| Nanofibrillated celluloses(CNFs)materials are the richest natural polymers on the planet,which have the advantages of low cost,rich sources,and environment-friendly.Therefore,in recent years,Nanofibrillated celluloses has been rapidly developing as an environmentally friendly and renewable nano-fiber.It has a good application prospect in the field of cement base materials and will bring a qualitative leap to the cement concrete field.Cemental materials are easily shrink and cause cracking.This article mix Nanofibrillated celluloses into the cement base material.By exploring the influence of macro mechanical properties and contraction and deformation performance of cement mortar by different water glue compared to different water glue,it is combined with hydrophilic thermal heat The test results and micro-structural analysis clarify the mechanism of improving the contraction and deformation of the plain material to improve the contraction and deformation.The main research content and conclusions of this article are as follows:(1)Three different Nanofibrillated celluloses of 0.05%,0.1%,and 0.2%(mass scores)were studied,and CNFs was added to the cement net slurry,and the influence of CNFs on the performance of cement net pulp is studied.It is found that the addition of CNFs has increased the yield stress and plastic viscosity of the cement slurry to varying degrees,and as the CNFs increases increases,when the CNFs doping is 0.2%,the plastic viscosity and yield stress are compared The blank group increased by 155%and 117%,respectively;the flow of the slurry conforms to the Modify Bingham model and the Herschel-Bulkley model,which shows the phenomenon of shear and thinning.(2)Explore the impact of the macro mechanical properties of Nanofibrillated celluloses on the macro mechanical properties of cement slurry and mortar,and study the two types of water glue ratio of 0.5 and 0.4.It is found that CNFs has a positive effect on the compressive strength of cement net pulp and mortar.At the comparison of the two kinds of water glue,as the age increases,the pressure resistance of cement slurry and mortar gradually increases;at the same age,as the CNFs doping increases,the pressure resistance strength will increase before the rise before the rise.The trend of decreased,0.1%CNFs doping has the most obvious effect on the pressure resistance strength;CNFs also has a certain positive effect on the resistance of cement mortar.The 7-days anti-folding strength of the cement mortar increased by about 14.0%compared with the blank group.(3)The influence of Nanofibrillated celluloses on cement mortar contraction and deformation performance,including self-contraction and dry contraction performance.Studies have found that CNFs has a certain degree of impact on the self-contraction performance and dry contraction of cement mortar.0.1%of CNFS is the best doping.The self-contraction rate of the 7-days age of the 0.4 cement mortar decreased by 74.6%and 29.6%compared with the blank group,respectively,and the 56-days aging dry contraction rate decreased by 9.9%and6.0%respectively compared with the blank group,respectively.(4)Research on the hydration and microstructures of Nanofibrillated celluloses composite cement base materials,mainly including hydrophilic heat testing,phase analysis,pore structure analysis,and scanning electron microscopy analysis.The results show that CNFs accelerates the hydration process of the cement by affecting the hydration rate and pore distribution of the cement,and the pore diameter is refined,thereby suppressing the contraction and deformation of the substrate;the SEM result shows that the addition of CNFs can change the density of cement mortar and increase anti-anti-anti-resistance The contraction ability is reduced to reduce the contraction and cracking inside the matrix and reduce the contraction rate. |
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