Efficiency of Scrap Rubber Particles on Strength of Cementitious Materials

2011 ◽  
Vol 374-377 ◽  
pp. 1374-1379 ◽  
Author(s):  
Guang Cheng Long ◽  
Zhe Li ◽  
You Jun Xie
Keyword(s):  
Loss Rate ◽  
Rubber Particle ◽  
Hydrophobic Effect ◽  
Research Programme ◽  
Strength Loss ◽  
Cementitious Materials ◽  
Mortar Sample ◽  
Deformation Effect ◽  
Rubber Particles ◽  
Set Up

An extensive research programme was set up to investigate the efficiency of scrap rubber particles on strength of cementitious materials. The index of strength loss rate of paste and mortar sample caused by increasing 1% volume rubber particles was proposed to analyze the efficiency of rubber particles in cementitious materials. And the corresponding mechanism was also discussed in this paper. Results indicate that in the investigated area, the loss rate in compressive strength both for paste and mortar almost ranges from 2% to 5% caused by increasing 1% rubber particles depending on the total volume of rubber particle added into sample. However, the loss rate in flexural strength of mortar by increasing 1% volume rubber particles is obviously different from that. Three roles of scrap rubber particles played in cementitious materials, named as deformation effect, equivalent-pore effect and hydrophobic effect, are responsible for the efficiency of scrap rubber particles on strength of cementitious material. The efficiency of rubber particles on strength of paste and mortar differs from each other due to the different microstructure between paste and mortar.

The Limitation of Evaluating Thermal Shock Resistance of Al2O3-SiO2 Refractory by Measuring Strength Loss Rate

2011 ◽  
Vol 295-297 ◽  
pp. 2309-2313
Author(s):  
Xin Liu ◽  
Dian Li Qu ◽  
Zhi Jian Li
Keyword(s):  
Thermal Shock ◽  
Thermal Shock Resistance ◽  
Loss Rate ◽  
Strength Loss ◽  
X Ray Diffraction ◽  
Initial State ◽  
X Ray ◽  
Cold Crushing Strength ◽  
Shock Experiment ◽  
Shock Resistance

This paper deeply studied the limitation of evaluating the thermal shock resistance of Al2O3-SiO2 refractory by measuring Strength Loss Rate (SLR). By means of supersonic, X-ray diffraction (XRD), the results were drawn as followed.1)After the thermal shock experiment for mullite based A-S refractory, which were composed by mullite and corundum, the supersonic velocity slowed down as it going through the sample while the cold crushing strength abnormally increased at initial state.2) The strength increased remarkably with the ascending of mullite fraction.3)It is inadequate to evaluate the thermal shock resistance of mullite based A-S refractory by strength loss rate.

Research on Modifier and Modified Process for Rubber-Particle Used in Rubberized Concrete for Road

2011 ◽  
Vol 243-249 ◽  
pp. 4125-4130 ◽  
Author(s):  
Shuai Tian ◽  
Tong Zhang ◽  
Ye Li
Keyword(s):  
Inorganic Salt ◽  
Rubber Particle ◽  
Volume Ratio ◽  
Alkaline Solutions ◽  
Rubberized Concrete ◽  
Function Mechanism ◽  
Mix Proportion ◽  
Optimum Proportion ◽  
Rubber Particles ◽  
The Impact

This paper studies the optimum proportion of rubber-particles in rubberized concrete for road, tests the impact of 12 modifiers and their modified processes in rubberized concrete and discusses the function mechanism of the modifiers in rubberized concrete. Research indicates: the optimum proportion of rubber-particles in rubberized concrete for road is low mix-proportion (volume ratio<5%); inorganic salt as modifier can markedly enhance the bonding strength between rubber-particles used in road and cement and improve the physical properties of rubberized concrete, among which CaCl2 produces the most effect; but organic solution, acidic or alkaline solutions are not fit to be used as modifiers in rubberized concrete for road.

Chapter 7.3 Mount Melbourne and Mount Rittmann

2021 ◽  
pp. M55-2018-43 ◽  
Author(s):  
Salvatore Gambino ◽  
Pietro Armienti ◽  
Andrea Cannata ◽  
Paola Del Carlo ◽  
Gaetano Giudice ◽  
...  
Keyword(s):  
Risk Mitigation ◽  
Research Programme ◽  
Monitoring Systems ◽  
Time Data ◽  
Long Period ◽  
Victoria Land ◽  
Geophysical Investigations ◽  
Antarctic Research ◽  
Set Up ◽  
The 1960S

AbstractMount Melbourne and Mount Rittmann are quiescent, although potentially explosive, alkaline volcanoes located 100 km apart in Northern Victoria Land quite close to three stations (Mario Zucchelli Station, Gondwana and Jang Bogo). The earliest investigations on Mount Melbourne started at the end of the 1960s; Mount Rittmann was discovered during the 1988–89 Italian campaign and knowledge of it is more limited due to the extensive ice cover. The first geophysical observations at Mount Melbourne were set up in 1988 by the Italian National Antarctic Research Programme (PNRA), which has recently funded new volcanological, geochemical and geophysical investigations on both volcanoes. Mount Melbourne and Mount Rittmann are active, and are characterized by fumaroles that are fed by volcanic fluid; their seismicity shows typical volcano signals, such as long-period events and tremor. Slow deformative phases have been recognized in the Mount Melbourne summit area. Future implementation of monitoring systems would help to improve our knowledge and enable near-real-time data to be acquired in order to track the evolution of these volcanoes. This would prove extremely useful in volcanic risk mitigation, considering that both Mount Melbourne and Mount Rittmann are potentially capable of producing major explosive activity with a possible risk to large and distant communities.

Influence of Rubber Particle Size on Functional Properties of a Composite Material Based on Scrap Tires and a Polymer Binder

2020 ◽  
Vol 850 ◽  
pp. 107-111
Author(s):  
Laimonis Mālers ◽  
Agnija Cirvele
Keyword(s):  
Particle Size ◽  
Composite Material ◽  
Functional Properties ◽  
Material Properties ◽  
Rubber Particle ◽  
Polymer Binder ◽  
Scrap Tires ◽  
Elongation At Break ◽  
Rubber Particles ◽  
Purposeful Selection

Functional properties of composite material based on mechanically grinded scrap tires with different particle size of fractioned crumb and polyurethane type polymer binder were investigated to estimate influence of rubber particles size and content on composite material properties (Shore C hardness, compressive stress at 10 % deformation, tensile strength, elastic modulus and elongation at break, apparent density). Optimization possibilities of composite material consisting of rubber particles with different sizes or fractions were investigated. The obtained results show that variation of composition of the composite material by changing size of rubber granulate have definite influence on selected properties of the material. Purposeful selection and mutual combination of rubber particles size included in material can ensure desirable and predictable mechanical properties of composite material.

Fracture behavior and deformation mechanisms of polypropylene/ethylene-propylene-diene blends

2016 ◽  
Vol 36 (7) ◽  
pp. 695-704 ◽  
Author(s):  
Yuhui Ao ◽  
Fang Feng ◽  
Huixuan Zhang
Keyword(s):  
Electron Microscopy ◽  
Deformation Mechanism ◽  
Fracture Behavior ◽  
Rubber Particle ◽  
Shear Yielding ◽  
Ethylene Propylene ◽  
Transmission Electron ◽  
Rubber Particles ◽  
The Matrix ◽  
Matrix Shear

Abstract The fracture behavior and deformation mechanism of polypropylene (PP)/ethylene-propylene-diene rubber (EPDM) were studied by scanning electron microscopy and transmission electron microscopy analyses. The deformation mechanism was investigated under different conditions. Voids were seen under all the conditions because of matrix shear yielding, indicating that rubber particle cavitation took place during the blend fracture process; moreover, the void size and density increased as the fracture surface was approached. However, the void density and extent of elongation of the rubber particles in the deformation zone decreased with increasing test speed rate. Many voids were positioned in the rubber particles, confirming that matrix shear yielding initiated by rubber particle cavitation was the main deformation mechanism during ductile fracture in the matrix.

Subject 01: exemplary Indigenous masculinity in Cold War genetics

2020 ◽  
Vol 53 (3) ◽  
pp. 311-332
Author(s):  
ROSANNA DENT
Keyword(s):  
Cold War ◽  
Indigenous People ◽  
Research Programme ◽  
Epidemic Disease ◽  
Mato Grosso ◽  
Central Brazil ◽  
Colonial Expansion ◽  
To Come ◽  
Set Up ◽  
Political Realities

AbstractIn 1962 a team of scientists conducted their first joint fieldwork in a Xavante village in Central Brazil. Recycling long-standing notions that living Indigenous people represented human prehistory, the scientists saw Indigenous people as useful subjects of study not only due to their closeness to nature, but also due to their sociocultural and political realities. The geneticists’ vision crystalized around one subject – the famous chief Apöwẽ. Through Apöwẽ, the geneticists fixated on what they perceived as the political prowess, impressive physique, and masculine reproductive aptitude of Xavante men. These constructions of charismatic masculinity came at the expense of recognizing how profoundly colonial expansion into Mato Grosso had destabilized Xavante communities, stripping them of their land and introducing epidemic disease. The geneticists’ theorizing prefigured debates to come in sociobiology, and set up an enduring research programme that Apöwẽ continues to animate even four decades after his death.

Study on the Corrosion Resistance of Polymer-Modified Reactive Powder Concrete

2011 ◽  
Vol 250-253 ◽  
pp. 548-553
Author(s):  
Dong Lin ◽  
Yu Fei Yuan ◽  
Zi Yun Wen
Keyword(s):  
Corrosion Resistance ◽  
Flexural Strength ◽  
Loss Rate ◽  
Processing Condition ◽  
Strength Loss ◽  
Sulphate Solution ◽  
Reactive Powder Concrete ◽  
Polymer Modification ◽  
Eds Analysis ◽  
Reactive Powder

In ordinary processing condition, using small amount (2%) of polymer to modify reactive powder concrete (RPC), the performance of modified and unmodified RPC was studied for their corrosion resistance with water-dip-in, acid-dip-in and sulphate solution-dip-in tests and was verified by the strength loss rate. The results show that not only the corrosion resistance but also the strength, especially the flexural strength, has been improved obviously after the polymer modification. The mechanism has been studied with SEM and EDS analysis.

TENSILE STRESS STRAIN BEHAVIOR OF POLYPROPYLENE TOUGHENED WITH BI-MODAL SEBS

2008 ◽  
Vol 22 (09n11) ◽  
pp. 1129-1134 ◽  
Author(s):  
HIROYUKI MAE ◽  
MASAKI OMIYA ◽  
KIKUO KISHIMOTO
Keyword(s):  
Rubber Particle ◽  
Bimodal Distribution ◽  
Tensile Tests ◽  
Strong Increase ◽  
In Situ Observation ◽  
Strain Rates ◽  
Blend Ratio ◽  
Strain Behavior ◽  
Rubber Particles ◽  
Localized Plastic Deformation

The objective is to characterize the effect of the bimodal distribution of rubber particles and its blend ratio on the mechanical properties of the thermoplastic polypropylene blended with two different styrene-ethylene-butadiene-styrene tri-block copolymer (SEBS) at the intermediate and high strain rates. Tensile tests are conducted at the nominal strain rates from 10−1 to 102 (1/sec). Phase morphology is investigated to estimate the bi-modal rubber particle size distribution. In addition, the in-situ observation is conducted during uniaxially stretching within transmission electron microscopy (TEM) step by step to investigate the deformation events depending on the elongation of samples. The elastic modulus increased gradually as the blend ratio of large rubber particle increased. An increase in the rupture strain was found for the bimodal rubber-particle distributed blend system where the blend ratios of small rubber particle and large rubber particle were the same. This is because the smaller particles dominant blend systems show the band-like craze deformation while the localized plastic deformation is taken place in the larger particles dominated blend systems. The synergistic effect of these rubber particles gives rise to a strong increase in the ductility of these bimodal rubber-particle distributed polypropylene systems.

Environment and access to resources in Africa

Africa ◽  
1989 ◽  
Vol 59 (1) ◽  
pp. 18-40 ◽  
Author(s):  
Piers Blaikie
Keyword(s):  
Future Orientation ◽  
Social Science Research ◽  
Research Programme ◽  
Science Research ◽  
Access To Resources ◽  
Research Issues ◽  
The Social ◽  
Set Up ◽  
Opening Paragraph ◽  
Agrarian Crisis

Opening ParagraphThis article has been written as a contribution to the future orientation of a research programme on the agrarian crisis in Africa, which has been set up by the Joint Committee on African Studies (JCAS) of the American Council of Learned Societies and the Social Science Research Council. The aim of this article is to provide an agenda for research on the environment and access to resources in Africa and is one of four which both provide a review of some of the most important research issues and suggest ways in which they might be tackled.

The Experimental Research on the Anti-Corrosion Performance of Concrete with Different Mineral Admixtures under Sulfate and Chloride Environment

2014 ◽  
Vol 638-640 ◽  
pp. 1431-1435
Author(s):  
Wen Xun Qian ◽  
Yan Chi Zhang ◽  
Xun Jie Chen ◽  
You Lin Ouyang
Keyword(s):  
Loss Rate ◽  
Chloride Ion ◽  
Strength Loss ◽  
Sulfate Attack ◽  
Mineral Admixtures ◽  
Corrosion Performance ◽  
Chloride Ion Penetration ◽  
Initial Stage ◽  
Chloride Environment ◽  
Permeability Of Chloride Ion

The performance of resistance to sulfate attack and permeability of chloride ion on concrete with different mineral admixtures (fly ash, slag single or both adding) under sulfate and chloride environment were discussed. The results indicated the performance of resistance to salt attack on concrete with appropriate mineral admixtures was improved. Under chloride environment, the resistance to sulfate attack coefficient of testing mortars descended, and compressive strength loss rate of concrete was raised after dry-wet cycles. Therefore, the performance of resistance to salt attack on concrete was decreased in this environment. Besides, on the initial stage of corrosion, the ability to resist chloride ion penetration of concrete was improved under sulfate environment, while the penetrating of chloride ion was accelerated on the later stage.

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