The Influence of Fine Fractions Content in Non-Cohesive Soils on Their Compactibility and the CBR Value

Abstract

The bearing capacity of subsoils is particularly important due to the intensive development of road and airfield pavements. Subgrade is classified due to frost susceptibility as non-frost-susceptible, low-frost-susceptible or frost-susceptible. Presented research included laboratory tests of low-frost-susceptible soils with limited potential for direct use. The main objective of this paper was focused on the study of changes of compactibility parameters and the CBR (Californian Bearing Ratio) values of silty sand (Pπ). For this purpose, seventeen soil samples with various fine fractions content (of 1.6% to 24.2%), were composed. Laboratory tests, based on soaked soil samples, encompassed the Proctor Compaction test and the CBR test. Additionally, measurements of moisture content in soaked soil samples before and after the penetration test and the displacement of annular surcharge rings while penetration test, were performed. Obtained results allowed for conclusions that penetration curves diverge from the standard curve locally, therefore direct reading of the CBR values from the penetration curves may lead to its significant overstatement. There was also noticed the dependence between the water flow in the soil and the fine fraction content. The research recognized the need for pressure measurement in soil samples during the penetration test.

Numerical Modelling of Thermal Regime of Railway Track - Structure With Thermal Insulation (Styrodur)

“…Observation of changes in soil properties and building materials caused by frost is the subject of research activities in several countries, especially the Nordic countries. Research activities are focused mainly on frost heaves (Long et al, 2018;Wang et al, 2014;Zhou et al, 2018), water freezing in porous materials (Kou et al, 2018;Lu et al, 2019;Zhang & Liu, 2018;Bąk & Chmielewski, 2019), thermal-technical parameters of soils and building materials (He et al, 2017;Kömle et al, 2007Kömle et al, , 2010Gnip et al, 2001). Significant results of Canadian research (Fredlund, 2019;Pentland, 2000;Soliman et al, 2008;Tam, 2009) led to the development of the SoilVision software (Fredlund, 2011) which addresses various problematic processes occurring in soils.…”

Functional Method of Designing Self-Compacting Concrete

“…The final amount of aggregate [ 69 , 70 , 71 , 72 , 73 ] in the concrete mix is calculated using Formula (9): …”

An assessment of how penetration curve adjustment affects the California bearing ratio (CBR)

“…Over the hundred years, the CBR method has been in use, there have been many studies to explore both soils and aggregates in order to find correlations between specific properties or parameters and CBR results. For soils, the literature reports findings which show strong correlations between CBR and the plastic limit of soil, maximum bulk density or fine fractions (Bąk & Chmielewski, 2019;Katte et al, 2019;Nguyen & Mohajerani, 2015;Rehman et al, 2015;Talukdar, 2014). But for aggregates, it is difficult to find a parameter that could be considered to significantly affect CBR results (Hydzik-Wiśniewska et al, 2018).…”