Research On Scouring Resistance And Application Of Planting Surface-hole Cast-in-situ Greening Concrete

Cast-in-situ green concrete is a new material which not only guarantees the strength requirement of concrete but also provides plant growth space.It also has surface hole construction technology.It can play a role in water and soil conservation and beautifying the environment when slope protection.Cast-in-situ greening concrete can be applied to highway slope,river slope and other occasions,and its application effect is closely related to paving thickness,surface hole parameters,slope gradient of slope,soil type,etc.Based on the anti-scour performance test,this paper studies the construction parameters of cast-in-situ green concrete and applies the research results to practical engineering.Firstly,the mix ratio design of in-situ green concrete is carried out by volume method.The internal alkalinity of in-situ green concrete is reduced by adding special additives.The in-situ green concrete is prepared by one-time feeding methods,"tampering+flapping"shaping and tank maintenance.The results show that the compressive strength,connectivity porosity,pH value and area ratio of grout meet the requirements.Secondly,a simulated wave bare slope scouring test was carried out to study the effects of scouring speed,slope gradient,soil type,surface hole parameters and paving thickness on soil erosion.The results show that when slope gradient is constant,soil erosion increases with the increase of scouring speed and decreases with the increase of paving thickness.When the scouring speed is constant,the amount of soil erosion increases with the increase of slope gradient,and the amount of soil erosion of sandy soil is more than that of clay.In addition,surface hole parameters have little influence on soil erosion in simulated wave scouring tests.Thirdly,simulated rainfall planting scouring test was carried out to study the influence of rainfall intensity,slope gradient,surface hole parameters and paving thickness on runoff erosion.The results show that when slope gradient is constant,runoff erosion increases with the increase of rainfall intensity and is positively correlated with runoff shear force.When rainfall intensity is constant,runoff erosion increases with the increase of slope gradient.The runoff erosion of table hole parameter A（hole depth 4.5cm,hole diameter 2.5cm,hole diameter 2.8cm）is less than that of table hole parameter B（hole depth 4cm,hole diameter 1cm,hole diameter 3.5cm）.Paving thickness has little influence on runoff erosion.Then,planting scouring test with high-speed water flow was carried out to study the influence of paving thickness and surface hole parameters on planting effect.The results show that the growth bonding performance of green-planted tall fescue and cast-in-situ green concrete specimens is excellent.Thicker paving thickness is not conducive to the development of green plant roots.Green plant growth of surface hole parameter A is better than that of surface hole parameter B.Finally,the research results of in-situ green concrete are applied to the project.When the soil is clay,the slope gradient is about 1:1.0 and the average width of the river is 1.5m,the paving thickness of 10cm is selected to carry out the slope protection construction.It is found that the planting effect is good and landscape.The in-situ green concrete slope protection guarantees the stability of the slope soil and shows good anti-scouring ability.The research results can provide basis for the application of cast-in-situ green concrete engineering.