Unconfined Compressive Strength of Weakly Cemented Compacted Sand under Different Loads

Geotechnical Engineering Journal of the SEAGS & AGSSEA ISSN 0046-5828

Vol. 54 No. 4 December 2023

Unconfined Compressive Strength of Weakly Cemented Compacted Sand under Different Loads

Messaouda Redjem, Mustapha Hidjeb, Ihcene Lamri, and Khaled Boudjellal

ABSTRACT: The exploitation of dune sand for public works, notably in Skikda’s northeastern region in Algeria, is a topic of significant interest, given the region’s rich sand resources, with the aim of optimizing its effective utilization.This context led to an experimental study focusing on the behavior of cement-stabilized dune sand under static and cyclic loads. The study included various tests: Compaction, California Bearing Ratio (CBR), and Unconfined Compression Strength (UCS). The normal Proctor compaction and CBR tests were carried out on specimens of sand with cement contents of 0, 2, 4 and 6%. The unconfined compression tests were carried out at rates of loading 0.05 mm/min and 0.1 mm/min. Cyclic displacement-controlled unconfined compression tests were performed at a frequency of 0.002 Hz. This tests were conducted on samples cured for 7 and 28 days with a cement content of 0, 2, and 4 %. The research aimed to understand how cement content, loading rate, curing time, frequency, and the number of cycles affect the mechanical properties of the soil. Results under static loading revealed that the low rate of loading, the increase in curing period, and the increase in cement content increased the UCS. This increase was notably evident in a sample with 4% cement content, aged 28 days, and loaded at 0.05 mm/min, showing a UCS approximately 29% higher than a similar sample tested at 0.1 mm/min. It has also been observed that at low loading rate, a denser soil-cement composite is obtained, leading to a more dilatant behavior, resulting in an increase in the modulus of elasticity. Under cyclic loading have shown that with a low frequency and increased cement content, along with an increase in the number of cycles and curing time, both the strength and elastic modulus increase. Conclusively, the results suggest that stabilizing dune sand with cement, considering factors such as low loading rates, curing time, low frequency, and increased cycles, significantly enhances the material’s resistance under various loading conditions.

KEYWORDS: Sand, Cement, UCS, Modulus of elasticity, and Different loads.