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Item Use of geothermal bridge deck deicing systems to mitigate concrete deterioration in Montana(Montana State University - Bozeman, College of Engineering, 2023) Turner, Ethan Joseph; Co-chairs, Graduate Committee: Kirsten Matteson and Mohammad KhosraviReinforced concrete bridge decks face deterioration from thermal stresses, frost action, and early-age cracking. This thesis presents experimental testing and numerical simulations on a bridge deck deicing system's ability to mitigate concrete deterioration. Two experimental bridge deck models were constructed with embedded heat exchanger tubing and instrumented with thermocouples and strain gauges. The models were tested in a cold chamber laboratory under conditions representative of Montana winter weather. The experimental results suggested that a bridge deck deicing system with an inlet temperature of 8 °C shows promise in deicing, reducing thermal movements, and mitigating early-age cracking through thermal shrinkage. The temperature and strain results of the experiment were used to validate a numerical model constructed in COMSOL Multiphysics. Inlet fluid temperatures of 10 °C and 50 °C, chosen from common ground temperatures in Montana, were tested to evaluate the system's effect on frost action and thermal stresses. With a 10 °C inlet fluid temperature, the system showed promise in deicing and mitigating concrete deterioration. While the system did not always raise the surface temperature above 0 °C, the consistent increase in temperature suggested that under certain weather conditions, the system could keep the top surface temperature above 0 °C for a longer period than with no system. The system was also successful in reducing the range of strain due to thermal movements. The system was not able to mitigate the effects of frost action or temperature gradients. The temperature gradients induced by the system were at times worse than without the system, but the difference was insignificant. With a 50 °C fluid temperature, the system was more effective in deicing and mitigating frost action. The range of strain from thermal movements was also reduced more than with a 10 °C inlet fluid temperature. The thermal gradients, however, were at times slightly greater than design gradients provided by design specifications. The excessive gradients, however, only occurred during extreme weather conditions that are less common in Montana. While not perfect, geothermal bridge deck deicing systems show promise for mitigating some mechanisms of concrete deterioration, while keeping other mechanisms within allowable limits.Item Development of non-proprietary ultra high performance concrete(Montana State University - Bozeman, College of Engineering, 2017) Snidarich, Richard Allen, Jr.; Chairperson, Graduate Committee: Michael BerryUltra-high performance concrete (UHPC) has mechanical and durability properties that far exceed those of conventional concrete. Particularly, UHPC has compressive and post-cracking tensile strengths of around 20 ksi and 0.72 ksi, respectively. Thus, elements made with UHPC are thinner/lighter than elements made with conventional concrete. The enhanced durability properties of UHPC also allow for longer service lives and decreased maintenance costs. However, using UHPC in conventional concrete applications has been cost prohibitive, with commercially available/proprietary mixes costing over 10 times conventional concrete mixes. The overall objective of this research was to develop and characterize economical non-proprietary UHPC mixes made with materials readily available in Montana. This objective was achieved by first identifying and obtaining suitable/economical materials to be used in UHPC. Specifically, the materials identified and used in this research were simply Type I/II portland cement, class F fly ash, fine masonry sand, silica fume, and high range water reducer. UHPC mixes were then developed/characterized/optimized by using a statistical experimental design procedure (response surface methodology). The mixes developed as part of this research obtained compressive strengths of approximately 20 ksi with flows of 11 inches, and costs of $300 per cubic yard (excluding freight of materials).Item Durability of concrete as affected by low air temperature at time of placing(Montana State University - Bozeman, College of Engineering, 1952) Swenson, Floyd D.Item Influence of aggregate particle shape upon concrete strength(Montana State University - Bozeman, College of Engineering, 1963) Stensatter, Gary AlanItem The potential alkali-aggregate reactivity of Montana concrete aggregates(Montana State University - Bozeman, College of Engineering, 1963) Stewart, Thomas GouldItem Concrete durability studies(Montana State University - Bozeman, College of Engineering, 1952) Wallace, Robert A.Item Building green : development and evaluation of an environmentally friendly concrete(Montana State University - Bozeman, College of Engineering, 2011) Roskos, Colter Eastman; Chairperson, Graduate Committee: Michael Berry; Michael Berry and Jerry Stephens were co-authors of the article, 'Identification and verification of self-cementing fly ash binders for 100 percent Portland cement replacement in concrete with glass aggregate' in the journal 'ASCE journal of materials in civil engineering' which is contained within this thesis.; Michael Berry and Jerry Stephens were co-authors of the article, 'Evaluation of fly ash based concretes containing glass aggregates for use in transportation applications ' in the journal 'TRB annual meeting 2012' which is contained within this thesis.; Timothy White, Michael Berry and Jerry Stephens were co-authors of the article, 'Structural performance of self-cementitious fly ash concretes with glass aggregates' in the journal 'ASCE journal of structural engineering' which is contained within this thesis.Concrete is the world's most used construction material, and although it offers some advantages over other building materials from an environmental perspective, its negative impacts in this regard are of growing concern as its use increases. This research investigated replacing 100 percent of the Portland cement and natural aggregates in structural grade concrete with self-cementing fly ashes (by-products of coal fired power plants) and pulverized glass (post-consumer glass from the container industry). Researchers at Montana State University identified 95 fly ashes from a screening of over 491 U.S. power plants that are potentially capable of replacing 100 percent of the Portland cement in conventional concrete. Samples were obtained for 15 of these ashes from which fly ash/glass concretes were made to evaluate their performance. Of these 15 fly ashes, 8 produced concretes with 28-day compression strengths of at least 3,000 psi, making these concretes potentially viable for standard construction applications. Two of these five ashes (from Wyoming and Kansas) were then used in scaled up bulk mixes to determine the mechanical properties (compressive and tensile strength, elastic modulus) and durability (ASR, abrasion, chloride permeability) of these "green" concretes. They exhibited satisfactory performance with some variances from the behavior of conventional concretes, while maintaining controllable set times and adequate workability. Reinforced concrete beams were further made with fly ash/glass concretes produced with the Wyoming and Kansas ashes, and then tested alongside those made with a previously studied Montana ash as well as with traditional Portland cement concrete. Three different reinforcing schemes were used with each of the four concretes to highlight separate failure mechanisms: yielding of the reinforcement, crushing of the concrete, and concrete beam shear. The failure behaviors were generally the same for elements with the same reinforcing scheme, independent of the concrete used. Some differences were seen, however, in the ultimate capacities of the fly ash/glass and traditional beams. Additionally, ultimate capacities predicted with the American Concrete Institute building code (ACI 318-08) were typically conservative compared to the measured capacities of the fly ash/glass beams (in the most unconservative case, the capacity was over predicted by only seven percent).