Methods of Preparing Horizontal Construction Joints in Mass Concrete
Author: Billy D. Neeley
Publisher:
Published: 1998
Total Pages: 0
ISBN-13:
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Author: 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: United States. Army. Corps of Engineers
Publisher:
Published: 1974
Total Pages: 120
ISBN-13:
DOWNLOAD EBOOKAuthor: Us Army Corps Of Engineers
Publisher: Military Bookshop
Published: 1995-06
Total Pages: 192
ISBN-13: 9781780397603
DOWNLOAD EBOOKThis manual provides guidance on evaluating the condition of the concrete in a structure, relating the condition of the concrete to the underlying cause or causes of that condition, selecting an appropriate repair material and method for any deficiency found, and using the selected materials and methods to repair or rehabilitate the structure. Guidance is also included on maintenance of concrete and on preparation of concrete investigation reports for repair and rehabilitation projects. Considerations for certain specialized types of rehabilitation projects are also given.
Author: American Society of Civil Engineers
Publisher: American Society of Civil Engineers
Published: 1995
Total Pages: 82
ISBN-13:
DOWNLOAD EBOOKAuthor: Tennessee Valley Authority
Publisher:
Published: 1966
Total Pages: 620
ISBN-13:
DOWNLOAD EBOOKMelton Hill Dam has two unique features: First, it is the only TVA dam on a tributary system which has a navigation lock; second, it is the first water financed from congressional appropriations - all power installation costs were paid from funds derived from the sale of power and/or proceeds from the sale of power bonds.
Author: ACI Committee 347--Formwork for Concrete
Publisher:
Published: 2014
Total Pages: 32
ISBN-13: 9780870319105
DOWNLOAD EBOOKAuthor:
Publisher:
Published: 2006
Total Pages: 326
ISBN-13: 9780965231091
DOWNLOAD EBOOKManual of integrated material and construction practices for concrete pavements.
Author: Billy D. Neeley
Publisher: Washington, DC : U.S. Army Corps of Engineers
Published: 1996
Total Pages: 98
ISBN-13:
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