详情

Developing a Low Shrinkage, High Creep Concrete for Infrastructure Repair

项目名称：	Developing a Low Shrinkage, High Creep Concrete for Infrastructure Repair
摘要：	Concrete repairs for bridge and pavements require high early strength such that traffic can be resumed as soon as possible. Currently, this is often achieved, by simply adding cement to a standard concrete mixture. This can have a detrimental effect on the repair because the higher cement content will inevitably lead to higher shrinkage. This has resulted in higher observed cracking and overall lower repair durability. In recent Utah Department of Transportation (UDOT) projects, internal curing (saturated lightweight aggregate) has been used to reduce shrinkage and improve overall concrete durability for bridge decks and pavements. Concrete mixtures used for repairs can also benefit from this technology, but must maintain a high early strength so operations may be resumed as soon as possible. Furthermore, increasing the concrete creep properties, while also decreasing the shrinkage, will result in further crack mitigation and ultimately durability. The primary objective of this research project is to develop concrete mixtures that exhibit favorable time-dependent properties to mitigate the potential for cracking in UDOT infrastructure repairs. Secondary objectives of this research project are to develop a set of material tests that can qualify future concrete designs for use in UDOT repairs. Major Tasks include: (1) Literature review: Investigate admixture performance to achieve the objectives of a high early strength and creep, low shrinkage concrete. Preliminary literature review has shown saturate lightweight aggregate and blast furnace slag are ideal candidates. (2) Laboratory Mixtures: Using results from the literature review, develop a test matrix for development of the candidate mixtures and perform tests. Laboratory testing will use ASTM standards (e.g., compressive creep, shrinkage, strength, modulus and freeze thaw and more) and customized testing (shrinkage, tensile creep and restrained shrinkage). (3) Small Scale Mock-ups: Using the best performing mixtures from Task 2 and working with UDOT engineers, identify situations of past poor performance and fabricate concrete repair situations at Utah State University. These mock-up repairs will be monitored for overall performance through the duration of the project and beyond if requested. Results can be compared to field observations. (4) Field Testing: Identify candidate location(s), where the repair concretes can be applied on in-service project. Monitor these locations using visual inspection, crack gages or other instrumentation depending on the situation. (5) Performance Specification: Using the results from the concrete testing, develop recommendations for a performance design specification for use by UDOT on future projects. (6) Report/Presentation: A final report will be submitted to UDOT in UDOT Research Format outlining the work performed in a logical manner. Interim reports will be prepared on a regular basis if requested. A final presentation will be given to the research committee as well as the UDOT Annual Conference (if requested). A UDOT newsletter article will also be provided upon request.
状态：	Completed
资金：	109953
资助组织：	Utah Department of Transportation
项目负责人：	Hales, Thomas
执行机构：	Utah State University, Logan
开始时间：	20141015
预计完成日期：	20161231
实际结束时间：	20170831
主题领域：	Bridges and other structures；Construction；Highways；Maintenance and Preservation；Materials；Pavements