Instrumentum Domesticum romà del Museu Episcopal de Vic. La col·lecció de segells en àmfora, tegula i morter

Les 39 marques que presentem pertanyen al fons del Museu Episcopal de Vico Es tracta, basicament, de marques ben conservades en petits fragments de ceramica, majoritariament pertanyen a àmfora, pero també existeix un petit grup en tegula, i una sola marca en mortero.

Un vaso apulo del estilo de figuras rojas en el Museo Episcopal de Vic (Barcelona)

Previo al inicio de nuestro estudio es obligado un recuerdo, y que éste sirva de pequeño homenaje al recientemente fallecido doctor Mons. Eduard Junyent Subid., Director de la Biblioteca-Archivo Episcopal y del Museo Astístico Arqueológico Episcopal de la ciudad de Vic, miembro de la Real Academia de las Buenas Letras de Barcelona, arqueólogo e ilustre historiador.

Correlation between species composition and soil properties in the pastures of Plana de Vic (Catalonia, Spain)

The correlation between the species composition of pasture communities and soil properties in Plana de Vic has been studied using two multivariate methods, Correspondence Analysis (CA) for the vegetation data and Principal Component Analysis (PCA) for the soil data. To analyse the pastures, we took 144 vegetation relevés (comprising 201 species) that have been classified into 10 phytocoenological communities elsewhere. Most of these communities are almost entirely built up by perennials, ranging from xerophilous, clearly Mediterranean, to mesophilous, related to medium-European pastures, but a few occurring in shallow soils are dominated by therophytes. As for the soil properties, we analysed texture, pH, depth, bulk density, organic matter, C/N ratio and the carbonates content of 25 samples, correspondingto representative relevés of the communities studied.

Improved Aggregate Gradation for Portland Cement Concrete Mixes, HR-563, 1996

Improving the aggregate gradation for a portland cement concrete mix may result in higher compressive strengths. With an improved gradation, the cement factor may be reduced to achieve a more economical concrete mix since cement is the most expensive component in a Portland cement concrete mix. This project located on I-80 westbound in Scott County, Iowa examined three different mixes. 1. Standard Class C mix with project aggregates. 2. Standard Class C mix with an improved aggregate gradation. 3. Standard Class C mix with an improved aggregate gradation and 10% cementitious reduction.

Vibratory Effects in Reinforced Portland Cement Concrete Pavement, MLR-97-2, 1997

A double mat of reinforcement steel consisting of No. 5 bars was placed in the longitudinal and transverse directions in a 26' wide, 10" thick pavement. The bars were placed on 12" centers with 2" of cover from the top and bottom surfaces. The special reinforcement is to provide additional strength in the pavement over an area of old coal mine tunnels. Auxiliary and standard paver vibrators were used to consolidate the concrete. There was concern that over-vibration could be occurring in some areas and also that a lack of consolidation may be occurring under the steel bars in some areas. A core evaluation study of the pavement was developed. The results showed that the consolidation and the air contents were satisfactory. Additional paving with reinforcement in the same area should use the same or similar method and amount of vibration as was used in the area evaluated in this study.

Early Entry Sawed Portland Cement Concrete Transverse Joint Ends, MLR-97-5, 2003

Experiments with early entry light sawing of Portland cement concrete (PCC) contraction joints began in Iowa in 1989. Since that time, changes in early sawing equipment have occurred as well as changes in specifications for sawing. The option to use early sawing for transverse contraction joints was specified in 1992. A problem happening occasionally with early sawing was the break out of some of the concrete around the end of the joint as the saw blade approached the edge of the slab. To prevent this, it was proposed that the sawing would terminate approximately 1/2" to 3/4" before the edge of the slab, creating a "short joint". This procedure would also leave a concrete "dam" to prevent the run-out and waste of the hot liquid joint sealant onto the shoulder. It would also eliminate the need for the labor and material for applying a duct tape dam at the open ends of each sawed joint to stop hot liquid sealant run-out Agreements were made with the contractor to apply the "short joint" technique for 1 day of paving. The evaluation and results are compared with an adjoining control section. The research found no negative aspects from sawing the "short joint". Three specific findings were noted. They are the following: 1) No joint end "blow-out" spalls of concrete occurred. 2) The need for the duct tape dam to stop liquid sealant overflow was eliminated. 3) Joint end corner spalls appear to be caused mainly by construction shouldering operations equipment. The "short joint" sawing technique can be routinely applied to early entry sawed transverse contraction joints with expectations of only positive results.

Effects of Deicing Salt Trace Compounds on Deterioration of Portland Cement Concrete, HR-271, 1987

A study was made of the detrimental effects of trace amounts of calcium sulfate (occurring naturally in halite deposits used for deicing) on portland cement concrete pavements. It was found that sulfate introduced as gypsum with sodium chloride in deicing brines can have detrimental effects on portland cement mortar. Concentrations of sulfate as low as 0.5% of the solute rendered the brine destructive. Conditions of brine application were critical to specimen durability. The mechanisms of deterioration were found to be due to pore filling resulting from compound formation and deposition. A field evaluation of deteriorating joints suggests that the sulfate phenomena demonstrated in the laboratory also operates in the field. A preliminary evaluation was made of remedies: limits on sulfates, fly ash admixtures, treatment of existing pavement, and salt treatments. This report gives details of the research objectives, experimental design, field testing, and possible solutions. Recommendations for further study are presented.

High Range Water Reducer in Portland Cement Concrete Made with D-Cracking Susceptible Coarse Aggregate, HR-1021, 1980

The objective of this research was to determine of the use of High Range Water Reducers (HRWR) (resulting in a lower water content ratio) with a D-cracking susceptible crushed limestone coarse aggregate would yield significant improvement in the durability.

Evaluation of Fly Ash in Portland Cement Concrete Pavement in Monona County, Iowa, HR-200, 1980

The primary objectives of this research project were: 1. Determine and recommend solutions for problems relating to shipping, storing and batching of fly ash. 2. Establish a procedure for batching, mixing and placing uniform concrete with specified air content and consistency. 3. Demonstrate that concrete of comparable quality can be produced.

Recycling of Portland Cement Concrete Roads in Iowa, MLR-77-6, 1977

We are depleting the once seemingly endless supply of aggregate available for concrete paving in Iowa. At the present time, some parts of our state do not have locally available aggregates of acceptable quality for portland cement concrete paving. This necessitates lengthy truck and rail hauls which frequently more than doubles the price of aggregate. In some parts of the state, the only coarse aggregates available locally are "d-cracking" in nature. Iowa's recycling projects were devised to alleviate the shortage of aggregates wherever they were found to have an economic advantage. We completed our first recycling project in 1976 on a 1.4 project in Lyon county. The data collected in this project was used to schedule two additional projects in 1977. The larger of these two projects is located in Page and Taylor county on Highway #2 and is approximately 15 miles in length. This material is to be crushed and re-used in the concrete paving, it is to be reconstructed on approximately the same alignment. The second project is part of the construction of Interstate I-680 north of council Bluffs where an existing 24 foot portland cement concrete roadway is to be recycled and used as the aggregate in the slip form econocrete subbase and the portland cement concrete shoulders.

Evaluation of Fly Ash in Portland Cement Concrete Paving in Woodbury County, Iowa, HR-201, Construction Report, 1979

The earliest overall comprehensive work on the use of fly ash in concrete was reported by Davis and Associates of the University of California in 1937. Since that time there have been numerous applications of the use and varying proportions of fly ash in portland cement concrete mixes. Fly ash is a pozzolanic powdery by-product of the coal combustion process which is recovered from flue gases and is generally associated with electric power generating plants. Environmental regulations enacted in recent years have required that fly ash be removed from the flue gases to maintain clean air standards. This has resulted in an increased volume of high quality fly ash that is considered a waste product or a by-product that can be utilized in products such as portland cement concrete. There are several sources of the high quality fly ash located in Iowa currently producing a combined total of 281,000 tons of material annually. Due to recent cement shortages and the rapidly increasing highway construction costs, the Iowa Department of Transportation has become interested in utilizing fly ash in portland cement concrete paving mixes. A preliminary review of the Iowa Department of Transportation Materials Laboratory study indicates that a substitution of fly ash for portland cement, within limits, is ·not detrimental to the overall concrete quality. Also the use of fly ash in concrete would reduce the cement consumption as well as provide a potential cost savings in areas where high quality fly ash is available without excessive transportation costs. The previously expressed concerns have shown the need for a research project to develop our knowledge of fly ash replacement in the Iowa Department of Transportation portland cement concrete paving mixes.

Una aproximació a l’estudi tècnic dels suports dels frontals d’altar romànics atribuïts als tallers de Vic i Ripoll

Aquest treball s’inclou dins la línia de recerca de la Secció de Conservació-Restauració delPatrimoni que es centra en l’estudi tècnic dels suports de fusta de frontals i retaules percaracteritzar-los i aportar noves informacions sobre els materials constitutius, els seussistemes de construcció i el seu origen. En aquest cas, l’estudi es centra en pintura sobretaula catalana del segle XII.La selecció de peces i l’acotació del tema van sorgir arrel d’un treball fi nal de màster (setembre2009) en el que ja es van estudiar els suports d’un conjunt de taules de fusta policromades dels segles XI, XIII i XIV custodiades al Museu Episcopal de Vic (MEV)...

Recycled Portland Cement Concrete Pavement in Iowa, HR-506, 1984

In recent years, there has been an increased interest in conservation of our resources, preservation of our environment and maintaining our ecology. Recycling of materials is a procedure that will immediately contribute to all of these desirable end results. Our economy is built on private enterprise and profit incentive and in the past, with abundant inexpensive resources, there was little incentive to recycle. Shortages of materials and energy (once considered abundant) along with regulations to protect the environment have emphasized the need for recycling. These environmental conditions coupled with the loss of purchase power by inflation has generated more interest in recycling in the transportation field. The Iowa Department of Transportation (Iowa DOT) is interested in recycling portland cement concrete (pcc) pavement to: 1. Provide aggregate where high quality aggregate is no longer economically available. 2. Eliminate the need for locations to waste the large amount of pavement rubble. 3. Conserve the present aggregate sources. 4. Reduce the need for disrupting land for quarrying purposes. 5. Save fuel and energy by reducing aggregate transportation.

Thin Bonded Portland Cement Concrete Overlay, HR-520, 1990

A four and one-half inch thick, bonded portland cement concrete (PCC) overlay and integral widening were used to rehabilitate a 4.5 mile section of Iowa route 141 from US 169 to Iowa 210 in Dallas County. There was a substantial amount of cracking in the old 20 feet wide PCC pavement. Most of the widening, which was tied to the original slab by dowel bars, was placed as a four feet wide section on one side. Coring has shown that the overlay is well bonded and testing with the Delamtect has shown less than 1% debonding. Midpanel transverse cracks in the old pavement have reflected through the overlay (as expected). Some new transverse cracking has occurred. This cracking has not caused any significant problems. In general, the overlay is performing quite well.