Ranganathan Kumar
Keyword(s):  
Oil Spills ◽  
Silicone Oil ◽  
Density Ratio ◽  
High Viscosity ◽  
Impact Behavior ◽  
Immiscible Fluid ◽  
Liquid Droplets ◽  
Liquid Drops ◽  
Low Viscosity ◽  
The Impact

The release of liquid hydrocarbons into the water is one of the environmental issues that have attracted more attention after deepwater horizon oil spill in Gulf of Mexico. The understanding of the interaction between liquid droplets impacting on an immiscible fluid is important for cleaning up oil spills as well as the demulsification process. Here we study the impact of low-viscosity liquid drops on high-viscosity liquid pools, e.g. water and ethanol droplets on a silicone oil 10cSt bath. We use an ultrafast camera and image processing to provide a detailed description of the impact phenomenon. Our observations suggest that viscosity and density ratio of the two media play a major role in the post-impact behavior. When the droplet density is larger than that of the pool, additional cavity is generated inside the pool. However, if the density of the droplet is lower than the pool, droplet momentary penetration may be facilitated by high impact velocities. In crown splash regime, the pool properties as well as drop properties play an important role. In addition, the appearance of the central jet is highly affected by the properties of the impacting droplet. In general, the size of generated daughter droplets as well as the thickness of the jet is reduced compared to the impact of droplets with the pool of an identical fluid.

scholarly journals ANALISIS FAILURE MODE EFFECT (FMEA) PADA PENGADAAN OBAT DAN PERBEKALAN KESEHATAN PADA ERA JAMINAN KESEHATAN NASIONAL DI PUSKESMAS WONOKROMO SURABAYA

2021 ◽  
Vol 5 (1) ◽  
pp. 47-56
Author(s):  
Nuning Farida ◽  
Amelia Lorensia ◽  
Budhi Setianto ◽  
Agus Aan Adriansyah
Keyword(s):  
Health Center ◽  
Failure Mode ◽  
Health Centre ◽  
Government Procurement ◽  
Public Healthcare ◽  
Regional Government ◽  
Pharmaceutical Supply Chain ◽  
Drug Procurement ◽  
Mode Effect ◽  
The Impact

Drug services in Public Healthcare are an important component whose availability influences the success of health efforts. District / City Health Office is a regional government work unit in the health sector, one of the tasks and authorities of which is to provide and manage public medicines for the district/city area. Effective pharmaceutical management in health service facilities is very important for patient welfare so risks must be identified and controlled. One of the efforts made by the City Health Office is to procure drugs using other methods that are legal according to government procurement of goods/services besides e-purchasing, which is called non-e-purchasing of drugs. Risks in the pharmaceutical supply chain are related to product discontinuity, product shortages, poor performance, patient safety, expense errors, and technological errors, all of which can result in system disruption. This study aims to determine the suitability of the plan with the realization of e- purchasing of drugs, identify problems that hamper the implementation of e-purchasing of drugs, determine the impact of obstacles on procurement, cost efficiency of drug procurement and determine the potential savings of drug procurement by e-purchasing for the period 2015 to 2019 by using the FMEA method, the e-purchasing data was collected at the Wonokromo Public Health Center in Surabaya. Study Failure Mode Effect (FMEA) in the procurement of drugs and UHC health supplies in Surabaya Wonokromo Health Center for the period of 2015-2019, it can be concluded that the absorption of capitation funds is more considered using the availability variable compared to the uptake of funds based on the rupiah value because the availability of more guarantees the need for treatment in the sustainable health centre. In this case, the perception of procurement actors in the analysis of UHC procurement process obstacles there are 41 obstacles, the role of E-purchasing is a very helpful system even though the implementation has not been perfect.

scholarly journals PENGARUH PELARUT (ETIL BENZENA), PERBANDINGAN STYRENE BUTADIENE RUBBER (SBR) TERHADAP STIREN, DAN JUMLAH INISIATOR (BPO) PADA PEMBUATAN HIGH IMPACT POLYSTYRENE (HIPS)

2010 ◽  
Vol 2 (2) ◽  
Author(s):  
Dwi Wahyuni
Keyword(s):  
Impact Strength ◽  
High Heat ◽  
High Impact ◽  
Styrene Butadiene Rubber ◽  
Ethyl Benzene ◽  
Butadiene Rubber ◽  
High Impact Polystyrene ◽  
Aerospace Material ◽  
Styrene Butadiene ◽  
The Impact

High impact polystyrene (HIPS) is the widely used material now, and also for the aerospace material as a communication instrument system and an electrical insulation. In order to produce HIPS, there are a view method which can be executed. In this case, the research is executed by the copolymerization processes of styrene butadiene rubber (SBR) solution in styrene. Variables which influence to the result properties (HIPS) are the SBR to styrene ratio, the solvent (ethyl benzene), the benzoyl peroxide initiator (BPO). The properties of the product are tensile strength, impact strength, softening point, melting point and the hardness. The result showed that the properties of the HIPS product was near of the HIPS high heat. The optimal processes condition was the solvent to the styrene monomer ratio was 0.05492, the SBR to the styrene ratio was 0.1236 and the BPO to the styrene ratio was 0,0003. The properties of the HIPS product were: the impact strength was (519-1215) N per cm, the tensil strength not more than was 106 N per cm, the elongation was (36-54) percent and the hardness was (65-69) shore A. This properties achieved at the mixing polymerization processes 4 scale in 11-12 hours, the early mixing at 4 scale 1 hours, the cutting chain 2 drops.

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