High-efficiency utilization of limestone tailings: Used as cementitious materials and fine aggregate to prepare karst structure filling material

2022 ◽  
Vol 316 ◽  
pp. 125841
Author(s):  
Yansheng Wang ◽  
Zhaofeng Li ◽  
Qing Jin ◽  
Ming Zhang ◽  
Zhihao Zhou
Keyword(s):  
High Efficiency ◽  
Cementitious Materials ◽  
Fine Aggregate ◽  
Filling Material

scholarly journals Utilization of tailings in cement and concrete: A review

2019 ◽  
Vol 26 (1) ◽  
pp. 449-464 ◽  
Author(s):  
Mifeng Gou ◽  
Longfei Zhou ◽  
Nathalene Wei Ying Then
Keyword(s):  
Compressive Strength ◽  
Cementitious Materials ◽  
Solid Wastes ◽  
Supplementary Cementitious Materials ◽  
Cement Clinker ◽  
Fine Aggregate ◽  
Granulated Blast Furnace Slag ◽  
Fine Aggregates ◽  
Compressive Strength Of Concrete ◽  
Cement And Concrete

AbstractOne of the advantages of cement and the cement concrete industry in sustainability is the ability to utilize large amounts of industrial solid wastes such as fly ash and ground granulated blast furnace slag. Tailings are solid wastes of the ore beneficiation process in the extractive industry and are available in huge amounts in some countries. This paper reviews the potential utilization of tailings as a replacement for fine aggregates, as supplementary cementitious materials (SCMs) in mortar or concrete, and in the production of cement clinker. It was shown in previous research that while tailings had been used as a replacement for both fine aggregate and cement, the workability of mortar or concrete reduced. Also, at a constant water to cement ratio, the compressive strength of concrete increased with the tailings as fine aggregate. However, the compressive strength of concrete decreased as the replacement content of the tailings as SCMs increased, even whentailings were ground into smaller particles. Not much research has been dedicated to the durability of concrete with tailings, but it is beneficial for heavy metals in tailings to stabilize/solidify in concrete. The clinker can be produced by using the tailings, even if the tailings have a low SiO2 content. As a result, the utilization of tailings in cement and concrete will be good for the environment both in the solid waste processing and virgin materials using in the construction industry.

Research on the Application of Fly Ash in High Water Filling Material

2013 ◽  
Vol 807-809 ◽  
pp. 1124-1128
Author(s):  
Feng Yi Li ◽  
Lei Chen ◽  
Guang Qi Li ◽  
Wei Xin Chen ◽  
Peng Fei Wang
Keyword(s):  
Fly Ash ◽  
Power Plant ◽  
High Efficiency ◽  
High Water ◽  
Packing Material ◽  
Filling Material ◽  
Comprehensive Utilization ◽  
Push Forward ◽  
Water Filling ◽  
Utilization Ratio

Fly ash is a coal-fired waste from the coal-consumed power plant. It has become a great concern as to how fly ash should be treated properly at home. At present, the comprehensive utilization ratio of fly ash is just 30% and utilization ratio of fly ash from coal gangue power plant is less than coal-fired power plant. The effect of different fly ash added to the high-water filling material on the filling result was analyzed and field test of filling in mined-out area was conducted in the Babao vertical shaft + 3211 section of Tonghua coal mining group. The result shows that fly ash of gangue power plant added into the high-water packing material can lower the filling material cost effectively. This research can lead to push forward the utilization of fly ash with high efficiency.

Water Penetration Resistance of Fly Ash Concrete Incorporating with Quarry Wastes

2017 ◽  
Vol 886 ◽  
pp. 159-163 ◽  
Author(s):  
Suppachai Sinthaworn
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
High Strength ◽  
Cementitious Materials ◽  
Fine Aggregate ◽  
Water Penetration ◽  
Strength Concrete ◽  
Fly Ash Concrete ◽  
Suitable Amount ◽  
Normal Strength

Slump of fresh concrete, compressive strength and water penetration depth under pressure of fly ash concrete incorporate with quarry waste as fine aggregate were investigated. The cementitious materials of the concrete includes ordinary Portland cement 80% and fly ash 20% by weight of cementitious. The mix proportions of the concrete were set into two classes of compressive strength. The results show that fly ash enhances workability of both concretes (normal concrete and concrete incorporate with quarry waste). Increasing the percentage of quarry dusts as fine aggregate in concrete seem negligible effect on the compressive strength whereas adding fly ash shows a slightly improve the compressive strength in the case of cohesive concrete mixture. Besides, adding the suitable amount of fly ash could improve the permeability of concrete. Therefore, fly ash could be a good admixture to improve the water resistant of normal strength concrete and also could be a supplemental material to improve the compressive strength of normal high strength concrete.

scholarly journals Influence of polymer fibers on rheological properties of cement mortars

2017 ◽  
Vol 7 (1) ◽  
pp. 228-236 ◽  
Author(s):  
Dorota Malaszkiewicz
Keyword(s):  
Rheological Properties ◽  
Volume Fraction ◽  
Fiber Type ◽  
Cementitious Materials ◽  
Plastic Viscosity ◽  
Synthetic Fiber ◽  
Rheological Parameters ◽  
Model Parameters ◽  
Fine Aggregate ◽  
Bingham Model

AbstractThe reinforcing effect of fibers in cement composites often results in the improvement of the brittle nature of cementitious materials. But the decrease in the workability of fresh concrete is often the disadvantage of fibers addition. Conventional single-point workability tests cannot characterize workability of concrete in terms of fundamental rheological parameters. To this end, this paper describes an investigation of the influence of synthetic fiber additions (fiber length in the range 12–50 mm and volume fraction in the range 0–4%) on the rheological properties of fiber reinforced fresh mortar (FRFM) and development of these properties over time. The rheometer Viskomat XL was used in this study. Within the limitations of the instrument and testing procedure it is shown that FRFMs conform to the Bingham model. Natural postglacial sand 0/4 mm was used as a fine aggregate and cement CEMI 42.5 R was used as a binder. Three commercial synthetic fibers were selected for these examinations. Rheological properties were expressed in terms of Bingham model parameters g (yield value ) and h (plastic viscosity). Based on the test results it was found out that the fiber type and volume fraction affected both the yield stress and plastic viscosity.

scholarly journals Lightweight high-strength concrete with the use of waste cenosphere as fine aggregate

2019 ◽  
Vol 24 (4) ◽  
Author(s):  
Felipe Basquiroto de Souza ◽  
Oscar Rubem Klegues Montedo ◽  
Rosielen Leopoldo Grassi ◽  
Elaine Gugliemi Pavei Antunes
Keyword(s):  
High Strength Concrete ◽  
Power Plants ◽  
Lightweight Concrete ◽  
Construction Materials ◽  
Hollow Structure ◽  
High Strength ◽  
Cementitious Materials ◽  
Partial Substitution ◽  
Fine Aggregate ◽  
Strength Concrete

ABSTRACT Cenosphere is a coal combustion by-product that presents interesting properties to be used in the production of cementitious materials, such as hollow structure, low density, low thermal conductivity and notably thermal stability. In addition, it displays pozzolanic reactivity under thermal curing. However, the cenosphere potential for the development of unique construction materials has not been fully investigated, remaining obscure for both power plants and the construction field. This study investigated the employment of waste cenosphere in partial substitution to sand for the obtainment of high-strength lightweight concrete materials. Cenosphere from a Brazilian power plant was chemically and physically characterized and the feasibility of its use in concretes was investigated. It was discovered that the power plant’s fly ash is composed of approximately 0.2% of cenosphere. In addition, the cenosphere displayed size ranging from 30 to 300 µm and were suitable for use as fine aggregate in concrete. Concrete with 33, 67, and 100% fine aggregate replacement by the waste cenosphere was produced. Cenosphere-based high strength concrete presented strength higher than 70 MPa and density as low as 1500 kg • m-3. Compared to mixes of reference, cenosphere application as fine aggregate improved the specific strength of high-strength concrete while maintaining equivalent mechanical properties.

scholarly journals Efficacy of Glass Fiber Reinforced Concrete by using Supplementary Cementitious Materials

2019 ◽  
Vol 8 (12) ◽  
pp. 4262-4268
Keyword(s):  
Glass Fibers ◽  
Coal Ash ◽  
Cementitious Materials ◽  
Fiber Reinforced Concrete ◽  
Supplementary Cementitious Materials ◽  
Waste Materials ◽  
Partial Substitution ◽  
Fine Aggregate ◽  
Conventional Concrete ◽  
Substitution Degree

Concrete is a building material which is being utilized excessively in the world adjacent to water. The nature is influenced due to the extraction of raw matter and also because of the evolution of gases like CO2 . In the ongoing years, there is a speedy growth in the production of waste materials like glass wastes, plastic, Ground Granulated Blast furnace Slag, silica fume, coal ash, wood ash, rice husk ash, etc. Controlling and discarding issues emerge due to these wastes and inflict havoc on the nature. So as to curtail these issues, the waste materials are used as additives or partial substitutions for cement and aggregates in construction field. This paper focuses on strength properties and durability of concrete containing glass fibers by partial substitution of cement and fine aggregate with GGBS and Coal ash respectively. For this work, mix design using IS method is prepared for M30 grade and the tests are conducted for various dosages of glass fibers as 0.5, 1%, 1.5% and 2% by weight of cement. The substitution degree of GGBS is 30% and that of coal ash is 20%. The obtained outcomes are contrasted with conventional concrete

scholarly journals Properties of Mortar with Recycled Aggregates, and Polyacrylonitrile Microfibers Synthesized by Electrospinning

Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 3849 ◽  
Author(s):  
Manuel J. Chinchillas-Chinchillas ◽  
Manuel J. Pellegrini-Cervantes ◽  
Andrés Castro-Beltrán ◽  
Margarita Rodríguez-Rodríguez ◽  
Víctor M. Orozco-Carmona ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Total Porosity ◽  
Cementitious Materials ◽  
Effective Porosity ◽  
Recycled Aggregates ◽  
Capillary Absorption ◽  
Fine Aggregate ◽  
Water Penetration

Currently it is necessary to find alternatives towards a sustainable construction, in order to optimize the management of natural resources. Thus, using recycled fine aggregate (RFA) is a viable recycling option for the production of new cementitious materials. In addition, the use of polymeric microfibers would cause an increase in the properties of these materials. In this work, mortars were studied with 25% of RFA and an addition of polyacrylonitrile PAN microfibers of 0.05% in cement weight. The microfibers were obtained by the electrospinning method, which had an average diameter of 1.024 µm and were separated by means of a homogenizer to be added to the mortar. Cementing materials under study were evaluated for compressive strength, flexural strength, total porosity, effective porosity and capillary absorption, resistance to water penetration, sorptivity and carbonation. The results showed that using 25% of RFA causes decreases mechanical properties and durability, but adding PAN microfibers in 0.05% caused an increase of 2.9% and 30.8% of compressive strength and flexural strength respectively (with respect to the reference sample); a decrease in total porosity of 5.8% and effective porosity of 7.4%; and significant decreases in capillary absorption (approximately 23.3%), resistance to water penetration (25%) and carbonation (14.3% after 28 days of exposure). The results showed that the use of PAN microfibers in recycled mortars allowed it to increase the mechanical properties (because they increase the tensile strength), helped to fill pores or cavities and this causes them to be mortars with greater durability. Therefore, the use of PAN microfibers as a reinforcement in recycled cementitious materials would be a viable option to increase their applications.

scholarly journals Suitability of Remediated PFAS-Affected Soil in Cement Pastes and Mortars

2020 ◽  
Vol 12 (10) ◽  
pp. 4300
Author(s):  
Andras Fehervari ◽  
Will P. Gates ◽  
Chathuranga Gallage ◽  
Frank Collins
Keyword(s):  
Contaminated Soils ◽  
Strength Loss ◽  
Cementitious Materials ◽  
Supplementary Cementitious Materials ◽  
Fine Aggregate ◽  
Cement Pastes ◽  
Supplementary Cementitious Material ◽  
Treated Soil ◽  
Fine Aggregates ◽  
Heat Treated

Australia and many other parts of the world face issues of contamination in groundwater and soils by per- and poly-fluoroalkyl substances (PFAS). While the pyrolytic treatment of contaminated soils can destroy PFAS, the resulting heat-treated soils currently have limited applications. The purpose of this study was to demonstrate the usefulness of remediated soils in concrete applications. Using heat-treated soil as a fine aggregate, with a composition and particle size distribution similar to that of traditional concrete sands, proved to be a straightforward process. In such situations, complete fine aggregate replacement could be achieved with minimal loss of compressive strength. At high fine aggregate replacement (≥ 60%), a wetting agent was required for maintaining adequate workability. When using the heat-treated soil as a supplementary cementitious material, the initial mineralogy, the temperature of the heat-treatment and the post-treatment storage (i.e., keeping the soil dry) were found to be key factors. For cement mortars where minimal strength loss is desired, up to 15% of cement can be replaced, but up to 45% replacement can be achieved if moderate strengths are acceptable. This study successfully demonstrates that commercially heat-treated remediated soils can serve as supplementary cementitious materials or to replace fine aggregates in concrete applications.

Study on Proportioning Test of Coal Solid Waste Paste Filling Material

2012 ◽  
Vol 524-527 ◽  
pp. 1086-1091
Author(s):  
Xin Guo Zhang ◽  
Ji Wen Bai ◽  
Heng Wang ◽  
Ning Jiang
Keyword(s):  
Fly Ash ◽  
Solid Waste ◽  
High Efficiency ◽  
Filling Material ◽  
Confined Water ◽  
Bleeding Rate ◽  
Mining Technique ◽  
Comprehensive Mechanization ◽  
Early Strength ◽  
Cementing Material

In order to excavate coal resourses which is under buildings, water bodies, railways and above confined water, a complete technology of new pumping paste comprehensive mechanization mining technique which is safety, high efficiency, high mining rate and environmental protection has been formed, the study on filling material is very important. In this thesis, the uniform experiment is used comprehensively on the proportioning test of mine solid waste such as coal gangue, fly ash etc. The results showed: (1) the collapsed slump of paste will increase obviously with the increase of the content of fly ash; (2) the paste stratified degree will decrease regularly with the increase of the content of fly ash; (3) the paste bleeding rate will reduce obviously with the increase of the content of fly ash; (4) the paste strength will increase gradually with the the increase of cementing material; (5) early strength agent can improve the early strength of filling test blocks to some extent, but the later strength growth is not obvious.

Study on Utilization of Silica-Calcium Tailings in Concrete

2014 ◽  
Vol 599 ◽  
pp. 93-97
Author(s):  
Xiao Wu Tian ◽  
Wei Guo Shen ◽  
Lai Shan ◽  
Liang Hong Cao ◽  
Qing Lan ◽  
...  
Keyword(s):  
Autogenous Shrinkage ◽  
Drying Shrinkage ◽  
Particle Morphology ◽  
Cementitious Materials ◽  
Early Age ◽  
Fine Aggregate ◽  
Safety Hazard ◽  
Total Shrinkage ◽  
Potential Safety ◽  
Large Production

The large production of tailings has caused soil, water and air pollution and serious potential safety hazard. The composition, particle morphology, particle size distribution of the silica-calcium tailings are investigated to assess the feasibility of using it in concrete in this paper. The silica-calcium tailings are mainly composed of quartz, calcite and dolomite. The results show that the tailings powder can stimulate the hydration of cement and fill the gradation gap between fine aggregate and cementitious materials in concrete as micronized sand to meet the requirements of concrete. The incorporation of silica-calcium tailings in concrete reduces the ultimate total shrinkage, autogenous shrinkage and drying shrinkage at early age.

Sign in / Sign up

Export Citation Format

Share Document