SP-261: 10th ACI International Conference on Recent Advances in Concrete Technology and Sustainability Issues最新文献_第2页

Nondestructive Testing of Cable Ducts in Concrete Columns and Walls Using the Impact-Echo Method 冲击回波法在混凝土柱墙电缆管道无损检测中的应用

SP-261: 10th ACI International Conference on Recent Advances in Concrete Technology and Sustainability Issues Pub Date : 2009-10-01 DOI: 10.14359/51663215

J. S. Clausen, A. Knudsen

{"title":"Nondestructive Testing of Cable Ducts in Concrete Columns and Walls Using the Impact-Echo Method","authors":"J. S. Clausen, A. Knudsen","doi":"10.14359/51663215","DOIUrl":"https://doi.org/10.14359/51663215","url":null,"abstract":"This paper describes how the appearance of cracks and spalling in concrete columns in a new eight-story office building brought about concerns that the injection of the ducts in the columns was of poor quality. The cracks were mainly present at one floor, and trial drillings into the ducts on columns with severe cracks disclosed the presence of water and loose gravel and aggregates. Opening a duct revealed that the duct was either partially empty, filled with compacted gravel, or fully grouted. It was decided to use the impact-echo (IE) method to investigate the columns and ducts. Each column contains four ducts with a 25 mm (1 in.) diameter reinforcing bar for distribution of the shear stress at the lower and upper 1.0 m (3 ft) to each floor. Testing was performed for each 0.1 m (4 in.) elevation in these areas. The criterion to approve the injection was that at least 0.7 m (2 ft) of the column at the floor or the ceiling was fully injected. After testing the columns on 3 floors, it was decided to investigate the ducts in the walls of the three stairwells of the building, as they were vital for transferring the stresses of the reinforcement down through the building. Verification of the IE-system by drilling cores showed that is possible to distinguish between empty ducts, fully injected ducts, and ducts with compacted gravel. More than 35,000 measurements were made. The examination of the ducts showed that approximately 63% of tests at the top and approximately 86% at the bottom of the columns and walls indicated full injection.","PeriodicalId":232163,"journal":{"name":"SP-261: 10th ACI International Conference on Recent Advances in Concrete Technology and Sustainability Issues","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127132545","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The Use of Pessimum Effect to Reduce the Expansion of Concretes Based on ASR Reactive Aggregates 利用消极效应降低ASR反应骨料混凝土的膨胀

SP-261: 10th ACI International Conference on Recent Advances in Concrete Technology and Sustainability Issues Pub Date : 2009-10-01 DOI: 10.14359/51663213

I. Moundoungou, D. Bulteel, E. Garcia-Diaz, P. Dégrugilliers

引用次数: 4

Experimental Study on a Barite Heavyweight Self-Consolidating Concrete 重晶石重型自固结混凝土试验研究

SP-261: 10th ACI International Conference on Recent Advances in Concrete Technology and Sustainability Issues Pub Date : 2009-10-01 DOI: 10.14359/51663204

D. Revuelta, M. C. Alonso, J. L. Garica, A. Barona

引用次数: 1

Structural Synthetic Fibers for Three-Dimensional Reinforcement of Concrete 用于混凝土三维加固的结构合成纤维

SP-261: 10th ACI International Conference on Recent Advances in Concrete Technology and Sustainability Issues Pub Date : 2009-10-01 DOI: 10.14359/51663201

V. Ramakrishnan

{"title":"Structural Synthetic Fibers for Three-Dimensional Reinforcement of Concrete","authors":"V. Ramakrishnan","doi":"10.14359/51663201","DOIUrl":"https://doi.org/10.14359/51663201","url":null,"abstract":"The strength, toughness properties and plastic shrinkage potential of the structural synthetic fiber reinforced concrete are evaluated in this paper. The test results indicated that there was a significant increase in the flexural strength and a slight increase in the first crack strength as the fiber content was increased from 0.5 to 2.0% by volume. The Japanese toughness factors and equivalent flexural strengths were also significantly increased as the fiber content increased. There was also a tremendous increase in impact strength with an increase in fiber content. Very high average residual strengths (ARS) (ASTM C 1399) were obtained and the ARS values increased as the fiber content increased. The contribution of structural synthetic fibers to plastic shrinkage reduction of concrete was studied using cement-rich concrete and the experimental results are reported in this paper. The fiber dosages used were 0.5, 1.0, and 2.0% by volume of concrete. The tests were conducted using 51 mm (2.0 in.) thick slab that was 1 m (3 ft) long and 0.6 m (2 ft) wide. The crack development was enhanced by using fans that can produce a wind velocity of 22 km/h (13.2 m/h). The performance of these fibers was compared using the crack areas of control slab with no fibers and fiber reinforced slabs. The results indicate that structural synthetic fibers at the dosages used, tremendously reduced the plastic shrinkage in concrete. The crack area reduction varied from 100 to 92% of the plain concrete. There was absolutely no cracking when a fiber dosage of 2.0% by volume of concrete was used.","PeriodicalId":232163,"journal":{"name":"SP-261: 10th ACI International Conference on Recent Advances in Concrete Technology and Sustainability Issues","volume":"76 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126307178","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A Brief History of Pullout Testing with Particular Reference to Canada - A Personal Journey 拉出测试简史，特别参考加拿大-个人旅程

SP-261: 10th ACI International Conference on Recent Advances in Concrete Technology and Sustainability Issues Pub Date : 2009-10-01 DOI: 10.14359/51663217

J. Bickley

引用次数: 1

Nondestructive Testing of Bridge Decks and Tunnel Linings Using Impulse-Response 基于脉冲响应的桥面和隧道衬砌无损检测

SP-261: 10th ACI International Conference on Recent Advances in Concrete Technology and Sustainability Issues Pub Date : 2009-10-01 DOI: 10.14359/51663216

J. S. Clausen, A. Knudsen

{"title":"Nondestructive Testing of Bridge Decks and Tunnel Linings Using Impulse-Response","authors":"J. S. Clausen, A. Knudsen","doi":"10.14359/51663216","DOIUrl":"https://doi.org/10.14359/51663216","url":null,"abstract":"This paper describes how the presence of poor bonding at interfaces between, asphalt, membranes and concrete on bridge decks or between the original concrete and repair patches of tunnel linings often causes a faster deterioration of the different materials, resulting in for example corrosion of the reinforcement, which can lead to spalling of the concrete cover layer. Visual inspections often only disclose these problems at a late state in the deterioration process and repair or replacement of portions or the whole structure can be expensive. Regular inspections combining visual and NDT tools, such as the impulse-response technique and verification of the results by drilling out a few cores, can disclose problems at an early state and provides valuable information of the actual condition of the structure. The use of the impulse-response technique gives the user an indication of the mobility and stiffness of the structures and hence a tool to evaluate the presence of conditions such as poor bonding or delaminations in the structure. Large areas can be tested rapidly and data are valuable for planning future strategies for maintenance or repair of a structure. This paper presents some typical case histories with emphasis on the advantages and limitations of the impulse-response technique.","PeriodicalId":232163,"journal":{"name":"SP-261: 10th ACI International Conference on Recent Advances in Concrete Technology and Sustainability Issues","volume":"10 Suppl 1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115579701","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

Shrinkage Reducing Effect of a Combination of Internal Curing and Shrinkage Compensating Agents on High-Performance Concrete 内养护与补缩剂复合对高性能混凝土的减缩效果

SP-261: 10th ACI International Conference on Recent Advances in Concrete Technology and Sustainability Issues Pub Date : 2009-10-01 DOI: 10.14359/51663199

M. Meddah, Masahiro Suzuki, R. Sato

{"title":"Shrinkage Reducing Effect of a Combination of Internal Curing and Shrinkage Compensating Agents on High-Performance Concrete","authors":"M. Meddah, Masahiro Suzuki, R. Sato","doi":"10.14359/51663199","DOIUrl":"https://doi.org/10.14359/51663199","url":null,"abstract":"This paper describes how water entraining agent using porous aggregate known as internal curing (IC) has become an important component of high-performance concrete (HPC). This paper presents part of the experimental results of an on-going research project regarding the effectiveness of porous ceramic waste aggregates called ‘PorCera’ (PC) as IC agent for high-performance structural concrete elements. Previous studies have proven the effectiveness of both the presoaked recycled porous ceramic coarse aggregate (PCCA) as an IC and shrinkage compensating agents in reducing autogenous shrinkage of HPC. The main purpose of this study is to investigate the synergistic effect of a combination of shrinkage compensating agents and the PorCera on silica fume HPC behavior. This hybrid curing technique includes a combination of shrinkage reducing agent (SRA), expansive additive (EA), and internal curing provided by the recycled PC. Its effect on compressive and split tensile strengths, autogenous shrinkage, and internal self-stress were investigated. Results indicate that HPC mixtures made with this hybrid curing system drastically reduce the amount of autogenous shrinkage, and consequently the induced internal stress and perform much better than the single incorporation of shrinkage compensating agents.","PeriodicalId":232163,"journal":{"name":"SP-261: 10th ACI International Conference on Recent Advances in Concrete Technology and Sustainability Issues","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130472806","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Shear Friction of Reinforced Self-Compacting Concrete Members 钢筋自密实混凝土构件的剪切摩擦

SP-261: 10th ACI International Conference on Recent Advances in Concrete Technology and Sustainability Issues Pub Date : 2009-10-01 DOI: 10.14359/51663206

P. Desnerck, G. Schutter, G. L. Taerwe

引用次数: 4

Analysis of the Relation between Hydration Heat and Autogenous Shrinkage of Concrete at Early Ages 混凝土早期水化热与自收缩关系分析

SP-261: 10th ACI International Conference on Recent Advances in Concrete Technology and Sustainability Issues Pub Date : 1900-01-01 DOI: 10.14359/51663212

E. B. Lee, Gyuyong Kim, K. Koo, H. J. Lee

引用次数: 0

Recent Investigation on the Use of Foundry Sand in Mortar Mixtures 铸造砂在砂浆混合料中的应用研究进展

SP-261: 10th ACI International Conference on Recent Advances in Concrete Technology and Sustainability Issues Pub Date : 1900-01-01 DOI: 10.14359/51663214

F. Tittarelli, S. Monosi, M. Ruello, G. Moriconi

{"title":"Recent Investigation on the Use of Foundry Sand in Mortar Mixtures","authors":"F. Tittarelli, S. Monosi, M. Ruello, G. Moriconi","doi":"10.14359/51663214","DOIUrl":"https://doi.org/10.14359/51663214","url":null,"abstract":"This paper describes how the used foundry sand (UFS) represents the highest amount of solid waste generated by foundries. At present, the general trend is disposal in landfills with two drawbacks: consumption of new raw materials and saturation of existing landfills. This material is classified non-hazardous and therefore its reuse is possible in several industrial sectors. In this study laboratory tests are presented regarding the reuse of waste foundry sand in mortar production by partly replacing the fine aggregate with UFS. The waste material was physically and chemically characterized and then it was added to mortars as fine aggregate replacement at dosage rates of 0%, 20%, and 30% sand by weight. At the dosage of 20%, an addition of previously washed UFS was also considered. The resulting washing water was used to manufacture cement pastes in order to investigate the effect of soluble UFS ions on the hydration kinetics of cement by thermogravimetric analysis. The obtained results showed that the addition of UFS decreases the compressive strength of mortars by about 30%, regardless of the addition rate, and has an accelerated setting effect on cement paste hydration. These undesirable effects are partially mitigated by using previously washed foundry sand.","PeriodicalId":232163,"journal":{"name":"SP-261: 10th ACI International Conference on Recent Advances in Concrete Technology and Sustainability Issues","volume":"80 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128957002","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0