scholarly journals Micromechanical Analysis of Cement Paste with Carbon Nanotubes

10.14311/1670 ◽  
2012 ◽  
Vol 52 (6) ◽  
Author(s):  
Vít Šmilauer ◽  
Petr Hlaváček ◽  
Pavel Padevět
Keyword(s):  
Carbon Nanotubes ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Fracture Energy ◽  
Cement Paste ◽  
Modulus Of Elasticity ◽  
High Strength ◽  
High Modulus ◽  
Reinforcement Material ◽  
Reinforced Cement

Carbon nanotubes (CNT) are an attractive reinforcement material for several composites, due to their inherently high strength and high modulus of elasticity. There are controversial results for cement paste with admixed CNT up to 500 µm in length. Some results show an increase in flexural or compressive strength, while others showing a decrease in the values. Our experiments produced results that showed a small increase in fracture energy and tensile strength. Micromechanical simulations on a CNT-reinforced cement paste 50×50 µm proved that CNT clustering is the crucial factor for an increasein fracture energy and for an improvement in tensile strength.

Fracture Mechanical Properties of Rocks and Mortar/Rock Interfaces

1994 ◽  
Vol 370 ◽  
Author(s):  
Manouchehr Hassanzadeh
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Fracture Energy ◽  
Modulus Of Elasticity ◽  
Splitting Tensile Strength ◽  
Coarse Grained ◽  
Interfacial Zone ◽  
Test Results

AbstractThis study has determined the fracture mechanical properties of 9 types of rock, namely fine-, medium- and coarse-grained granites, gneiss, quartzite, diabase, gabbro, and fine- and coarse-grained limestones. Test results show among other things that quartzite has the highest compressive strength and fracture energy, while diabase has the highest splitting tensile strength and modulus of elasticity. Furthermore, the strength and fracture energy of the interfacial zone between the rocks and 6 different mortars have been determined. The results showed that, in this investigation, the mortar/rock interfaces are in most cases weaker than both mortars and rocks.

scholarly journals The Mechanism of Reinforced Backfill Body with Flexible Mesh

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Xiaosheng Liu ◽  
Weijun Wang ◽  
Quan Liu ◽  
Chao Yuan
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Laboratory Experiments ◽  
Physical And Mechanical Properties ◽  
High Strength ◽  
Strengthening Effect ◽  
Passive Resistance ◽  
Metal Mines ◽  
Reinforcement Material

The backfill of metal mines is easily damaged by the disturbance due to their low strength. We proposed a method that uses flexible meshes as the backfill skeleton to enhance the strength of the backfill. The physical and mechanical properties of the flexible mesh-reinforced filling body are investigated by combining theoretical analysis and laboratory experiments. The strengthening effect is remarkable with the flexible meshes. With the friction-passive resistance between the high-strength reinforcement material and the filling body, the insufficient tensile strength of the filling body is compensated and the reinforcement is improved. The ultimate compressive strength is increased by 1.07 to 1.35 times, and the elastic modulus is increased by 1.08 to 4.42 times. We concluded that the essence of strengthening the flexible mesh-reinforced filling is to increase the cohesive force of the filling and increase the ability to resist external load damage.

scholarly journals Investigating the Behavior of Concrete and Mortar Reinforced with Aluminum Waste Strips

2018 ◽  
Vol 7 (4.37) ◽  
pp. 211
Author(s):  
Rawa Shakir Muwashee ◽  
Hamid Athab Al-Jameel ◽  
Qusay Abdulhameed Jabai
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Modulus Of Elasticity ◽  
Fiber Reinforced Concrete ◽  
Low Density ◽  
High Modulus ◽  
Aluminum Strip ◽  
Lower Strain ◽  
Cracks Propagation

Composite  concrete such as fiber reinforced concrete is widely used in structures because of its excellent properties such as compressive, flexural and tensile strengths and also high modulus of elasticity because it gives lower strain values under loading and too fewer cracks propagation. In this study, Aluminum strips was prepared by cutting the Coca- Cola cans as strips in concrete. The reason of using Aluminum strip is low density and good tensile strength (about 310 MPa) and also has a good ductility.  The results of this study show good improvements in compressive, tensile and  flexural strengths using 117 tested specimens for both concrete and mortar. In brief, about 22 % increment in compressive strength of Aluminum strip concrete  and flexural strength increases from 3.31 MPa to 11.20 MPa when using Aluminum strips with 2.5 % by volume of concrete. The reinforced mortar with Aluminum strips demonstrates significant increments which are 27% for compressive strength and more than 100% for both flexural and tensile strengths comparing with reference mix.  

scholarly journals Evaluation of Concrete Material Properties at Early Age

CivilEng ◽  
2020 ◽  
Vol 1 (3) ◽  
pp. 326-350
Author(s):  
Osamah Obayes ◽  
Emad Gad ◽  
Tilak Pokharel ◽  
Jessey Lee ◽  
Kamiran Abdouka
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Fracture Energy ◽  
Material Properties ◽  
Modulus Of Elasticity ◽  
Inverse Analysis ◽  
Splitting Tensile Strength ◽  
Early Age ◽  
Concrete Compressive Strength ◽  
The Relationship

This article investigates the development of the following material properties of concrete with time: compressive strength, tensile strength, modulus of elasticity, and fracture energy. These properties were determined at seven different hydration ages (18 h, 30 h, 48 h, 72 h, 7 days, 14 days, 28 days) for four pure cement concrete mixes totaling 336 specimens tested throughout the study. Experimental data obtained were used to assess the relationship of the above properties with the concrete compressive strength and how these relationships are affected with age. Further, this study investigates prediction models available in literature and recommendations are made for models that are found suitable for application to early age concrete. Results obtained indicate that the relationship between the splitting tensile strength and concrete compressive strength can be approximated with a power function between 0.7 and 0.8, and this correlation is not affected by age. Fracture energy of the concrete and modulus of elasticity values obtained in this study correlate well with the square root of the compressive strength and it was found that this relationship holds true for all hydration ages investigated in this paper. Inverse analysis on the wedge-splitting test was conducted to determine the direct tensile strength. Values of tensile strength obtained from the inverse analysis have been validated numerically by carrying out finite element analysis on the wedge split, and anchor pull-out tests. The ratio of the tensile strength obtained from the inverse analysis to the splitting tensile strength was found to be in the range of 0.5–0.9 and 0.7 on average.

Mechanical Properties of Reactive Power Concrete and Ultra-High Strength Concrete with Coarse Aggregate

2014 ◽  
Vol 629-630 ◽  
pp. 112-118
Author(s):  
Juan Yang ◽  
Gai Fei Peng
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Fracture Energy ◽  
High Strength Concrete ◽  
Reactive Power ◽  
Coarse Aggregate ◽  
High Strength ◽  
Splitting Tensile Strength ◽  
Strength Concrete ◽  
Maximum Value

An experimental investigation on the variation of compressive strength, splitting tensile strength and fracture energy, with the ratios of water to binder (W/B) of ultra-high strength concretes, including the reactive power concrete (RPC) and ultra-high strength concrete with coarse aggregate (UHSC), has been carried out. The W/B varied between 0.14 and 0.22 at a constant increment of 0.02. It was observed that, compressive strength of RPC almost remained the unchanged, when the W/B was between 0.14 and 0.18. However, it decreased dramatically when the ratios were 0.20 and 0.22. For UHSC, the compressive strength was the highest value at the ratio of 0.18. The results of the two concretes could not comply with the Abrams' generalized W/B ratio law. Moreover, splitting tensile strength of RPC and UHSC decreased continually as the ratio increased from 0.14 to 0.22. Fracture energy of RPC was more or less the same when the ratios were between 0.16 and 0.20, and the maximum value was at 0.14. Fracture energy was observed to be almost no variation for UHSC at all ratios

scholarly journals PERFORMANCE OF HIGH STRENGTH LIGHTWEIGHT CONCRETE USING PALM WASTES

2018 ◽  
Vol 19 (2) ◽  
pp. 30-42
Author(s):  
Md. Nazmul Huda ◽  
Mohd Zamin Jumaat ◽  
A. B. M. Saiful Islam ◽  
Walid A. Al-Kutti
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Modulus Of Elasticity ◽  
Coarse Aggregate ◽  
Lightweight Concrete ◽  
High Strength ◽  
Splitting Tensile Strength ◽  
Palm Shell

The performance of high strength structural lightweight concrete (LWC) using the palm wastes, oil palm shell (OPS) as well as palm oil clinker (POC) has been reported. Existing literatures used either OPS or POC individually for production of LWC. Each concept has their own advantages-disadvantages. In this study, both OPS and POC have been put together as coarse aggregate on the way to see the improvement of mechanical properties of waste based LWC. To achieve this purpose, regular coarse aggregate has been fully replaced by OPS and POC in the concrete. This structural grade lightweight concrete is named as palm shell and clinker concrete (PSCC). Attempts have been made with the series of OPS and POC mixture aimed at identifying for better performance. The quantity of OPS and POC mix has been varied as 30%, 40%, 50%, 60% and 70%. Mechanical properties of PSCC like density, workability, compressive strength at different ages, flexural strength, splitting tensile strength as well as modulus of elasticity have been evaluated. It is revealed that the proposed PSCC has extensive potential in terms of high compressive strength and good material behavior to perform as a better LWC. The study could offer structural lightweight concrete of compressive strength up to 46 MPa that is 31% higher than the control mix. The usage of 50% OPS to 50% POC coarse aggregate by vol. in the concrete mix is found to be the optimum mix. Furthermore, simple correlations have been developed which can easily predict compressive strength, splitting tensile strength, flexural strength, modulus of elasticity and ultrasonic pulse velocity of lightweight concrete.

MEEHANITE GB300

Alloy Digest ◽  
2020 ◽  
Vol 69 (11) ◽  
Keyword(s):  
Thermal Conductivity ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Gray Cast Iron ◽  
High Strength ◽  
Heat Treating ◽  
Spheroidal Graphite ◽  
Cast Irons ◽  
Test Pieces ◽  
Temperature Performance

Abstract Meehanite GB300 is a pearlitic gray cast iron that has a minimum tensile strength of 300 MPa (44 ksi), when determined on test pieces machined from separately cast, 30 mm (1.2 in.) diameter test bars. This grade exhibits high strength while still maintaining good thermal conductivity and good machinability. It is generally used for applications where the thermal conductivity requirements preclude the use of other higher-strength materials, such as spheroidal graphite cast irons, which have inferior thermal properties. This datasheet provides information on physical properties, hardness, tensile properties, and compressive strength as well as fatigue. It also includes information on low and high temperature performance as well as heat treating, machining, and joining. Filing Code: CI-75. Producer or source: Meehanite Metal Corporation.

Effect of CO2 Curing on the Strength of High Strength Pervious Concrete

2020 ◽  
Vol 846 ◽  
pp. 207-212
Author(s):  
Ming Gin Lee ◽  
Yung Chih Wang ◽  
Wan Xuan Xiao ◽  
Ming Ju Lee ◽  
Tuz Yuan Huang
Keyword(s):  
Carbon Dioxide ◽  
Compressive Strength ◽  
Modulus Of Elasticity ◽  
High Strength ◽  
Pervious Concrete ◽  
Control Group ◽  
Curing Time ◽  
Compressive Strength Of Concrete ◽  
Curing Pressure

This study was conducted to assess the effect of CO2 curing on the compressive strength of high strength pervious concrete. The factors studied to evaluate compressive strength of concrete on CO2 curing pressure, curing time, and age of specimen at testing. Three Aggregate sizes, three CO2 curing pressures, three CO2 curing time, and three testing ages were used in this investigation. The research tried to produce a high strength pervious concrete and use carbon dioxide for curing to find out whether it could enhance the compressive strength. The results show that the compressive strength of the control group increases rapidly and its 90-day compressive strength closed to 60 MPa. The 1-day compressive strength has a major impact after CO2 curing and their strength decreased by about 0% to 50% as compared to the control group. However, it is observed that there is only slight difference in relationship between modulus of elasticity and compressive strength obtained from 100 by 200mm cylinders with CO2 curing.

Influence of Nano Particles in the Flexural Behavior of High-Strength Reinforced Concrete Beams

2021 ◽  
Vol 1160 ◽  
pp. 25-43
Author(s):  
Naglaa Glal-Eldin Fahmy ◽  
Rasha El-Mashery ◽  
Rabiee Ali Sadeek ◽  
L.M. Abd El-Hafaz
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
High Strength Concrete ◽  
High Strength ◽  
Reinforced Concrete Beams ◽  
Nano Particles ◽  
Flexural Behavior ◽  
Single Type ◽  
Strength Concrete ◽  
Flexural Ductility

High strength concrete (HSC) characterized by high compressive strength but lower ductility compared to normal strength concrete. This low ductility limits the benefit of using HSC in building safe structures. Nanomaterials have gained increased attention because of their improvement of mechanical properties of concrete. In this paper we present an experimental study of the flexural behavior of reinforced beams composed of high-strength concrete and nanomaterials. Eight simply supported rectangular beams were fabricated with identical geometries and reinforcements, and then tested under two third-point loads. The study investigated the concrete compressive strength (50 and 75 N/mm2) as a function of the type of nanomaterial (nanosilica, nanotitanium and nanosilica/nanotitanium hybrid) and the nanomaterial concentration (0%, 0.5% and 1.0%). The experimental results showed that nano particles can be very effective in improving compressive and tensile strength of HSC, nanotitanium is more effective than nanosilica in compressive strength. Also, binary usage of hybrid mixture (nanosilica + nanotitanium) had a remarkable improvement appearing in compressive and tensile strength than using the same percentage of single type of nanomaterials used separately. The reduction in flexural ductility due to the use of higher strength concrete can be compensated by adding nanomaterials. The percentage of concentration, concrete grade and the type of nanomaterials, could predominantly affect the flexural behavior of HSRC beams.

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.

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