Download or read book Evaluation of Portland Cement Concrete Coefficient of Thermal Expansion Test Protocol and the Impact of CTE on Performance of Jointed Concrete Pavements written by Shervin Jahangirnejad and published by . This book was released on 2009 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Determination of Coefficient of Thermal Expansion Effects on Louisiana s PCC Pavement Design written by Hak-Chul Shin and published by . This book was released on 2009 with total page 2 pages. Available in PDF, EPUB and Kindle. Book excerpt: PROBLEM: The coefficient of thermal expansion (CTE) is a fundamental property of construction materials such as steel and concrete. Although the CTE of steel is a well-defined constant, the CTE of concrete varies substantially with aggregate type, mix design, and moisture condition. The Mechanistic-Empirical Pavement Design Guide (MEPDG) demonstrates the importance of CTE in design and performance of Portland cement concrete (PCC) pavements. It is known that CTE has significant effects on slab cracking, curling and warping, joint faulting, and pavement smoothness. A better understanding of CTE effects on performance of Louisiana's PCC pavements is needed. OBJECTIVE: After summarizing the current practice for measuring CTE of PCC, the researcher will determine the variance of CTE for concrete mixes used in Louisiana and provide recommendations for use of CTE in PCC pavement design. Additionally, the current specification for maximum spacing of transverse joints in jointed plain concrete pavement (JPCP) will be evaluated.
Download or read book Construction Materials and Structures written by S.O. Ekolu and published by IOS Press. This book was released on 2014-12-05 with total page 1562 pages. Available in PDF, EPUB and Kindle. Book excerpt: The two volumes of these Proceedings contain about 200 conference papers and 10 keynote papers presented at the First International Conference on Construction Materials and Structures, held in Johannesburg, South Africa from 24 to 26 November 2014. It includes sections on Materials and characterization; Durability of construction materials; Structural implications, performance, service life; Sustainability, waste utilization, the environment; and Building science and construction.
Download or read book Quantifying Coefficient of Thermal Expansion Values of Typical Hydraulic Cement Concrete Paving Mixtures written by Neeraj J. Buch and published by . This book was released on 2008 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: A laboratory investigation was conducted to determine the coefficient of thermal expansion (CTE) of a typical Michigan Department of Transportation (MDOT) concrete paving mixture made with coarse aggregate from eight different sources. The primary aggregate class included limestone, dolomite, slag, gravel and trap rock. The CTE was determined using the provisional AASHTO TP60 protocol. Three replicate test specimens were fabricated for each mixture-age combination. Furthermore, the report also discusses the practical (significance) impact of the test variables on the transverse cracking performance of jointed plain concrete pavements.
Download or read book Quantifying Coefficient of Thermal Expansion Values of Typical Hydraulic Cement Concrete Paving Mixtures written by Neeraj J. Buch and published by . This book was released on 2008 with total page 97 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effect of Portland Cement Concrete Characteristics and Constituents on Thermal Expansion written by Md Sarwar Siddiqui and published by . This book was released on 2014 with total page 408 pages. Available in PDF, EPUB and Kindle. Book excerpt: The coefficient of thermal expansion (CTE) is one of the major factors responsible for distresses in concrete pavements and structures. Continuously reinforced concrete pavements (CRCPs) in particular are highly susceptible to distresses caused by high CTE in concrete. CRCP is a popular choice across the U.S. and around the world for its long service life and minimal maintenance requirements. CRCP has been built in more than 35 states in the U.S., including Texas. In order to prevent CRCP distresses, the Texas Department of Transportation (TxDOT) has limited the CTE of CRCP concrete to a maximum of 5.5 x10-6 strain/oF (9.9 x10-6 strain/oC). Coarse aggregate sources that produce concrete with CTE higher than the allowable limit are no longer accepted in the TxDOT CRCP projects. Moreover, CTE is an important input in the Mechanistic-Empirical Pavement Design Guide (MEPDG). Small deviations in input CTE can affect the pavement thickness significantly in MEPDG designs. Therefore, accurate determination of concrete CTE is important, as it allows for enhanced concrete structure and pavement design as well as accurate screening of CRCP coarse aggregates. Moreover, optimizing the CTE of concrete according to a structure's needs can reduce that structure's cracking potential. This will result in significant savings in repair and rehabilitation costs and will improve the durability and longevity of concrete structures. This study found that the CTEs determined from saturated concrete samples were affected by the internal water pressure. As a result, the TxDOT method yielded higher values than did the American Association of State Highway and Transportation Officials (AASHTO) method. To further investigate the effect of internal water pressure, an analytical model was developed based on the poroelastic phenomenon of concrete. According to the model, porosity, permeability, and the rate of temperature change are the major factors that influence the internal water pressure development. Increasing the permeability of concrete can reduce the internal water pressure development and can thus improve the consistency of measured CTE values. Preconditioning concrete samples by subjecting them to several heating and cooling cycles prior to CTE testing and reducing the rate of temperature change improved the consistency of the CTE test results. Concrete CTE can be reduced by blending low-CTE aggregates with high-CTE aggregates and reducing the cement paste volume. Based on these findings, a concrete CTE optimization technique was developed that provides guidelines for the selection of concrete constituents to achieve target concrete CTE. A concrete proportioning technique was also developed to meet the need for CTE optimization. This concrete proportioning technique can use aggregate from any sources, irrespective of gradation, shape, and texture. The proposed technique has the potential to reduce the cement requirement without sacrificing performance and provides guidelines for multiple coarse and fine aggregate blends.
Download or read book Task 6 written by Kejin Wang and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The present research project was designed to determine thermal properties, such as coefficient of thermal expansion (CTE) and thermal conductivity, of Iowa concrete pavement materials. These properties are required as input values by the Mechanistic-Empirical Pavement Design Guide (MEPDG). In this project, a literature review was conducted to determine the factors that affect thermal properties of concrete and the existing prediction equations for CTE and thermal conductivity of concrete. CTE tests were performed on various lab and field samples of portland cement concrete (PCC) at the Iowa Department of Transportation and Iowa State University. The variations due to the test procedure, the equipment used, and the consistency of field batch materials were evaluated. The test results showed that the CTE variations due to test procedure and batch consistency were less than 5%. Concrete CTE values were significantly affected by different types of coarse aggregate. The CTE values of Iowa concrete made with limestone+gravel, quartzite, dolomite, limestone+dolomite, and limestone were 7.27, 6.86, 6.68, 5.83, and 5.69 microstrain/degree F (13.08, 12.35, 12.03, 10.50, and 10.25 microstrain/degree C), respectively, which were all higher than the default value of 5.50 microstrain/degree F in the MEPDG program. The thermal conductivity of a typical Iowa PCC mix and an asphalt cement concrete (ACC) mix (both with limestone as coarse aggregate) were tested at Concrete Technology Laboratory in Skokie, Illinois. The thermal conductivity was 0.77 Btu/hr ft degree F (1.33 W/m K) for PCC and 1.21 Btu/hr ft degree F (2.09 W/m K) for ACC, which are different from the default values (1.25 Btu/hr ft degree F or 2.16 W/m K for PCC and 0.067 Btu/hr ft degree F or 1.16 W/m K for ACC) in the MEPDG program. The investigations onto the CTE of ACC and the effects of concrete materials (such as cementitious material and aggregate types) and mix proportions on concrete thermal conductivity are recommended to be considered in future studies.
Download or read book Demonstration and Field Evaluation of Alternative Portland Cement Concrete Pavement Reinforcement Materials written by and published by . This book was released on 2003 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt: Transverse joints are placed in portland cement concrete pavements to control the development of random cracking due to stresses induced by moisture and thermal gradients and restrained slab movement. These joints are strengthened through the use of load transfer devices, typically dowel bars, designed to transfer load across the joint from one pavement slab to the next. Epoxy coated steel bars are the materials of choice at the present time, but have experienced some difficulties with resistance to corrosion from deicing salts. The research project investigated the use of alternative materials, dowel size and spacing to determine the benefits and limitations of each material. In this project two types of fiber composite materials, stainless steel solid dowels and epoxy coated dowels were tested for five years in side by side installation in a portion of U.S. 65 near Des Moines, Iowa, between 1997 and 2002. The work was directed at analyzing the load transfer characteristics of 8-in. vs. 12-in. spacing of the dowels and the alternative dowel materials, fiber composite (1.5- and 1.88-in. diameter) and stainless steel (1.5-in. diameter), compared to typical 1.5-in. diameter epoxy-coated steel dowels placed on 12-in. spacing. Data were collected biannually within each series of joints and variables in terms of load transfer in each lane (outer wheel path), visual distress, joint openings, and faulting in each wheel path. After five years of performance the following observations were made from the data collected. Each of the dowel materials is performing equally in terms of load transfer, joint movement and faulting. Stainless steel dowels are providing load transfer performance equal to or greater than epoxy-coated steel dowels at the end of five years. Fiber reinforced polymer (FRP) dowels of the sizes and materials tested should be spaced no greater than 8 in. apart to achieve comparable performance to epoxy coated dowels. No evidence of deterioration due to road salts was identified on any of the products tested. The relatively high cost of stainless steel solid and FRP dowels was a limitation at the time of this study conclusion. Work is continuing with the subject materials in laboratory studies to determine the proper shape, spacing, chemical composition and testing specification to make the FRP and stainless (clad or solid) dowels a viable alternative joint load transfer material for long lasting portland cement concrete pavements.
Download or read book Summary Report on the Evaluation of Rigid Pavement Long life Strategies written by David Jones (Engineer) and published by . This book was released on 2007 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mechanistic empirical Pavement Design Guide written by American Association of State Highway and Transportation Officials and published by AASHTO. This book was released on 2008 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Coefficient of Thermal Expansion of Portland Cement Concrete in Utah and Pavement Performance written by Michael Thomas Rigby and published by . This book was released on 2010 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Evaluation of Recycled Concrete for Use as Aggregates in New Portland Cement Concrete Pavements written by Spencer Ray Boyle and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book One cycle Slow freeze Test for Evaluating Aggregate Performance in Frozen Concrete written by Virginia Polytechnic Institute and published by . This book was released on 1969 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt: Investigation was conducted to develop a simple and fast test that could be used to identify aggregates that cause poor concrete performance when frozen. A one-cycle slow- freeze test was developed and evaluated by correlating results with the durability factor obtained from astm method c290 (the standard freezing and thawing test in water). The test method and testing procedures are presented in detail.
Download or read book The Structural Design of Concrete Pavements written by United States. Public Roads Administration and published by . This book was released on 1943 with total page 178 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Guide for the Local Calibration of the Mechanistic empirical Pavement Design Guide written by and published by AASHTO. This book was released on 2010 with total page 202 pages. Available in PDF, EPUB and Kindle. Book excerpt: This guide provides guidance to calibrate the Mechanistic-Empirical Pavement Design Guide (MEPDG) software to local conditions, policies, and materials. It provides the highway community with a state-of-the-practice tool for the design of new and rehabilitated pavement structures, based on mechanistic-empirical (M-E) principles. The design procedure calculates pavement responses (stresses, strains, and deflections) and uses those responses to compute incremental damage over time. The procedure empirically relates the cumulative damage to observed pavement distresses.
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 Demonstration and Field Evaluation of Alternative Portland Cement Concrete Pavement Reinforcement Materials written by James K. Cable and published by . This book was released on 1998 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The function of dowel bars is the transfer of a load across the transverse joint from one pavement slab to the adjoining slab. In the past, these transfer mechanisms have been made of steel. However, pavement damage such as loss of bonding, deterioration, hollowing, cracking and spalling start to occur when the dowels begin to corrode. A significant amount of research has been done to evaluate alternative types of materials for use in the reinforcement of concrete pavements. Initial findings have indicated that stainless steel and fiber composite materials possess properties, such as flexural strength and corrosion resistance, that are equivalent to the Department of Transportation specifications for standard steel, 1 1/2 inch diameter dowel bars. Several factors affect the load transfer of dowels; these include diameter, alignment, grouting, bonding, spacing, corrosion resistance, joint spacing, slab thickness and dowel embedment length. This research is directed at the analysis of load transfer based on material type and dowel spacing. Specifically, this research is directed at analyzing the load transfer characteristics of: (a) 8-inch verses 12-inch spacing, and (b) alternative dowel material compared to epoxy coated steel dowels, will also be analyzed. This report documents the installation of the test sections, placed in 1997. Dowel material type and location are identified. Construction observations and limitations with each dowel material are shown.
