ACI Foundation Funds Four Research Projects for 2017
The ACI Foundation will provide $200,000 of research funding through four $50,000 research grants this year. Projects are vetted and selected by the Foundation’s working group on research, the Concrete Research Council. Information about this year’s awarded projects are below.
CRC 32: An Experimental Study on the Effect of Wall-Slab Connection Details in Liquid Containing Structures
Concrete liquid containing structures (CLCS) are primarily used for the storage of water, wastewater, and other industrial wastes. These critical facilities require careful design and detailing to optimize meeting serviceability requirements for crack and leakage control with construction and maintenance costs. Inconsistency among the design standards of CLCS and debate on the validity of some of the provisions in codes and standards stems from a lack of understanding of the behavior of these structures under static and seismic loading. The main objective of this project is to develop performance criteria for design of CLCS through full-scale experimental investigations that assures a safe, leak-resistant structure. The research program involves testing several specimens representing a segment of wall-base slab connection region with different base connection details while under liquid pressure. The results from this study will be analyzed to make code recommendations to ACI Committee 350, potentially leading to new design code standards.
Principal Investigator: Reza Kianoush, Ryerson University
Co-Funder: Natural Sciences and Engineering Research Council of Canada (NSERC)
Supporting ACI Committee: 350, Environmental Engineering Concrete Structures
CRC 37: Minimizing the effect of pumping on SCC workability and freeze-thaw durability
Pumping is a widely-used technique to place concrete in formworks, however, the pumping operation affects the workability and the air-void distribution of concrete. Self-consolidating concrete (SCC) can either lose its self-consolidation capacity or its stability when being pumped, and it has been shown that an increase in air void spacing factor due to pumping is significantly larger than that of conventional vibrated concrete. As some agencies impose requirements on the concrete after placement, improved guidelines are necessary for both the pumping operation and the concrete mix design to minimize any negative effect of pumping on concrete workability and freeze-thaw resistance.
The main goal of the research is to understand which parameters of pumping and concrete mix design have the largest effect on the workability and air-void systems and apply the results to improved guidelines for concrete producers and contractors to assure the quality of the concrete placed in the formworks by pumping. Two main groups of parameters will be investigated: pumping parameters and concrete properties. This knowledge will enable the researchers to predict changes in concrete workability and air-void distribution.
Principal Investigator: Dimitri Feys, The Curators of the University of Missouri on behalf of Missouri University of Science and Technology
Co-Funders: RECAST Tier 1 UTC (Monetary), The Curators of the University of Missouri (Rolla)
Supporting ACI Committee: 237 Self Consolidating Concrete
CRC 45: Benchmark Tests on Anchoring Columns to Foundations
The primary objective of this project is to clarify which ACI 318 provisions should apply to the design of column-foundation connections, or whether alternative provisions should be developed for these connections. This study will conduct physical tests on representative geometries to explore the design requirements for tension, compression, and moment loading cases. The designs will be based on representative design approaches, and the results will provide direct evidence on the efficacy of those design procedures. In addition, the project will provide guidance on the use of existing ACI 318 anchoring-to-concrete provisions in a range of applications.
Principal Investigator: Jack Moehle, University of California, Berkeley
Co-Funders: Hilti Aktiengesellschaft & Ron Klemencic of Magnusson Klemencic Associates, Inc.
Supporting ACI Committee: 318, Structural Concrete Building Code, Subcommittee B, Anchorage and Reinforcement
CRC 49: Evaluating the Performance and Feasibility of Using Recovered Fly Ash and Fluidized Bed Combustion Fly Ash as Concrete Pozzolan
This research project will help determine if and how recovered stockpiled fly ash and fluidized bed combustion (FBC) fly ash can be used as viable and high performance pozzolans for concrete. Supplementary cementitious materials (SCM) are key ingredients in today’s concrete and can vastly improve the durability and sustainability of concrete mixtures. While the demand for fly ash (the most commonly used SCM) and other suitable pozzolans continues to escalate, the supply of high-quality and economically available fly ash has been shrinking. While alternative sources of fly ash do exist (e.g., landfilled or ponded fly ash), these have not been used due to lack of guidelines and protocols to evaluate the performance of these ashes and identify necessary beneficiation procedures before they can be incorporated into concrete mixtures. This study seeks to evaluate the feasibility, performance, and beneficiation of two promising alternative sources of fly ash: recovered dry disposed (stockpiled) fly ash, and FBC fly ash. The project findings will be used to potentially develop new ACI guidelines for the evaluation and use of recovered fly ash and FBC fly ash in concrete.
Principal Investigator: Farshad Rajabipour, Pennsylvania State University
Co-Funder: Pennsylvania Coal Ash Research Group
Supporting ACI Committee: 232, Fly Ash in Concrete