Olefinic homo- and copolymers including polystyrene, polybutadi- ene, polyisoprene and polystyrene-polybutadiene di-block coplymers are widely used commercial products and most of them can be prepared from anion polymerization. During the last step of the anionic co- and homo- polymerizations, different terminating agents were used to terminate the polymerization and to generate products containing various inorganic salts, which have profound effects on the transparency of the final polymers. For example, polymers containing lithium chloride (LiCl) are generally opaque in appearance while polymers containing lithium methoxide (Li(OCH3)) or lithium hydroxide (LiOH) are transparency. This study concerns the effect of the inorganic salts on the polymers¡¦ transparency. Inorganic salts such as LiCl, zinc chloride (ZnCl2), alumi- num chloride (AlCl3) were added to the polymer solution to prepare various salt/polymer solution for the study of their transparency, solution viscosity, light scattering and morphology of the solid product after solvent removal. Basically, LiCl will complex with tetrahydrofuran (THF, as activator for anionic polymerization) and the resulting complex were encompassed by the polymer coil in the solution and further aggregation occurred form particle large enough to scatter light. Size of the salt/polymer aggregates was determined by the polymer concentration, salt content, amounts of THF and the solvent applied. The large the particle size, the immense the light scattered and therefore, the reduced transparency of the salt/polymer solution and the resulting solid product after solvent removal. Particle size formed during the termination step is the key factor determining the transparency of the final solid polymers.

The Wisconsin Department of Transportation (WisDOT) uses approximately 11,000,000 tons of aggregate per year for transportation projects. Being able to select durable aggregates for use in transportation projects is of considerable importance, if the aggregate deteriorates then the constructed facility requires premature repair, rehabilitation or replacement. Realizing the importance and also that deficiencies in the current WisDOT testing protocol may exist, it has been concluded that the durability-testing program for Wisconsin aggregates needs to be updated. For example, WisDOT is currently using the Sodium Sulfate Soundness Test (ASTM C 88) to measure durability, a test that was put in place in 1960. The ability of this test to predict durability performance and simulate field conditions is questionable and it has also been criticized for its lack of precision. It should also be noted that the use of recycled and reclaimed aggregates has increased in recent years and not all typical durability tests can be used for testing these aggregates. The Sulfate Test in particular cannot be used for testing Recycled Concrete Aggregates (RCA) because the chemical reaction produces erroneous and misleading results. This project has identified recent advances in the understanding and testing of aggregate durability. An in depth literature review has been conducted and from the compiled information a laboratory testing program was developed. Selection of the tests was based upon the tests' precision, efficiency, and predictive capabilities. In the laboratory-testing phase of this project the proposed durability tests along with current WisDOT durability tests were used to evaluate the full range of Wisconsin aggregates. From the test results it was found that the WisDOT aggregate testing protocol could be reduced substantially by eliminating many of the testing requirements for aggregates that have a vacuum saturated absorption of less than 2%. Also, the addition of several tests was ruled out due to their lack of correlation with field performance records. The Micro-Deval abrasion test is recommended for inclusion in WisDOT testing protocol as a test to measure the abrasion resistance of aggregate while the L.A. Abrasion test is better suited as a measure of aggregate strength. Additional conclusions were made based on the durability testing conducted and an overall testing protocol has been developed and is recommended for implementation by WisDOT. / Master of Science

No description available.

No description available.

This research targets Metakaolin as main material, with various kinds of combination materials and binder, and uses a mechanism to make colding metakaolin lightweight aggregate and then makes five different proportion of metakaolin lightweight aggregate, with an aim to know the effects of different proportion on aggregate through the destruction of point load , sift analysis , and unit weight. Choosing suitable aggregate based on ACI norm to set three groups of different water-cement ratio A(0.54)¡BB(0.46)¡BC(0.35) to mix into lightweight aggregate concrete, this is to find out the correlation between physical properties and mechanical behavior of metakaolin lightweight aggregate concrete through pressure resistance , splitting off , absorption capacities. The result shows that different proportions of metakaolin lightweight aggregate also take different effects, a suitable formula is selected in accordance with the application. Of all the groups, group D (cement¡Gslaked lime¡Gmetakaolin¡Gfly ash¡Gsand =12.5%¡G12.5%¡G28.125%¡G 9.375%¡G37.5%) has the best mechanical and physical performance. The mechanical properties such as pressure resistance and splitting strength of aggregate made from metakaolin lightweight aggregate concrete can meet up with CNS and ASTM norms, and it is superior to fly ash lightweight aggregate concrete.

Fort Hood Military Reservation is a 900 km2 military installation located between Killeen, Copperas Cove, and Gatesville in central Texas. It supports two full armored divisions which require year-round, live-fire maneuvers and training (Ft. Hood, 2003). As a result of the constant foot traffic and use of heavy equipment, the soils on the training ranges have become increasingly compacted, eroded, and stripped of vegetation. This study evaluated the impact that selected soil amendments would have on soil aggregation, infiltration, and levels of glomalin. A field study was done on plots located inside Fort Hood on a Nuff silty clay (fine-silty, carbonatic, thermic Udic Calciustoll). The plots were amended with composted dairy manure, inorganic fertilizers, and native grass seed. Aggregate stability was determined using a wet sieving procedure and total glomalin values were quantified using a Bradford assay. Field measurements of infiltration rates were taken using a drip-type rainfall simulator. Aggregate stability exhibited decreased values over time for all treatments but two (Site Prep / No Seed and Site Prep / Compost / Seed). In addition, three treatments changed significantly over time (from before treatment application to after treatment application). These treatments were the Site Prep / Compost / No Seed, No Prep / No Seed, and No Prep / Seed treatments. Levels of glomalin increased significantly over time for all treatments (p-value <0.001). Glomalin was correlated to aggregate stability after treatments were applied (p-value <0.01) but not before (p-value 0.89). In addition, infiltration rates were not related to glomalin (p-value 0.9) or aggregate stability (p-value 0.09). Additional sampling of Fort Hood beyond the plot study demonstrates significant differences in aggregate stability, infiltration rates, and levels of glomalin. Measurements taken from ten sites showed no correlations between aggregate stability, infiltration rates, or glomalin. Organic C was correlated to percent water stable aggregates (%WSA) and levels of glomalin. These results illustrate the relationship between organic C and aggregate stability as well as glomalin levels in maintaining infiltration rates and reducing soil loss by erosion.

No description available.

Es wurden Poly(2-isopropyl-2-oxazolin)-Makroinitiatoren mit terminaler Ammoniumtrifluoracetat-Endgruppe synthetisiert, die anschließend für die Ammonium vermittelte NCA Polymerisation in NMP eingesetzt wurden. Die hierbei synthetisierten Poly(2-isopropyl-2-oxazolin)-block-poly(L-glutamat) (PIPOX-PEP) Blockcopolymere hatten eine Molekulargewichtsverteilung von 1,2 (UZ). Es wurde beobachtet, dass Poly(2-isopropyl-2-oxazolin) bei langen Zeiten oberhalb der LCST irreversibel sphärische Strukturen bildet, die eine hierarchische Struktur besitzen und bei denen es sich möglicherweise um "large compound micelles" handelt. PIPOX-PEP kann in wässeriger Lösung bei langen Zeiten oberhalb der LCST "cottonball" Strukturen bilden. Die Aggregate wurden mittels Lichtstreuung, NMR und TEM charakterisiert. Im Rahmen der Arbeit wurden Strukturbildungsmodelle entwickelt. / A convenient procedure for the synthesis of well-defined poly(2-isopropyl-2-oxazoline)-block-poly(L-glutamate) (PIPOX-PEP) through combined cationic/anionic ring-opening polymerization is described. The key step is the preparation of an ω-(ammonium trifluoroacetate)-poly(2-isopropyl-2-oxazoline), which is used as a macroinitiator for the “ammonium-mediated” polymerization of γ-benzyl L-glutamate N-carboxyanhydride (NCA). PIPOX is a thermoresponsive polymer exhibiting a lower critical solution temperature (LCST) near human body temperature, while PEP responds to changes in pH (helix-to-coil transition). The phase behavior of aqueous PIPOX and PIPOX-PEP solutions has been characterized by means of light scattering, NMR spectroscopy, and transmission electron microscopy (TEM). Phase transition is usually reversible, but renders irreversible when solution are annealed for longer times at 65 °C, far above the LCST. Coagulate particles with hierarchical ordering in the range of nanometers to micrometers, considered as “large compound micelles” or “cottonballs”, are then produced. A tentative mechanism for the formation of such particles is described.

Stone matrix asphalt (SMA) mixtures rely on stone-on-stone contacts among particles to resist applied forces and permanent deformation. Aggregates in SMA should resist degradation (fracture and abrasion) under high stresses at the contact points. This study utilizes conventional techniques as well as advanced imaging techniques to evaluate aggregate characteristics and their resistance to degradation. Aggregates from different sources and types with various shape characteristics were used in this study. The Micro-Deval test was used to measure aggregate resistance to abrasion. The aggregate imaging system (AIMS) was then used to examine the changes in aggregate characteristics caused by abrasion forces in the Micro-Deval. The resistance of aggregates to degradation in SMA was evaluated through the analysis of aggregate gradation before and after compaction using conventional mechanical sieve analysis and nondestructive X-ray computed tomography (CT). The findings of this study led to the development of an approach for the evaluation of aggregate resistance to degradation in SMA. This approach measures aggregate degradation in terms of abrasion, breakage, and loss of texture.

This research project entails analyses of both alcoholic route C8S3 J-aggregate bundles and the interactions of a polyethylene glycol additive with alcoholic route C8S3 J-aggregates. First, the C8S3 J-aggregate bundles are characterized by both polarized and non-polarized spectroscopy methods. Orientation of the tubular bundled molecular complex was achieved, depending on the experiment, through a combination of flow cell experiments and cover slip deposited sample analysis. Next, isolated alcoholic route C8S3 J-aggregates were investigated using a polyethylene glycol (PEG) additive which has been shown, through absorbance and fluorescence emission spectroscopy, to selectively and reversibly remove the outer wall of the J-aggregate tubule. Spectroscopic analyses have indicated that the addition of a PEG additive left behind an in-tact inner wall tubule without the use of oxidizing agents, a feat never before accomplished with the C8S3 monomer. / text