scholarly journals The Influence of the Aircraft Operating Fluids on the Mechanical Parameters of the Airport Surface Concrete

Materials ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3081 ◽  
Author(s):  
Wojciech Żebrowski ◽  
Paweł Wolka ◽  
Marzena Kurpinska
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Mechanical Parameters ◽  
Cement Concrete ◽  
Concrete Properties ◽  
Airport Pavement ◽  
Compressive Strength Of Concrete ◽  
Student’S T ◽  
The Impact ◽  
Student’S T Test

The authors of the article assessed the impact of operating fluids used to service aircraft on changing mechanical parameters of cement concrete intended for airport pavement. The research concerned concrete designed with the use of CEM I 42.5N LH NA low-alkali cement, broken granite aggregate, fine washed aggregate, and admixtures. The analysis included the assessment of changes in differences in endurance parameters over various research periods of up to 140 days. The obtained results allowed to carry out statistical analysis using the student’s T-test. Research has shown a significant impact of operational fluids used in aircraft on the surface concrete properties of the airport. A reduction in the compressive strength of concrete exposed to one of the tested operating liquid to a reduction of 7.2% was observed over a period of 140 days, while there was no significant impact of operating fluids on tensile strength at splitting.

scholarly journals Effects of a New Type of Shrinkage-Reducing Agent on Concrete Properties

Materials ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 3018 ◽  
Author(s):  
Mari Masanaga ◽  
Tsuyoshi Hirata ◽  
Hirokatsu Kawakami ◽  
Yuka Morinaga ◽  
Toyoharu Nawa ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Reducing Agent ◽  
Splitting Tensile Strength ◽  
Freezing And Thawing ◽  
Shrinkage Cracking ◽  
Air Voids ◽  
Concrete Properties ◽  
The Impact ◽  
Shrinkage Reducing Agent

Shrinkage-reducing agents have been developed to mitigate shrinkage and to control cracks in concrete. This study aims to evaluate the impact of a newly developed shrinkage-reducing agent (N-SRA) on concrete properties and to compare its properties with a conventional shrinkage-reducing agent (C-SRA). The hydration rate, compressive strength, splitting tensile strength, shrinkage, occurrence of cracking, and freezing and thawing were investigated. N-SRA showed higher surface tension than C-SRA and reduced shrinkage to the same degree as C-SRA with half the dosage of C-SRA. The addition of N-SRA or C-SRA did not influence the early compressive strength but slightly reduced splitting tensile strength at seven days. Concrete with N-SRA showed higher compressive strength at 28 days than those of concrete with C-SRA or without SRA. Furthermore, concrete with N-SRA extended the period for the occurrence of shrinkage cracking under restrained conditions. It was found that N-SRA provided excellent freezing and thawing resistance because of the formation of good air voids, while C-SRA demonstrated inefficient behaviour in such an environment.

scholarly journals Effect of Replacing Cement with Factory Waste (Steel, Aluminum and Copper) on the Compressive Strength of Concrete

2019 ◽  
Vol 13 (4) ◽  
pp. 114
Author(s):  
Hesham Alsharie
Keyword(s):  
Compressive Strength ◽  
Cement Mortar ◽  
Cementitious Material ◽  
Cement Concrete ◽  
Supplementary Cementitious Material ◽  
Concrete Properties ◽  
Concrete Cylinders ◽  
Negative Effect ◽  
Compressive Strength Of Concrete ◽  
Original Strength

The steel, aluminum and copper waste from the factories has a negative effect on the environment. This study investigates the possible reuse of steel, aluminum and copper waste as a supplementary cementitious material and its effect on concrete properties. This paper proposes a model for the prediction of the compressive strength of cement concrete and mortar as the cement was replaced with steel, aluminum and copper waste with the following by weight percentages: 0%, 5%, 10%, and 15%.The tests performed in this paper are conducted to the following samples: (50 * 50 * 50 mm) mortar samples, (150 * 150 * 150 mm) concrete cubes, and (150 * 300 mm) concrete cylinders. Tests are performed at the periods of 7 and 28 days. The results show that the use of steel waste (Fe15%) increased compressive strength of concrete by 18.5% and copper waste by (Cu15%) increased it by 15.77%, aluminum (Al15%) increased it by 12.95% and steel waste (Fe15%) increases compressive strength of cement mortar by 9.55% as compared to pure mixing. Consequently, adding steel waste to concrete gives it a compressive strength of more than the double of its original strength.

Study on Rubber Particles Modified Concrete

2013 ◽  
Vol 477-478 ◽  
pp. 953-958 ◽  
Author(s):  
Lei Wang ◽  
Yan Hua Huang
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Elastic Modulus ◽  
Apparent Density ◽  
Splitting Tensile Strength ◽  
Cement Concrete ◽  
Concrete Properties ◽  
Rubber Particles

After rubber particles are incorporated into ordinary cement concrete, properties of concrete are changed. Specifically, by comparison with concrete without rubber particles, it reduces that the collapsed slump, apparent density, cubic compressive strength, splitting tensile strength and elastic modulus of rubber particles modified concrete. And when less than 50% of sand is replaced by rubber particles, rubber modified concrete can meet requirements of workability. Besides, its self-weight decreases, which is favorable for its structure to resist earthquakes.

Variasi Penambahan Sika Cim Dan Fiber Kawat Pada Beton Mutu Fc’ 30 Mpa

2018 ◽  
Vol 9 (2) ◽  
pp. 67-73
Author(s):  
M Zainul Arifin
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Curing Temperature ◽  
Test Results ◽  
Concrete Compressive Strength ◽  
Normal Concrete ◽  
Astm Method ◽  
Additive Type ◽  
Composition Variation ◽  
Compressive Strength Of Concrete

This research was conducted to determine the value of the highest compressive strength from the ratio of normal concrete to normal concrete plus additive types of Sika Cim with a composition variation of 0.25%, 0.50%, 0.75%, 1.00%, 1.25%, 1 , 50% and 1.75% of the weight of cement besides that in this study also aims to find the highest tensile strength from the ratio of normal concrete to normal concrete in the mixture of sika cim composition at the highest compressive strength above and after that added fiber wire with a size diameter of 1 mm in length 100 mm with a ratio of 1% of material weight. The concrete mix plan was calculated using the ASTM method, the matrial composition of the normal concrete mixture as follows, 314 kg / m3 cement, 789 kg / m3 sand, 1125 kg / m3 gravel and 189 liters / m3 of water at 10 cm slump, then normal concrete added variations of the composition of sika cim 0.25%, 0.50%, 0.75%, 1.00%, 1.25%, 1.5%, 1.75% by weight of cement and fiber, the tests carried out were compressive strength of concrete and tensile strength of concrete, normal maintenance is soaked in fresh water for 28 days at 30oC. From the test results it was found that the normal concrete compressive strength at the age of 28 days was fc1 30 Mpa, the variation in the addition of the sika cim additive type mineral was achieved in composition 0.75% of the cement weight of fc1 40.2 Mpa 30C. Besides that the tensile strength test results were 28 days old with the addition of 1% fiber wire mineral to the weight of the material at a curing temperature of 30oC of 7.5%.

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 Towards Sustainable Concrete Composites through Waste Valorisation of Plastic Food Trays as Low-Cost Fibrous Materials

2021 ◽  
Vol 13 (4) ◽  
pp. 2073 ◽  
Author(s):  
Hossein Mohammadhosseini ◽  
Rayed Alyousef ◽  
Mahmood Md. Tahir
Keyword(s):  
Compressive Strength ◽  
Low Cost ◽  
Impact Resistance ◽  
Food Tray ◽  
World Population ◽  
Fibrous Materials ◽  
Palm Oil Fuel Ash ◽  
Waste Plastic ◽  
Compressive Strength Of Concrete ◽  
The Impact

Recycling of waste plastics is an essential phase towards cleaner production and circular economy. Plastics in different forms, which are non-biodegradable polymers, have become an indispensable ingredient of human life. The rapid growth of the world population has led to increased demand for commodity plastics such as food packaging. Therefore, to avert environment pollution with plastic wastes, sufficient management to recycle this waste is vital. In this study, experimental investigations and statistical analysis were conducted to assess the feasibility of polypropylene type of waste plastic food tray (WPFT) as fibrous materials on the mechanical and impact resistance of concrete composites. The WPFT fibres with a length of 20 mm were used at dosages of 0–1% in two groups of concrete with 100% ordinary Portland cement (OPC) and 30% palm oil fuel ash (POFA) as partial cement replacement. The results revealed that WPFT fibres had an adverse effect on the workability and compressive strength of concrete mixes. Despite a slight reduction in compressive strength of concrete mixtures, tensile and flexural strengths significantly enhanced up to 25% with the addition of WPFT fibres. The impact resistance and energy absorption values of concrete specimens reinforced with 1% WPFT fibres were found to be about 7.5 times higher than those of plain concrete mix. The utilisation of waste plastic food trays in the production of concrete makes it low-cost and aids in decreasing waste discarding harms. The development of new construction materials using WPFT is significant to the environment and construction industry.

Improving the structural performance of reinforced geopolymer concrete incorporated with hazardous heavy metal waste ash

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Suresh Kumar Arunachalam ◽  
Muthukannan Muthiah ◽  
Kanniga Devi Rangaswamy ◽  
Arunkumar Kadarkarai ◽  
Chithambar Ganesh Arunasankar
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Medical Waste ◽  
Source Material ◽  
Geopolymer Concrete ◽  
Deformation Capacity ◽  
Cement Concrete ◽  
Content Type ◽  
Load Carrying ◽  
Reinforced Cement

Purpose Demand for Geopolymer concrete (GPC) has increased recently because of its many benefits, including being environmentally sustainable, extremely tolerant to high temperature and chemical attacks in more dangerous environments. Like standard concrete, GPC also has low tensile strength and deformation capacity. This paper aims to analyse the utilization of incinerated bio-medical waste ash (IBWA) combined with ground granulated blast furnace slag (GGBS) in reinforced GPC beams and columns. Medical waste was produced in the health-care industry, specifically in hospitals and diagnostic laboratories. GGBS is a form of industrial waste generated by steel factories. The best option to address global warming is to reduce the consumption of Portland cement production and promote other types of cement that were not a pollutant to the environment. Therefore, the replacement in ordinary Portland cement construction with GPC is a promising way of reducing carbon dioxide emissions. GPC was produced due to an alkali-activated polymeric reaction between alumina-silicate source materials and unreacted aggregates and other materials. Industrial pollutants such as fly ash and slag were used as raw materials. Design/methodology/approach Laboratory experiments were performed on three different proportions (reinforced cement concrete [RCC], 100% GGBS as an aluminosilicate source material in reinforced geopolymer concrete [GRGPC] and 30% replacement of IBWA as an aluminosilicate source material for GGBS in reinforced geopolymer concrete [IGRGPC]). The cubes and cylinders for these proportions were tested to find their compressive strength and split tensile strength. In addition, beams (deflection factor, ductility factor, flexural strength, degradation of stiffness and toughness index) and columns (load-carrying ability, stress-strain behaviour and load-deflection behaviours) of reinforced geopolymer concrete (RGPC) were studied. Findings As shown by the results, compared to Reinforced Cement Concrete (RCC) and 100% GGBS based Reinforced Geopolymer Concrete (GRGPC), 30% IBWA and 70% GGBS based Reinforced Geopolymer Concrete (IGRGPC) (30% IBWA–70% GGBS reinforced geo-polymer concrete) cubes, cylinders, beams and columns exhibit high compressive strength, tensile strength, flexural strength, load-carrying ability, ultimate strength, stiffness, ductility and deformation capacity. Originality/value All the results were based on the experiments done in this research. All the result values obtained in this research are higher than the theoretical values.

Experimental Study on Sand and Cement Replacement by Termite Mound Soil

2019 ◽  
pp. 279-287
Author(s):  
Harish R ◽  
Ramesh S ◽  
Tharani A ◽  
Mageshkumar P
Keyword(s):  
Experimental Study ◽  
Experimental Investigation ◽  
Compressive Strength ◽  
Natural Environment ◽  
Fine Aggregate ◽  
Test Results ◽  
Termite Mound ◽  
Cement Concrete ◽  
Cement Ratio ◽  
Compressive Strength Of Concrete

This paper presents the results of an experimental investigation of the compressive strength of concrete cubes containing termite mound soil. The specimens were cast using M20 grade of concrete. Two mix ratios for replacement of sand and cement are of 1:1.7:2.7 and 1:1.5:2.5 (cement: sand: aggregate) with water- cement ratio of 0.45 and varying combination of termite mound soil in equal amount ranging from 30% and 40% replacing fine aggregate (sand) and cement from 10%,15%,20% were used. A total of 27 cubes, 18 cylinders and 6 beams were cast by replacing fine aggregate, specimens were cured in water for 7,14 and 28 days. The test results showed that the compressive strength of the concrete cubes increases with age and decreases with increasing percentage replacement of cement and increases with increasing the replacement of sand with termite mound soil cured in water. The study concluded that termite mound cement concrete is adequate to use for construction purposes in natural environment.

scholarly journals The Influence of Replacing Sand with Waste Glass Particle on the Physical and Mechanical Parameters of Concrete

2018 ◽  
Vol 4 (7) ◽  
pp. 1646
Author(s):  
Hamed Dabiri ◽  
Mohammad Kazem Sharbatdar ◽  
A. Kavyani ◽  
M. Baghdadi
Keyword(s):  
Compressive Strength ◽  
Glass Particle ◽  
Waste Glass ◽  
Waste Materials ◽  
Alkali Silica Reaction ◽  
Colored Glass ◽  
Mechanical Parameters ◽  
Practical Solution ◽  
Compressive Strength Of Concrete ◽  
Harmful Effects

Glass is a special type of materials which is widely used in various forms and colors for different usages. Colored bottles comprise a large part of waste glass. To reduce the destructive effects of waste glass on the environment, it might be recycled. However, some indecomposable waste materials are buried. This will have harmful effects on the environment. A practical solution for reducing non-recyclable waste colored glass is using them as replacements for materials in other industries such as concrete industry. The effect of replacing aggregate with waste glass particle on the compressive strength and weight of concrete is investigated in this study. To achieve the goal, totally 27 cubic specimens were created; 6 specimens were made of concrete, while waste glass particle was added to the mix of other specimens. To prevent Alkali Silica Reaction (ASR), Microsilica was added to the mix of specimens containing glass. Generally, Results indicated that replacing aggregate with glass particle more than 30% lead to increment in compressive strength of concrete. The weight of concrete remains almost the same in all of the specimens. Briefly, based on the results it could be concluded that the optimum percentage for replacing aggregate with glass particle is 50%.

scholarly journals Analgesic prescribing habits and patterns of Canadian chief urology residents: A national survey

2020 ◽  
Vol 14 (6) ◽  
Author(s):  
Ali Dergham ◽  
Greg Hosier ◽  
Melanie Jaeger ◽  
J. Curtis Nickel ◽  
D. Robert Siemens ◽  
...  
Keyword(s):  
Pain Management ◽  
Response Rate ◽  
Formal Training ◽  
Knowledge Gaps ◽  
Opioid Prescribing ◽  
Review Course ◽  
Student’S T ◽  
The Impact ◽  
Student’S T Test

Introduction: Prior studies have identified significant knowledge gaps in acute and chronic pain management among graduating urology residents as of five years ago. Since then, there has been increasing awareness of the impact of excessive opioid prescribing on long-term narcotic use and development of adverse narcotic-related events. However, it is unclear whether the attitudes and experience of graduating urology residents have changed. We set out to evaluate the attitudes and experience of graduating urology residents in prescribing opioid/non-opioid analgesia for acute (AP), chronic non-cancer (CnC), and chronic cancer (CC) pain. Methods: Graduating urology residents were surveyed at a review course in 2018. The survey consisted of open-ended and close-ended five-point Likert scale questions. Descriptive statistics, Mann-Whitney U-test, and Student’s t-test were performed. Results: A total of 32 PGY5 urology residents completed our survey (92% response rate). The vast majority agreed that formal training in managing AP/CnC/CC to be valuable (91/78/81%). Most find their training in CnC/CC management to be inadequate and are unaware of any opioid prescribing guidelines; 66% never counsel patients on how to dispose of excess opioids. In general, 88% are comfortable prescribing opioids, whereas most are very uncomfortable prescribing cannabis or antidepressants (100%/78%). Residents reported the Acute Pain Service as the highest-rated resource for information, and dedicated textbooks the least. Conclusions: This survey demonstrated that experience in pain management remains variable among urology residents. Knowledge gaps remain, particularly in the management of chronic cancer/non-cancer pain.

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