scholarly journals Stabilization/Solidification of Zinc- and Lead-Contaminated Soil Using Limestone Calcined Clay Cement (LC3): An Environmentally Friendly Alternative

2020 ◽  
Vol 12 (9) ◽  
pp. 3725 ◽  
Author(s):  
Vemula Anand Reddy ◽  
Chandresh H. Solanki ◽  
Shailendra Kumar ◽  
Krishna R. Reddy ◽  
Yan-Jun Du
Keyword(s):  
Compressive Strength ◽  
Contaminated Soil ◽  
Contaminated Soils ◽  
Low Cost ◽  
Construction Material ◽  
Environmentally Friendly ◽  
Cementitious Materials ◽  
Low Carbon ◽  
Untreated Soil ◽  
Calcined Clay

Due to increased carbon emissions, the use of low-carbon and low-cost cementitious materials that are sustainable and effective are gaining considerable attention recently for the stabilization/solidification (S/S) of contaminated soils. The current study presents the laboratory investigation of low-carbon/cost cementitious material known as limestone-calcined clay cement (LC3) for the potential S/S of Zn- and Pb-contaminated soils. The S/S performance of the LC3 binder on Zn- and Pb-contaminated soil was determined via pH, compressive strength, toxicity leaching, chemical speciation, and X-ray powder diffraction (XRPD) analyses. The results indicate that immobilization efficiency of Zn and Pb was solely dependent on the pH of the soil. In fact, with the increase in the pH values after 14 days, the compressive strength was increased to 2.5–3 times compared to untreated soil. The S/S efficiency was approximately 88% and 99%, with increase in the residual phases up to 67% and 58% for Zn and Pb, respectively, after 28 days of curing. The increase in the immobilization efficiency and strength was supported by the XRPD analysis in forming insoluble metals hydroxides such as zincwoodwardite, shannonite, portlandite, haturite, anorthite, ettringite (Aft), and calcite. Therefore, LC3 was shown to offer green and sustainable remediation of Zn- and Pb-contaminated soils, while the treated soil can also be used as safe and environmentally friendly construction material.

scholarly journals Characteristics of Hollow Compressed Earth Block Stabilized Using Cement, Lime, and Sodium Silicate

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Walid Edris ◽  
Faris Matalkah ◽  
Bara’ah Rbabah ◽  
Ahmad Abu Sbaih ◽  
Reham Hailat
Keyword(s):  
Compressive Strength ◽  
Portland Cement ◽  
Sodium Silicate ◽  
Low Cost ◽  
Construction Material ◽  
Early Age ◽  
Compressed Earth Block ◽  
Earth Block ◽  
Lower Production ◽  
Northern Jordan

Abstract This research aims to produce a Compressed Earth Block (CEB) product using locally available soil collected from northern Jordan. The CEB mixture was further stabilized using Portland cement, lime, and sodium silicate. The research significance is based upon the urgent need of most developing countries (e.g. Jordan, Egypt…etc) to build more durable and low-cost houses by using locally available materials. As a result, CEB was identified as a cheap and environmentally friendly construction material. CEB specimens were thoroughly characterized by studying the mechanical properties and durability characteristics. Blocks of 30 x 15 x 8 cm with two holes of 7.5 cm in diameter have a potential for higher enduring, higher compressive strength, better thermal insulation, and lower production cost. Blocks were manufactured with an addition of 8 % for either Portland cement or lime, as well as 2 % of sodium silicate to the soil. The results showed that the addition of 8 % of cement to the CEB achieves satisfactory results in both mechanical and durability properties. Also, the addition of sodium silicate was found to enhance the early-age compressive strength however it affected negatively the durable properties of blocks by increasing the erosion rate and deterioration when exposed to water.

Performance of Stabilized Earth with Wheat Straw and Slag

MRS Advances ◽  
2020 ◽  
Vol 5 (25) ◽  
pp. 1285-1294 ◽  
Author(s):  
W Benhaoua ◽  
K. Grine ◽  
S. Kenai
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Low Cost ◽  
Construction Material ◽  
Soil Samples ◽  
Capillary Absorption ◽  
Wetting And Drying ◽  
Environment Friendly ◽  
Granulated Blast Furnace Slag ◽  
Local Soil

ABSTRACTStabilized earth is a very ancient material that has been used in many countries as a low cost, environment friendly construction material. However, its durability under humid environments is low. Stabilization using cement, lime and natural fibres could enhance its durability and lowers the risk of cracking. This paper presents an experimental investigation into the performance of stabilised local soil by either, cement mixed with a proportion of granulated blast furnace slag (GBFS) /or straw naturel fibres. Unconfined compressive strength (UCS), shrinkage, wetting and drying, capillary absorption and thermal conductivity tests were performed on both untreated soil samples and stabilised soil samples. The results show that stabilising the soil with cement and GBFS increased both compressive strength, durability, thermal conductivity and decreased the capillary absorption and the shrinkage. The addition of natural wheat fibres increased the capillary absorption but leads to a decrease in the thermal conductivity and to a further reduction in the shrinkage and hence a better insulating less prone to cracking material.

scholarly journals Waste Management Technique Applied in the Preparation of Bio Concrete Material

2019 ◽  
Vol 8 (4) ◽  
pp. 9226-9230
Keyword(s):  
Compressive Strength ◽  
Water Absorption ◽  
Construction Industry ◽  
Coarse Aggregate ◽  
Low Cost ◽  
Construction Material ◽  
Raw Material ◽  
Management Technique ◽  
Increasing Demand ◽  
Poly Ethylene

Due to Modernization and urbanization constructing industries are fast growing also it leading to high demand of constructing materials because of expensive prices, and for the construction industry, usage of steel is currently limited heavily Many studies have been carried out to identify highly available, low cost innovative material to use in construction industry as a solution to meet the ever increasing demand for raw material. Bamboo was used as a construction material as a coarse aggregate, steel reinforcement. Bamboo has a higher compressive strength than wood, brick, or concrete and a tensile strength that rivals steel. water absorption in bamboo was the main problem used for construction .because The durability of the concrete is largely affected by absorption of water. Also poly ethylene bags are widely used in the country and its disposal after use causes more problems ,Mismanaged waste of polyethylene bags is the current threatening to the environment this waste is largely availbe its abundant high resistance to insects, fungi, animals, as well as molds, mildew, rot and many chemicals. In this study cubic bamboo was used as a coarse aggregate and it was coated with the waste LDPE bag melt ,as one of the coating material and other one is neem oil.and it was investigated to find the water absorption and turbidity, antifungal activity and compressive strength some other parameters in bamboo material with coatings it was observed that compared to untreated bamboo the polyethylenene coated bamboo material shows reduction in water absorption level and turbity.

scholarly journals Compressive Strength Characteristics of Cemented Tailings Backfill with Alkali-Activated Slag

2018 ◽  
Vol 8 (9) ◽  
pp. 1537 ◽  
Author(s):  
Gaili Xue ◽  
Erol Yilmaz ◽  
Weidong Song ◽  
Shuai Cao
Keyword(s):  
Compressive Strength ◽  
Mine Tailings ◽  
Low Cost ◽  
Cementitious Materials ◽  
Cementitious Material ◽  
Solid Wastes ◽  
Fine Grained ◽  
Activated Slag ◽  
The Relationship ◽  
Alkali Activated

With the use of glauberite mineral (GM) and sodium hydroxide (SH) alkaline catalysts to stimulate slag powder’s internal cementation activity and incorporate the two fine-grained solid wastes, such as quicklime (Q) and desulfurized ash (DA), a new cementitious material suitable for mine tailings was developed to replace traditional ordinary Portland cement (OPC) for reducing cement-related costs. A series of uniaxial compressive strength (UCS) tests were carried out on cemented tailings backfill (CTB) samples containing different activators. The results showed that (1) the highest UCS values of 14-day and 28-day cured CTB samples were 1.259 MPa and 2.429 MPa, respectively, and the effect of different activator types was in the order of SH > GM > DA > Q and SH > GM > Q > DA; (2) the relationship between UCS and activator dosages followed the function y = ax3 − bx2 + cx − d. Compared with the OPC 32.5 R cemented samples, the minimum strength growth factor was 1.45, and the maximum reached 2.03; (3) the optimal proportion of DA slag formula was 4.5% or 5.0% Q, 19% DA, 2.5% GM, and 0.7% SH. The aforesaid new cementitious materials met the mine’s UCS requirements with a relatively low cost (17.04–17.20 €/ton) and solved the stacking problem of solid wastes on the surface well. Ultimately, this study provides a useful reference for the development of mineral binders.

scholarly journals Limestone and Calcined Clay-Based Sustainable Cementitious Materials for 3D Concrete Printing: A Fundamental Study of Extrudability and Early-Age Strength Development

2019 ◽  
Vol 9 (9) ◽  
pp. 1809 ◽  
Author(s):  
Chen ◽  
Li ◽  
Chaves Figueiredo ◽  
Çopuroğlu ◽  
Veer ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Setting Time ◽  
Cementitious Materials ◽  
Strength Test ◽  
Test Method ◽  
Strength Development ◽  
Early Age ◽  
Ambient Conditions ◽  
Calcined Clay ◽  
Green Strength

The goal of this study is to investigate the effects of different grades of calcined clay on the extrudability and early-age strength development under ambient conditions. Four mix designs were proposed. Three of them contained high, medium, and low grades of calcined clay, respectively, and one was the reference without calcined clay. In terms of extrudability, an extrusion test method based on the ram extruder was introduced to observe the quality of extruded material filaments, and to determine the extrusion pressure of tested materials at different ages. For evaluating the very early-age strength development, the penetration resistance test, the green strength test, and the ultrasonic pulse velocity test were applied. Furthermore, the mechanical properties of the developed mix designs were determined by the compressive strength test at 1, 7 and 28 days. Finally, the main finding of this study was that increasing the metakaolin content in calcined clay could significantly increase the extrusion pressures and green strength, shorten the initial setting time and enhance the compressive strength at 1, 7, and 28 days.

Experimental Study on HMPE Fiber Reinforced Concrete

2012 ◽  
Vol 598 ◽  
pp. 336-340
Author(s):  
Hisen Hua Lee ◽  
Yen Shuo Chen ◽  
Chi Wen Cheng
Keyword(s):  
Compressive Strength ◽  
Reinforced Concrete ◽  
Experimental Testing ◽  
Low Cost ◽  
Construction Material ◽  
Volume Ratio ◽  
Fiber Material ◽  
Reinforce Concrete ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced

Abstract. Concrete as a most popular construction material has many advantages such as easiness to be formed into various shapes, common availability and relative low cost. However, the low tensile strength and brittleness are disadvantages for wider application of the material. In this study, an advanced material of high strength and strong abrasion resistance HMPE fiber was used to reinforce concrete properties. A series of experimental testing were carried out to examine the properties of both fresh and hardened HMPE fiber reinforced concrete. It was found that the addition of an HMPE fiber material in concrete may enhance its compressive strength as high as 20% increment without water-reducing admixture. If a water-reducing admixture was applied, the increment of compressive strength may reach as high as 25% for 1.5% volume ratio of fiber contained in concrete.

scholarly journals Hydration Properties of Cement with Liquefied Red Mud Neutralized by Nitric Acid

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2641
Author(s):  
Sukpyo Kang ◽  
Hyeju Kang ◽  
Byoungky Lee
Keyword(s):  
Compressive Strength ◽  
Nitric Acid ◽  
Cement Paste ◽  
Red Mud ◽  
Positive Impact ◽  
Low Cost ◽  
Construction Material ◽  
Construction Materials ◽  
Aluminum Production ◽  
Hydration Properties

An increasing amount of red mud (RM) is being generated globally due to the growth in aluminum production. To avoid RM pollution, low-cost methods for effectively recycling RM are being investigated. We propose a method for recycling RM as a construction material. Liquefied RM (LRM) was neutralized by nitric acid and added to cement paste, and the hydration heat, compressive strength, and hydration products were investigated. The cement paste with neutralized LRM had a higher compressive strength than that of plain cement paste and cement paste with LRM without neutralization at 1 day of aging; this indicates that nitric acid neutralization increases the early-age strength. Furthermore, the cement paste with 10% neutralized LRM showed 28 days-compressive strength and hydration heating curves similar to the plain mixture, indicating the positive impact of LRM neutralization on the strength. It was noted that a greater quantity of portlandite was produced earlier in cement paste with neutralized LRM than in that without. Therefore, the proposed method of using RM as a concrete additive has the potential to reduce the cost and environmental impact of both construction materials and RM waste management.

scholarly journals Evaluation of Zero-Valent Iron for Pb(II) Contaminated Soil Remediation: From the Analysis of Experimental Mechanism Hybird with Carbon Emission Assessment

2021 ◽  
Vol 13 (2) ◽  
pp. 452
Author(s):  
Junfang Sun ◽  
Angran Tian ◽  
Zheyuan Feng ◽  
Yu Zhang ◽  
Feiyang Jiang ◽  
...  
Keyword(s):  
Soil Remediation ◽  
Contaminated Soil ◽  
Contaminated Soils ◽  
Carbon Emission ◽  
Physical Adsorption ◽  
Extraction Procedure ◽  
Economic Benefits ◽  
Zero Valent Iron ◽  
Order Kinetic ◽  
Low Carbon

Carbon emission is one of the main causes of global climate change, thus it is necessary to choose a low-carbon method in the contaminated soil remediation. This paper studies the adsorption ability of ZVI on Pb(II) contaminated soils under different working conditions. The removal efficiency of Pb(II) was 98% because of the suitable ZVI dosage, log reaction time and low initial solution concentration. The whole balancing process was much fast according to the pseudo-second-order kinetic and Freundlich isothermal model. Moreover, sequential extraction procedure (SEP) showed Pb(II) was transformed from Fe/Mn oxides-bound form to residual form in Pb(II) contaminated soils. From scanning electron microscopy (SEM), Brunauer-Emmett-Teller method (BET) and X-ray diffraction (XRD) results, it was confirmed that zero-valent iron (ZVI) stabilizes Pb(II) pollutants mostly through the combination of chemical adsorption and physical adsorption. The economic and carbon emission assessments were used to compare the cost and carbon emissions of different methods. The results show that ZVI adsorption has excellent economic benefits and low carbon emission.

scholarly journals The Influence of Thermo-Mechanical Activation of Bentonite on the Mechanical and Durability Performance of Concrete

2019 ◽  
Vol 9 (24) ◽  
pp. 5549 ◽  
Author(s):  
Safi Ur Rehman ◽  
Muhammad Yaqub ◽  
Muhammad Noman ◽  
Babar Ali ◽  
Muhammad Nasir Ayaz Khan ◽  
...  
Keyword(s):  
Portland Cement ◽  
Mechanical Activation ◽  
Mechanical Performance ◽  
Experimental Testing ◽  
Construction Material ◽  
Cementitious Materials ◽  
Supplementary Cementitious Materials ◽  
Low Carbon ◽  
Acid Attack ◽  
Split Tensile Strength

Despite presenting a very high global warming toll, Portland cement concrete is the most widely used construction material in the world. The eco-efficiency, economy, and the overall mechanical and durability performances of concrete can be improved by incorporating supplementary cementitious materials (SCMs) as partial substitutions to ordinary Portland cement (OPC). Naturally found bentonite possesses pozzolanic properties and has very low carbon footprint compared to OPC. By applying activation techniques, the reactivity of bentonite can be improved, and its incorporation levels can be maximized. In this study, the influence of mechanical and thermo-mechanical activation of bentonite is investigated on properties of concrete. Bentonite was used for 0%, 10%, 15%, 20%, 25%, 30%, and 35% mass replacements of OPC. Mechanical (compressive strength and split tensile strength) and durability (water absorption, sorptivity coefficient, and acid attack resistance) properties were studied. Results of experimental testing revealed that, concrete containing bentonite showed good mechanical performance, while durability was significantly improved relative to control mix. Application of thermo-mechanical activation can enhance the incorporation levels of bentonite in concrete. At 15% and 25%, bentonite produced optimum results for mechanical and thermo-mechanical activation, respectively. Bentonite inclusion is more beneficial to the durability than the mechanical strength of concrete.

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