Evaluation of PCC Specification Changes Impact on Durability: 1992 - 1997 Core Study, MLR-98-06, 2005

In 1990, early distress had shown up on US 20 in Hamilton/Webster counties, three years after paving. Since that time, over a dozen more projects, constructed between 1984 and 1994, have been found to exhibit similar early distress. Several changes to the concrete and Portland cement specifications occurred in 1994 and 1996. This study was undertaken to investigate in place concrete pavements before and after specification changes were implemented. The objective of this research is to evaluate the impact of Portland cement and concrete specification changes made in 1994 and 1996 on PCC durability. Cores were obtained in 1998 and 2003 from projects constructed in 1992, before specification changes, and 1997 after specification changes. The following is a brief summary of the conclusions: 1. The pavements in the study constructed under the new specifications are performing much better after 5 years of service than the pavements constructed under the old specifications. 2. According to ISU, micro-cracking is evident in all concrete that has been in service, due to thermal stresses and loading stresses. Also, the low vacuum SEM will desiccate the concrete enough to cause micro-cracking. The SEM should not be used as a tool to indicate micro-cracking. 3. Use of Type II cement (C3A <8%) and a 3.0% SO3 limit does not completely eliminate ettringite infilling in air voids, as indicated in the bottom of the 1997 cores. 4. In areas of high moisture (bottom of the core), infilling is present in most of the 1997 cores. 5. Low air content and high spacing factor in the top of 1992 cores apparently causes F/T cycling cracking and then increased moisture paths from cracking causes infilling. 6. Use of ground granulated blast furnace slag (GGBFS) and fly ash reduces ettringite infilling either by diluting the aluminate (C3A) or lowering permeability, which slows ingress of moisture. 7. The specification changes that made the biggest impact on pavement durability are the limits on vibration and increase in air content in September 1994. 8. Investigations of cores from pavements placed in 2002 and 2003 indicate improved air contents and spacing factors. In-place air content and spacing factors should be monitored to determine if appropriate air void parameters are being met.

Iowa LSCA long range plan, 1992-1996

This five-year plan,1992-1996,describes the needs, goals, objectives, and methodology for each of the Library Services and Construction Act goals. The LSCA long range plan is revised and issued on an annual basis.

Summary of Legislation: Iowa General Assembly, 1992

This summary of legislation enacted by the General Assembly has been prepared for the use of legislators and other interested parties. The summary of each legislative enactment has been assigned to a major subject category. This compilation provides interested persons with quick reference to legislation enacted in specific areas and generally informs persons of the contents and effective date of the legislation. NOTE: This is a large file and may take a few minutes to load.

Formats radifònics "tot-notícies" a l'Estat Espanyol : naixement i consolidació de "Catalunya Informacio"(1992-1997)

Fa 20 anys que la ràdio española gaudeix de la libertad informativa que li va ser negada durant la dictadura. En aquests 20 anys, l’evolució del macro-gènere información ens ha portat des de l’anomenat “boom de la ràdio informativa” fins al naixement, al nostre país, de les primeres emissores dedicades íntegrament a la información, en primer lloc, Catalunya Informació, i més tard, Radio 5 Todo Noticias. El que pretenem amb aquest estudié s tractar del naixement i la consolidació del primer format radiofònic informatiu, un format sobre el qual no hi ha encara gaires referències bibliogràfiques.

Image Analysis for the Characterization of Materials for Highway Construction : Phase I, Progress Report, HR-346, 1992

The major objective of this project is to evaluate image analysis for characterizing air voids in Portland cement contract (PCC) and asphalt concrete (AC) and aggregate gradation in asphalt concrete. Phase 1 of this project has concentrated on evaluation and refinement of sample preparation techniques, evaluation of methods and instruments for conducting image analysis, and finally, analysis and comparison of a select portion of samples. Preliminary results suggest a strong correlation between the results obtained from the linear traverse method and image analysis methods for determining percent air voids in concrete. Preliminary work with asphalt samples has shown that damage caused by a high vacuum of the conventional scanning electron microscope (SEM) may too disruptive. Alternative solutions have been explored, including confocal microscopy and low vacuum electron microscopy. Additionally, a conventional high vacuum SEM operating at a marginal operating vacuum may suffice.

Investigation of Rapid Thermal Analysis Procedures for Prediction of the Service Life of PCCP Carbonate Coarse Aggregate: Phase I, Progress Report, HR-337, 1992

The major objective of this research project is to utilize thermal analysis techniques in conjunction with x-ray analysis methods to identify and explain chemical reactions that promote aggregate related deterioration in Portland cement concrete. The first year of this project has been spent obtaining and analyzing limestone and dolomite samples that exhibit a wide range of field service performance. Most of the samples chosen for the study also had laboratory durability test information (ASTM C 666, method B) that was readily available. Preliminary test results indicate that a strong relationship exists between the average crystallite size of the limestone (calcite) specimens and their apparent decomposition temperatures as measured by thermogravimetric analysis. Also, premature weight loss in the thermogravimetric analysis tests appeared to be related to the apparent decomposition temperature of the various calcite test specimens.

Evaluation of Recycled Rubber in Asphalt Concrete - Black Hawk County, HR-330B, Construction Report, 1992

The disposal of discarded tires has become a major problem. Different methods of recycling have been researched. Currently, Iowa is researching the use of ground recycled crumb rubber from discarded tires in asphalt rubber cement. Six projects have been completed in Iowa using asphalt rubber cement. This project is located on IA 947 (University Avenue) in Cedar Falls/Waterloo. The project contains one section with asphalt rubber cement used in both the binder and surface courses and one section using asphalt rubber cement in the surface course with a conventional binder. There are two control sections where conventional asphalt pavement was placed.

Mukautettu tilintarkastuskertomus suomalaisissa pörssiyrityksissä vuosina 1992-2002

Tutkimuksen päätavoitteena oli selvittää kuinka yleistä tilintarkastuskertomuksen mukauttaminen on suomalaisissa pörssiyrityksissä. Alatavoitteina oli selvittää mukauttamisen riippuvuutta toimialasta khin neliö testin avulla, mukautusten vertaileminen ajallisesti, mukautettujen tilintarkastuskertomusten analysoiminen sekä tutustua tilintarkastajan erilaisiin raportointitapoihin. Tutkimuksessa on sekä kvalitatiivisia että kvantitatiivisia piirteitä. Tutkimusajanjakso käsitti 11 tilinkautta vuosien 1992-2002 välillä. Tutkimusaineisto koostuu 154:n suomalaisen pörssilistatun yhtiön 892:sta tilinpäätöksestä tilintarkastuskertomuksineen. Tutkimuksessa havaittiin että tilintarkastuskertomuksen mukauttaminen suomalaisissa pörssiyhtiöissä on varsin harvinaista, ainoastaan 3,1tutkituista tilintarkastuskertomuksista oli mukautettuja. Toimialoittaisessa vertailussa ei voitu luotettavasti havaita mukauttamisen olevan toimialasta riippuvaista. Ajallisestimukautetut tilintarkastuskertomukset olivat jakautuneet varsin tasaisesti koko tarkasteluajanjaksolle, eikä suuria eroja vuosien välillä ollut havaittavissa.

20 años de automatizacion de préstamo interbibliotecario en España (1992-2012)

Se presenta la evolución en los últimos veinte años (1992-2012) de la automatización del préstamo interbibliotecario en las bibliotecas universitarias españolas. A partir de los distintos procesos que se llevan a cabo en este servicio, envío de peticiones, localización y recepción de documentos y gestión interna, se identifican cada uno de los programas utilizados y se pone de manifiesto como han evolucionado cada uno de los procedimientos en paralelo a la propia tecnología.

Kalojen kasvaimet ovat harvinaisia : kooste vuosilta 1992-2005

Summary: Fish tumours are rare : findings from 1992-2005

Trends in self-reported prevalence and management of hypertension, hypercholesterolemia and diabetes in Swiss adults between 1992 and 2007

PURPOSE: to assess the trends of prevalence of self-reported cardiovascular risk factors (CV RFs: hypertension, hypercholesterolemia, diabetes) and their management for the period of 1992 to 2007 in Switzerland. METHODS: four health interview surveys conducted between 1992 and 2007 in representative samples of the Swiss population (63,782 subjects overall). Self-reported CV RFs prevalence, treatment and control levels were computed after weighting. Weights were calculated by raking ratio such that the marginal distribution of the weighted totals conforms to the marginal distribution of the target population. Multivariate analysis was conducted using logistic regression. RESULTS: prevalence of all CV RFs increased between 1992 and 2007. Also, the prevalence of self-reported treatment among subjects with CV RFs increased, as confirmed by multivariate analysis: OR for hypolipidemic treatment relative to 1992: 0.64 [0.52-0.78]; 1.39 [1.18-1.65] and 2.00 [1.69-2.36] for 1997, 2002 and 2007, respectively. Still, in 2007, circa 40% of hypertensive, 60% of hypercholesterolemic and 50% of diabetic subjects weren't treated. On the other hand, there is an increase of the prevalence of controlled RFs as reported by treated subjects. This was confirmed by multivariate analysis 12.1 [12.0 - 12.2]; 4.16 [4.1 - 4.23] and 2.85 [2.79 - 2.90] for hypertension, hypercholesterolemia and diabetes, respectively, in 2007, relative to 1992. CONCLUSION: the prevalence of self-reported hypertension, hypercholesterolemia and diabetes increased between 1992 and 2007 in the Swiss population. Despite a good control of treated subjects, still a significant percentage of subjects with CV RFs are not treated.