• Title/Summary/Keyword: normal aggregate

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Experimental Study on the Strength of Concrete Specimens Mixed with Tire Chips (폐타이어 입자혼입 콘크리트의 강도별 특성 실험)

  • Son, Ki-Sang
    • Journal of the Korean Society of Safety
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    • v.20 no.2 s.70
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    • pp.84-90
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    • 2005
  • This study is to use results of the experiment on the influence to the strength by mixing powders of wasted tires into regular remicon within a range of little effectiveness in durability, applicability, economic aspect, and workability, to put it to practical use and to apply as basic data from a view of recycling wasted tires as construction materials. And the concrete, which was mixed with 10mm particles with ratio of $0.5\%\;and\;1.0\%$ respectively at 270 of mixing strength, was reduced by $27\%$ in compressive strength compared to normal concrete, whereas concrete mixed with other than 10mm particles showed lower decrease ratio compared to the former by reducing only $1.0\%\~1.5\%$. it is found that as strength increases, the less in quantity of aggregate and the more increase in quantity of cement. When considered to the above result, it is estimated that concrete mixed with wasted tire particles could be better used in conditions of compressive force rather than tensile force, and could also be used for structures with flexural strengths as well. In conclusion, higher strengths could be made using waste tire mix.

Performance of adding waste glass and sewage sludge to reservoir-sediment aggregates

  • Chiou, Ing-Jia;Chen, Chin-Ho;Lin, Chia-Ling
    • Computers and Concrete
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    • v.13 no.1
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    • pp.83-96
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    • 2014
  • Accumulated annual reservoir sedimentation in Taiwan was 14.6 million m3 in 2010, seriously endangering reservoir safety and the water supply. In addition, the sintering temperature of reservoir-sediment aggregates (RSAs) is very high, and very energy consuming consequently. Therefore, to explore the effects of admixtures on sintering behavior and performance of the aggregates, two different admixtures are blended, waste-glass and municipal sewage sludge, into reservoir sediment to make artificial aggregates. Experimental results show that the lightweight characteristics of waste-glass/reservoir-sediment aggregates (WGRSAs) are more significant than those of sewage sludge/reservoir-sediment aggregates (SSRSAs). Moreover, as sintering temperature increases, the specific gravity of WGRSAs drops more apparently. The optimum sintering temperature of pure reservoir-sediment aggregates (PRSAs), SSRSAs, and WGRSAs was $1150^{\circ}C$, $1100^{\circ}C$, and $1050^{\circ}C$, respectively. The PRSAs are normal weight with better strength; the WGRSAs are lightweight and energy-saving; and the SSRSAs are lightweight with normal strength.

The Fundamental Study on Reusing Method of Ready-Mixed Concrete Sludge as Cement Binder (시멘트계 결합재로서 레미콘 슬러지의 재활용 방안에 관한 기초적 연구)

  • Park Jin-Sub;;;Kang Byeung-Hee
    • Proceedings of the Korean Institute of Building Construction Conference
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    • v.y2004m10
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    • pp.21-26
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    • 2004
  • This study deals with the Hydrated Ability of the Ready-Mixed Concrete's Sludge which is the recycling technology of that sludge. The experiment gathers sludge from Ready-mixed factory. shatters these into pieces in dry condition and understands the differences between current using Portland cement. And then. this examines the possibility of the recycle as a bonding agent through the Compressive Strength and considers the recovery of the hydration. This experiment concludes the same Chemical Composition with the normal Portland cement. while. under the appropriate procedure in hydration recovery. this sludge can be used as the bonding agent in cement. The chemical composition of solid Remicon sludge shows that it has 1.8 times $SiO_2$ than the normal Portland cement. meaning lots of aggregate in Remicon sludge. Also. the specific gravity of Remicon sluge increases with the rise of Baking Temperature and has no difference between 2.77 and 2.94. The mortar flow used for combining the baking material of Remicon sludge does was not changed and is the highest between $750^{\circ}C{\cdot}120min\;and\;800^{\circ}C{\cdot}180min$. Additionally. the Compressive Strength increases with the age, certifying the same Hydrated Ability like cement and the best condition for hydration is $750^{\circ}C{\cdot}120min.$

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Dual-Encoded Features from Both Spatial and Curvelet Domains for Image Smoke Recognition

  • Yuan, Feiniu;Tang, Tiantian;Xia, Xue;Shi, Jinting;Li, Shuying
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.13 no.4
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    • pp.2078-2093
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    • 2019
  • Visual smoke recognition is a challenging task due to large variations in shape, texture and color of smoke. To improve performance, we propose a novel smoke recognition method by combining dual-encoded features that are extracted from both spatial and Curvelet domains. A Curvelet transform is used to filter an image to generate fifty sub-images of Curvelet coefficients. Then we extract Local Binary Pattern (LBP) maps from these coefficient maps and aggregate histograms of these LBP maps to produce a histogram map. Afterwards, we encode the histogram map again to generate Dual-encoded Local Binary Patterns (Dual-LBP). Histograms of Dual-LBPs from Curvelet domain and Completed Local Binary Patterns (CLBP) from spatial domain are concatenated to form the feature for smoke recognition. Finally, we adopt Gaussian Kernel Optimization (GKO) algorithm to search the optimal kernel parameters of Support Vector Machine (SVM) for further improvement of classification accuracy. Experimental results demonstrate that our method can extract effective and reasonable features of smoke images, and achieve good classification accuracy.

Investor Sentiment Timing Ability of Mutual Fund Managers: A Comparative Study and Some Extensions

  • CHUNHACHINDA, Pornchai;WATTANATORN, Woraphon;PADUNGSAKSAWASDI, Chaiyuth
    • Journal of Distribution Science
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    • v.20 no.9
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    • pp.83-95
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    • 2022
  • Purpose: This study aims to explore an ability to time market-wide investor sentiment of mutual fund managers in an emerging market. Research design, data, and methodology: Based on data of Thai mutual fund market over the period of 2000-2019, our sample includes 283 equity funds, consisting of 204 bank-related funds and 79 nonbank-related funds. We perform our regression analyses at the aggregate and portfolio levels. Results: Under the non-normal distribution of return, we find different behaviors between the best- and worst-performing funds in an ability to time market-wide investor sentiment in Thailand, which is dissimilar to the findings in the U.S. Bottom fund managers act as sentiment hedgers, who decrease (increase) an exposure of investment portfolios when the investor sentiment is high (low). Oppositely, top fund managers are likely to chase investor sentiment. Conclusion: We find that only the worst-performing fund managers, especially for bank-related funds are able to time the market-wide investor sentiment. An advantage of gaining information from their bank's clients is a key success. A competition in the mutual fund industry, an ability to predict fundamentals, and financial literacy are possible reasons to explain the main findings found in this study.

PRECISE LARGE DEVIATIONS FOR AGGREGATE LOSS PROCESS IN A MULTI-RISK MODEL

  • Tang, Fengqin;Bai, Jianming
    • Journal of the Korean Mathematical Society
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    • v.52 no.3
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    • pp.447-467
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    • 2015
  • In this paper, we consider a multi-risk model based on the policy entrance process with n independent policies. For each policy, the entrance process of the customer is a non-homogeneous Poisson process, and the claim process is a renewal process. The loss process of the single-risk model is a random sum of stochastic processes, and the actual individual claim sizes are described as extended upper negatively dependent (EUND) structure with heavy tails. We derive precise large deviations for the loss process of the multi-risk model after giving the precise large deviations of the single-risk model. Our results extend and improve the existing results in significant ways.

Flexural Behavior of Reinforced High-Strength Concrete Beams using Fly Ash Artificial Lightweight Aggregate (석탄회 인공경량골재를 사용한 고강도 철근콘크리트 보의 휨거동)

  • 진인철;박완신;윤현도;정수영
    • Proceedings of the Korea Concrete Institute Conference
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    • 1999.10a
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    • pp.589-592
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    • 1999
  • This paper is experimental study on the flexural strength and ductility capacity of reinforced high-strength concrete beams using fly ash artificial lightweight concrete beams and five reinforced high-strength normal concrete beams with different tensile reinforcement ratio were tested to investigate their behavior. Test result show that the ratio of flexural strength between experimetal results and those by ACI code decrease as the compressive strength of concrete increase. Also, The reinforced concrete beams behave more brittly than those with equal reinforcement ratio($\rho$/$\rho$b) as the compressive strength of concrete increase.

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Mechanical Characteristics of Recycled Structural Concrete with Fly Ash (Fly Ash를 사용한 구조용 재생 콘크리트의 역학적 특성)

  • 김진영;김장우;이봉학;박제선
    • Proceedings of the Korea Concrete Institute Conference
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    • 1994.10a
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    • pp.229-234
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    • 1994
  • Various of batches of recycled concretes were produced with different rations of recycled aggregate (20% and 50%) and admixtures based on workable range of slump value and using a fixed w/c ration. Mechanical characteristics of the recycled concretes were evaluated. Test results showed that, in general, relatively high strength recycled concrete could be obtained using a plasticiser. The concrete using fly ash showed somewhat reduced strength, lower elastic modulus and relatively high strain, in general. However, the strength reduction ratio of the recycled concrete due to adding fly ash was relatively minor, compared with normal concrete. Since it has been known that the fly ash is used in place of cement and gives an improved long term strength, a further study may be warranted for a possibility of using fly ash without degrading the strength required.

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Spectroscopic Evidence for Aggregation of Stilbene Derivatives in Solution

  • Aguiar, M.;Akcelrud, L.;Pinto, M.R.;Atvars, T.D.Z.;Karasz, F.E.;Saltiel, Jack
    • Journal of Photoscience
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    • v.10 no.1
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    • pp.149-155
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    • 2003
  • The absorption, fluorescence and fluorescence-excitation spectra of concentrated toluene solutions of selected para substituted trans-stilbene derivatives provide strong evidence for aggregation. A red-shifted fluorescence spectrum peaking at 420 nm gains in intensity as the stilbene concentration is increased. The excitation spectrum of this new emission is well to the red of the normal stilbene absorption spectrum, consistent with the appearance of a red shifted shoulder in the UV spectrum. Formation of a fluorescent ground state dimer (or higher aggregate) is proposed to account for these observations. The presence of polar substituents is crucial to the formation of this ground state complex.

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A Global TraHlc Conool Architecture For Isolating Network Attacts h Highspeed Intemet Backbone Networle (인터넷 백본망상에서 네트워크 공격 고립을 위한 전역 트래픽 제어 구조)

  • 노병희
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.29 no.5B
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    • pp.491-497
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    • 2004
  • In this Paper, we W a Hovel global traffic control architecture to isolate malicious network attacks and protect network infrastructure in Internet backbone networks. Unlike existing methods based on individual packets or flows, since the proposed detection and control methods are operated on the aggregate traffic level, the computational complexity can k significantly reduced, and they are applicable to develop a global defense architecture against network attack. Experimental results show that the proposed scheme can detect the network attack symptoms very exactly and quickly and protect the network resources as well as the normal traffic flows very efficiently.