信息熵未确知测度理论在混凝土再生粗骨料质量优选中的应用

2017-11-15 21:28:46 土木建筑与环境工程2017年5期

孙艳云+郝伟

摘 要:随着中国城镇化建设进程的加快,建筑垃圾的产量将越来越多,再生混凝土的应用不仅能够解决建筑废弃物日益增多的难题,而且可以节约大量的砂石资源。为了对混凝土再生粗骨料质量进行排序和优选,基于信息熵—未确知测度理论构建了混凝土再生粗骨料质量评价模型。根据《混凝土用再生骨料标准》确定评价指标体系和单指标测度函数;利用信息熵理论确定各指标的权重,依据各个指标的样本实测结果计算单指标测度评价矩阵和多指标测度评价向量;按照置信度识别准则进行质量等级评判并应用实例分析检验该方法的有效性。结果表明,信息熵未确知测度理论不仅可以对单个样本进行质量等级评价,还对评价结果处于同一级别内的样本质量的好坏进行排序。

关键词:粗骨料;未确知测度理论;质量评价;信息熵

中图分类号:TU528

文献标志码:A 文章编号:1674-4764(2017)05-0087-06

Abstract:With the acceleration of Chinas urbanization drive, construction wastes are on the rise. The application of recycled coarse aggregate could reduce the increasing construction wastes and save abundant sand resources. In order to sort and optimize the quality of recycled coarse aggregate, the quality evaluation model of recycled coarse aggregate is established based on the information entropy theory. The evaluation index system and single-index measurement functions are determined on the basis of Recycled Coarse Aggregate for Concrete. The weights of these indices are obtained from the information entropy theory. The evaluation matrix of single-index measurement and multiple-index evaluation vector are calculated according to the field data. The quality grade is assessed with credible recognition criteria. An analysis instance is shown, which verified the effectiveness of the proposed model. The result shows that the information entropy and uncertainty measurement theory can be applied to quality evaluation of single sample and distinguish quality of the same grade.

Keywords:coarse aggregate; uncertainty measurement theory ; quality assessment; information entropy

随着中国经济的发展和城镇化建设步伐的加快,产生的建筑垃圾越来越多,然而这些建筑垃圾并没有得到再利用,大多数采取填埋或堆放的处理方式,这不仅浪费了土地资源,而且影响城市环境和卫生质量。从保护环境和节约资源的观点出发,再生混凝土粗骨料在建筑工程中的应用受到人们越来越广泛的关注[1-2]。再生混凝土粗骨料是绿色建材,不仅符合可持续发展的要求,而且具有广泛的应用前景,世界上许多发达国家和地区早已对利用旧混凝土生产再生混凝土粗骨料进行了研究[3-8]。尽管中国对混凝土再生粗骨料的研究起步较晚,但许多高等院校和科研机构在再生骨料方面做了很多的基础研究工作,并获得了大量的科研成果[9-13]。再生混凝土研究的一个重要方向就是再生混凝土骨料(recycled concrete aggregate, RCA)质量等级的划分与评判[14]。如何根据再生混凝土结构构件所处环境与拟建工程类别选择相应等级的再生粗骨料成为一个重要的研究课题[15]。GB/T 25177—2010仅给出了微粉含量、泥块含量、压碎指标、坚固性等单指标评价标准,而没有对再生混凝土粗骨料的综合质量进行等级划分。笔者基于试验得出各单指标评价结果,运用信息熵确定各单项指标的权重,利用未确知测度理论建立再生混凝土粗骨料质量等级评价模型。

1 信息熵未确知测度理论

3.6 评价结果分析

从表3的评价结果,不难发现,除M1的质量等级为C2级外,其余4个样本的评价结果相同都为C1级,而在C1级范围内M2、M3、M4、M5從好到坏的排序为:M3、M4、M2、M5。信息熵未确知测度理论不仅可以对单个样本进行质量等级评价,而且,对同一等级范围内的样本质量优劣进行区分。

4 结论

1)对各指标的权重应用信息熵理论赋权,避免了人为主观因素的影响,使评价结果更具有科学性。

2)信息熵未确知测度理论通过用测度函数建立单指标测度矩阵的方法克服了样本位于同一评价等级范围内时难以区分其质量优劣的问题,使评价结果更加准确。endprint

3)基于信息熵未确知测度理论,并参考中国混凝土用再生骨料标准,建立再生混凝土粗骨料质量评价模型,对多个样本的质量等级进行评价和排序,可以在有限的条件下实现对再生混凝土粗骨料的科学利用,为资源的节约和合理使用提供了重要依据。

参考文献:

[1] 吕智英. 混凝土再生骨料的研究动态与发展趋势[J].混凝土,2010(6):77-81.

LYU Z Y.Study dynamics and development trend of recycled aggregate and concrete [J]. Concrete,2010(6):77-81.(in Chinese)

[2] 孙跃东,周德源.我国再生混凝土的研究现状和需要解决的问题[J].混凝土,2006(4):25-28.

SUN Y D,ZHOU D Y. The present study state and problems to be solved on recycled concrete in China [J].Concrete,2006(4):25-28.(in Chinese)

[3] 朱红兵,赵耀,雷学文. 再生混凝土研究现状及研究建议[J]. 公路工程,2013,38(1):98-102.

ZHU H B,ZHAO Y,LEI X W.Current situation and suggestion on recycled concrete research[J].Highway Engineering, 2013,38(1):98-102.(in Chinese)

[4] ETXEBERRIA M,VAZQUEZ E,MARI A,et al.Influence of amount of recycled coarse aggregates and production process on properties of recycled aggregate concrete[J].Cement and Concrete Research,2007,37:735-742.

[5] KHATIB J M. Properties of concrete incorporating fine recycled aggregate [J].Cement and Concrete Research,2005,35:763-769.

[6] VIVIAN W Y,TAM C M A.Diversifying two-stage mixing approach(TSMA) for recycled aggregate concrete:TSMAS and TSMASC[J].Construction and Building Materials,2008,22:461-468.

[7] POON C S,SHUI Z H,LAM L.Effect of microstructure of ITZ on compressive strength of concrete prepared with recycled aggregates[J]. Construction and Building Materials,2004,18:461-468.

[8] MARTA S D J, PILAR A G.Study on the influence of attached mortar content on the properties of recycled concrete aggregate[J]. Construction and Building Materials,2009,23:872-877.

[9] LI X P.Recycling and reuse of waste concrete in China.Part I.Material behaviour of recycled aggregate concrete[J].Conservation and Recycling,2008,53:36-40.

[10] 于江,梁芮,秦擁军. C30再生粗骨料混凝土的性能试验研究[J]. 建筑科学,2015,31(1):59-63.

YU J,LIANG R,QIN Y J.Study on properties of C30 recycled coarse aggregate concrete [J].Building Science,2015,31(1):59-63.(in Chinese)

[11] 崔正龙,童华彬,吴翔宇. 再生粗骨料的形态及性质对混凝土力学性能影响研究[J]. 硅酸盐通报,2014,33(9):2429-2433.

CUI Z L,TONG H B,WU X Y. Shapes and properties of recycled coarse aggregate on mechanical properties of concrete [J].Bulletin of the Chinese Ceramic Society,2014,33(9):2429-2433.(in Chinese)

[12] 李秋义,李云霞,朱崇绩.基于需水量比和强度比的再生粗骨料分类方法[J].材料科学与工艺,2007,15(4) :480-483.

LI Q Y,LI Y X,ZHU C J.The study on the classification method o f the recycled coarse aggregate based on the ratio of water dosage and the ratio of compressive strength[J]. Materials Science & Technology, 2007,15 (4) :480-483.(in Chinese)endprint

[13] 严捍东,吴仕成,桂苗苗. 再生粗骨料最大堆积密度及其对混凝土性能影响[J]. 建筑材料学报,2015,18(3):482-485.

YAN H D,WU S C,GUI M M. Maximum packing density of recycled coarse aggregate and its effects on properties of concrete[J].Journal of Building Materials,2015,18(3):482-485.(in Chinese)

[14] 王思源,朱平華,姚荣,等. 再生混凝土粗骨料质量等级模糊综合评估方法[J].混凝土,2010(7):87-89.

WANG S Y,ZHU P H,YAO R,et al. Fuzzy synthesis method for evaluating quality class of recycled concrete coarse aggregate[J].Concrete, 2010(7):87-89.(in Chinese)

[15] 鲍学英,王起才,张磊. 基于灰色关联分析的再生混凝土粗骨料质量优选研究[J]. 硅酸盐通报,2014,33(4): 741-745.

BAO X Y,WANG Q C,ZHANG L.Research on quality optimization of recycled concrete coarse aggregate based on grey correlation analysis [J].Bulletin of the Chinese Ceramic Society,2014,33(4):741-745.(in Chinese)

[16] 马超. 基于未确知测度理论矿井通风系统安全评价研究[D].西安:西安科技大学,2005:26-29.

MA C .The safety evaluation study of the ventilation system in coal mine based on the theory of the uncertainty measurement theory[D].Xi′an: Xi′an University of Science and Technology, 2005:26-29.(in Chinese)

[17] 郑一峰,李龙,房玮,等.基于信息墒一未确知测度理论的公路桥梁耐久性评价[J].东北大学学报(自然科学版),2014(8):1206-1210.

ZHENG Y F,LI L,FANG W,et al.Durability assessment of highway bridges based on information entropy and uncertainty measurement theory[J]. Journal of Northeastern University(Natural Science),2014(8):1206-1210.(in Chinese)

[18] QING S.Attribute reduction of multi-valued information system based on conditional information entropy [C]//Proceedings of IEEE International Conference on Granular Computing.Beijing:Science Press,2008:562-566.

[19] ZENG H L,XIAO H Z.Redundant date processing based on rough-fuzzy approach[J].Rough Sets and Knowledge Technology,2006,20(3):156-161.

[20] 李军霞,工常明,王钢城.基于组合赋权一未确知测度理论的滑坡危险性评价[J].岩土力学,2013,34 (2) :468 -474.

LI J X,WANG C M,WANG G C.Landslide risk assessment based on combination weight-uncertainty measurement theory [J].Rock and Soil Mechanics,2013,34 (2):468-474.(in Chinese)

(编辑 胡玲)endprint