scholarly journals Evaluation for the Leaching of Cr from Coal Gangue Using Expansive Soils

Processes ◽  
2019 ◽  
Vol 7 (8) ◽  
pp. 478 ◽  
Author(s):  
Yan Zhang ◽  
Hassan Baaj ◽  
Rong Zhao
Keyword(s):  
Heavy Metal ◽  
Compressive Strength ◽  
Unconfined Compressive Strength ◽  
Building Materials ◽  
Negative Impact ◽  
Expansive Soil ◽  
Coal Gangue ◽  
Engineering Properties ◽  
Leaching Behavior ◽  
The Impact

Coal gangue can cause significant heavy metal pollution in mining areas, which would have a negative impact on the environment and human health. The objective of this research is to investigate the relationship between expansive soil amount and the leaching behavior of Chromium from coal gangue and the engineering properties of coal gangue used as building materials. The leaching behavior of Chromium from coal gangue was observed using atomic absorption spectrometry. A column leaching experiment was conducted to examine the impact of leaching time and heavy metal concentration. Furthermore, the unconfined compressive strength test was employed to evaluate the engineering properties of coal gangue with expansive soil. The results of the study demonstrate that pH of leachate solutions, leaching time, and expansive soil amounts in mixtures have important influence on Chromium concentration. The leachate solutions, which behave like alkaline, provide a positive environment for adsorbing Cr. Adding expansive soil can reduce leached concentrations of Chromium from coal gangue when compared to leachate of original coal gangue. It was found that 30% expansive soil was an improved solution because it delayed the cumulative concentration to reach the limitation line. Moreover, the unconfined compressive strength of coal gangue was boosted through adding expansive soil.

An Experimental Study on Swelling Properties of Expansive Soil Treated with Iron Furnace Slag

2020 ◽  
Vol 27 (3) ◽  
pp. 61-66
Author(s):  
Yaseen Yaseen ◽  
Jawdat Abbas
Keyword(s):  
Compressive Strength ◽  
Unconfined Compressive Strength ◽  
Expansive Soil ◽  
Swelling Pressure ◽  
Industrial Wastes ◽  
Engineering Properties ◽  
Swelling Properties ◽  
Waste Products ◽  
Iron Slag ◽  
Furnace Slag

Using industrial waste materials in the treatment of problematic soils is an environmentally friendly and cost-effective technique. It helps in decreasing disposal issues induced by various industrial wastes. Also, it is crucial to understand the behaviour of these waste products before use. This paper presents experimental research in the treatment of expansive soil by the utilization of iron furnace slag. Laboratory program was performed to examine the effect of iron furnace slag on enhancing the engineering properties of expansive soil. Several tests included liquid limits, plastic limits, free swell percentage, swelling pressure, and unconfined compressive strength were conducted on untreated and treated soils. The efficiency of adding 0, 2, 4, and 6 percentages of iron slag to the soil was investigated. The results of the natural and iron slag stabilized soils showed that iron slag has a notable effect on strength parameters and considerable improvement in plasticity and swelling properties. The addition of iron slag to the soil increased the unconfined compressive strength while reduced the swelling potential of soil. It is concluded that the utilization of iron slag to improve the properties of expansive soil is successful and useful

scholarly journals Evaluation of Cohesive Soil Mixed With Fly Ash and Reinforced With Nylon Fibre

2017 ◽  
Vol 7 (2 (S)) ◽  
pp. 193
Author(s):  
Utkarsh Gawande ◽  
Shubham Kanhake ◽  
Arjun Lahane ◽  
Prasanna Naghbhide
Keyword(s):  
Compressive Strength ◽  
Shear Strength ◽  
Fly Ash ◽  
Bearing Capacity ◽  
Unconfined Compressive Strength ◽  
Expansive Soil ◽  
Engineering Properties ◽  
Black Cotton Soil ◽  
Nylon Fiber ◽  
Properties Of Soil

Black cotton soil is a expansive soil. And mostly found in Vidarbha region of Maharashtra, this soil is highly unstable and it should be stabilize for carry out construction work. Materials like fly ash, rise husk, nylon fiber are used to make soil stable. Addition of such material will increase the physical, chemical and engineering properties of soil. Some of the properties which are improved are CBR value, shear strength, liquidity index, plasticity index, unconfined compressive strength (UCS) and bearing capacity, etc. The main objective of this study was to evaluate the effect of fly ash in stabilization of Black cotton soil. Mainly UCS and other properties of soil were calculated. The tests were conducted on Soil-Fly Ash mixtures, by increasing the Fly Ash percentage in Black cotton soil like 25%, 50%, 75%, and 100%, and then the soil was tested on Soil-Fly Ash - Fibre mixture by adding the fiber in increasing order like 0.5%, 1%, 1.5%. Results were obtained for mixed proportion of 75% soil and 25% fly ash which has unconfined compressive strength of 173 KN/m2. And by adding 1% of nylon fiber in same proportion of soil – fly ash the unconfined compressive strength increased to 243.12 KN/m2. Increase in UCS value can help in reducing the thickness of earthen roads and pavements and increase the bearing capacity and shear strength of soil. With analysis of results it was found that the fly ash along with nylon fiber has good potential to be used as an additive for improving engineering properties of expansive soil.

scholarly journals Modification of Engineering Properties of Clayey Soil by Addition of Mine Waste

2019 ◽  
Vol 8 (12) ◽  
pp. 2343-2347
Keyword(s):  
Compressive Strength ◽  
Unconfined Compressive Strength ◽  
Clayey Soil ◽  
Mine Waste ◽  
Expansive Soil ◽  
Economic Benefits ◽  
Engineering Properties ◽  
Sustainable Construction ◽  
Dry Density ◽  
Maximum Dry Density

The potential of using iron ore mine waste with an highly compressible clayey soil soil from North Karnataka, India, is investigated in this study. Mining activities lead to the production of waste materials during their extraction and processing stages. The waste maybe in the form of an overburden, waste Rock, Mine Water, or Tailings, depending on the geology, type of processing technology used and the resources mined. The lack of storage space has also been a major concern for the mineral producing agencies, thus paving ways for its better utilization in various construction processes. The collected mine waste was added to expansive soil in different percentages and the mix was tested for Atterberg limits, compaction characteristics, Unconfined compressive strength and California bearing Ratio. It was found that the liquid limit and plasticity index of the soil reduced with addition of mine waste while strength improved. Based on test results of maximum dry density and unconfined compressive strength, a mix of 40% mine waste with 60% expansive clayey soil is recommended for low cost roads. Blending mine waste with expansive soil paves way for sustainable construction besides economic benefits

scholarly journals Fire Resistance Behaviour of Geopolymer Concrete:An Overview

Buildings ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 82
Author(s):  
Salmabanu Luhar ◽  
Demetris Nicolaides ◽  
Ismail Luhar
Keyword(s):  
Compressive Strength ◽  
Thermal Resistance ◽  
Building Materials ◽  
Elevated Temperatures ◽  
Construction Materials ◽  
Flexural Behavior ◽  
Thermal Shrinkage ◽  
Physico Chemical ◽  
The Impact ◽  
Loss Of Strength

Even though, an innovative inorganic family of geopolymer concretes are eye-catching potential building materials, it is quite essential to comprehend the fire and thermal resistance of these structural materials at a very high temperature and also when experiencing fire with a view to make certain not only the safety and security of lives and properties but also to establish them as more sustainable edifice materials for future. The experimental and field observations of degree of cracking, spalling and loss of strength within the geopolymer concretes subsequent to exposure at elevated temperature and incidences of occurrences of disastrous fires extend an indication of their resistance against such severely catastrophic conditions. The impact of heat and fire on mechanical attributes viz., mechanical-compressive strength, flexural behavior, elastic modulus; durability—thermal shrinkage; chemical stability; the impact of thermal creep on compressive strength; and microstructure properties—XRD, FTIR, NMR, SEM as well as physico-chemical modifications of geopolymer composites subsequent to their exposures at elevated temperatures is reviewed in depth. The present scientific state-of-the-art review manuscript aimed to assess the fire and thermal resistance of geopolymer concrete along with its thermo-chemistry at a towering temperature in order to introduce this novel, most modern, user and eco-benign construction materials as potentially promising, sustainable, durable, thermal and fire-resistant building materials promoting their optimal and apposite applications for construction and infrastructure industries.

scholarly journals Experimental Study on Improvement of Marine Soft Soil with Alkali Residue

2018 ◽  
Vol 53 ◽  
pp. 04021
Author(s):  
SHAO Yong ◽  
LIU Xiao-li ◽  
ZHU Jin-jun
Keyword(s):  
Experimental Study ◽  
Compressive Strength ◽  
Unconfined Compressive Strength ◽  
Void Ratio ◽  
Soft Soil ◽  
Compressive Modulus ◽  
Engineering Properties ◽  
Test Results ◽  
Use Of Resources ◽  
One Year

Industrial alkali slag is the discharge waste in the process of alkali production. About one million tons of alkali slag is discharged in China in one year. It is a burden on the environment, whether it is directly stacked or discharged into the sea. If we can realize the use of resources, it is a multi-pronged move, so alkali slag is used to improve solidified marine soft soil in this paper. The test results show that the alkali residue can effectively improve the engineering properties of marine soft soil. Among them, the unconfined compressive strength and compressive modulus are increased by about 10 times, and the void ratio and plasticity index can all reach the level of general clay. It shows that alkali slag has the potential to improve marine soft soil and can be popularized in engineering.

scholarly journals Experimental Study on Dynamic Mechanical Properties of Coal Gangue Concrete

2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Zhishu Yao ◽  
Yu Fang ◽  
Weihao Kong ◽  
Xianwen Huang ◽  
Xuesong Wang
Keyword(s):  
Compressive Strength ◽  
Coarse Aggregate ◽  
Split Hopkinson Pressure Bar ◽  
Dynamic Strength ◽  
Coal Gangue ◽  
Fine Aggregate ◽  
Dynamic Mechanical ◽  
Fine Aggregates ◽  
Mine Support ◽  
The Impact

In order to study the static and dynamic mechanical characteristics of the coal gangue concrete used in the mine support structure, the compressive strength test, the drop weight impact test, and the Split Hopkinson Pressure Bar (SHPB) test were conducted. The compressive strength, initial and final impacting energy, dynamic strength, and failure characteristic of concrete were obtained of the concrete single-doped with coal gangue coarse aggregate, single-doped with coal gangue fine aggregate, and codoped with coal gangue coarse and fine aggregates. The results show that (1) it is feasible that employing coal gangue to replace natural coarse and fine aggregates in concrete can prepare C30 and C40 concrete; (2) the addition of coal gangue fine aggregate has a positive effect on the impact energy of the initial and final cracks of concrete, while the addition of coal gangue coarse aggregate has a negative effect on it; (3) compared with the static strength, the dynamic strength of concrete is improved no matter whether coal gangue is added to concrete; (4) the incorporation of coal gangue coarse aggregate will make the concrete shear surface smooth; (5) at the given impacting pressure, the concrete with coal gangue coarse aggregate has greater particle breakage and those with coal gangue fine aggregate has less. The research of this study can be a reference for the application of gangue concrete in mine support structures.

scholarly journals Chemical Sand Consolidation: From Polymers to Nanoparticles

Polymers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1069 ◽  
Author(s):  
Fahd Saeed Alakbari ◽  
Mysara Eissa Mohyaldinn ◽  
Ali Samer Muhsan ◽  
Nurul Hasan ◽  
Tarek Ganat
Keyword(s):  
Compressive Strength ◽  
Negative Impact ◽  
Production Performance ◽  
Polymer Materials ◽  
Rock Permeability ◽  
Sand Control ◽  
Materials Used ◽  
The Impact ◽  
Chemical Material ◽  
Chemical Materials

The chemical sand consolidation methods involve pumping of chemical materials, like furan resin and silicate non-polymer materials into unconsolidated sandstone formations, in order to minimize sand production with the fluids produced from the hydrocarbon reservoirs. The injected chemical material, predominantly polymer, bonds sand grains together, lead to higher compressive strength of the rock. Hence, less amounts of sand particles are entrained in the produced fluids. However, the effect of this bonding may impose a negative impact on the formation productivity due to the reduction in rock permeability. Therefore, it is always essential to select a chemical material that can provide the highest possible compressive strength with minimum permeability reduction. This review article discusses the chemical materials used for sand consolidation and presents an in-depth evaluation between these materials to serve as a screening tool that can assist in the selection of chemical sand consolidation material, which in turn, helps optimize the sand control performance. The review paper also highlights the progressive improvement in chemical sand consolidation methods, from using different types of polymers to nanoparticles utilization, as well as track the impact of the improvement in sand consolidation efficiency and production performance. Based on this review, the nanoparticle-related martials are highly recommended to be applied as sand consolidation agents, due to their ability to generate acceptable rock strength with insignificant reduction in rock permeability.

Correlation of Unconfined Compressive Strength and California Bearing Ratio in Laterite Soil Stabilization Using Varied Zeolite Content Activated by Waterglass

2020 ◽  
Vol 998 ◽  
pp. 323-328
Author(s):  
Achmad Bakri Muhiddin ◽  
Marthen M. Tangkeallo
Keyword(s):  
Compressive Strength ◽  
Unconfined Compressive Strength ◽  
Soil Stabilization ◽  
Dry Weight ◽  
Engineering Properties ◽  
High Plasticity ◽  
Curing Time ◽  
Laterite Soil ◽  
Zeolite Content ◽  
Meta Silicate

In remote areas, most roads still use pavements that are very sensitive to climate change, especially those using clay pavements with high plasticity. In addition to the issue of cost, the difficulty of obtaining a proper source of material is another problem that has led to soaring prices for materials. In this regard, a study was conducted using local materials, namely zeolite as a stabilizing material added with waterglass as activating agent. The research began with samples of laterite soil and natural zeolite for XRD test (microstructure testing), and then testing for laterite soil’s index properties and engineering properties, namely Unconfined Compressive Strength and CBR value. The purpose of the test is to determine the correlation between the Unconfined Compressive Strength (UCS) and the soil bearing capacity (CBR) caused by adding zeolite as stabilizer material and waterglass as activator with increasing curing time. Laterite soils contain a brownish red iron oxide. The stabilizing material zeolite contains a crystalline mineral of alumina silicate SiO2. While waterglass composed of sodium meta silicate. Stabilization carried out by mixing 4%, 8%, 12%, 16%, and 20% of zeolite with addition of 2% waterglass, percentage was measured based on soil dry weight. Specimens were tested at curing time of 0, 7, 14, and 28 days. The test result shows increasing UCS and CBR values with increasing percentage of zeolite. At mix of 20% zeolite and 2% waterglass, the unconfined compressive strength reaches 23.54 kg/cm2 with CBR value 58% at 28 days of curing time.

scholarly journals Analysis of strength characteristics of carbon fiber–reinforced microbial solidified sand

2019 ◽  
Vol 11 (11) ◽  
pp. 168781401988442 ◽  
Author(s):  
Rongkang Qiu ◽  
Huawei Tong ◽  
Xiaotian Fang ◽  
Yuan Liao ◽  
Yadong Li
Keyword(s):  
Compressive Strength ◽  
Carbon Fiber ◽  
Unconfined Compressive Strength ◽  
Fiber Content ◽  
Strength Characteristics ◽  
Carbonate Content ◽  
Positive Role ◽  
Compressive Strength Test ◽  
Soil Process ◽  
The Impact

Microbial solidified sand effectively enhances the strength of the soil, but it will cause brittle failure. In order to reduce the impact of microbial solidification sand brittleness, an improved method for adding carbon fiber to microbial solidified sand is proposed. The qualitative analysis was based on unconfined compressive strength test, calcium carbonate content determination, and penetration test. The results show that the addition of fiber in the microbial solidified sand can significantly increase the unconfined compressive strength of the sample. The unconfined compressive strength of the sample increases first and then decreases with the increase of fiber addition. The addition of fibers during the soil process enhances the toughness of the specimen and causes plastic damage during the failure of the specimen. Based on the analysis of the microstructure of the sample, the effect of fiber bundles on the strength characteristics of the sample is discussed when the fiber content is higher than the optimal fiber content. The addition of carbon fiber to microbial solidified sand can greatly improve the strength of the sample and increase the toughness, which plays a positive role in improving the safety and stability of the project.

Sign in / Sign up

Export Citation Format

Share Document