Browse > Article
http://dx.doi.org/10.4334/JKCI.2010.22.3.419

Study on Material Segregation of Grout and Filling Characteristic of Grouting for Post-Tensioned Concrete Beam  

Lee, Jun-Ki (Research Institute of Construction Technology, Samsung C&T Corp.)
Choi, Joon-Ho (Research Institute of Construction Technology, Samsung C&T Corp.)
Yoon, Jeong-Seob (Civil Division, Samsung C&T Corp.)
Cho, In-Sung (Research Center, Chemicon Company Ltd.)
Publication Information
Journal of the Korea Concrete Institute / v.22, no.3, 2010 , pp. 419-426 More about this Journal
Abstract
This paper discusses a series of experiments including material improvement in order to ensure quality of grouting for the post-tensioned structure. In presstressed concrete, grouting refers to the construction procedure of filling empty space of duct enclosing the prestress tendons using cementitious material, To date, adequate quality control of the grouting has not been established in Korea because the relationship between the grouting and durability of post-tensioned structure is not well-recognized. The Korean standard does not consider the important material characteristic, wick effect, which is caused by tendons in the ducts, and furthermore current standard testing method does not quantify reasonable material segregation. As a result, the grout material, which satisfies the current material standards, may well exhibit excessive bleeding of water or shrinkage during construction. In this study, international codes and standards related to grouting were surveyed. The mix proportions of the constituents and novel admixtures were suggested to meet equivalently with these standards. Performance of this enhanced grout was compared with common domestic grouts using the international standard testing method. A series of mock-up specimens considering geometry of PC beam was constructed and grout flow pattern was observed as the grout was injected. It was observed that the grouting performance was highly influenced by material properties and filling characteristic can be varied depending on geometry of ducts.
Keywords
PC grout; durability; material separation; anti-bleeding; quality control;
Citations & Related Records
연도 인용수 순위
  • Reference
1 ASTM C 940-98a, Standard Test Method for Expansion and Bleeding of Freshly Mixed Grouts for Preplaced-Aggregate Concrete in the Laboratory, ASTM international, 2003.
2 대한토목학회, 철도공사전문시방서(토목편), 대한토목학회, 2004, 290 pp.
3 JHS 420, PCグラウトのブリ一ディング率及び積化率試方法(鉛直管方法), コンクリ一/ト標準示方書(規準編), 2004.
4 Woodward, R., “Durability of Post-Tensioned Tendons on Road Bridges in the UK,” Durability of Post-Tensioning Tendons, fib-IABSE Technical Report Bulletin, No. 15, 2001.
5 한국콘크리트학회, 콘크리트표준시방서, 한국콘크리트학회, 2009, 319 pp.
6 Corven Engineering Inc., “Mid-Bay Bridge Post-Tensioning Evaluation,” Final Report, to Florida Department of Transportation District 3, Tallahassee, Florida, 2001.
7 Poston, R. W., Frank, K. H., and West, J. S., “Enduring Strength,” ASCE Civil Engineering, 2003.
8 ACI Committee 222.2R-01, “Corrosion of Prestressing Steels,” ACI Manual of Concrete of Practice, Committee Report 222.2R-01.
9 국토해양부, 도로공사표준시방서, 국토해양부, 2009, pp. 6-178.
10 PTI Grouting Specifications Committee, Specification for Grouting of Post-Tensioned Structures, PTI Guide Specification, Post-Tensioning Institute, 2003.
11 土木學會, コンクリ一ト標準示方書(施工編), 土木學會, 2007, 400 pp.
12 BS EN 445, Grout for Prestressing Tendons-Test Methods, British Standards Institution, 2007.
13 BS EN 447, Grout for Prestressing Tendons-Basic Requirements, British Standards Institution, 2007.
14 대한토목학회, 토목공사 표준일반시방서, 대한토목학회, 2005, 277 pp.
15 KS F 2432, 주입 모르타르의 컨시스턴시 시험방법, 한국표준협회, 2004.