The deterioration of today's infrastructure particularly roadways and bridge decks has continued to increase over the years due to the larger axle loads, higher traffic volumes of densely populated cities. These highly congested areas have required the need to repair and rehabilitate the affected pavements in a timely manner with minimal traffic interruptions. Different rapid hardening binders were tested in this project to evaluate and characterize their performance when subjected to concrete distresses such as alkali-silica reaction, delayed ettringite formation, corrosion, freezing and thawing, salt scaling, sulfate attack, material incompatibility and volume changes. Among the cements tested were calcium aluminate cement, calcium sulfoaluminate cement, accelerated portland cement, alkali-activated fly ash, and three other proprietary blends available to the public. This thesis will summarize the preliminary findings of a comprehensive laboratory study focusing on rapid repair materials -- the final results of this study will be included in future publication (theses and final project report). / text

Currently, in Texas, there is a need for different repairs on pavements and bridge decks; rapid repair materials designed for these repairs are available but the service life and durability of these products are often inadequate. Thus, the goal for the Texas Department of Transportation (TxDOT) is to implement repairs with an extended service life in a timely manner, in order to cause minimal disruption. Research performed under TxDOT Project 6723 (Development of Rapid, Cement-based Repair Materials for Transportation Structures) evaluated a wide range of rapid repair materials, including calcium aluminate cement (CAC), calcium sulfoaluminate cement (CSA), fly ash alkali activated blends, and ordinary portland cement. Some of the properties which contribute to a long-term service life are: mechanical properties, early-age volume change, and the heat evolution; often, the early-age development of these repair materials can cause later durability issues. These properties were examined through a variety of experiments and test in the laboratory, as well as, in the field. / text

The U.S. military must have the ability to rapidly deploy troops and equipment anywhere in the world as part of a contingency operation. Recent military operations have highlighted the critical need for rapid repair procedures and materials for military use on sub-standard, in-theater airfields. The U.S. Army Corps of Engineers, Engineer Research and Development Center is currently addressing these problems through a program titled ?Joint Rapid Airfield Construction?. This study involves the development of a method using rapid setting grouts and recycled concrete pavement (RCP) to repair portland cement concrete (PCC) pavements. A laboratory study was conducted to evaluate material properties in order to gain an understanding of expected field performance. Eight full scale repairs were constructed using two rapid setting grouts, two types of equipment, and two concrete slabs. The repairs were successfully trafficked with simulated C-17 aircraft wheel loads to verify the structural capacity, and ultimately the procedures.

Master of Science / Department of Civil Engineering / Mustaque A. Hossain / Based on a 2017 report on infrastructure by the American Society of Civil Engineers, 13% of Kansas public roads are in poor condition. Furthermore, reconstruction of a two-lane concrete pavement costs between $0.8 and $1.15 million dollars per lane mile. High early strength Portland cement concrete pavement (PCCP) patches are widely used in pavement preservation in Kansas due to the ability to open to traffic early. However, these repairs done by the Kansas Department of Transportation (KDOT) deteriorate faster than expected, though, prompting a need for inexpensive, durable high early strength concrete repair mixtures that meet KDOT standards (i.e., a 20-year service life). This study developed an experimental matrix consisting of six PCCP patching mixture designs with varying cement content and calcium chloride dosage. The mixtures were subjected to isothermal calorimetry, strength testing, drying shrinkage, and various durability tests. The effects of cement content and calcium chloride dosage on concrete strength and durability were then investigated. In addition, the compressive strength development with time, the split tensile versus compressive strength relationship, and the shrinkage strain of the PCCP patching mixtures were compared to established relationships provided by the American Concrete Institute (ACI). Results showed a maximum 3% increase in total heat generated by various concrete paste samples in isothermal calorimetry testing. The minimum compressive strength of 1,800 psi required by KDOT could likely be obtained using any of the PCCP mixtures, regardless of the cement content or calcium chloride dosage used in the study. Furthermore, surface resistivity tests for mixtures containing calcium chloride could result in erroneous measurements. Only one mixture satisfied the maximum expansion and minimum relative dynamic modulus of elasticity required by KDOT. Some ACI relationships for shrinkage and strength development do not appear to be valid for high early strength PCCP patching mixtures.

Concrete pavements are a suitable alternative for high-traffic volume roads, concentrated loads and roads exposed to severe weather conditions. In Sweden, among other reasons, the scarcity of concrete pavements is attributed to the need for more national knowledge and expertise in the field. The most recent concrete pavement was constructed seventeen years ago in Uppsala. Concrete pavements are renowned for their longevity and durability. Jointed plain concrete pavements (JPCP) are the most frequent type of concrete pavements. However, it is important to note that the joints in concrete pavements are critical components that can lead to various distresses, necessitating rehabilitation. Rehabilitating concrete pavements is particularly challenging in areas with heavy traffic and requires substitute routes because of the imperative to maintain traffic flow during construction. Developing effective detours might involve significant alterations to the existing routes or building temporary roads, which entails substantial cost investment and time consumption. A literature review has been conducted to study the available methods that can be used to repair concrete pavements. The strategy for selecting a repair technique is based on rehabilitating the concrete pavement within a short work window, deterring traffic congestion and ensuring the long service life of the pavements. The study showed that the precast concrete technology based on the precast slab is a promising technology that effectively shortens the lane closure for repairing damaged pavements and produces durable pavements, thereby extending the service life of pavements. However, the construction or rehabilitation cost of concrete pavement using precast slabs is 1.6 to 4 times higher than that of conventional cast-in-place concrete. Therefore, rehabilitation using precast slabs is inappropriate for low-traffic roads and temporary routes. Joints are crucial for the rehabilitation of concrete pavements with precast slabs. The structural performance of concrete pavement is, however, greatly affected by the joints, as the presence of joints creates a discontinuity between adjacent slabs and thus diminishes the load transfer to the abutting slab. To maintain the structural integrity of the pavement system, dowel bars are used at the transverse joints. A numerical study has been conducted to evaluate the influence of various dowel-related parameters on the interaction between adjacent concrete slabs. The study revealed that the dowel bar’s position, mislocation and diameter had an obvious effect on joint efficiency, while the bond between the concrete slab and the dowel bar slightly affected the load transfer efficiency. It was also investigated that the dowel bar’s intended performance, i.e., load transfer efficiency, was reduced as the joint gap between adjacent slabs increased. / Betongbeläggningar är ett lämpligt alternativ för högtrafikerade vägar, koncentrerad belastning och vägar utsatta för svåra väderförhållanden. I Sverige är betongvägar sällsynta vilket bl.a. beror på brist på kunskap och kompetens. Den senaste betongvägen byggdes för sjutton år sedan i Uppsala.Betongbeläggningar är kända för sin långa livslängd och hållbarhet. Den vanligaste typen av betongvägar är fogade, oarmerade betongbeläggningar. Ändå är det viktigt att notera att fogarna i betongbeläggningar är kritiska komponenters om kan leda till olika olägenheter, vilket kräver rehabilitering. Att rehabilitera betongbeläggningar är särskilt utmanande i områden med intensiv trafik som kräver ersättningsvägar på grund av nödvändigheten att upprätthålla trafikflödet under reparationsarbetena. Att ta fram en effektiv omledning av trafiken kan innebära antingen väsentliga förändringar och förlängningar av befintliga rutter eller byggande av tillfälliga vägar, vilket medför betydande kostnadsinvesteringar och tidsåtgång. En litteraturöversikt har genomförts för att studera de tillgängliga metoderna som kan användas för att reparera betongbeläggningar. Strategin för valet av reparationsmetod bygger på att rehabilitera betongbeläggningen inom ett kort arbetsfönster, förhindra trafikstockningar och säkerställa lång livslängd för beläggningen. Studien visade att förtillverkade betongplattor är en lovande metod som effektivt förkortar avstängningen av körfält för att reparera skadad beläggning och producerar hållbara betongbeläggningar med lång livslängd. Rehabiliterings kostnaden för betongbeläggning med prefabricerade plattor är emellertid 1,6 till 4 gånger högre än den för konventionell platsgjuten betong. Därför är rehabilitering med förtillverkade betongplattor olämplig för vägar med låg trafik och temporära rutter. Fogar är vidare nödvändiga vid reparation med förtillverkade betongplattor.Betongbeläggningens strukturella prestanda påverkas dock kraftigt av fogar, eftersom förekomsten av fogar skapar en diskontinuitet mellan intilliggande plattor och därmed minskat lastöverföringen till den angränsande plattan. För att upprätthålla den strukturella integriteten hos beläggningssystemet används dymlingar i de tvärgående fogar. En numerisk studie har genomförts med olika parametrar för att utvärdera dymlingens inverkan på fogens effektivitet. Studien visade att dymlingens position, felplacering och diameter har en tydlig inverkan på fogens effektivitet, medan vidhäftningen mellan dymling och betongplatta enbart verkar ha en marginell inverkan på fogens effektivitet. Studien visade också att dymlingens prestanda, dvs. lastöverföringsförmågan, minskade då fogöppningen eller glappet mellan två närliggande plattor ökade. / <p>QC 240207</p>

Composite materials have a wide range of applications in civil and structural engineering due to their advantages in mechanical properties and higher strengths over the base materials alone. Polymer-concrete composites are particularly attractive for use in industrial and infrastructure applications from combining the higher mechanical properties of the concrete in tension and the high tensile strength and ductile properties of the polymeric materials. However, these materials tend to be more expensive that typical concrete composites. This thesis explores the mechanical properties of two different polymer-concrete composites and their effectiveness in civil and structural applications: polymer concrete for rapid repair and 3D printed plastic-concrete composite members for energy absorption. The North Atlantic Treaty Organization (NATO) requires that emergency repair of military runways should be completed within 4 hours. In coordination with Luna Innovations Incorporated, a polymer concrete was developed by Luna for use as a rapid repair material for military runways to meet this requirement through its rapid heat curing. Its mechanical properties including its compressive and flexural strength, bond strength in various orientations, workability, modulus of elasticity, and coefficient of thermal expansion were tested and compared against another rapid repair material. The Tri-Service Pavements Working Group Manual recommendations for rigid repair materials were used as the requirements in determining whether the polymer concrete was an adequate rapid repair material. The polymer concrete formulation that was down-selected for further testing met these requirements for all tests except for the coefficient of thermal expansion. This was due to the resin itself having a high volumetric expansion when exposed to greater temperatures. As the polymer concrete is still under development, future tests are to be performed to determine the impact of the higher expansion on the surrounding runways. Additionally, inspired from naturally forming nacre found in some seashells, a 3D printed plastic-concrete beam structure was developed and tested in flexure to determine its energy absorption capabilities. The nacreous structure allows the material to experience a strain-hardening behavior, thus allowing for energy dissipation in the beam as it deflects from further applied load. It is theorized that the energy absorption capabilities would be suitable for withstanding the effects of dynamic loadings in structures, such as earthquake and blast loads. Multiple beam structures were developed and tested to determine the impact of percent-polymeric material and layout had on the energy dissipation. Overall, the specimens with more polymer in the cross-section demonstrated larger load vs. crack mouth displacement curves and fracture energy. These specimens demonstrated a higher toughness as well, making them more suitable for use in structural applications. As the project is still in development, future tests and analysis must be performed to determine their strength properties and feasibility as a structural material. The results of this thesis highlight the benefits of novel polymer composites in industrial and infrastructure applications, such as improved rapid setting characteristics and significantly enhanced mechanical and energy absorbing performance. Future work is needed to optimize these performance metrics, such as freeze thaw cycling, fatigue, and durability tests for the polymer concrete and analysis of moment capacity for the bioinspired nacreous composites. / Master of Science / Composite materials have a wide range of applications in civil and structural engineering due to their advantages in mechanical properties and higher strengths over the base materials alone. Polymer concrete composites are not as widely used due to their greater initial costs. However, they are very attractive in industrial and infrastructure applications because of the improved behavior in tension. This thesis explores the mechanical properties of two different polymer-concrete composites and their effectiveness in civil and structural applications: polymer concrete for rapid repair and 3D printed plastic-concrete composite members for energy absorption. The North Atlantic Treaty Organization (NATO) requires that emergency repair of military runways should be completed within 4 hours. In coordination with Luna Innovations Incorporated, a polymer concrete was developed by Luna for use as a rapid repair material for military runways to meet this requirement through its rapid heat curing. Its mechanical properties were tested and compared against another rapid repair material. The polymer concrete formulation that was down-selected for further testing met the requirements of the military for all tests performed except for the coefficient of thermal expansion. As the polymer concrete is still under development, future tests are to be performed to determine the impact of the higher expansion on the surrounding runways. Additionally, inspired from naturally forming nacre found in some seashells, a 3D printed plastic-concrete beam structure was developed and tested in bending to determine its energy absorption capabilities. The nacreous structure allows the material to experience a strain-hardening behavior, thus allowing for energy dissipation in the beam as it deflects from further applied load. It is theorized that the energy absorption capabilities would be suitable for withstanding the effects of earthquake and blast loads in structures. Multiple beam structures were developed and tested to determine the impact of percent-polymeric material and layout had on the energy dissipation. Overall, the specimens with more polymer in the cross-section demonstrated greater energy absorption capabilities. As the project is still in development, future tests and analysis must be performed to determine their strength properties and feasibility as a structural material. The results of this thesis highlight the benefits of novel polymer composites in industrial and infrastructure applications, such as improved rapid setting characteristics and significantly enhanced mechanical and energy absorbing performance. Future work is needed to optimize these performance metrics, such as freeze thaw cycling, fatigue, and durability tests for the polymer concrete and analysis of moment capacity for the bioinspired nacreous composites.

For repairing concrete transportation infrastructure, such as pavements and bridges, much importance is placed on early-age strength gain as this has a major impact on scheduling and opening to traffic. However, the long-term performance and durability of such repair materials are often not satisfactory, thus resulting in future repairs. This research project focuses on the evaluation of the durability of various rapid-setting cementitious materials. The binders studied in this project include calcium aluminate cement (CAC), calcium sulfoaluminate cement (CSA), Type III portland cement, alkali-activated fly ash (AAFA) , and various prepackaged concrete materials. In addition, selected CAC and CSA mixtures were further modified with the use of a styrene-butadiene latex. The durability aspects studied include freezing-and-thawing damage and the implications of air entrainment in these systems, alkali-silica reaction, sulfate attack, and permeability of the concrete matrix and potential corrosion. / text