Download or read book Report of Results of an Investigation of Core Strengths Obtained from Concrete Pavement Constructed with Specified Mixing Times of 90 75 and 60 Seconds written by New Jersey. State Highway Department. Division of Roads and published by . This book was released on 1963 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Report on Pervious Concrete written by ACI Committee 522 and published by . This book was released on 2010 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This report provides technical information on pervious concrete's application, design methods, materials, properties, mixture proportioning, construction methods, testing, and inspection. The term 'pervious concrete' typically describes a near-zero-slump, open-graded material consisting of portland cement, coarse aggregate, little or no fine aggregate, admixtures, and water." [p. 1]
Download or read book Investigation of Parameters Effecting Concrete Core Performance for Quality Control and Assurance written by Marc Johnson and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The ever-evolving concrete construction industry has required stronger concrete, faster turnarounds, and better durability. To achieve this, the concrete mixtures have changed drastically, including a large amount of cementitious materials, lower amount of water relative to the amount of cementitious materials, supplementary cementitious materials, and chemical admixtures. Each of these changes alters the properties and the behaviour of both fresh and hardened concrete. The standards and codes relating to the quality control and assurance of concrete structures were based on research conducted decades ago, which utilized on concrete mixtures which contained none of these changes and would not meet the expectations of modern concrete construction. The parameters of core testing, time, location, and direction of core extraction, the condition of the core between extraction and testing, the diameter, and the length-to-diameter (l/d) ratio of the core, all have effects on the results of the compressive strength test. Due to the property changes caused by the modern concrete mixtures, the effect that these parameters had on the result of the compressive strength test may or may not be true nowadays. At the request of the Ministry of Transportation of Ontario, an experimental project was conducted to determine the effects that various parameters have on the day 28 compressive strength of concrete samples, and which combination of these parameters would be optimal for quality assurance testing purposes. In total, 8 sets of concrete structures were created and tested, totaling 884 concrete samples, of which 713 underwent compression testing. These sets of concrete samples included beams, wall sections to represent girder webs, large box structures, manhole risers, and standard concrete cylinders which were constructed in the University of Waterloo laboratory and in pre-cast manufacturer facilities. Other tests were conducted, including the bulk resistivity, rapid chloride permeability, and air void systems. These tests are not discussed in this thesis but were discussed elsewhere [1]. The purpose of this project was to determine how different core parameters affected the compressive strength results, and how modern concrete mixtures adhere to the current practices outlined in standards and codes. These parameters are the time of coring (day 3, 7, 14, and 28), location of the core along the length and height of a structure, direction of core extraction (perpendicular or parallel to the direction of casting), the condition of the core between extraction and testing (sealed in plastic or soaked in a saturated calcium hydroxide solution), the diameter of the core (75 mm or 100 mm), and the core l/d ratio (2 or 1.5). A statistical analysis was carried out at a 95% confidence level to determine these effects. Each sample set varied a parameter to isolate its effect on the compressive strength. Once isolated, the effect of the parameters was determined through statistical comparisons. The time of coring was found to have no significant effect on the day 28 compressive strength, regardless of how the core was conditioned between the coring and testing day. The height and length along a structure was also found to be insignificant, provided the concrete mixture included supplementary cementitious materials (SCMs) which reduce the bleed water. A similar conclusion was found for the direction of coring: provided the concrete mixture includes SCMs which reduce bleed water, there was no significant difference between the two directions of coring: perpendicular and parallel to the casting direction. However, the condition in which the core is stored between coring and testing was found to be significant. The cores which were soaked had a 2.3% lower compressive strength than cores sealed in plastic, as recommended by ASTM C42 [2]. The soaked cores were also half as variable with a coefficient of variation (CoV) of 4.73% compared to 9.31% for the sealed cores. The strength correction factor (SCF) in ACI 214 [3] of 0.917 for equating a sealed core compressive strength to a soaked core was found to be inadequate for the data presented, which found 0.977 to be adequate. Similar for the diameter of the samples: 75 mm diameter samples were found to have a 1.5% higher and 25% more variable compressive strength than 100 mm diameter samples. The SCF found in ACI 214 [3] was found to be adequate for the data presented. Lastly, the l/d ratio models presented in CSA A23.1 [4], ASTM C42/C39 [2, 5], and ACI 214 [3] were found to not adequately represent the data in this project. Instead, a modified version of the ACI 214 model was suggested; however, this model was sensitive to the input data. Another suggestion is to calculate a SCF for each unique concrete mixture and structure type by averaging the compressive strengths of samples with the standard l/d ratio of 2 to the compressive strengths of samples with a non-standard l/d ratio (i.e. F_(l⁄d)=f_(c,l⁄d=2)⁄f_(c,l⁄d≠2) ). This second method provided SCFs on par with the modified ACI 214 model, while compensating for sensitivity in the concrete mixtures and construction techniques. Once all the effects of the parameters discussed above are combined, the variability of 100 mm diameter samples with an l/d ratio of 1.5 was found to be less than the variability of 75 mm diameter samples with an l/d ratio of 2. To ensure equivalent variability in sets of samples, additional cores should be extracted, depending on the CoV of the sample data and the non-standard parameters. For example, with a CoV of 6.1%, four saturated cores with a 100 mm diameter and an l/d ratio of 1.5 or five saturated cores with a 75 mm diameter and an l/d ratio of 2 would be required to be equivalent to three standard cores. To ensure the same probability of passing quality assurance testing, where the average compressive strength of three cores must be at least 0.85f_c^' with no single value below 0.75f_c^' [3, 4], the limits may be changed to accommodate the increased variability associated with non-standard parameters on the core. For instance, with a CoV of 6.1%, five 75 mm diameter cores with an l/d ratio of 2 having no single value below 0.66f_c^' would be equivalent to the current three 100 mm diameter cores with an l/d ratio of 2 having no single value below 0.75f_c^'. All of findings above lead to the conclusions that concrete samples from modern concrete mixtures, which include high cementitious contents, low water to cementitious materials ratio, SCMs, and chemical admixtures, are not represented adequately by the current codes and standards.
Download or read book Stormwater Management written by Martin P. Wanielista and published by John Wiley & Sons. This book was released on 1992-11-11 with total page 618 pages. Available in PDF, EPUB and Kindle. Book excerpt: Designed for both students and practicing professionals, it addresses critical issues of water quality, focusing on the illustration and application of both hydrologic and economic water management techniques. Stresses applications using worked examples, case studies and problems. Software is to assist in solving more complex problems and to apply demonstrated techniques. The software discussed in the book is available for download at http://www.cee.ucf.edu/software/swm1993.zip
Download or read book Standard Practice for Concrete written by United States. Army. Corps of Engineers and published by . This book was released on 1974 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Superpave Mix Design written by Asphalt Institute and published by . This book was released on 2001-01-01 with total page 102 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Lime Stabilization written by and published by Transportation Research Board National Research. This book was released on 1987 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt: For many years, various forms of lime, including products with varying degrees of purity, have been utilized successfully as soil stablizing agents. The state of the art in lime treatment based on a comprehensive analysis of current practice and technical literature is presented in this report. References are included for more information.
Download or read book AASHTO Guide for Design of Pavement Structures 1993 written by American Association of State Highway and Transportation Officials and published by AASHTO. This book was released on 1993 with total page 622 pages. Available in PDF, EPUB and Kindle. Book excerpt: Design related project level pavement management - Economic evaluation of alternative pavement design strategies - Reliability / - Pavement design procedures for new construction or reconstruction : Design requirements - Highway pavement structural design - Low-volume road design / - Pavement design procedures for rehabilitation of existing pavements : Rehabilitation concepts - Guides for field data collection - Rehabilitation methods other than overlay - Rehabilitation methods with overlays / - Mechanistic-empirical design procedures.
Download or read book Prestress Losses in Pretensioned High strength Concrete Bridge Girders written by Maher K. Tadros and published by Transportation Research Board. This book was released on 2003 with total page 73 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The HCM includes three printed volumes (Volumes 1-3) that can be purchased from the Transportation Research Board in print and electronic formats. Volume 4 is a free online resource that supports the rest of the manual. It includes: Supplemental chapters 25-38, providing additional details of the methodologies described in the Volume 1-3 chapters, example problems, and other resources; A technical reference library providing access to a significant portion of the research supporting HCM methods; Two applications guides demonstrating how the HCM can be applied to planning-level analysis and a variety of traffic operations applications; Interpretations, updates, and errata for the HCM (as they are developed);A discussion forum allowing HCM users to ask questions and collaborate on HCM-related matters; and Notifications of chapter updates, active discussions, and more via an optional e-mail notification feature."--Publisher.
Download or read book Standard Practice for Shotcrete written by American Society of Civil Engineers and published by American Society of Civil Engineers. This book was released on 1995 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Integrated Materials and Construction Practices for Concrete Pavement written by and published by . This book was released on 2006 with total page 326 pages. Available in PDF, EPUB and Kindle. Book excerpt: Manual of integrated material and construction practices for concrete pavements.
Download or read book Concrete Pavement Maintenance Manual written by Burks Green and published by . This book was released on 2001 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Backpacker written by and published by . This book was released on 2007-09 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt: Backpacker brings the outdoors straight to the reader's doorstep, inspiring and enabling them to go more places and enjoy nature more often. The authority on active adventure, Backpacker is the world's first GPS-enabled magazine, and the only magazine whose editors personally test the hiking trails, camping gear, and survival tips they publish. Backpacker's Editors' Choice Awards, an industry honor recognizing design, feature and product innovation, has become the gold standard against which all other outdoor-industry awards are measured.
Download or read book Design and Control of Concrete Mixtures written by Steven H. Kosmatka and published by . This book was released on 1988 with total page 224 pages. Available in PDF, EPUB and Kindle. Book excerpt: Portland Cement Association reference, dealing with fundamentals, cold weather concreting, curing, admixtures, aggregates, mixing, and much more.
Download or read book Pervious Concrete Pavements written by Paul D. Tennis and published by . This book was released on 2004 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Binder Characterization and Evaluation written by David A. Anderson and published by Strategic Highway Research Program (Shrp). This book was released on 1994 with total page 504 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Precast Concrete Pavement Technology written by Shiraz D. Tayabji and published by . This book was released on 2013 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt: "TRB's second Strategic Highway Research Program (SHRP 2) Report S2-R05-RR-1: Precast Concrete Pavement Technology reviews the available precast concrete pavement (PCP) systems; summarizes PCP applications; and offers suggested guidelines for the design, fabrication, installation, and selection of PCP systems. " -- Publisher's description.
