scholarly journals Mechanical Properties and Deterioration Instability of Filling Body with Gangue-Cement Material Based on AE Experiment

2022 ◽  
Vol 2022 ◽  
pp. 1-18
Author(s):  
Guofeng Yu ◽  
Yunchun Han ◽  
Xiaoyang Yu ◽  
Ren Bao ◽  
Jiaxing Guo ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Energy ◽  
Cementitious Materials ◽  
Cementitious Material ◽  
Linear Deformation ◽  
Forming Mechanism ◽  
Damage And Failure ◽  
Filling Materials ◽  
Key Factor ◽  
Failure Types

Gangue materials have been used to solve mine disasters with a support tunnel along the goaf and filling mining. Mastering the properties and damage characteristics of filling materials is an important basis for effective implementation. Based on the conventional uniaxial compression acoustic emission (AE) test, the effects of cementitious materials, ratio between water and cementitious material, gangue particle size, and grading parameters on the mechanical properties of gangue-cement samples were analyzed. The stage characteristics of compression deformation were studied. The fracture propagation characteristics and rock mass failure types induced by different graded gangues were revealed. The fracture forming mechanism from clustered damage and failure was interpreted. The results show that the compressive strength of the backfill increases with the increase of cementitious material; however, it decreases with the increase of water binder ratio. Controlling the proportion and dosage of materials was the key factor to realizing pumpability and stability. Combined with the deformation and AE characteristics, the failure stage of the backfill body is divided into three stages: linear deformation-low energy changing, block compression-high energy changing, and gentle stability-stable energy changing. Affected by the gangue distribution, the load in each stage will induce fracture to produce five distribution modes of single, turning, breakthrough, bifurcated, and collapsed surrounding gangue. In the process of loading failure, different gradation and particle sizes will also change its stress concentration characteristics, resulting in the transformation of rock failure types. The surface structure and roughness of gangue play an important role in the compressive performance of cement paste. The research results try to provide some guidance for efficient filling mining.

Study on CO2 Sequestration Property of Cement Based Composite Cementitious Materials Containing Steel Slag Used in Road

2011 ◽  
Vol 311-313 ◽  
pp. 1949-1952 ◽  
Author(s):  
Ying Li Gao ◽  
Ling Cheng
Keyword(s):  
Mechanical Properties ◽  
Growth Rate ◽  
Compressive Strength ◽  
Mass Fraction ◽  
Carbon Emission ◽  
Steel Slag ◽  
Cementitious Materials ◽  
Current Situation ◽  
Cementitious Material

Cement based composite cementitious material containing steel slag used in road has been prepared to deal with the current situation that the transportation carbon emission increased year by year. In this material, 40% cement has been replaced by equivalent steel slag, which has the ability of CO2sequestration. This paper studied the CO2sequestration effect and the mechanical properties of the pure cement, the pure steel slag, and the cement based composite cementitious materials containing steel slag. It has been shown that the cement based composite cementitious materials containing steel slag have excellent CO2sequestration property. The mass fraction growth rate of carbon reached 10.86% after 1 hour carbonation experiment, the value between which of pure cement and pure steel slag, and the compressive strength of the composite cementitious materials at 28-day age can reach 45.3MPa, meeting the requirements of road.

Mechanical Properties and Microstructure Analysis of Copper Tailings Solidifying with Different Cementitious Materials

2014 ◽  
Vol 878 ◽  
pp. 171-176 ◽  
Author(s):  
Xu Quan Huang ◽  
Hao Bo Hou ◽  
Min Zhou ◽  
Wei Xin Wang
Keyword(s):  
Mechanical Properties ◽  
Blast Furnace ◽  
Blast Furnace Slag ◽  
Calcium Silicate Hydrate ◽  
Steel Slag ◽  
Cementitious Materials ◽  
Cementitious Material ◽  
Hydration Products ◽  
New Type ◽  
Furnace Slag

With new type steel slag-blast furnace slag-fluorgypsum-based cemented material, P O42.5 cement, commonly used cementation agent in China, mechanical properties and microstructure of tailings solidification bodies are studied. The hydration products and morphology tailings concretion body in 60 days are analyzed by SEM and XRD test, which reveals the tailings cementation mechanism solidifying with different cementitious material. Furthermore, a large number of slender bar-like ettringite crystals and filamentous network-like calcium-silicate-hydrate gels bond firmly each other, which is the most important reason why steel slag-blast furnace slag-fluorgypsum base cemented material has the best tailings cementation mechanical properties.

Effect of Red Mud on Mechanical Properties of Loess–Containing Aluminosilicate Based Cementitious Materials

2009 ◽  
Vol 610-613 ◽  
pp. 155-160
Author(s):  
Jian Hua Wan ◽  
Heng Hu Sun ◽  
Ying Ying Wang ◽  
Chao Li
Keyword(s):  
Mechanical Properties ◽  
Red Mud ◽  
Cementitious Materials ◽  
Cementitious Material ◽  
The Other ◽  
Term Strength ◽  
Other Hand ◽  
Early Strength ◽  
The One

The effect of the thermal treated red mud on mechanical properties of loess –containing aluminosilicate based cementitious materials is investigated. And the characteristic of hydration production is tested using XRD, SEM and EDAX methods. The results show that the thermal treated red mud not only has excellent cementitious properties but also can improve the mechanical properties of loess –containing aluminosilicate based cementitious materials. Moreover when the content of red mud is 5%, the improved effect is optimal. On the one hand, the alkaline ingredients of red mud can promote abundant ettringites to produce at early ages. And the ettringites contribute to early strength of the cementitious material. On the other hand, the content of red mud is too high to improve the long-term strength.

scholarly journals Influence of functionalized nanosilica with different functional groups in the properties of cementitious composites: A review

2021 ◽  
Vol 10 (8) ◽  
pp. e27719817349
Author(s):  
Yuri Sotero Bomfim Fraga ◽  
Gabriel Lima Oliveira Martins ◽  
João Henrique da Silva Rêgo
Keyword(s):  
Mechanical Properties ◽  
Structural Analysis ◽  
Functional Groups ◽  
Scientific Community ◽  
Cementitious Materials ◽  
Cementitious Material ◽  
Nano Composites ◽  
Cementitious Composites ◽  
Narrow Size Distribution ◽  
Recent Developments

The use of supplementary nano cementitious material (SNCM) to improve the mechanical properties and durability performances of cementitious composites (cement paste, mortar and concrete) has received remarkable attention in recent studies. The use of nanosilica as SNCM is a consolidated practice in the scientific community. However, recent developments in the synthesis of monodisperse and narrow-size distribution of nanoparticles by functionalization methods provide a significant improvement to the development of silica-group nano composites (among the functional groups: amine, carboxyls and glycol groups), the so-called functionalized nanosilica (FNS). This article aims to raise a literature review on the properties of FNS in cementitious materials and the advanced techniques of nano/micro structural analysis used to characterize cementitious composites containing FNS’s.

scholarly journals Effect of Fineness on Mechanical Properties of Cementitious Material Made from Magnesia Slag

2021 ◽  
Vol 290 ◽  
pp. 01011
Author(s):  
Dan Cheng ◽  
Jianxun Ma ◽  
Yilei Zhang ◽  
Xuhui Chen ◽  
Wenxiao Li
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Cementitious Materials ◽  
Cementitious Material ◽  
Cement Clinker ◽  
Production Environment ◽  
Portland Cement Clinker ◽  
Cementing Material ◽  
Magnesia Slag

Magnesium slag is a kind of solid waste discharged by magnesium alloy related industries in the process of producing magnesium products or their alloys. Its composition is similar to Portland cement clinker, so it has great potential to be used as a new cementing material. In this paper, magnesium slag cementitious material specimens with different fineness were made by imitating the actual production environment. The flexural strength and compressive strength of specimens with different curing ages were tested, and the influence of fineness on them was analyzed. The results show that the fineness has a significant effect on the mechanical properties of pure magnesium slag cementitious materials. Its effect on the early strength is greater than that on the later strength. But the flexural strength and compressive strength will not always increase with the increase of fineness. There is a reasonable range of fineness.

scholarly journals Advances of graphene- and graphene oxide-modified cementitious materials

2020 ◽  
Vol 9 (1) ◽  
pp. 465-477 ◽  
Author(s):  
Juan Wang ◽  
Yaoqun Xu ◽  
Xiaopeng Wu ◽  
Peng Zhang ◽  
Shaowei Hu
Keyword(s):  
Mechanical Properties ◽  
Graphene Oxide ◽  
Literature Review ◽  
Frost Resistance ◽  
Cement Hydration ◽  
Cementitious Materials ◽  
Sulfate Attack ◽  
Cementitious Material ◽  
Control Group ◽  
Detailed Review

AbstractEmerging nanomaterials provide an invaluable opportunity for the development of cementitious materials. Many scholars have explored the influence of graphene (GP) and graphene oxide (GO) on the performance of the cementitious materials. This article reviews the previous research on the effect of GP and GO on the properties of cementitious materials. Detailed review of the mechanical properties and durability of cementitious materials containing GP or GO nanofilms is presented, and the mechanism is discussed. The mechanical properties of GO-cementitious materials are significantly enhanced. The optimal improvement of GO-modified compressive, flexural, and tensile strengths is 77.3%, 78.3%, and 78.6%, respectively. The durability of GO- and GP-modified cementitious material is compared with the control group. The incorporation of GP or GO significantly improves the sulfate attack resistance, and the transport properties can be decreased, while the frost resistance of GO- and GP-modified cementitious materials needs further research. This literature review shows that the microstructure of GO- and GP-modified cementitious material is improved in three aspects: accelerating the cement hydration, refining the pore structure, and hindering the crack propagation.

scholarly journals Influence of Gating System Parameters of Die-Cast Molds on Properties of Al-Si Castings

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3755
Author(s):  
Štefan Gašpár ◽  
Tomáš Coranič ◽  
Ján Majerník ◽  
Jozef Husár ◽  
Lucia Knapčíková ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Computer Modelling ◽  
Permanent Deformation ◽  
Surface Hardness ◽  
Technological Parameters ◽  
Inlet System ◽  
Die Cast ◽  
Key Factor ◽  
Fine Grained Structure ◽  
Design Solutions

The resulting quality of castings indicates the correlation of the design of the mold inlet system and the setting of technological parameters of casting. In this study, the influence of design solutions of the inlet system in a pressure mold on the properties of Al-Si castings was analyzed by computer modelling and subsequently verified experimentally. In the process of computer simulation, the design solutions of the inlet system, the mode of filling the mold depending on the formation of the casting and the homogeneity of the casting represented by the formation of shrinkages were assessed. In the experimental part, homogeneity was monitored by X-ray analysis by evaluating the integrity of the casting and the presence of pores. Mechanical properties such as permanent deformation and surface hardness of castings were determined experimentally, depending on the height of the inlet notch. The height of the inlet notch has been shown to be a key factor, significantly influencing the properties of the die-cast parts and influencing the speed and filling mode of the mold cavity. At the same time, a significant correlation between porosity and mechanical properties of castings is demonstrated. With the increasing share of porosity, the values of permanent deformation of castings increased. It is shown that the surface hardness of castings does not depend on the integrity of the castings but on the degree of subcooling of the melt in contact with the mold and the formation of a fine-grained structure in the peripheral zones of the casting.

Impact of the SiC addition on the morphological, structural and mechanical properties of Cu-SiC composite powders prepared by high energy milling

2021 ◽  
Author(s):  
Nailton T. Câmara ◽  
Rafael A. Raimundo ◽  
Cleber S. Lourenço ◽  
Luís M.F. Morais ◽  
David D.S. Silva ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Energy ◽  
Composite Powders ◽  
High Energy Milling

scholarly journals Coir Fibers Treated with Henna as a Potential Reinforcing Filler in the Synthesis of Polyurethane Composites

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1128
Author(s):  
Sylwia Członka ◽  
Anna Strąkowska ◽  
Agnė Kairytė
Keyword(s):  
Mechanical Properties ◽  
High Energy ◽  
Dynamic Mechanical Properties ◽  
Milling Process ◽  
Coir Fiber ◽  
Lawsonia Inermis ◽  
Coir Fibers ◽  
Mechanical Performances ◽  
The Impact ◽  
Reinforcing Filler

In this study, coir fibers were successfully modified with henna (derived from the Lawsonia inermis plant) using a high-energy ball-milling process. In the next step, such developed filler was used as a reinforcing filler in the production of rigid polyurethane (PUR) foams. The impact of 1, 2, and 5 wt % of coir-fiber filler on structural and physico-mechanical properties was evaluated. Among all modified series of PUR composites, the greatest improvement in physico-mechanical performances was observed for PUR composites reinforced with 1 wt % of the coir-fiber filler. For example, on the addition of 1 wt % of coir-fiber filler, the compression strength was improved by 23%, while the flexural strength increased by 9%. Similar dependence was observed in the case of dynamic-mechanical properties—on the addition of 1 wt % of the filler, the value of glass transition temperature increased from 149 °C to 178 °C, while the value of storage modulus increased by ~80%. It was found that PUR composites reinforced with coir-fiber filler were characterized by better mechanical performances after the UV-aging.

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