Download or read book Overview of Latex Modified Concrete Overlays written by Michael M. Sprinkel and published by . This book was released on 1984 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt: Twelve bridges with latex modified concrete (LMC) overlays ranging in age from new to 13 years were studied and their general condition found to be good. The half-cell and chloride data were inconclusive because background data were not available for the older overlays, but the data should be useful some 5 to i0 years from now if similar data are collected at that time for comparison. The shear strength of the bond between the LMC overlays and the base concretes was about the same or greater than that of the base concrete, which indicates that good bonds were achieved and have been maintained. The permeability to chloride ions based on the rapid permeability test was an average of 773 coulombs (very low) for a 1.25 in. thick LMC overlay and 4,590 coulombs (high) for the base concretes. The inverse of the ratio of the logarithm of the permeability of the LMC overlay to that of the base concrete was 1.27, which provides a very conservative indication of the relative benefits to be obtained from the LMC overlay as compared to an A4 concrete overlay. The three sets of cost assumptions developed indicate that an LMC overlay costs 6% to 31% more than an A4 concrete overlay. Considering that the benefit-to-cost ratio ranged from 0.97 to 1.20, it was concluded that for bridges in which the low permeability provided by the LMC overlay is needed, the benefits usually obtained are worth the extra cost when compared to that of an A4 concrete overlay.
Download or read book Specification for Latex Modified Concrete Overlays written by American Concrete Institute and published by . This book was released on 2012-06 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Latex modified Concretes and Mortars written by V. Ramakrishnan and published by Transportation Research Board. This book was released on 1992 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt: This synthesis wil be of interest to materials engineers, construction engineers, maintenance engineers, pavement contractors and others interested in the use of latex-modified mortars (LMM) and concretes ( LMC). Information is provided on material properties of various LMM and LMC, as well as current construction practices used for LMM and LMC. Potential applications for LMM and LMC are also included. The use of innovative modified portland cement mortars and concretes for construction and maintenance applications is growing. This report of the Transportation Research Board describes the current state of the practice with respect to the use of latex-modified portland cement concretes and mortars. The extent of use of each material (including case histories), based on results of surveys of state highway agencies and a review of the literature, is summarized.
Download or read book Specification for Latex modified Concrete Overlays written by ACI Committee 548, Polymers in Concrete and published by . This book was released on 2012 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Twenty Year Performance of Latex Modified Concrete Overlays written by MM. Sprinkel and published by . This book was released on 1993 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fourteen bridge decks with latex-modified concrete (LMC) overlays ranging in age from two to twenty years and two overlays without latex were studied. The high quality portland cement concrete overlays without latex showed greater negative increases in half-cell potentials, greater increases in chloride content, and a higher percentage of higher rates of corrosion than the LMC overlays. Also, for these two bridges, higher shear and tensile rupture strengths were obtained at the bond interface with LMC than with concrete without latex. Higher rupture strengths were not obtained on the other bridges because of the low strength of the scarified surface of the base concrete. The permeability, half-cell, chloride, rate-of-corrosion, and bond, strength data indicate that the overlays are performing satisfactorily. Also, LMC overlays placed on decks with less than 2 lb/yd3 (1.2 kg/m3) of chloride ion at the rebar can be expected to have a service life in excess of twenty years.
Download or read book Latex modified Concrete Overlay Containing Type K Cement written by Michael M. Sprinkel and published by . This book was released on 2005 with total page 21 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hydraulic cement concrete overlays are usually placed on bridges to reduce the infiltration of water and chloride ions and to improve skid resistance, ride quality, and surface appearance. Constructed in accordance with prescription specifications, some overlays have performed well for more than 30 years whereas others have cracked and delaminated before the overlay was opened to traffic. Shrinkage of the concrete is the most common cause of cracking in overlays. The use of Type K (expansive) cement should increase the probability that concrete overlays with minimal cracks will be constructed. This report describes the Virginia Department of Transportation's first experience with the use of Type K cement for the construction of a latex-modified concrete overlay. One lane of the overlay was constructed with traditional Type I/II cement, and the other lane with Type K cement. With the exception of the cement, the requirements for the overlays were the same. The evaluation of the overlays included measurements for slump, temperature, air content, compressive strength, permeability to chloride ion, shrinkage, and bond strength. As expected, the shrinkage of the concrete containing Type K cement was much less than that of the concrete containing Type I/II cement. Other properties were similar. The use of Type K cement is estimated to increase the cost of the concrete approximately 2.6 percent, or about $1/yd2 for an overlay 1.5 in thick. This is much less than the cost to seal the shrinkage cracks in an overlay: $10/yd2. Greater savings can also come from the longer service life of a crack-free overlay. To gain more experience, the Virginia Department of Transportation should construct additional latex-modified concrete overlays using Type K cement.
Download or read book Evaluation of Very High Early Strength Latex Modified Concrete Overlays written by John D. Wenzlick and published by . This book was released on 2006 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Very early strength Latex modified Concrete Overlay written by Michael M. Sprinkel and published by . This book was released on 1998 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper describes the installation and condition of the first two very-early-strength latex modified concrete (LMC-VE) overlays constructed for the Virginia Department of Transportation. The overlays were prepared with a special blended cement rather than the Type I/II cement used in the conventional latex-modified concrete (LMC) overlay. LMC-VE mixture proportions, installation equipment, and procedures are similar to those used for conventional LMC overlays. However, when working with LMC-VE, the contractor must work faster because the concrete loses slump rapidly and the curing period is approximately 3 rather than 72 hours. Tests of the compressive strength of the LMC-VE overlay performed during the early hours after installation indicated that traffic could be placed on the overlay within 3 hours rather than within the 4 to 7 days required for the conventional LMC overlay. Tests of bond strength and permeability to chloride ion indicated that the overlays are performing satisfactorily and can be used as an alternative to LMC to extend the life of bridge decks. Pending continuing favorable test results, it is anticipated that LMC-VE overlays can be used when construction during short lane closure periods is highly desirable. Use of LMC-VE may reduce inconvenience to motorists; allow for installation at night; provide negligible to very low permeability; and provide high strength, particularly high early strength.
Download or read book Study of High Density and Latex Modified Concrete Bridge Deck Overlays written by Delmo E. Koop and published by . This book was released on 1982 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt: Portland cement concrete overlay surfacings for bridge decks which will effectively resist de-icing salt solution penetration are a major concern. The report compares the relative effectiveness of latex modified concrete and high density concrete overlays.
Download or read book High early strength latex modified concrete overlay written by and published by . This book was released on 1988 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report describes the condition of the first high early strength latex modified concrete (LMC-HE) overlay to be constructed for the Virginia Department of Transportation. The overlay was prepared with type III cement and with more cement and less water than used in the conventional latex modified concrete (LMC) overlay. Tests of the bond and compressive strength of the LMC-HE overlay performed during the first 24 hours after installation .indicated that traffic could be placed on the overlay within 24 hours rather than the 4 to 7 days required for the conventional LMC overlay. Tests of the bond strength and permeability to chloride ion conducted after 1 year in service indicate that the overlay is performing satisfactorily. Pending continuing favorable test results, it is anticipated that LMC-HE overlays can be used in situations in which it is desirable to accelerate construction, to reduce inconvenience to motorists, to allow for installation during off-peak traffic periods such as weekends, to provide a more rapid cure in cold weather, to provide low permeability (compared to concrete without latex), and to provide high strength, particularly, high early strength.
Download or read book Cracking Causes and Resistance in Very Early Strength Latex Modified Concrete Overlays with and Without Nonmetallic Fibers written by Thomas Frederick-Norris Stirewalt and published by . This book was released on 2021 with total page 125 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Standard Specification for Latex modified Concrete LMC Overlays ACI 548 4 93 written by ACI Committee 548 and published by . This book was released on 1992 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Tension Strength of Latex Modified Bonded Concrete Overlays written by Patrick Austin Crowder and published by . This book was released on 2011 with total page 186 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Preliminary Performance Criteria for the Bond of Portland cement and Latex modified Concrete Overlays written by and published by . This book was released on 1989 with total page 102 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Investigation of Chloride Contents in Latex Modified Concrete Overlays written by R. H. Lowry and published by . This book was released on 1976 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Polymer modified Hydraulic cement Mixtures written by Louis A. Kuhlmann and published by ASTM International. This book was released on 1993 with total page 162 pages. Available in PDF, EPUB and Kindle. Book excerpt: A dozen papers from a June 1992 symposium in Louisville, Kentucky review the current use of organic polymers dispersed in water and formulated to add to portland cement. One sets out the status of ASTM's forthcoming specification and test methods. Others discuss such aspects as solid grade acrylic c
Download or read book Berufsberatung written by Bundesanstalt für Arbeit Landesarbeitsamt Rheinland-Pfalz-Saarland and published by . This book was released on 1986 with total page 37 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sportlehrerausbildung, ESSM, Hochschule, Sportstudium.
