Methods of Preparing Horizontal Construction Joints in Mass Concrete
Author: Billy D. Neeley
Publisher: Washington, DC : U.S. Army Corps of Engineers
Published: 1996
Total Pages: 98
ISBN-13:
DOWNLOAD EBOOKRead and Download eBook Full
Author: Billy D. Neeley
Publisher: Washington, DC : U.S. Army Corps of Engineers
Published: 1996
Total Pages: 98
ISBN-13:
DOWNLOAD EBOOKAuthor: Waterways Experiment Station (U.S.)
Publisher:
Published: 1963
Total Pages: 38
ISBN-13:
DOWNLOAD EBOOKAuthor: William O. Tynes
Publisher:
Published: 1973
Total Pages: 62
ISBN-13:
DOWNLOAD EBOOKAuthor: U.S. Army Engineer Waterways Experiment Station
Publisher:
Published: 1959
Total Pages: 44
ISBN-13:
DOWNLOAD EBOOKAuthor: James E. McDonald
Publisher:
Published: 1966
Total Pages: 42
ISBN-13:
DOWNLOAD EBOOKAuthor: Billy D. Neeley
Publisher:
Published: 1998
Total Pages: 0
ISBN-13:
DOWNLOAD EBOOKAuthor: Neeley, Billy D
Publisher: Washington, DC : U.S. Army Corps of Engineers
Published: 1998
Total Pages: 40
ISBN-13:
DOWNLOAD EBOOKThis report presents the results of a research program examining the effects of different methods of preparing horizontal construction joints in mass concrete construction. The purpose of the research program was to confirm existing guidance or, if necessary, update it. This is the second and final report. The joint moisture conditions at the time of concrete placement were: (a) continuously moist, (b) dry, and (c) dry and then remoistened. There was no cleaning of the joint surface prior to placement of a second lift. The concrete mixture used in the first lift was proportioned to minimize bleeding and the resulting laitance. Jointed specimens were tested for direct tensile strength and shear strength. The results indicated that an addition of a small quantity of silica fume does decrease bleeding and reduce loose, flaky laitance. However, a smooth, somewhat glassy surface appears to interfere with the bonding of the next lift of concrete. Bond strengths are not as good as those when the horizontal construction joints are cleaned by high-pressure water cutting or by air-water cutting, and then allowed to dry approximately 24 hr immediately prior to placement of the next lift of concrete. This technique is not recommended. Current guidance concerning joint cleaning procedures should be followed.
Author:
Publisher:
Published: 1998
Total Pages: 0
ISBN-13:
DOWNLOAD EBOOKThis report presents the results of a research program examining the effects of different methods of preparing horizontal construction joints in mass concrete construction. The purpose of the research program was to confirm existing guidance or, if necessary, update it. This is the second and final report. The joint moisture conditions at the time of concrete placement were: (a) continuously moist, (b) dry, and (c) dry and then remoistened. There was no cleaning of the joint surface prior to placement of a second lift. The concrete mixture used in the first lift was proportioned to minimize bleeding and the resulting laitance. Jointed specimens were tested for direct tensile strength and shear strength. The results indicated that an addition of a small quantity of silica fume does decrease bleeding and reduce loose, flaky laitance. However, a smooth, somewhat glassy surface appears to interfere with the bonding of the next lift of concrete. Bond strengths are not as good as those when the horizontal construction joints are cleaned by high-pressure water cutting or by air-water cutting, and then allowed to dry approximately 24 hr immediately prior to placement of the next lift of concrete. This technique is not recommended. Current guidance concerning joint cleaning procedures should be followed.
Author: American Concrete Institute
Publisher:
Published: 2002
Total Pages: 988
ISBN-13:
DOWNLOAD EBOOKAuthor: U.S. Army Engineer Waterways Experiment Station
Publisher:
Published: 1975
Total Pages: 438
ISBN-13:
DOWNLOAD EBOOK