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Multifunctional corrosion control system as a sustainable approach for reinforced concrete elements

项目名称：	Multifunctional corrosion control system as a sustainable approach for reinforced concrete elements
摘要：	Reinforced Concrete (RC) structures are vital to the US’ infrastructure due to their high durability and superior mechanic performance when used as prime materials for bridges, superstructures and other civil engineering applications. Despite of such importance, the RC elements have been deteriorated rapidly when exposed to corrosive environments. The deterioration mechanism is known to follow the evolution concept under steady state conditions including three different stages: (1) mass transport of the ionic corrosive precursors (chlorides) within the concrete matrix, (2) activation of the metallic rebar due to a loss of native passive layer, and (3) increase charge transfer reaction rate of the rebar which leads to corrosion products at the rebar and possible concrete cracking. This could be the cause of the current inadequate performance levels encountered in infrastructure elements in region 6. Corrosion inhibitors can be utilized to decrease the corrosion kinetics and therefore increase the durability of reinforced concrete elements. Recently, a green synthesized organic compound, 1-benzyl-4-phenyl-1H-1,2,3-triazole (BPT), was shown to be a successful green organic corrosion inhibitor for mild steel. Studies suggested that the BPT adsorbs chemically onto the steel and acts as a mixed inhibitor, suppressing both the anodic and cathodic corrosion kinetics of steel. In addition, microcapsules have shown to be an efficient way for a controlled inhibitor release that prevents its leaching in reinforced concrete structures. On the other hand, geopolymers (GPs) comprised of a long range of covalently bonded alumino-silicates, with amorphous network structure are generally considered as a suitable substitute for OPC for many structural applications due to their high strength and durability. The use of recycled waste materials or natural abundant materials for the production of GPs have attracted world-wide attention as it presents an environment-friendly aspect that may shed light on for replacing traditional OPC by its sustainability. Compared to the production of OPC is energy consuming and contributes to significant CO2 emission, the geopolymers utilize materials such as fly-ash, which is a byproduct of coal combustion, or natural precursor materials (clays, basalt rocks, etc.) and their derivates (metakaolin), which does not involve net CO2 emission. Recent studies have shown that GP based cements can hinder the corrosion of reinforcement steel in concrete structures when compared to OPC, mostly because of lower chloride ingress (due to barrier protective capabilities) and the highly alkaline pH nature of geopolymer cements. A collaborative research study is formulated by teams from TAMU and UTSA to investigate the long-term durability of multifunctional RC system (MFRC) and optimize the materials balance for transportation infrastructure in Region 6. As a part of the proposed study, durability tests under corrosive environment are to be conducted on MFRC over different periods of time. Both material characterization studies related to micro to macro behavioral changes during different exposure of MFRC and steel rebar will be carried out as a part of this research. It is apparent that DOT can benefit greatly if a research project is undertaken to develop an effective management system for corrosion control and mitigation actions. The proposed study and the design guidelines for MFRC systems would be beneficial to all state DOTs within the Tran-SET membership, as it will provide new approach for eco-friendly and inspective but corrosion resistant transportation infrastructure in Region 6. Developed technology for corrosion in MFRC can be used to build new infrastructure, but also as a maintenance strategy for the existing ones. The proposed research with MFRC, should provide sustainable, greener, and alternative technological applicability for the existing reinforced concrete infrastructures to be maintained more durably. Therefore, the proposed collaborative study focuses on these Tran-SET’s areas: Area 4: Improving durability and extending the life of the infrastructure (Sub-area: Application of new materials and technologies); Area 6: Preserving the existing transportation system. Two doctoral students will work with PIs in the execution of the proposed research tasks. The expected deliverable from this project is a technical report summarizing all tasks from both institutes including necessary design guidelines of durable reinforced MFRC. Results of this project will be also disseminated in related workshops and conferences, and presented to the potential industry partners.
状态：	Active
资金：	220000
资助组织：	Office of the Assistant Secretary for Research and Technology
项目负责人：	Mousa, Momen
执行机构：	Texas A&M University, College Station<==>University of Texas at San Antonio
开始时间：	20200801
预计完成日期：	20220201
主题领域：	Bridges and other structures；Highways；Maintenance and Preservation；Materials