The Utah Department of Transportation (UDOT) has fully implemented the Mechanistic-Empirical Pavement Design Guide for pavement design but has been using primarily level-three design inputs obtained from correlations to aggregate base materials developed at the national level. UDOT was interested in investigating correlations between laboratory measurements of resilient modulus, California bearing ratio (CBR), and other material properties specific to base materials commonly used in Utah; therefore, a statewide testing program was needed. The objectives of this research were to 1) determine the resilient modulus of several representative aggregate base materials in Utah and 2) investigate correlations between laboratory measurements of resilient modulus, CBR, and other properties of the tested materials. Two aggregate base materials were obtained from each of the four UDOT regions. Important material properties, including particle-size distribution, soil classification, and the moisture-density relationship, were investigated for each of the sampled aggregate base materials. The CBR and resilient modulus of each aggregate base material were determined in general accordance with American Society for Testing and Materials D1883 and American Association of State Highway and Transportation Officials T 307, respectively. After all of the data were collected, several existing models were evaluated to determine if one or more of them could be used to predict the resilient modulus values measured in this research. Statistical analyses were also performed to investigate correlations between measurements of resilient modulus, CBR, and other properties of the tested aggregate base materials, mainly including aspects of the particle-size distributions and moisture-density relationships. A set of independent predictor variables was analyzed using both stepwise regression and best subset analysis to develop a model for predicting resilient modulus. After a suitable model was developed, it was analyzed to determine the sensitivity of the model coefficients to the individual data points. For the aggregate base materials tested in this research, the average resilient modulus varied from 16.0 to 25.6 ksi. Regarding the correlation between resilient modulus and CBR, the test results show that resilient modulus and CBR are not correlated for the materials tested in this research. Therefore, a new model was developed to predict the resilient modulus based on the percent passing the No. 200 sieve, particle diameter corresponding to 30 percent finer, optimum moisture content, maximum dry density (MDD), and ratio of dry density to MDD. Although the equation may not be applicable for values outside the ranges of the predictor variables used to develop it, it is expected to provide UDOT with reasonable estimates of resilient modulus values for aggregate base materials similar to those tested in this research.

Light-weight aggregate has been used successfully for structural and non-structural applications, and its most common use has been in light-weight concrete. Limited research has been done on light-weight grout though and there are no standards in place. The research performed in this study is intended to increase the knowledge of light-weight grout specifically made with expanded shale aggregate. The research presented herein is a pilot study and consists of preliminary aggregate and grout testing that resulted in the mix design of six grout types: three fine grout designs and three coarse grout designs. Conventional normal-weight aggregate was employed in the first grout mix. A light-weight aggregate batch was made with the same material proportions, as well as the same target water-cement (w/c) ratio and cement content. The weight of the cement was increased by 30 percent in the third grout type of each set to determine the effect on strength. The slump, component temperature, unit weight, air content, segregation, cement content, w/c ratio, and compressive strength for each grout type was gathered throughout testing. Correlations between grout testing results are examined and discussed. In addition, the effectiveness of expanded shale grout, other light-weight grouts, and normal-weight grout with respect to compressive strength to cement content ratio are determined. Results of the testing show that all six grout types studied in this research reached the minimum 28-day strength of 13.8 MPa (2000 psi) ASTM standard. In addition, the results indicate that the cement content in expanded shale light-weight grout would need to be increased to reach comparable compressive strengths to that of the normal-weight grout. The comparison between the compressive strength to cement content ratio of the different grouts indicate that normal-weight grout is more efficient. In addition, light-weight grout made with blast furnace slag grout is slightly more efficient than that made with expanded shale; however, this observation was only possible after several crucial assumptions were made about an existing blast furnace slag study. These strength-cement ratios do not account, however, for the benefits of reduced dead loads, improved thermal insulation, and improved sound insulation that could potentially influence the choice of the material used in and the life-cycle cost of the construction. Additional research should be done to verify the results of the ratios and the assumptions made herein. Furthermore, a life-cycle analysis needs to be conducted before a definite conclusion is made about which type grout is more efficient.

Yes / Concrete requires a vast amount of aggregate and cement production. Although there are some efforts in the literature to reduce the amount of Portland cement in the concrete mixture to lessen the greenhouse gas release, a limited number of studies were conducted to investigate the possibility of using this geopolymer mixtures to serve as a structural component. Therefore, this study firstly aimed to produce geopolymer concrete from construction and demolition waste-based precursors, including masonry units (red clay brick, roof tile, hollow brick, etc.) and glass. In addition, recycled aggregates produced from the concrete waste portion of the CDW were used to obtain 100% recycled construction material on the scale of the binder and aggregate phase. Then, this study investigated the possible use of this proposed geopolymer concrete to produce structural components that perform similar to conventional concrete. Therefore, the structural properties of reinforced geopolymer concrete beams produced from the recycled construction demolition wastes were evaluated in this study by conducting laboratory experiments. To this end, bending tests were performed on reinforced conventional concrete beam specimens and reinforced geopolymer concrete beam specimens. The test observations clearly showed that construction demolition waste could be recycled to produce new constructional components, considering its advantage of promoted sustainability. / The authors gratefully acknowledge the European Union’s Horizon 2020 Research and Innovation Programme’s financial assistance under Grant Agreement No: 869336 and Acronym: ICEBERG and the financial assistance of the Scientific and Technical Research Council (TUBITAK) of Turkey and the British Council under Grant no:218M102. This work was also supported by Newton Prize 2020.

In this thesis, I take a theoretical dynamic stochastic general equilibrium (DSGE) approach to investigate optimal aggregate dividend policy. I make the following contribution: 1. I extend the standard DSGE model to incorporate a residual dividend policy, external financing and default and find that simulated optimal aggregate payouts are much more volatile than the observed data when other variables are close to the values observed in the data. 2. I examine the sensitivity of optimal aggregate dividend policy to the level of the representative agent¿s habit motive. My results show that, when the habit motive gets stronger, the volatility of optimal aggregate payouts increases while the volatility of aggregate consumption decreases. This is consistent with the hypothesis that investors use cash payouts from well diversified portfolios to help smooth consumption. 3. I demonstrate that the variability of optimal aggregate payouts is sensitive to capital adjustment costs. My simulated results show that costly frictions from changing the capital base of the firm cause optimal aggregate dividends and real investments to be smooth and share prices to be volatile. This finding is consistent with prior empirical observations. 4. I run simulations that support the hypothesis that optimal aggregate dividend policy is similar when the representative firm is risk averse to when it has capital adjustment costs. In both cases, optimal aggregate dividends volatility is very low. 5. In all calibrated DSGE models, apart from case 4, optimal aggregate payouts are found to be countercyclical. This supports the hypothesis that corporations prefer to hold more free cash flows for potential investment opportunities instead of paying dividends when the economy is booming, but is inconsistent with observed data. Keywords: Dynamic Stochastic General Equilibrium (DSGE), real business cycle, utility function, habits, dividends

This dissertation includes three chapters. The first chapter studies the impact of financial shocks and financial frictions on business cycle dynamics in China's economy. The second and third chapters focus on the driving force of structural change and its impact on aggregate fluctuations using an input-output network approach. In the second chapter, I study two questions: (i) How has the U.S. production network structure changed from 1970 to 2017? (ii) What impact does that have on aggregate fluctuations? This paper shows that a few industries, like Finance and Insurance and Professional Services, have become much more central input suppliers over time, while others, like Paper Manufacturing, have become far less important. Therefore, the third chapter considers the driving force behind such structural change. In particular, I study the question of what determines the size of an industry in a production network. China has been one of the world's fastest-growing economies over the past several decades and emerged quickly from the global financial crisis of 2008. Chapter 1, titled DO FINANCIAL SHOCKS DRIVE REAL BUSINESS FLUCTUATIONS IN CHINA, investigates to what extent financial shocks can shape business cycle fluctuations in China. Specifically, I document the cyclical properties of China's macroeconomy and financial market and show the procyclicality of dividend payout and the countercyclicality of debt repurchases with real GDP. To account for these features, I use the real business cycle model incorporating debt and equity financing developed by Jermann and Quadrini (2012) to study how the dynamics of macroeconomic and financial variables are affected by financial shocks in China. This paper finds that financial shocks contribute significantly to business cycle fluctuations in China and can account for over 60% of the variations in the growth rate of output, investment, hours worked, and debt repurchases. Hulton's Theorem states that the impact of an industry-specific shock on the aggregate economy is entirely captured by the size of this industry, regardless of its position in the production network. Chapter 2, titled THE IMPORTANCE OF INPUT-OUTPUT NETWORK STRUCTURE IN THE US ECONOMY, proposes the idea that the network structure in isolation plays an essential role in shaping GDP growth and growth volatility. First, I introduce a new measure of network structure named centrality dispersion and document that the U.S. production network has become sparsely connected from 1970 to 2017, where many industries relied on a few central input suppliers for production. Such changes are associated with slower GDP growth and higher volatility. To account for this evidence, I embed input-output linkages into a multisector real business cycle model and provide a nonlinear characterization of the impact of network structure quantified using centrality dispersion on the macroeconomy. Finally, I study model-implied relationships between production network structure, GDP growth, and growth volatility. The calibrated model accounts for approximately one-quarter of the variation in real GDP growth and 40% of GDP volatility, as observed in the data. Chapter 3, titled THE NETWORK ORIGIN OF INDUSTRY SIZE VARIATIONS, quantifies the origin of industry size variations using the features of a production network. In the analysis, I perform an exact variance decomposition of industry total sales into the supplier, buyer, and final demand components. The findings suggest that matching with many buyers in the network, especially many large buyers is essential in understanding industry size variations. More importantly, these buyer characteristics have become increasingly important in contributing to industry size variations over the 1967-2012 period. Finally, I provide new empirical evidence related to the decomposition results. The evidence reveals a strengthening negative correlation between industry size and the concentration of customer networks in the long run. / Economics

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yes / There are very few, if any, available experimental investigations on aggregate interlock capacity along diagonal cracks in lightweight concrete deep beams. As a result, the shear design provisions including the modification factor of ACI 318-08 and EC 2 for lightweight concrete continuous deep beams are generally developed and validated using normal weight simple deep beam specimens. This paper presents the testing of 12 continuous beams made of all-lightweight, sand-lightweight and normal weight concrete having maximum aggregate sizes of 4, 8, 13 and 19 mm. The load capacities of beams tested are compared with the predictions of strut-and-tie models recommended in ACI 318-08 and EC 2 provisions including the modification factor for lightweight concrete. The beam load capacity increased with the increase of maximum aggregate size, though the aggregate interlock contribution to the load capacity of lightweight concrete deep beams was less than that of normal weight concrete deep beams. It was also shown that the lightweight concrete modification factor in EC 2 is generally unconservative, while that in ACI 318-08 is conservative for all-lightweight concrete but turns to be unconservative for sand-lightweight concrete with a maximum aggregate size above 13 mm. The conservatism of the strut-and-tie models specified in ACI 318-08 and EC 2 decreased with the decrease of maximum aggregate size, and was less in lightweight concrete deep beams than in normal weight concrete deep beams.

Over the past decade, the market for wireless service has grown at an unprecedented rate. The industry has grown from cellular phones and pagers to broadband and ultra-broadband (also called ultra-wideband) wireless services that can provide voice, data, and full-motion video in real time. This growing hunger for faster data rates and larger bandwidths has prompted a need for a deeper understanding of the wireless channels upon which these devices communicate. In order for the visions of real time full-motion video, multimedia, and high speed data delivery inherent in the 3rd and 4th generations of wireless communication standards to be fully realized, system design engineers must have a thorough understanding of the wireless channels upon which these devices operate. Additionally, for these networks to deliver their promised data rates, they must operate at very high microwave and millimeter-wave frequencies, where large segments of spectrum are readily obtained. Unfortunately, little is known about the propagation characteristics at these frequencies and bandwidths. As a consequence, there has been a significant demand for wireless test equipment that is capable of characterizing these new wireless channels. The objective of this research was to design and develop a wireless test instrument that can not only characterize these new wireless channels, but has the portability to be quickly and easily re-located to various measurement sites, as well as the flexibility to characterize a wide variety of frequencies and bandwidths in addition to the ultrawideband channels investigated in this work. This measurement system is also designed to be capable of characterizing both the magnitude and phase response of these wireless channels, which not only provides a more complete channel characteristic, but the potential capability to measure the Doppler spectrum introduced by a dynamic channel. / Master of Science