Joint ACI/ICRI Meeting

    September 20, 2018
    6:00 PM - 8:00 PM
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    St. Arnold's Brewery
    2000 Lyons Ave
    Houston, TX 77020
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    Come join us for some great beer and food (both included with the registration costs). After about an hour of drinks and networking we'll have the following presentation. 

    Developing Performance Engineered ASR Resistant Concrete Based on Emerging Rapid Aggregate and Concrete ASR Test Methods

    The current approach of formulating ASR resistant concrete heavily depends on ASCM C 1260/1567 and ASTM C 1293 tests. However, the limitations of these tests are well documented over times and the demand for a rapid and reliable ASR test methods is growing. The main objective of this study was to develop rapid aggregate and concrete test methods and a combined innovative approach for formulating performance based ASR resistant concrete mixes. An innovative step by step approach has been developed to formulate ASR resistant concrete mixes based on four recommended steps. In step 1, determination of aggregate ASR composite activation parameter (CAP) and threshold alkalinity (THA) by using a rapid aggregate chemical test called volumetric change measuring device (VCMD) is performed. The lower the CAP the higher the reactivity is. Based on the measured CAP and THA, mix design formulation is conducted in step 2 by applying mix design controls and special protection measures. In step 3, verification and adjustment of the mix developed in step 2 is performed based on THA and pore solution alkalinity (PSA) relationship - PSA needs to be below THA in order to prevent/minimize ASR. Mix design validation by using a newly developed accelerated concrete cylinder test (ACCT) is a part of step 4. Job concrete mixes made of aggregates with different levels of ASR reactivity were tested using the above approach with the four steps. The CAP-based method shows better correlation with ASTM C1293 than ASTM C1260 and was found to be effective to consistently identify the aggregates belong to false positive (i.e., failed by C1260 but passed by C1293) and negative (passed by C1260 but failed by C1293) categories. The proposed approach has the ability to rapidly assess the ASR potential of each aggregate at various alkali loadings and tailoring mix design depending on the level of protection needed. This approach will enable industries to be prepared in the event when good quality Class F ashes will no longer be readily available. The locally available aggregate and SCM materials can be judiciously used to formulate ASR resistant mixtures with the proposed approach.

    Presented by:
    Dr. Anol K. Mukhopadhyay

    Dr. Anol K. Mukhopadhyay is a Research Scientist of Texas A&M Transportation Institute (TTI) and an Adjunct Graduate Faculty of Zachry Department of Civil Engineering at Texas A&M University. Dr. Anol K Mukhopadhyay has 20 years of research and project management experience in industry and academia and has been actively involved in developing, improving, and implementing technologies for highway and airfield concrete pavements and bridges for more than 16 years. His areas of research includes concrete durability (especially ASR), recycled and waste materials, nano-materials in concrete, cement chemistry, coal combustion by-products, cement paste rheology, high performance concrete (HPC), UHPC, concrete microstructures and petrography. He served/ serving as a principal investigator in numerous research project sponsored by IPRF / AAPTP under FAA, TxDOT, Oklahoma Department of Transportation (ODOT), Bureau of Reclamation and other industries to improve concrete durability in pavement, bridge and dam structures and promote recycling. He is a nationally and internationally recognized expert on concrete durability (especially ASR) and has been invited to conduct workshops, technical sessions and/or be a keynote speaker / panelist in several conferences. He is a Chair of ACI 221 (aggregate committee) and voting member of numerous technical committees in ACI, ACI-SDC, TRB, ASTM, AASHTO and ICMA. He is a secretary for the Society of Concrete Petrographers. Currently, he is mainly working on HPC and UHPC and ASR evaluation for precast concrete mixes. His aggregate chemical ASR testing method (VCMD) has recently been accepted as a full standard by AASAHTO (T364) and a draft version of his ASR concrete cylinder test is presented to AASHTO to be considered as a provisional standard. His work on “Evaluation of Alkali -Silica Reactivity Potential of Aggregate and Concrete by Using the VCMD Method: Performance Based Approach” was nominated for the best practice-ready paper award by the Design and Construction Group of the TRB in 2007. He received the outstanding researcher award from TTI in 2017.

    Sponsored by:

              

     

    Tickets

    $45.00 Chapter Member

    $45.00 Non-Member Ticket

    $10.00 Student

    $500.00 Glass Sponsorship