scholarly journals Study on the Mechanical Properties of Fly-Ash-Based Light-Weighted Porous Geopolymer and Its Utilization in Roof-Adaptive End Filling Technology

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4450
Author(s):  
Luchang Xiong ◽  
Bowen Fan ◽  
Zhijun Wan ◽  
Zhaoyang Zhang ◽  
Yuan Zhang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Porous Structure ◽  
High Efficiency ◽  
Influence Factor ◽  
Structure Model ◽  
Plastic Yielding ◽  
Working Face ◽  
Secondary Air

This paper aims to study the porous structure and the mechanical properties of fly-ash-based light-weighted porous geopolymer (FBLPG), exploring the feasibility of using it in roof-adaptive end filling technology based on its in-situ foaming characteristics and plastic yielding performance. A porous structure model of FBLPG during both the slurry and solid period was established to study their influence factor. In addition, this study also built a planar structure model in the shape of a honeycomb with bore walls, proving that the bore walls possess the characteristics of isotropic force. FBLPG shows a peculiar plastic yielding performance in the experiment where its stress stays stable with the gradual increase of the deformation, which can guarantee the stability of a filling body under the cycled load from the roof. At the same time, the in-situ foaming process combined with the unique filling technique can make the FBLPG filling body fully in contact with the irregular roof. This roof-adaptive end filling technology makes it a successful application in plugging the 1305 working face, which avoids problems of the low tight-connection ratio and secondary air-leakage channel resulted from the traditional filling technology, effectively improving coal production in terms of safety and high efficiency.

Performance of Wood-Polymer Composite Prepared by In Situ Synthesis of Terpolymer within Wood

2010 ◽  
Vol 34-35 ◽  
pp. 1165-1169 ◽  
Author(s):  
Yong Feng Li ◽  
Bao Gang Wang ◽  
Qi Liang Fu ◽  
Yi Xing Liu ◽  
Xiao Ying Dong
Keyword(s):  
Mechanical Properties ◽  
Porous Structure ◽  
Polymer Composite ◽  
Value Added ◽  
Untreated Wood ◽  
Modulus Of Rupture ◽  
Hydroxyl Group ◽  
Wood Polymer ◽  
Wood Polymer Composite

In order to improve the value-added applications of low-quality wood, a novel composite, wood-polymer composite, was fabricated by in-situ terpolymerization of MMA, VAc and St within wood porous structure. The structure of the composite and the reaction of monomers within wood were both analyzed by SEM and FTIR, and the mechanical properties were also evaluated. The SEM observation showed that the polymer mainly filled up wood pores, suggesting good polymerizating crafts. The FTIR results indicated that under the employed crafts, three monomers terpolymerized in wood porous structure, and grafted onto wood matrix through reaction of ester group from monomers and hydroxyl group from wood components, suggesting chemical combination between the two phases. The mechanical properties of the wood-polymer composite involving modulus of rupture, compressive strength, wearability and hardness were improved 69%, 68%, 36% and 210% over those of untreated wood, respectively. Such method seems to be an effective way to converting low-quality wood to high-quality wood.

scholarly journals Hybrid Fly Ash-Based Geopolymeric Foams: Microstructural, Thermal and Mechanical Properties

Materials ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 2919 ◽  
Author(s):  
Giuseppina Roviello ◽  
Laura Ricciotti ◽  
Antonio Jacopo Molino ◽  
Costantino Menna ◽  
Claudio Ferone ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Circular Economy ◽  
Coal Fly Ash ◽  
Silicate Solution ◽  
Thermal And Mechanical Properties ◽  
Blowing Agent ◽  
Materials Used

This research investigates the preparation and characterization of new organic–inorganic geopolymeric foams obtained by simultaneously reacting coal fly ash and an alkali silicate solution with polysiloxane oligomers. Foaming was realized in situ using Si0 as a blowing agent. Samples with density ranging from 0.3 to 0.7 g/cm3 that show good mechanical properties (with compressive strength up to ≈5 MPa for a density of 0.7 g/cm3) along with thermal performances (λ = 0.145 ± 0.001 W/m·K for the foamed sample with density 0.330 g/cm3) comparable to commercial lightweight materials used in the field of thermal insulation were prepared. Since these foams were obtained by valorizing waste byproducts, they could be considered as low environmental impact materials and, hence, with promising perspectives towards the circular economy.

Improvement in mechanical properties of SBR/Fly ash composites by in-situ grafting-neutralization reaction

2018 ◽  
Vol 354 ◽  
pp. 849-855 ◽  
Author(s):  
Shuyan Yang ◽  
Ping Liang ◽  
Xiaokang Peng ◽  
Yanxue Zhou ◽  
Kaihui Hua ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Neutralization Reaction

Flexural Performance of Geopolymer Concrete Modified with Pozzalonic Minerals and Secondary Reinforcement

2018 ◽  
Vol 15 (2) ◽  
pp. 459-469
Author(s):  
D. R. Anand Rejilin ◽  
R. Murugesan ◽  
V. Bravin Ebanesh
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Secondary Reinforcement ◽  
Fibre Reinforcement ◽  
Percentage Increase ◽  
Cement Concrete ◽  
Flexural Performance ◽  
Micro Cracks ◽  
Structural Applications

Concrete, the versatile building material is relevantly used for structural applications for its ease of application and in situ adaptability. Decline of raw materials, cost and environmental issues related to unsustainable usage of cement, persuades the construction industries for an alternate binder similar to cement. Geoploymer concrete known for its eco-friendly manufacturing process and economic approach makes the, GPC a viable substitute for cement concrete. At elevated temperature, GPC undergoes polymerisation reaction and develops three dimensional amorphous components which exhibits enriched mechanical properties. To achieve the in-situ application of geoploymer concrete and to overcome the requirement of heat during polymerisation reaction, fly ash based GPC was modified with different proportions of GGBS and OPC and curing it with ambient temperature for enhancing its mechanical behaviour. Variation in temperature during the initial stages of casting process produces micro cracks which are prevented by addition of Secondary reinforcements which furthermore improved the mechanical properties. A constant percentage of GUJCON fiber as secondary reinforcement was added to all the modified proportions. The fly ash based GPC replaced with GGBS and OPC showed improved split and compressive strength at 100% and 40%. Further improvement of strength was observed with 12% replacement of GGBS with OPC to GGBS based GPC. The flexural performance of the modified GPC with optimum proportions of GGBS and OPC was compared with conventional cement concrete beam. The percentage increase in strength of GGBS based GPC with optimum OPC content when compared with conventional specimens showed 53% improvement in strength. When fibre reinforcement was added in prescribed quantity, it promoted the mechanical strength and reduced micro cracks by which the load carrying capacity was increased to 66%. The structural performance of modified GPC was found to be suitable for in situ applications in ambient curing condition.

Polymerization Craft of Wood-PSt Composite and its Performance

2010 ◽  
Vol 139-141 ◽  
pp. 1419-1423
Author(s):  
Yun Lin Fu ◽  
Yong Feng Li ◽  
Yi Xing Liu ◽  
Bao Gang Wang
Keyword(s):  
Mechanical Properties ◽  
Porous Structure ◽  
Compression Strength ◽  
Modulus Of Elasticity ◽  
Cellular Structure ◽  
In Situ Polymerization ◽  
Wood Polymer ◽  
Composite Wood ◽  
Wood Polymer Composite

A novel Wood-Polymer Composite, Wood-PSt composite combining both advantages of wood and polystyrene was fabricated by determining the polymerization craft of monomer in wood porous structure through impregnating monomer into wood pores and followed by in-situ polymerization through a thermal-catalyst treatment. The performance was examined, and its structure was also characterized by SEM and FTIR. The results indicate that the optimum polymerizing craft is: 80oC, 8h and 3% AIBN. Under the optimum craft, the mechanical properties involving modulus of elasticity and compression strength were linearly increased with content of polystyrene. SEM and FTIR show that styrene polymerized under the employed polymerization craft, and the resultant polystyrene relatively full generated in wood cellular structure, in accordance with the results of the optimum polymerizing craft. Such composite having good mechanical properties and biomass features can be widely used in fields of construction, traffic and furniture.

scholarly journals Effect of fly ash on the strength of cement paste at early age

2020 ◽  
Vol 61 (HTCS6) ◽  
pp. 10-18
Author(s):  
Dung Trong Nguyen ◽  
Lam Van Tang ◽  
Hung Xuan Ngo ◽  
Phi Van Dang ◽  
Cuong Anh Ho ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Cement Paste ◽  
Power Plants ◽  
Building Materials ◽  
High Efficiency ◽  
Thermal Power ◽  
Early Age ◽  
Technical Specifications ◽  
Mineral Additives

In Vietnam, thermal power plants produce millions of tons of fly ash per year and cause a lot of problems for the environment. The re-use of fly ash as mineral additives in the production of building materials such as cement, concrete etc is a comprehensive solution that brings high socio-economic efficiency. However, to achieve high efficiency, the technical specifications index of fly ash needs to be studied and evaluated in detail because the content of added fly ash is very important for producing and manufacturing processes. This paper aims to study the influence of Formosa fly ash on the mechanical properties at the early age of cement paste. The mechanical properties of the samples which contain alternatively 10÷30% of fly ash was measured at the early ages (1, 3, and 7 days) by experimental methods. In addition, the microstructure analysis and differential thermal analysis methods have been used to interpret the obtained results.

Analysis of Influence Factors on Strength of Mudstone with Soft-Hard Alternant Strata in Nanning Basin

2011 ◽  
Vol 204-210 ◽  
pp. 891-894 ◽  
Author(s):  
Fu Rong Ma ◽  
Xin Gui Zhang ◽  
Nian Ping Yi
Keyword(s):  
Mechanical Properties ◽  
Structural Damage ◽  
Influence Factor ◽  
Influence Factors ◽  
Final Analysis ◽  
Test Methods ◽  
Control Measures ◽  
Rock Interaction ◽  
Special Environment

The mudstone is formed under the special environment with soft-hard alternant strata in Nanning Basin . The composition,engineering and mechanical properties have a certain complexity and specificity,so the parameters of the mudstone are discrete and variable by which the strength characteristics are influenced. According to the problem of the strength of mudstone,the influence factor is analysed on the strength of mudstone with soft-hard alternant strata in Nanning Basin through the composition, stress history, geological environment, water-rock interaction and disturbance, etc.. The analysis shows that in the final analysis the reduction of the mechanical properties of mudstone is due to structural damage, stress weakening and energy weakening.And the measures of improving the bearing capacity of mudstone are discussed from the test methods, construction control measures, in situ testing and engineering design.

The Research and Application of Airport Pavement Recycled Concrete

2014 ◽  
Vol 525 ◽  
pp. 465-468 ◽  
Author(s):  
Xiao Jun Liu ◽  
Chen Fei Zhu ◽  
Yong Gen Wu ◽  
Qing Tao Liu
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
High Efficiency ◽  
Recycled Concrete ◽  
Concrete Research ◽  
Recycled Aggregates ◽  
High Quality ◽  
Waste Concrete ◽  
Airport Pavement

The overhauling, rebuilding and enlarging of airport pavement often produce vast waste concrete. Use of these concrete as recycled aggregates, make recycled concrete. And by adopting the “double-mixed” technique with high quality fly ash and high efficiency admixture, optimizing the mix proportions design of pavement recycled concrete, research its mechanical properties and verify its application effect.

scholarly journals Mechanical Properties and Control Rockburst Mechanism of Coal and Rock Mass with Bursting Liability in Deep Mining

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Ming-tao Gao ◽  
Zhen-qi Song ◽  
Hui-qiang Duan ◽  
Heng-qi Xin ◽  
Jian-quan Tang
Keyword(s):  
Mechanical Properties ◽  
Large Diameter ◽  
Confining Pressure ◽  
Test System ◽  
Peak Strength ◽  
Dissipated Energy ◽  
Engineering Practice ◽  
Working Face ◽  
And Control

In order to study the mechanism of the dynamic disaster of rockburst in a deep coal mine and the prevention and control measures of weakening shock, the MTS815.03 servocontrolled rock mechanics test system is used to test the coal, rock, and combined specimens with the buried depth of nearly 1200 m in Xinwen Mining Area. And their mechanical properties, energy evolution, and bursting properties are studied and analyzed. The rationality of the test results is also verified by the in-situ engineering practice. The key conclusions are as follows: (1) There is a relation between the ratio of elastic modulus Ee before peak strength to descending modulus Ed after peak strength and the bursting properties. For the fractured coal, the descending modulus Ed is relatively small, and the Ee/Ed is relatively large and presents progressive ductile failure with low probability and risk of rockburst. For the less fractured rock, the descending modulus Ed is relatively large, and the Ee/Ed is relatively small and presents brittle failure, which is very similar to the characteristics of rockburst. (2) For the same type of rock, with the increase of confining pressure, the Ee/Ed gradually increases, indicating the reduction of rockburst strength. Therefore, the greater the support strength provided to the surrounding rock surface of the roadway, the smaller the failure degree of rockburst. (3) With the increase of confining pressure, after peak strength, the elastic energy of coal specimens decreases slowly, and the dissipated energy increases slowly, indicating that the increase of confining pressure can effectively limit the energy dissipation and release after coal specimen failure. So, in the in-situ engineering practice, it is an important measure to improve the surface restraint and support strength of the coal roadway for reducing the occurrence intensity and probability of rockburst. (4) The combined measures of “the mining of double liberating seam + the implementation of large-diameter pressure relief borehole in advance of working face” is the very effective way to eliminate the rockburst accidents of working face in a protected coal seam and has an important guiding significance for the safe mining of rockburst mine.

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