| Cement concrete pavements are widely used in main roads,national roads and provincial roads due to their long service life,good integrity,strong mechanical properties and high bearing capacity.However,under the influence of various factors,road surface diseases such as broken plates and emptying continue to expand,which seriously affects road life and driving safety.Currently,common treatment methods include plate changing and grouting repair.Among them,the under-slurry grouting repair technology has the characteristics of fast,convenient,good effect and mature theory,and has been widely used in road repair.At the same time,it has become popular in recent years to seek new types of repair materials.research direction.Therefore,this paper aims to obtain a new type of repair material with improved mechanical properties,good volume stability,good rinsability,initial condensation,and short final condensation through indoor orthogonal test and indoor simulation repair.A lower clearance maintenance project is required.Main research contents and conclusions:Through indoor tests,the influence of main materials on the properties of various indexes of the materials is analyzed to determine the types,diameters,water-cement ratios,polymer types and dosage ranges of the preferred fibers.Among them,fiber reinforced materials are selected from glass fiber,the fiber length is 100-300μm,the fiber content is controlled within 1%;the water-cement ratio is between 0.26 and 0.28;the polymer is selected from VAE emulsion,and the dosage is in the range of 0.6-0.9%.The amount of aluminum sulfate is controlled between 0.7 and 1.0%.The surface of the preferred fiber is modified by three methods such as chitosan polymer coating,silane coupling agent and surface active oxidant,so that the surface of the fiber can be successfully introduced into a hydrophilic group or other polymer coating material,which can not only change The dispersibility of the fiber in the slurry can also enhance the mechanical properties of the slurry,and at the same time increase the meshing force of the fiber and the cement-based material.Preferably,the glass fiber is suspended in water by chitosan coating for 19 min in the cement slurry.The coefficient of variation of the resistivity in the body is 0.260 and the characterization results of the SEM electron micrograph are superior to other methods and other fiber materials.Considering comprehensively,the method of coating glass fiber after the reaction of 0.4% by mass of dilute acetic acid with chitosan is the best fiber surface modification method.According to the previous optimization experiment,the dosage level of each factor was selected,and the relationship between each factor and the evaluation index was obtained through orthogonal test analysis.The optimal balance method was used to determine the optimal fit of fiber-polymer composite reinforced cement-based grouting material.Ratio,watercement ratio is 0.28,VAE polymer content is 1.0% of cement quality,modified glass fiber content is 0.7% of cement quality,aluminum sulfate early strength agent is 0.8% of cement quality and silicone elimination The foaming agent content was 0.5%.By testing the properties of the optimum mix ratio grouting material and comparing it with the performance of the grouting material on the market,the initial fluidity is 294 mm,the fluidity of 30 min is 283mm;the filling depth is 68 mm,the slurry is grouted.Fully stratified;initial and final setting time 142 min,202min;1d,7d,28 d flexural compressive strength is 7.8MPa,12.28 Mpa,14.83 Mpa and 27 Mpa,46.3Mpa,61.84Mpa;7d,28 d impact toughness 136.53 J,149.18J;at the same time comprehensively compare the performance of other grouting materials,fully verify the feasibility and applicability of fiber-polymer composite reinforced cement-based grouting materials. |
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