The Research On The Compatibility Of Pore Structure And Laws Of Vegetation Growth In Eco-porous Concrete

The pore structure and characteristics of eco-porous concrete directly affect the growth space and growth path of plant rhizomes,and decide whether their roots can penetrate into the soil through the concrete slab.In addition,they have an important impact on the growth law,life cycle and life span of plants.Through the analysis of eco-porous concrete aggregate gradation theory,combined with the porosity,pore size,porosity,fractal dimension of cross-section and other pore structure characteristics,the compatibility between pore structure and vegetation root was explored.And,the planting performance evaluation index of eco-porous concrete was investigated.Furthermore,the relation between the characteristics and permeable performance,the planting performance were discussed.Finally,the planting technology of vegetation was presented.The researchs were of great significance for improving the preparation technology system of eco-porous concrete,guiding vegetation planting and promoting the wide application of eco-porous concrete.The main achievements of this thesis are as follows:(1)The stacking model of eco-porous concrete can be described by "stacking density theory".Based on the "stacking density theory",the forming method of the eco-porous concrete have been put forward.The basic unit model of the eco-porous concrete was built,and the calculation formula of the porosity was derived from the eco-porous concrete with single particle size aggregate and the five plane body configuration;(2)Based on the relative dynamic elastic modulus,the freeze-thaw damage variable DF of eco-porous concrete was defined,and the function relation between the freeze-thaw damage variable DF and the number of freeze-thaw cycles was obtained when the fly ash content were 0%,10%and 20%respectively.This characterization parameter can effectively evaluate the degree of freeze-thaw damage,or predict the ability of freeze-thaw damage of porous concrete;(3)Through analysis of opening porosity,equivalent pore size and fractal dimension of eco-porous concrete with the grain-size-ranges of 9.5?16 mm,16?19 mm and 19-26.5mm repectively,it was concluded that the size of the coarse aggregate and the concentration of the particle size were the key factors affecting the pore structure characteristics of eco-porous concrete;(4)The relation between the opening porosity,equivalent pore size,plane porosity,fractal dimension of the pore and the permeability of the eco-porous concrete were discussed,and the equivalent pore size can be used as the main parameter to evaluate the water permeability of the eco-porous concrete;(5)The method of evaluating the compatibility of the pore structure of the eco-porous concrete and the structure of the plant root was put forward,that is,the method of permeability coefficient,which can effectively and reasonably measure the growth performance of the eco-porous concrete;(6)Based on the climatic characteristics of Hunan and its southern region and the pore structure characteristics of the eco-porous concrete,combined with the selected four typical subtropical grass species and their growth characteristics,the eco-porous concrete vegetation planting technology was proposed,which laid the foundation for the formulation of the relevant regulations of eco-porous concrete.