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A ternary-blend concrete (65% cement, 25% slag, and 10% fly ash) containing fractionated reclaimed asphalt pavement (FRAP) as a partial replacement (0%, 20%, 35%, and 50%) for coarse aggregate was investigated through a comprehensive laboratory testing program. With increasing FRAP replacement, the concrete workability increased, unit weight decreased, and air content was mainly unaffected. The source of the measured strength and modulus reductions was linked to the interface between the FRAP particle and the paste. The incorporation of FRAP did not significantly impact the concrete free drying shrinkage but did reduce the restrained ring shrinkage strains. The freezing-and-thawing durability was acceptable for all tested FRAP contents. Fracture results indicated that FRAP addition did not statistically affect the initial or total fracture energy of the concrete. Mixtures containing up to 50% coarse FRAP may be used in concrete pavement and still produce acceptable fresh and hardened properties.

Large-scale load testing was completed on both plain and fiber-reinforced concrete slabs-on-ground. The fiber-reinforced concrete used a new synthetic macrofiber. Although the synthetic fibers did not alter the tensile cracking load of the plain concrete slab, the flexural cracking load of the plain concrete slab was increased by 25 and 32% with synthetic fiber addition of 0.32 and 0.48% by volume, respectively, for the center loading configuration. Similarly, synthetic fibers at 0.48% volume fraction increased the flexural cracking load of plain concrete slab under edge loading by 28%. The ultimate load capacity of the plain concrete slab under center loading was increased by 20 and 34% with the addition of 0.32 and 0.48% synthetic fibers, respectively. Embedded strain gauges in the concrete slabs and deflection profile measurements indicated the fibers effectively distributed the load throughout the slab volume as cracking progressed, resulting in the increased concrete slab flexural and ultimate capacities. [PUBLICATION ABSTRACT]

It is important to monitor the evolution of concrete stiffening and setting in a continuous fashion because these developments can indicate when to initiate curing strategies, appropriate time windows for sawcutting of contraction joints, the rate of early concrete strength gain, and proper formwork removal times. In the laboratory, early-age concrete setting and hardening have been investigated using penetration resistance or embedded sensors, but these methods have limited suitability for field application. Therefore, an in-place measurement technique for determination of concrete setting times has been sought for many years, particularly because of its potential to provide more reliable information for concrete construction decisions. Recently, contactless ultrasonic testing approaches have been deployed for material characterization and defect detection applications. Staszewski et al applied scanning measurements of ultrasonic waves using three-dimensional laser vibrometry to detect fatigue cracks in metallic structures. Castaings and Cawley used contactless air-coupled ultrasonic transmitter and receiver sets to detect crack-like defects in plates. Safaeinili et al.

Joint raveled or spalled damage (henceforth called joint damage) can affect the safety and long-term performance of concrete pavements. It is important to assess and quantify the joint damage over time to assist in building action plans for maintenance, predicting maintenance costs, and maximize the concrete pavement service life. A framework for the accurate, autonomous, and rapid quantification of joint damage with a low-cost camera is proposed using a computer vision technique with a deep learning (DL) algorithm. The DL model is employed to train 263 images of sawcuts with joint damage. The trained DL model is used for pixel-wise color-masking joint damage in a series of query 2D images, which are used to reconstruct a 3D image using open-source structure from motion algorithm. Another damage quantification algorithm using a color threshold is applied to detect and compute the surface area of the damage in the 3D reconstructed image. The effectiveness of the framework was validated through inspecting joint damage at four transverse contraction joints in Illinois, USA, including three acceptable joints and one unacceptable joint by visual inspection. The results show the framework achieves 76% recall and 10% error.

Differential expansion and contraction between the top and bottom of a concrete slab results in curling. Curling affects stresses and deflections and is an important component of any mechanistic-empirical design procedure. A significant portion of curling can be attributed to the combined effects of nonlinear \"built-in\" temperature gradients, irreversible shrinkage, moisture gradients, and creep, which can be represented by an effective built-in temperature difference (EBITD). Several instrumented test sections utilizing several design features were constructed and evaluated using the Heavy Vehicle Simulator (HVS) in Palmdale, California. These instrumented slabs were loaded with a half-axle edge load without wander in order to study the effects of curling and fail the slab sections under accelerated pavement testing. A procedure for estimating EBITD using loaded slab deflections was developed using the HVS results. The advantages of using loaded slab deflections are that they can be used for measuring EBITD of slabs with high negative built-in curl and can also be adapted for a Falling Weight Deflectometer, making the procedure efficient and cost-effective for the back-calculation of EBITD of in-service pavements. Differences in restraints and variability in concrete material properties resulted in EBITDs ranging from â[euro]\"5�C to greater than â[euro]\"30�C. The HVS field tests were also used to examine Miner's hypothesis along with various fatigue damage models. Results indicate test slabs cracked at cumulative damage levels significantly different from unity. New models that incorporate stress range and loading rate along with peak stresses were developed. The coefficients for these models were developed to incorporate transverse cracking, longitudinal cracking, and corner breaks. The models can also be used for slabs that exhibit high negative EBITD. For slabs susceptible to high shrinkage gradients, microcracking resulting from restraint stresses during early ages can significantly reduce the slab's nominal strength. Early-age restraint can vary considerably from one slab to another, depending on restraint. A procedure to model slab strength reduction and slab size was developed using nonlinear fracture mechanics principles. A parameter called the \"effective initial crack depth\" is introduced to characterize the early-age surface microcracking.

This work documents the first version of the U.S. Department of Energy (DOE) new Energy Exascale Earth System Model (E3SMv1). We focus on the standard resolution of the fully--coupled physical model designed to address DOE mission-relevant water cycle questions. Its components include atmosphere and land (110km grid spacing), ocean and sea ice (60km in the mid-latitudes and 30km at the equator and poles), and river transport (55km) models. This base configuration will also serve as a foundation for additional configurations exploring higher horizontal resolution as well as augmented capabilities in the form of biogeochemistry and cryosphere configurations. The performance of E3SMv1 is evaluated by means of a standard set of Coupled Model Intercomparison Project Phase 6 Diagnosis, Evaluation, and Characterization of Klima (CMIP6 DECK) simulations consisting of a long pre-industrial control, historical simulations (ensembles of fully coupled and prescribed SSTs) as well as idealized CO2 forcing simulations. The model performs well overall with biases typical of other CMIP-class models, although the simulated Atlantic Meridional Overturning Circulation is weaker than many CMIP-class models. While the E3SMv1 historical ensemble captures the bulk of the observed warming between pre-industrial (1850) and present-day, the trajectory of the warming diverges from observations in the second half of the 20th century with a period of delayed warming followed by an excessive warming trend. Using a two-layer energy balance model, we attribute this divergence to the model's strong aerosol-related effective radiative forcing (ERFari+aci = -1.65 W m-2) and high equilibrium climate sensitivity (ECS = 5.3 K).