Compatibility between flooring materials on concrete - development of test method

I syfte att utveckla en ny provningsmetod för golvmaterial/system på betong beträffande fläkningskraft, relativ fuktighet och emissioner av organiska ämnen studerades 60 provkroppar. Provkroppen, tre identiskt lika av vardera i syfte att studera noggrannheten, byggdes upp som ett verkligt golv inuti en stålform (standard ventilationsdelar i stål - lock och fläns) vilken satt kvar under hela testperioden. I botten av formen göts betong upp till 8 mm under ovankanten vilken torkades under en månad, av två olika kvalitéer antingen med vattencementtal 0.40 eller med vattencementtal 0.60. Ovanpå betongen inuti stålformen göts 8 mm avjämningsmassa som torkades ut en månad, av två olika kvalitéer. Tre olika typer av ytbeläggning användes, linoleum, gummi och PVC, vilka applicerades antingen med alkalibeständigt lim eller med standard polyakrylatlim

A Study of Personality and Family- and School Environment and Possible Interactional Effects in 244 Swedish Children—A Multiple Regression Analysis

The aim of the study was to examine relationships between psychosocial family- and school environment and personality as assessed by the Junior Eysenck Personality Questionnaire (EPQ-J) and possible personality interactional effects. The study was based on 244 Swedish girls and boys, 10-19 years old, who filled in the Family- and School Psychosocial Environment (FSPE) questionnaire and the EPQ-J. A multiple regression analysis showed that the FSPE-factor Family conflicts and school discipline predicts Psychoticism (antisocial personality), and that the FSPE-factor Warmth, support and openness from parents, siblings and peers predict Extraversion. Sex, Psychoticism and the size of sibling group predicted Neuroticism. Spanking was reported in various degrees by 8.1 percent of the children, and this factor was related to Psychoticism. These results support socialization theories. The most unexpected finding was the impact of interactions between personality variables themselves, influencing the FSPE’s predictability of Neuroticism. Discussion about the advantage of the use of statistic control in a multiple regression, possible causal links between psychosocial environment and personality, limitations and further research propositions concludes the article

Self-compacting concrete for submerged repair of harbours or water power plant dams

In this project the objectives were to investigate freezing and thawing resistance (internal frost resistance and salt frost scaling) of submerged cast SCC at different w/c and different air content for repair of concrete for water power plant dams and harbours in severe conditions. The objective was also to compare the result with the corresponding properties of normal submerged cast concrete, NC. w/c of the NC varied between 0.45 and 0.78. The air content of NC varied between 1 and 11% vol. For SCC the w/c varied between 0.35 and 0.49 with an air content varying between 1 and 8%. Finally the objective was to give recommendations how to produce SCC for repair of water power plant dams and harbours in severe conditions durable to freezing and thawing attack

Quasi-instantaneous and Long-term Deformations of High-Performance Concrete with Some Related Properties

This report outlines an experimental and numerical study on quasi-instantaneous and long-term deformations of High-Performance Concrete, HPC, with some related properties. For this purpose about two hundred small cylinders and about one thousand cubes of eight types of HPC were cast. The age at loading varied between 18h and 28 days. Other principal properties of HPC were studied up to 4 years' age. Creep deformations of the HPC were studied from 0.01 s of loading time until 5 years' age. The work also includes observations of recovery at unloading and transversal deformations (Poisson's ratio). Elastic modulus and dynamic modulus of elasticity were studied on both young and mature concrete. Parallel studies were performed on shrinkage, strength, hydration, carbonation and on internal relative humidity of HPC. Supplementary dimensional studies were performed on twenty larger cylinders. Field studies were carried out on almost thirty prestressed beams. The results show good correlation between maturity and the quantity of creep of HPC. The results also show good correlation between, on one hand, the stress level and the mix design of the HPC and, on the other hand, the creep properties of HPC given a constant loading time. The phenomenon named autogenous shrinkage was observed during the study. The autogenous shrinkage was related to the self-desiccation and chemical shrinkage in HPC. Also the elastic properties of HPC were dependent on the moisture state at testing. The field studies on beams confirmed the findings in the laboratory. The short-term studies indicated that the creep rate (related to unit stress) of mature HPC was fairly independent of the compressive strength. The short-term basic creep rate (related to unit stress) of HPC after heat curing was observed to be twice as large at -1°C as at other temperatures. Besides loading time, the long-term compliance of HPC was mainly dependent on the maturity and the compressive strength both when loading the HPC and at 28 days' age. The creep was slightly reduced by use of 10% silica fume instead of 5%. The calculated long-term total compliance of the present study coincided reasonably well with previous research, taking into account that the exact HPC mix was unknown. However, the observed creep compliance was slightly larger than previously seen. The initial compliance calculated according to the previous studies was more affected by the strength than were the results of the present study. The following principal results were obtained: · Elastic modulus was related to compressive strength and porosity as demonstrated in normal strength concrete, NSC. · The creep rate (related to unit stress) was dependent on both the duration of loading and the maturity of the HPC. · Creep properties of the HPCs obtained by the quasi-instantaneous loading were applicable to the long-term studies performed with a much lower loading rate. · Specific creep was shown to be reduced with increase in silica fume content. Autogenous shrinkage was reduced by the use of granulated silica fume instead of silica fume slurry due to the greater fineness

Gamma-Ray Emitting Radionuclides in People Living in Northern Sub Arctic Regions

In 1960 Caesium-137 activity from atmospheric nuclear weapons test was discovered in measurements at the whole body gamma-ray counting laboratory in Lund. This event initiated measurements of the Swedish Sami population, and in products from reindeer that bite lichens in the Swedish mountains. A semi-portable whole-body counter designed with a detection limit for 137Cs at high radiation background areas which was good enough for measuring people with high body concentration of 137Cs. The 137Cs activity concentration in Sami people increased during 1963–1965 from 300 to 600 Bq/kg body weight. Some individual males had values above 1000 Bq/kg. The catastrophic nuclear accident on the 25–26 April 1986 at the Chernobyl Nuclear Power Plant caused a massive release of fission- and neutron-activation products to the atmosphere. Already the following day the atmospheric plume of released radioactivity reached Sweden and was deposited over the central part of Sweden also in Sami populated reindeer raising districts. During 1991 and 1992 whole-body content of 137Cs was measured in the Sami population of northern Sweden and similar levels were found as during 1963–1965. These levels are about twice those estimated in people living in the Chernobyl contaminated area

Global distribution of 7Be, 210Pb and, 210Po in the surface air (with Appendix A-E)

In the effort of modelling the global distribution 7Be, 210Pb and 210Po in surface air, the results from exploration of radioactivity exploration from the Arctic to the Antarctic during 1980 to 1996 are compiled with the results reported by other authors. Partial least square regression modelling PLS-regression, predict missing 7Be, 210Pb and 210Po values of air concentration or annual deposition. All available data of air concentration and deposition, of these radionuclides are then correlated with geophysical parameters. The results indicate that the global latitudinal distribution of 7Be air concentration was rather flat, with an overall global average of 4.2 (SE 0.4) mBq.m-3, although with a slight dip at the equator and decrease towards high latitudes. The corresponding latitudinal distribution was also flat, and decreased slightly at high and low altitudes, with overall global average of 7Be annual deposition was 1500 (SE 100) Bq.m-3.a-1. The 7Be deposition rate estimated from reported annual mean air concentration and annual deposition is 13.4 +/- 1.7 (SE) mm.s-1. By using PLS-r modelling of either air concentrations or annual depositions, the average deposition rate of 7Be was estimated to 12.3 +/- 1.6 (SD) mm.s-1. The 7Be deposition-rate don´t vary significantly with longitude, latitude or geometrical average year of sampling date. Linear regression with height, however, is negative with a coefficient of - 0.02. At sea level, the 7Be deposition-rate was estimated to 13 mm.s-1, while at a height of 800 m it was predicted to be 7 mm.s-1. The 16 values of 7Be deposition rate, reported in the literature, are widely scattered (SD = 18) with an average of about 18 mm.s-1. The latitudinal distribution of the activity concentration of 210Pb in air showed a maximum of about 600 +/- 200 micoBq.m-3 around 45 oN with a steady decrease towards higher and lower latitudes. Minimum values of 400 micoBq.m-3 and 80 micoBq.m-3 were estimated at 90 oN and at 90 oS respectively. The latitudinal distribution of all 210Pb air concentration values (micoBq.m-3) is given by the following equation: log10[210Pb] = 2.52 + 0.0083·(Latitude) - 9.87.10-5· (Latitude)2. The latitudinal distribution of all 210Pb annual deposition values (Bq.m-2.a-1) showed a maximum of about 200 +/- 100 Bq.m-2.a-1 around 45 oN, with a steady decrease towards higher and lower latitudes. A minimum of 100 Bq.m-2.a-1 was predicted at 90 oN, although a value of 17 +/- 4 Bq.m-2.a-1 has been recorded at 84.4 oN 2.3 oW. At 90 oS the predicted 210Pb annual deposition was 3 Bq.m-2.a-1. The 210Pb deposition rate was estimated 12.5 +/- 0.7 mm.s-1 with no significant variation with latitude, height, or average of interval of sampling date. With longitude, however, the 210Pb deposition rate varied significantly (linear k=0.02) R=0.99. The values of 210Po air concentration around 20 - 45 oN ranged between 50 – 1000 micoBq.m-3 with a mean of 200 micoBq.m-3, and the 210Po annual deposition ranged between 20-800 Bq.m-2.a-1 with a mean of 100 Bq.m-2.a-1. The longitudinal distribution of the 210Po/210Pb activity ratios follow a narrow linear relation from 0.2 at 90 oW to 1.0 at 170 oE. While the 210Po air concentration and annual deposition are widely distributed along the longitudes with a slight decrease west of the Greenwich meridian