| As one of the main energy sources in China,coal plays a vital role in the development of China's energy economy.Frequent occurrences of gas outburst seriously affect the development of coal economy.Gas extraction is usually adopted to collect and prevent gas accidents,and the quality of hole sealing largely determines the extraction efficiency of underground gas.Therefore,a kind of hole sealing material with excellent performance can effectively ensure the maximum effect of gas extraction.At present,cement base is generally used as hole sealing material in coal mines,which has obvious characteristics such as easy operation,wide use of materials,low price and excellent sealing effect,etc.,and is the most widely used in gas extraction.But this kind of material is also more obvious shortcomings,especially in:mine hole sealing material of high temperature and high humidity environment setting time is not stable,the early stage of the late hardness is low,easy to crack,less liquid,slow development of compressive strength,and even can not meet job requirements,etc,which avoid the fracture is the most main hole sealing materials.In order to improve the defects of the above materials,this paper has carried out related research on cement materials,through the addition of additives and organic materials to improve its various properties.Polymer water absorbing resin is also known as super water absorbing polymer(SAP).SAP synthesized by acrylamide and acrylic acid polymerization grafting method with mass ratio of 70:30 was used in the experiment.In the case of making special cement base,SAP can be used as an air entrainer to optimize material tolerance to temperature in some ways;It can be used as the internal curing material of cement base under the condition of low water sand ratio parameter,which can effectively prevent the shrinkage of concrete and reduce the crack of concrete.In cement base,the bridging effect between fibers is used to form a high-density tension system inside the cement material,which increases the anti-strain capacity by nearly 100 times and improves the self-healing performance of concrete.Function of the nanoscale materials have excellent physical and chemical properties,its small size can more fully combined with the slurry,compared with traditional materials,and the incorporation of nano materials particles can significantly improve cement base early mechanical properties,the nano nickel zinc ferrite,not only have excellent physical and chemical properties of nanomaterials Fe3+after mixed with cement can improve the early strength,and the bibulous crack resistance of SAP with the combination of early performance of nanometer nickel zinc ferrite possess between the filling effect can have mutual coordination effect,on this basis,to join the traditional inorganic materials ferric sulfate,A polymer-sub-nanometer-inorganic material ternary system was formed to study its effect on the properties of cement samples.Combined with the above,this paper firstly explored the influence of SAP on cement-based materials.The experimental fixed water-cement ratio was 0.38(W/C=0.3 8),and SAP with mass ratio of 0.2%,0.4%and 0.6%were added to cement samples respectively for the study of various properties,before the late strength comprehensively,SAP choose mass ratio of 0.3%is the best group,its compressive strength is 1d,3d,7d,28d were 9.852 MPa,19.563 MPa,27.355 MPa and 41.737 MPa,the benchmark group rate 47.8%,2.9%,13.4%and 26.4%respectively.Microscopic structure observation,after joining SAP form a negatively charged crosslinked network structure,medium produce ionization reaction after adding water,make the gay charged ions produces a repulsive force,make the tricalcium aluminate,C3S substances such as the reaction rate is accelerated,accelerated the ettringite and the formation of hydrated calcium silicate,on the other hand to promote the precipitation of dihydrate gypsum,increase the intensity of alkaline concentration and the plastic.On single doped SAP of experimental parameters,paper introduces the nanometer nickel zinc ferrite distribution to further improve the physical and chemical properties of cement sample,the test data show that the experimental group in SAP+0.3%to 1%and the nano nickel zinc ferrite when the optimal effect in general,the compressive strength is 1d,3d,7d,28d were 9.306 MPa,24.632 MPa,30.590 MPa,42.817 MPa,Combined with microscopic analysis,and nanometer materials in the early hydration in SAP particles under the action of ionized form a strong high-energy particle structure,this structure make cement internal more close-grained,tricalcium aluminate,such as C3S into CH speed,SAP and the nano ferrite composite effectively improve the early strength cement specimen and the maintenance performance.As a widely used inorganic material,ferric sulfate can be combined with SAP and subnanometer ni-Zn ferrite to form a new temological system.The data show that the experimental group has the optimal performance in all aspects when 0.3%SAP+1%nanometer Ni-Zn ferrite+0.7%ferric sulfate,and its compressive strength is 10.127MPa,24.271MPa,32.314MPa and 43.254MPa,respectively.Micro showed that sulfuric acid root and cement generated in the CH can generate small size CaSO4 and NaOH,promoted the tricalcium aluminate generated process of hydration of calcium sulphoaluminate form stable structure,nanometer materials and ferric sulfate in cement after Fe3+ belongs to high cation,its strong compression effect can apply to C-A-H molecular form of double shell,further promoted the generation of C-A-H component make sample density of ascension.Figure[41]table[7]reference[60]... |
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