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For many years, techniques improving weak soils by means of additional elements incorporated into their structures have been applying in geotechnical structures (earth structures). An example of such a procedure is the use of geosynthetics enabling to solve geotechnical problems related to anti-erosion protection, as well as filtration and draining. In addition to geosynthetics, randomly distributed fibers are used. Fibers mixed with soil perform a function similar to the function of the root system of protective vegetation and enable the creation of flexible and easy to green construction. During the research, the influence of the type of fibers and their amount on erosion of slope located in the suburbs of Bielsko-Biala (Poland) was determined. Soil parameters and fiber properties were determined before their placement. Research on the physical properties of the soils and fibers morphological structure and strength was carried out in accordance with applicable standards. Subsequently, the slope stability was assessed during many months of exploitation. During the research, 2 m wide plots were created on the slope, covered with soil mixed with various amount of fibers. Fibers mixed with soil form a spatial grid retaining soil particles washed out by streams of surface water flowing down, limit the negative impact of erosion and increase slope stability. Natural fibers store excess water in soil, which promotes the development of protective vegetation.

Changes in climatic conditions in the world often affect the variability of water relations and soil erosion. Observed phenomena lead to removal of the most valuable soil surface layer from slopes, washout of minerals, deterioration of slope structure and also destruction of protective vegetation. Geotextiles are used to protect slopes from effects of erosion. Depending on the type of used raw material as well as production technology, geotextiles are used for long-term or temporary protection (biodegradable). Biodegradable geotextiles under influence of atmospheric factors undergo gradual decomposition. The substances released as a result of decomposition cause soil fertilization, which promotes development of protective vegetation. The aim of the research is to assess impact of exploitation time on selected physical, mechanical and hydraulic properties of innovative geotextiles in form of meandrically arranged Kemafil ropes made of wool and recycled fibers installed on slope in Jasienica Economic Zone in Międzyrzecze. The research was carried out in the Laboratory of Geosynthetics and Textile Products of the University of Bielsko-Biala in accordance with the applicable European standards. Nonwovens used for production of geotextiles were tested before installation, as well as after 6 and 12 months from their installation. Geotextiles reduce speed of rainwater flowing down from the surface of slope and store its excess. Waste raw materials used for production of geotextiles enable products effectively protecting slope against water erosion.

Paper deals with application of geotextile ropes in erosion protection of slope of gravel pit in Nieboczowy, Poland. For protection of the slope the segments formed from thick ropes were applied. The ropes with the diameter of 120 mm were produced by the Kemafil technology. Ropes were made from strips of stitch-bonded nonwoven produced from a mixture of recycled natural and synthetic fibres and strips of wool needle-punched nonwoven. The protected slope had the length of 4 to 6 m, slope inclination from 1:1 to 1:1.8 and total area of approximately 150 m2. It will be shown that installed ropes restrain soil so there is no slope failure in protected section even in case of low soil shear strength parameters and unfavourable hydraulic conditions. Generally slope surface in protected section is without rills and gullies. This case also shows that plants are very good anti-erosion measure. Thanks ropes installed on the slope, favourable conditions for plants growth are created and maintained.

Coarse wool from Polish mountain sheep, often treated as a useless by-product of sheep husbandry, was used to produce pile carpets with tufting technique. Raw wool was used in the small-scale spinning mill to spin prototype rug yarns, which were then used for the production of carpets. The carpets with cut and loop piles of two different heights and densities were manufactured. During examinations, the basic parameters of raw wool, yarns, and tufted fabrics were determined. Then, the soundproofing properties of carpets were analyzed. To characterize the acoustic properties of the carpets, the sound absorption coefficient and transmission loss were measured. The measurements were carried out in one-third octave bands in the frequency range of 80–5000 Hz using the impedance tube method. It was stated that the wool of Polish mountain sheep is coarse, highly differentiated both in thickness and length and contains a significant content of medullated fibers and kemp. Despite its poor characteristics, the wool can be used for the production of rag yarns suitable for the production of pile carpets with tufting technique. The carpets possess acceptable sound absorbing capacity comparable to other similar products obtained from other wool types, which is dependent on both pile types and their parameters. The carpets exhibit low transmission loss, which is influenced, to a lesser extent, by the change in the parameters of the pile layer. [ABSTRACT FROM AUTHOR]

Wool insulating materials provide good acoustic insulation and are increasingly used for room insulation. These insulating materials are usually produced using nonwoven techniques. The structure and nonwovens parameters affect the acoustic properties of the product. During the investigation, acoustic properties of needle punched and stitch-bonded wool nonwovens were examined. Sound absorption coefficient and noise reduction coefficient for monolayer and multi-layer structures were determined. Relations between acoustic characteristics and nonwoven thickness, surface density, and air permeability were revealed. For the multi-layer structures, an increase of sound absorption with an increase in layer numbers was observed. The increase in sound absorption coefficient was correlated with the decrease in air permeability. [ABSTRACT FROM AUTHOR]

Positive influence of wool mixed with soil on slope stability and its greening were examined. Mixtures of poor quality wool as well as polyester and polypropylene fibers with soil were obtained. The mixture was used to cover meandrically arranged ropes installed on the slope. After several weeks, intense greening of the slope was observed. Grass cover grown from seeds sown on the slope was very diverse, depending on types of fibers used for soil reinforcements. In places covered with soil mixed with wool, intense and dark green grass tillers were observed. In order to determine influence of wool on intense grass growth, progress of wool biodegradation was studied. Additionally, the content of different forms of nitrogen in soil during slope exploitation was analyzed. Wool biodegradation was investigated during observations with electron scanning microscope. It was revealed that biological damage of wool was accelerated by mechanical damage of fibers, that took place during bale opening and mixing wool with soil. As a result of biodegradation of wool keratin organic nitrogen was released. Due to ammonification process, it was converted into ammonium and later, via nitrification, into nitrate form. Both forms were available for growing grass and promoted its quick development. [ABSTRACT FROM AUTHOR]

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Textile waste was used for production of thick ropes designed for the protection of slopes against sliding and erosion. For the production of ropes, scraps of insulating materials produced from poor quality wool and scraps of nonwoven manufactured from blend of recycled fibres were applied. The ropes were installed on the slope in a disused gravel pit. Stabilisation of the slope and behaviour of the materials used were analysed during two vegetation seasons. Investigations confirmed the usefulness of the technology for the protection of steep slopes. [ABSTRACT FROM AUTHOR]

Innovative geotextiles built from meandrically arranged thick ropes were produced. For the production of the geotextiles, the strips of woollen nonwoven were used. The segments of the geotextiles were installed on the bank of a drainage ditch. The behaviour of the geotextiles during 1 year was observed. It was demonstrated that the geotextiles installed in the ditch provide immediate protection of the bank. In the soil-covered wool, the process of slow biodegradation was initiated. Because of a low biodegradation rate at the end of the growing season, when the protective vegetation was not well developed, the geotextiles maintained their protective potential. In the following months, the biodegradation led to further destruction of wool fibres. During the biodegradation, the organic compounds rich in nitrogen were released into the soil. In spring, at the beginning of new growing season, the compounds acted as effective fertilizers, promoting the growth of protective vegetation. The vegetation growing on the bank provided an effective protection and took over the protective function of the geotextiles. [ABSTRACT FROM AUTHOR]