An Experimental Study On The Preparation Of Basic Grouting Material For A High-performance Wind Turbine

With the development of China's economy and society,wind power generation is a kind of clean energy supported by the state that has not opened a broad application market.However,the wind power construction in China is in the early stage of industry development,and the research of various basic connection modes is also in the early stage.The products of grouting connection section also need universal research to promote the maturity of technology.Although the present grouting products such as sleeve grouting material have higher strength and similar performance,the sleeve grouting material is not suitable for offshore wind power foundation installation and there are no related examples of offshore grouting.It is of great practical significance to develop a kind of foundation grouting material with high strength,sulfate resistance and good working performance.The test of admixture content such as polycarboxylic acid water reducer,calcium sulphoaluminate expander and defoamer shows that the admixture can obviously change the working performance of low water binder ratio and improve the strength.According to the performance index and economy of the foundation grouting material of wind turbine,the optimum dosage of admixture is determined as follows:polycarboxylic acid water reducer0.8,defoamer 0.2 and plastic expander 0.015.The test shows that under the condition of low water/binder ratio,the strength of the grouting material is more than 50 MPa,the strength of the later stage is more than 100 MPa,the fluidity is about 320 mm,and the state is good.Good viscosity.Different cement-sand ratio and water-sand ratio correspond to different flow degree and strength.Under the condition of water-sand ratio 0.21,the optimum content of mineral admixture is determined by orthogonal test:fly ash 8%,silica fume 3%and mineral powder 4%.The results of water-cement ratio,cement-sand ratio,mineral admixture ratio and water reducing agent dosage show that the main and secondary order of influence on the compressive strength of wind turbine foundation grouting material is water-cement ratio>cement-sand ratio>water reducing agent>mineral admixture ratio.The optimum ratio of water to cement is 0.21,the ratio of cement to sand is 1,the ratio of mineral admixture is30%,and the dosage of water reducing agent is 0.8%by orthogonal test.Sand does not affect the strength of the grouting material,but the flow degree of the grouting material becomes smaller,and the reasonable gradation can improve the later compressive strength of the foundation grouting material of the wind turbine.The optimum combination of fine aggregate is 20%Emery for the purpose of:40?70,iron tailings 15%,40?70quartz sand 30%,70?120 quartz sand 35%.Resistance test show that sulfate erosion of grouting material not only does not play a role in structural failure,but also plays a positive role in filling slurry voids.The compressive strength increased by about 5%and 8%respectively.SEM microscopic analysis shows that the calcium silicate gel stacking is dense and the ettringite crystal is increasing,the slurry is more dense,the grouting material is slightly expanded in the later stage,and the strength is stable in the later stage.