详情

Durable and Sustainable Concrete through Performance Engineered Concrete Mixtures

项目名称：	Durable and Sustainable Concrete through Performance Engineered Concrete Mixtures
摘要：	As funds to construct, maintain, and preserve today's highway infrastructure become increasingly stretched, it is imperative that the criteria for selection of concrete mixtures and acceptance of placed concrete reliably ensure durability. The long service life expectations of pavements, bridges, and other components are often difficult to meet by using typical tests for specification and acceptance, which center around three criteria: slump, air content, and compressive strength. These three criteria are only loosely related to deterioration phenomena and so do not always ensure satisfactory field performance. Consistent with the focus of Moving Ahead for Progress in the 21st Century Act (MAP-21) legislation on performance, there is a desire by Federal Highway Administration (FHWA), public agencies, and industry to move towards performance-engineered construction materials. Performance-engineered concrete mixtures include optimized mixture designs (materials selection, gradation, cement content, etc.) which, paired with advanced quality assurance methods, provide substantially improved durability, economy and sustainability. Over the past several decades, research has led to new understanding of deterioration mechanisms, advancements in concrete mixture design, and better field and laboratory tests to aid in quality assurance/quality control (QA/QC). With this new knowledge, a FHWA initiative to move to performance-engineered concrete mixtures is underway. This initiative has resulted in development of a proposed American Association of State Highway and Transportation Officials (AASHTO) provisional specification and commentary, AASHTO MP XX-17, "Performance Engineered Concrete Pavement Mixtures," which has been submitted to AASHTO in September 2016 for balloting by member states. As stated in Section 1 of AASHTO MP XX-17, "This document seeks to provide Agencies with tools to prepare a specification for concrete pavement mixtures that moves closer to measuring and basing acceptance on parameters that are truly critical to the long-term performance of the system (AASHTO 2016)." Although developed for pavement concrete mixtures, the approach outlined in AASHTO MP XX-17 could be extended to include specifications for performance-engineered concrete mixtures utilized for other infrastructure (bridges, lower grade uses, etc.) as well. Development and implementation of performance-related specifications is an extensive undertaking, and the shift will impact all stakeholders in the construction process. Therefore, the scope of work in this proposed project supports an initial effort to move towards a specification for performance-engineered concrete mixtures by 1) utilizing existing data to identify areas in need of improvement, 2) targeting the establishment of performance-related criteria using three rapid, early age QA/QC tests of interest to North Carolina Department of Transportation (NCDOT), and 3) providing a "roadmap," outlining recommended tasks towards implementation of performance measures, performance goals, and QA/QC protocol in other areas. Research performed as part of this project will leverage existing data with new, targeted data to efficiently evaluate three promising technologies for rapid, early-age evaluation of concrete durability, and to provide guidance for other performance and prescriptive (such as water-cementitious ratio or paste content) measures for consideration. Initial work will focus on analysis of data on currently utilized and historically utilized concrete mixtures, linking existing mixture characteristics, early-age test results, and field performance to identify trends associated with adequate and inadequate durability. Based on the results of data mining, literature review, and a survey of other state highway agency efforts to implement performance-related specifications for concrete mixtures, a laboratory program will be developed that will 1) provide data to support development of specification provisions for the Super Air Meter (SAM), surface resistivity meter, and Box Test, and 2) provide preliminary data to support identification of additional performance and prescriptive measures that could be further explored for use in performance-engineered concrete specifications. Using the findings of this study, a "roadmap" for additional tasks recommended to facilitate a move towards a performance-engineered concrete specification will be prepared, along with project special provisions and/or provisional specifications that could be utilized by NCDOT on an initial trial basis. One notable component of the proposed project will be additional laboratory study to evaluate the performance of concrete mixtures that include the combination of both fly ash and portland limestone cement (PLC). Previous findings by the research team on NCDOT RP 2015-03 indicated significant durability performance benefits in mixes that contained the two materials. In addition to conventional concrete mixtures, the proposed laboratory study will include several mixtures containing fly ash and PLC to better understand the potential enhanced durability and economy, provide additional justification for use, and generate additional data to support the movement towards performance engineered concrete mixtures. Ultimately, this project will result in cost savings for construction and QA/QC, and extended life of concrete pavements and bridges. University of North Carolina, Charlotte (UNC) Charlotte seeks funding of $280,025 for the proposed 24-month research study
状态：	Active
资金：	280025
资助组织：	North Carolina Department of Transportation
项目负责人：	Kadibhai, Mustansir A
执行机构：	Univeristy of North Carolina - Charlotte
主要研究人员：	Cavalline, Tara
开始时间：	20170801
预计完成日期：	0
实际结束时间：	20190731