Properties of Crushed Red-Bed Soft Rock Mixtures Used in Subgrade

Abstract

Slaking red-bed soft rocks are widely distributed in the south of Anhui Province, China, and several highways will go through this area. It is important to evaluate their physical and mechanical characteristics for the purpose of using this kind of soft rocks as materials for road construction. In this paper, the compacting tests, the resilient modulus tests, the California bearing ratio (CBR) tests, and permeability tests have been carried out on crushed red-bed soft rock mixtures. The test results showed that, for a given degree of compaction, the resilient modulus decreases linearly with the increase of moisture content. For a given moisture content, the resilient modulus and CBR values increase linearly with the increase of compaction degree, while the soaking swelling, water absorption capacity, and permeability coefficient decrease linearly. In other words, the strength and water stability are enhanced with the increase of the degree of compaction. The results demonstrate that the crushed red-bed soft rock mixtures can be directly used as materials for the highway construction by taking corresponding measures.

Basic chemical compositions combination rules and quantitative criterion of red beds

“…This study mainly focuses on the influence of mineral compositions on geomorphic characteristics, particularly the layered structure and color of red beds. The mineral compositions of red beds (1,536 groups data) were collected from the previous studies as shown in Supplementary Table 1 (e.g., (Bai et al 2020;Chen et al 2014;Jian et al 2009;Li et al 2023;Li et al 2015;Li et al 2013;Liu et al 2020;Marat et al 2022;Wang et al 2018;Wang et al 2014;Wang et al 2017;Yao et al 2016;Zha et al 2022;Zhang et al 2016;Zhang et al 2020;Zhang et al 2021)). These studies used semi quantitative or quantitative methods in XRD technology to statistically analyze the differences in mineral composition between different red beds (e.g., quartz, feldspar, mica, hematite, clay minerals, and calcite), as detailed in the aforementioned literatures.…”

Influence of Elevation on Slake Durability Index of Quartz Mica Schist: A Case Study of East Slope of Manjiazhai Open Pit

“…e disintegration of soft rock is a physical phenomenon with complex mechanism. In order to reveal this mechanism, some researchers have carried out tests on rock disintegration to characterize the variation law of the disintegration process under the macroscopic conditions such as the number of cycles, the hydraulic properties, and the mass of disintegration residues [3,4]. At the same time, X-ray diffraction, mercury injection test, and CT scanning were used to study the material composition, fracture propagation degree, and void ratio of soft rock to explain the internal factors of disintegration [5][6][7].…”

Mechanical Properties of Sandstone Cement-Stabilized Macadam

“…At present, the research on sedimentary rocks used in highway engineering mainly focuses on the performance of red sandstone, and its uniaxial compressive strength and indirect tensile strength are superior to white sandstone and yellow sandstone [15]. Yao et al [16] evaluated the physical and mechanical properties of red sandstone distributed in southern Anhui, with the aim of using this soft rock as a road construction material. The results demonstrated that the mixture consisting of sandstone can be directly applied into highway construction after particular preliminary steps are performed.…”