Research On Preparation Technology Of Grass-planted Ecological Concrete In Karst Mountains

The vegetation in karst mountain area is destroyed,the land using rate is decreased,the contradiction between human and nature is obvious,the problem of rocky desertification is more and more prominent,and the occurrence rate of geological disasters is higher;in order to alleviate the contradiction between human and nature and provide a more effective way to control the karst landform,the ecological concrete of planting grass is introduced into the research.Based on literature review and laboratory experiments,this paper analyzes the composition of raw materials,mix proportion design,plant growth observation and practical development strategy of grass planting ecological concrete by using orthogonal experimental design,design-expert12 software simulation analysis and analytic hierarchy process.The conclusions are as follows(1)By introducing the composition of grass planting ecological concrete,according to the principle of high quality,low price,nearby selection and laboratory test,the ordinary portland cement produced by Guizhou gang'an Cement Co.,Ltd.with stable quality,the self supplied water of Anshun water supply company with qualified quality and convenient access,and the Anzhuang sand and stone plant of daxiqiao Town,Xixiu District,Anshun City with single particle size of(16-31.5)mm were selected The results show that the main raw materials are crushed stone,fly ash of Anshun Power Plant with 72% strength activity index,compound fertilizer with27.8% total nutrients produced by Anshun Yingshan Hongxing agricultural fertilizer Co.,Ltd.,high performance polycarboxylate superplasticizer with 24% water reducing rate produced by Wuhan Huaxuan High Tech Co.,Ltd.,and grass bermudagrass.(2)The particle size of aggregate is 16-19 mm,19-26.5mm and 26.5-31.5mm,the target porosity is 20%,25% and 30%,the water cement ratio is 0.27,0.30 and 0.33,and the waste ratio is 15%,20% and 25%;The results show that the effect of 28 day compressive strength is target porosity > waste ratio > aggregate particle size > water cement ratio;the effect of porosity is target porosity > water cement ratio > aggregate particle size > waste ratio;the effect of pH value is waste ratio > water cement ratio >target porosity > aggregate particle size;the optimal combination of orthogonal test is target porosity 21.077%,water cement ratio 0.274 818%.(3)Choose boric acid to reduce alkali by chemical method,the concentration of boric acid is 3%,and the pH value can be effectively reduced to 8.9.Choose sowing in plum rain season,and carry out natural conservation.Analyze the effect of bermudagrass planting from germination rate,growth speed and appearance evaluation.Through the observation of plant growth,it is found that the grass seeds begin to germinate in about 10 days,and germinate in about 30 days More than half of them can achieve full coverage in about two months,and the three groups of the experiment have achieved normal growth;through observation,it is found that pH value affects the germination rate and growth speed of plants,and also affects the appearance quality of plants;after planting,it is found that after planting,it has little effect on the degree of resistance to pressure.(4)This paper introduces the analytic hierarchy process(AHP)to analyze the main influencing factors of the preparation technology system of grass planting ecological concrete in karst mountain area,and through modeling,layered comparison and evaluation calculation,it is determined that the selection of materials and man-made management occupy the dominant position in the system of grass planting ecological concrete in karst mountain area,especially the selection of cement and aggregate.From the perspective of "material process engineering",the development mode of grass planting ecological concrete circular economy is determined.It is concluded that the "green" and "ecological" plant concrete industrial system should be built by reducing the consumption of non renewable resources,making full use of waste resources,establishing environmental protection and ecological awareness.From the aspects of grass planting ecological concrete structure engineering,structural characteristics and ecological restoration,this paper puts forward the application strategies for the characteristics of karst landform,so as to protect nature and beautify nature at the same time,and finally realize the harmonious coexistence of human and nature.