Cemented stabilized rammed earth (CSRE) is a building material used to build load bearing walls from locally available soil. The article analyzes the influence of soil mineral composition on CSRE compressive strength. Compression tests of CSRE samples of various mineral compositions, but the same particle size distribution, water content, and cement content were conducted. Based on the compression strength results and analyzed SEM images, it was observed that even small changes in the mineral composition significantly affected the CSRE compressive strength. From the comparison of CSRE compressive strength result sets, one can draw general qualitative conclusions that montmorillonite lowered the compressive strength the most; beidellite also lowered it, but to a lesser extent. Kaolinite lightly increased the compressive strength.

The paper presents a study on the shrinkage properties of three clay soils from Poland. Shrinkage limit, volumetric shrinkage and relative volumetric shrinkage were determined, tested according to PN-88/B-04481 (1988) and BS1377: Part 2 (1990) and correlated with the index properties of soils. The shrinkage limit was also calculated from Krabbe’s (1958) equation. The results showed that shrinkage limit values obtained by the BS method are lower than those obtained using the PN method, but the values calculated from Krabbe’s equation differ significantly. While no strong correlation was found between shrinkage limit and index soil parameters, linear relationships were obtained between volumetric shrinkage and initial moisture content, shrinkage range, plasticity index and clay content. Following multivariable regression analysis, the relative volumetric shrinkage was expressed as a function of plasticity index and moisture content. This function can be used to predict volumetric changes of the foundations based on the moisture content and material properties of the soil. L’article présente une étude sur les propriétés de retrait de trois sols argileux de Pologne. La limite de retrait, le retrait volumique et le retrait volumique relatif ont été déterminés à partir d’essais normalisés [PN-88/B-04481 (1988) et BS1377: Partie 2 (1990)] et corrélés avec les paramètres d’identification géotechnique des sols. La limite de retrait a également été calculée à partir de l’équation de Krabbe (1958). Les résultats ont montré que les valeurs des limites de retrait obtenues par la méthode BS sont inférieures à celles obtenues en utilisant la méthode PN, mais les valeurs calculées à partir de l’équation de Krabbe diffèrent de manière significative. Bien qu’aucune corrélation forte n’ait été trouvée entre la limite de retrait et les paramètres d’identification géotechnique du sol, des relations linéaires ont été obtenues entre le retrait volumique et la teneur en eau initiale, l’amplitude de retrait, l’indice de plasticité et la teneur en argile. A partir d’une analyse de régression multivariée, le retrait volumique relatif a été exprimé en fonction de l’indice de plasticité et de la teneur en eau. Cette fonction peut être utilisée pour prévoir les changements volumiques des sols basés sur la teneur en eau et les propriétés géotechniques des sols.

The performed investigations were focused on analysing the variability of geological-engineering properties in clay soils from central-eastern Europe with regard to microstructures. Thirty-nine soils differing in origin, lithology and microstructure type were selected for analysis. Results of studies on lithological and physical and mechanical parameters were analysed, coupled with quantitative microstructural parameters based on microstructure images. The relationships between lithological, physical and mechanical and pore space parameters were determined with regard to microstructure types. Sediment origin and diagenesis, and soil microstructure and pore space parameters had influence on the geological-engineering properties. Such approach allows for predicting engineering parameters based on soil microstructure types and their pore space parameters.

The selected parameters of the Wartanian and Odranian tills, with relation to their spatial occurrence, grain size distribution, mineralogical composition, matric suction and other physical characteristics, are presented. The assessment of the lithogenesis and stress history on the microstructure is attempted. The comparison of the compression and permeability characteristics from field and laboratory tests has been performed. Laboratory consolidation tests carried out with up to 20MPa vertical stress, revealed two yield stress values, one in the range of a couple hundreds kPa, the other in the range of a couple thousands kPa. Based on those results, the reliability of the soil preconsolidation assessment, with the use of the two different methods is discussed. The aspect of the triaxial strength reduction under the dynamic loading of diverse frequency and amplitude is raised. The research results depict a variety of possible geological-engineering characteristics, under the divergent constraints scenarios, of compression or strength weakening origin. The effects of the specialized research program will widen the possibilities of physio-mechanical and structural characterization of soils for geological-engineering purposes.

The paper presents the basic problem related with practical application of carbonate rocks in construction: are carbonate aggregates produced from such rocks favorable for building engineering, particularly for road design and construction? To resolve this problem, (1) the geological-engineering properties of aggregates are presented, (2) the correlation between petrographic and engineering parameters is shown, and (3) a strict correlation between the geological-engineering properties and the freezing-thawing and crushing resistance is recognized. This knowledge has allowed to assess the usefulness of asphalt concrete (AC) made from dolomite and limestone aggregates in the design and construction of road surface structures. The petrography was characterized using optical microscopy and scanning electron microscopy (SEM) coupled with energy-dispersive X-ray spectroscope (EDS). Engineering properties were determined in accordance with European and Polish norms and guidelines. Statistical and design calculations were performed using dedicated software. The petrographic properties, and selected physical and mechanical parameters of the aggregates, were tested to show their influence on the freezing–thawing and crushing resistance. Strong functional relationships between the water adsorption, and the freezing–thawing and crushing resistance have been observed. Aggregate strength decreased after saturation with increasing concentrations of salt solutions. Calculations of AC fatigue durability and deformation allow for reducing the thickness of the road surface structure by about 20% in comparison to normative solutions. This conclusion has impact on the economy of road design and construction, and allows for a rational utilization of rock resources, which contributes to sustainable development of the construction industry.

Determination of swell index and swelling pressure from suction tests – a case study of Neogene clays from Warsaw (Poland)