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Durability assessment of monolithic rammed earth walls

Narloch P. L., Woyciechowski P., Dmowska E., Halemba K.

Archives of Civil Engineering

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2015

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Vol. 61, nr 2

73--88

EN

One of the main threats to constructions made from rammed earth is destruction due to exposure to water. The way to limit this dangerous phenomenon is to supplement the local soil mixtures with stabilizing agents. The main component used is Portland cement. This article analyses the results of research which focused on the resistance of rammed earth to water erosion. Because of the lack of national standards regarding the method of examining the durability of rammed earth, the research was based on the New Zealand standard NZS 4298: 1998. The results confirm the possibility of using rammed earth stabilized by cement in a temperate climate.

PL

Jednym z głównych zagrożeń dla konstrukcji wykonywanych w technologii ziemi ubijanej jest destrukcja pod wpływem wody. Sposobem na ograniczenie tego niebezpiecznego zjawiska jest uzupełnienie mieszanki lokalnie dostępnych gruntów o składniki stabilizujące. Najczęściej stosowanym składnikiem jest cement portlandzki. W niniejszym artykule przeanalizowano wyniki badań odporności ziemi ubijanej na erozję wodną. Ze względu na brak krajowych norm dotyczących sposobu badania trwałości ziemi ubijanej, badania zostały wykonane w oparciu o normę nowozelandzką NZS 4298: 1998. Uzyskane wyniki pozytywnie weryfikują możliwość stonowania ziemi ubijanej stabilizowanej cementem w klimacie umiarkowanym.

2

Nematode communities along the transect shelterbelt - ecotone - crop field

Dmowska E.

Polish Journal of Ecology

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2007

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Vol. 55, nr 4

665-680

EN

The study was carried out in western Poland (Turew region) in two shelterbelts of different age (the younger - 6 years old and the older - 11 years old) planted cross croplands, in adjacent field and in the field located in deforested area (control field). Soil samples were taken twice: in the autumn and spring from the centre of each shelterbelt, from the ecotone, and in the field at a distance of 15 and 50 m from the edge of the shelterbelts. The density of nematode communities fluctuated unpredictably, in autumn it was very low and ranged from 276 to 641 x 10[^3] in spring it ranged from 388 to 1931 x 10[^3] individuals per 1 m[^2]. Most numerous trophic groups were: bacterivores, fungivores and obligate plant feeders, while facultative plant feeders, omnivores and predators achieved low level. The abundance of predators in older shelterbelt was significantly (P [less-than or equal to] 0.05) higher than that in the younger one and decreased with increasing distance from the shelterbelt towards the field. The communities in shelterbelt and its ecotone were more diverse, which was reflected by the higher number of genera (19-31) and higher values of Shannon-Wiener diversity index H'(3.3 - 4.0), than those in the fields where the number of genera ranged from 15 to 25 and Shannon-Wiener diversity index H' ranged from 2.5 to 3.5. In the younger shelterbelt and in the control field the soil food-web assessed with indices derived from analysis of nematode communities was considered as composed mainly of basal components, i.e. cosmopolitan species feeding on bacteria and fungi occurring everywhere even in degraded environments. While the web in older shelterbelt was consisted mainly of enrichment components, i.e. bacteria feeding species of very short life cycle, with high food requirements which occur in the environment rich in bacteria. The values of Channel Index which informs about the predominant pathway of decomposition (through bacteria or fungi) showed that in majority of sites bacterial processes predominated. Only in the older shelterbelt the participation of fungal decomposition channel was higher (>50%) and increased with increasing distance from the shelterbelt towards the centre of the field. The results of Correspondence Analysis showed that first two axis explained 40.3% of the variance. The generic composition of nematode communities in the 11 years old shelterbelt differed from that in the 6-years old shelterbelt. Nematode communities inhabiting the ecotone of younger shelterbelt were very similar to the communities in the shelterbelt, while the communities in ecotone of older shelterbelt differed from those in the shelterbelts. Nematode communities inhabiting the control field were similar to those inhabiting the field adjacent to younger shelterbelt.

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Nematodes colonizing power plant ash dumps. 2, Nematode communities in ash dumps covered with turf - effect of reclamation period and soil type

Dmowska E.

Polish Journal of Ecology

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2005

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Vol. 53, nr 1

37-51

EN

Changes in the below-ground system of ash dumps reclaimed by covering with turf were estimated using parameters and indices based on analysis of nematode communities. Higher trophic diversity, higher values of Maturity Index (MI), and higher complexity of food-web structure were expected when reclamation proceeded. The study was carried out for three years in chronosequences of ash dumps. Two of the dumps were reclaimed shorter and were studied between the 2tnd and 5th year of reclamation, the first one was reclaimed by covering with turf with mineral soil (S-M), the second one with turf with organogenic soil (S-O). The third ash dump reclaimed in longer time, covered with turf with organogenic soil was studied between the 8th-11th year of reclamation (L-O). Until the fourth year of reclamation S-O site provided better conditions for the development of nematodes than S-M site; trophic diversity and MI were higher in S-O site in comparison with S-M site. Later on most parameters and indices were similar in S-M and S-O site. Longer reclamation resulted in higher total abundance, higher abundance of bacteriovores, plant feeders and omnivores, and also higher biomass of bacteriovores and plant feeders. However, changes in the below-ground system of reclaimed ash dumps were very slow because even after 11 years of reclamation the ash dump had the features of a degraded environment.

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Nematodes colonizing power plant ash dumps. 1, Soil nematodes in ash dumps non-reclaimed and reclaimed by adding mineral soil and sowing grass

Dmowska E.

Polish Journal of Ecology

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2001

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Vol. 49, nr 3

231-241

EN

Soil nematode communities were analyzed (total abundance, number of taxa, diversty indices of genera and species, trophic structure) in ash dumps that were waste products of the coalfired power plants. The samples were taken on four occasions during three years from three sites: non-reclaimed ash, reclaimed for 3-5 years, and reclaimed for 11-13 years. The values of the parameters analysed increased with the time of reclamation. Nonetheless, even after more than ten years of reclamation, nematode communities were more similar to those observed in degraded environments than in grasslands. They consisted mainly of bacterial- and fungal-feeding nematodes, whereas plant-feeders and omnivores were scarce, and predators were absent. All sites were dominated by bacterial-feeding nematodes of the genus Acrobeloides. Among fungal-feeding nematodes, Aphelenchoides were abundant in the initial period of reclamation, and later on Aphelenchus avenae.

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Wpływ metali ciężkich zawartych w odpadach z huty ołowiu na zespoły nicieni glebowych

Ilieva-Makulec K., Dmowska E.

Chemia i Inżynieria Ekologiczna

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1998

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Vol. 5, nr 8-9

707-711

PL

Badano działanie następcze metali ciężkich Cd, Zn i Pb na nicienie glebowe po wapnowaniu. Badania prowadzono na poletkach doświadczalnych wapnowanych trzykrotnie wapnem z kopalni węgla brunatnego w dawce dwa razy większej niż hydrolityczna kwasowość gleby (2Hh), wapnowanych dwukrotnie i trzykrotnie odpadami z huty ołowiu (2h) oraz niewapnowanych. Analiza gleby przeprowadzona w roku pobierania prób, tj. wiosną 1996 r., wykazała różnice w zawartości metali ciężkich w glebie badanych poletek. W glebie wapnowanej trzykrotnie odpadami z huty ołowiu, najbardziej skażonej metalami ciężkimi, zawartość Cd i Zn po czterech latach po wapnowaniu była bliska ilości przewidzianej dla gleb o podwyższonym stopniu skażenia. W glebie tej stwierdzono istotnie niższą liczebność nicieni bakteriożernych, grzybożernych i roślinożernych oraz mniejszą różnorodność rodzajową nicieni niż w pozostałych glebach.

EN

The effect of heavy metals Cd, Zn and Pb on soil nematodes was investigated after liming. Some of the experimental fields were treated three times with lime (2Hh) from the brown coal mine or twice or three times treated with lime waste (2Hh) from lead-works and other were untreated. Chemical analysis of soil from the test fields in the year of sampling, spring 1996 showed some differences in heavy metal contains. In soil with the highest content of Cd, Pb and Zn (three times repeated usage of lime waste from lead-works) the abundance of bacterial-feeding, fungal-feeding and plant-feeding and also genera diversity were significant lower then in the other soils.