, Former University Researcher, Civil, Environmental and Geo-Engineering
New cementitious products and chemical admixtures are now being introduced to the market on a daily basis. In addition, new sources of sand and coarse aggregate are being marketed as older sources become depleted. Finally, concrete mix design, placement and curing practices are also being modified as contractors look for ways to complete projects more quickly and to make use of the materials described previously. One result of these developments is that the Minnesota Department of Transportation (MnDOT) is being challenged to continually evaluate the effects of using these newer materials and practices on the potential performance of concrete that is placed in transportation-related structures in the state of Minnesota. Research is needed to assist MnDOT in determining the physical and mechanical properties of concrete being used in MnDOT construction and to provide a basis for developing guidelines that will help to ensure the use of suitable materials and practices in future construction. The goal of this project is to assist MnDOT in determining select physical and mechanical properties for concrete specimens obtained from laboratory and/or field-cast concrete products. The properties of specific interest in this project are the Young's modulus (modulus of elasticity), compressive strength, thermal coefficient of expansion/contraction, freeze-thaw durability and hardened air void system parameters. The results of groups of tests will be analyzed to provide assessments of variability and probable performance using standard statistical analysis techniques along with commonly accepted thresholds associated with acceptable performance for each parameter.