New Clayey Deposit and Their Potential as Raw Material for Red or Structured Ceramics: Technological Characterization

Mineralogical and technological characterization of ceramic raw materials from a new deposit located at Caxias city, Maranhão State—Brazil, was accomplished to determine their potential as raw materials for the ceramics industry in northeastern Brazil. The ceramic raw materials were collected from three different locations on the site and characterized by X-ray fluorescence (XRF), X-ray diffraction (XRD), differential thermal analysis (DTA), and thermogravimetry (TG). The XRF analysis of the fraction < 2 μm revealed that most samples had SiO2 (35–51 wt%), Al2O3 (19–29 wt%), Fe2O3 (2–21 wt%), MgO (0.7 to 4.5 wt%) and K2O (0.9 to 5 wt%) as components. Quartz, kaolinite, illite, hematite and montmorillonite were the main mineral phases identified. DTA and TG analysis confirmed the mineral identification. The technological potential of the ceramic raw materials was investigated by: cation exchange capacity (CEC), plastic behavior (Atterberg Limits), linear shrinkage at 950 °C (LSF), flexural strength (FS), apparent porosity (AP), water absorption (WA) and bulk density (BD). The main experimental results—WA (9–17%), AP (19–31%), FS (2.0–23 MPa), and the Atterberg limits—indicated that the ceramic raw materials investigated have high potential to be used to develop mass for red or structured ceramics, such as bricks and roof tiles.

Black Cotton Soil Stabilization by Using Fly Ash - Kota Stone Slurry Mix

The usage of waste material for stabilizing black cotton soil has been a sustainable interest. Kota stone slurry is a waste from kota stone and fly ash is a waste from industries containing high amount of sodium and magnesium, was used as a soil stabilizer for blac cotton soil improvement in this study. This research investigated the effects of sizes and percentages of kota stone slurry mix and fly ash on the physical and strength properties, which included particle size distribution, Atterberg limits, compaction, and unconfined compressive strength (UCS) of blac cotton soil. Micro structural characterization, including the scanning electron microscopic, energy dispersive X-ray spectroscopy, and X-ray diffraction was conducted on both untreated and treated black cotton soil samples to examine the mechanism of strength development. The addition of kota stone slurry and fly ash reduced the water holding capacity, which then caused the reduction in soil plasticity (from 18 to 11%) and optimum water content (from 20 to 16%) along with the increase in peak dry density (from 1.66 to 1.74 Mg/m3). The strength of black cotton soil may increased from 50 to almost 220 kPa. The optimum kota stone slurry and fly ash contents, providing the highest UCS, were at 20 and 30% for 0.063 mm kota stone slurry and fly ash and 0.15 mm kota stone slurry and fly ash, respectively. The UCS improvement of treated marine clay is attributed to the formation of cementation compounds, mainly aluminum magnesium silicate hydrate (A–M–S–H). The outcome of this research will allow the use of RBT as a low-carbon soil stabilizer across civil engineering applications. Keywords: Stablization, Fly ash, kota stone slurry, Atterberg limits, Compaction, and unconfined compressive strength

The Role of Electrochemistry and Mineralogy in the Geotechnical Behavior of Salinized Soils

The Atterberg limits are essential information and the first step in soil classification for geotechnical purposes. Established laboratoryprocedures use distilled water in the plasticity and liquid limits determination. However, saline solutions frequently interact with soilsin the construction environment through fluid percolation processes. This work aims to understand the variation of the geotechnicalbehavior of two standard materials with different mineralogical compositions (kaolinitic and smectitic) when affected by NaCl ionicsolutions in different concentrations. The purpose is to simulate different soils in environments with the presence of saline solutions.This paper reports an experimental program in which a kaolinite-rich and a smectite-rich material received NaCl solutions in threedifferent concentrations (0.6 %, 3.5 %, and 15.0 %) and had their Atterberg limits determined under these conditions. Additionally,non-contaminated samples of both materials have had their limits measured using distilled water. Physical characterization testsincluded hygroscopic moisture, grain size distribution, grain density, plastic limit (PL), and liquid limit (LL). These data allowed thedetermination of the Skempton activity index (AI), plasticity index (PI), consistency index (CI), classification of soils in the UnifiedSoil Classification System (USCS), and in the Highway Research Board (HRB) with the group index (GI). Mineralogy was determinedby X-ray diffraction and physical chemistry by measuring pH in H2O and KCl, determining the ΔpH, the point of zero-charge (PZC),and the surface electrical potential (Ψo). The results show that the pH values rise with increasing salinity, while ΔpH, PZC, Ψo, LL,AI, PI, GI decrease with increasing salinity. The PL decreases with the increase in salinity for smectite and increases for kaolinite. TheUSCS and HRB demonstrate that the materials start to behave as fewer plastic materials with increased salinity. It is concluded that thevariations in the physicochemical parameters of the environment control and modify the geotechnical behavior of the fine-grained soils.

A Study On The Influence Of Sodium Salt Solution On The Atterberg Limits And Swelling Of Bentonite Clay

Due to industrialization and subsequent rise in urbanisation, our groundwater system and geoenvironmental reserves are getting degraded due to detrimental effects of industrial wastes discarded off into the geo-environment. Basic components like water, air and soil all get degraded resulting unacceptable loss of their natural virtues like purity, renewability, stability, sustainability and tolerability. Major industrial effluents like salt solutions, chemicals, artificial dyes, heavy metals, pharmaceutical residues and sewages etc., are posing the major problems for the ecosystem and their subparts. Since, bentonite clay has peculiar characteristics of high swelling and high pollutant absorbing capacity along with low hydraulic conductivity, it is used as a geotechnical clay liner. However, the geotechnical parameters of bentonite get affected on interaction with cations present in salt solutions. This investigation was carried out in order to observe the influences of salt solutions on bentonite and the results obtained depicts that the varying salt concentrations have a definite influence on Atterberg limits, swelling of bentonite.

Influence of parameters on the development of landslides in the Estrada de Ferro Vitória-Minas slopes

Landslides have been the object of extensive studies in the world, not only for their importance as active agents of modifications of relief forms, but also because can damages and losses to people and exposed structures, affecting various kinds of enterprises. This study had as objective the determination of influencing parameters on the development of landslides in the slopes aside of Estrada de Ferro Vitória-Minas (EFVM). EFVM is located in the southeastern region in Brazil and is an important railroad for the transportation of iron ore to the steel mills and for exportation, as well as for passenger transportation. The database used herein was collected from field work in EFVM, together with image processing and data in laboratory tests. The parameters selected to be evaluated were Atterberg limits, cohesion, friction angle, permeability and classification of soil in the slopes. Estimates were done on the volumes and areas of landslides that have already occurred in the slopes. Among the studied parameters, the results obtained for the Atteberg limits and soil cohesion were the most relevantly correlated with the field results, which is in accordance with other studies from literature. It is concluded that Atterberg limits are directly related to soil ruptures, and soil cohesion contributes to soil stabilization in slopes.