Research And Application Of New Technology For Building Roof And Wall Greening

Roof greening,as an innovative technology integrating garden landscape,architectural design and civil construction,is an important way to effectively improve the quality of the urban environment.Greening of roofs and walls is different from ground landscaping.The environment of roofs and walls is more severe.The roof has strong solar radiation,high wind speed,and fast evaporation.The sun illuminance of different facing walls varies greatly.The substrate is easily eroded by rain and snow,and the loss of moisture and nutrients is fast.Limited by the bearing capacity of the roof layer and the fixed structure of the wall,the substrate material,thickness and filling amount have strict requirements.The requirements for drought resistance,cold resistance and lodging resistance are extremely high.Subject to environmental protection requirements,the preparation of substrates must also avoid dust pollution and runoff pollution of roofs and walls.Therefore,roof and wall greening has many technical challenges.Although there are many researches on roof greening substrates at home and abroad,there are not many studies on the nutrient changes after planting plants on different substrates and the impact on the urban water environment.Moreover,most researches on the drought resistance of roof greens tend to be green roof plants.Ignore the influence of roof greening base material on drought resistance of plants.Different types of wall greening and substrates have a great impact on plants.Therefore,in response to these problems,this paper selected several representative patented technologies in the field of roof and wall greening-roof greening planting blocks,pumping light base materials,construction waste preparation base materials,ecological nutrition bags,planting tanks new technologies such as green wall greening and scar irrigation.Using SU,CAD and other software to test plan,using field tests,regular sampling and observation,detailed analysis of the test data,a comparative study on the greening effect of the red beetle grass on different roof greening substrates,the impact of roof runoff water quality and the effect of rainwater interception,Drought resistance in extreme weather and the adaptability of different plants and substrates in planting trough wall greening.The main research is as follows:(1)In terms of comparison of roof greening substrates,this study selects three patented roof greening substrates-roof greening planting blocks,pumped light substrates,and construction waste substrates.Using ordinary soil as a reference,set up4 experimental blocks of the same area on the roof,plant celestial grasses of the same height and quantity,and compare and observe the nutrient content,p H value,and plant cover and height of the substrate multiple times within a year variety.It was found that the coverage and height of the four kinds of substrates for bergamot were sorted in descending order:roof greening planting blocks>pumped light substrates>construction waste substrates>ordinary soil.Patented substrates such as roof greening planting blocks,pumping light weight,and construction waste have better greening effects than ordinary soils for roof greening.(2)In terms of roof green runoff water quality and rainwater retention,this research set up four planting troughs with faucets on the roof.The planting troughs were filled with ordinary soil,roof greening planting blocks,pumped light substrates,and construction waste preparation bases.The same amount and height of bergamot grass was planted in the substrate,and the water quality(TK,TP,TN,PH,COD,BOD5)and runoff collection time of the runoff water samples were compared and observed several times.There are obvious differences in the changes of runoff water quality and rainwater interception effect of different roof greening substrates.The changes in the early stage are large,and the latter tend to stabilize.(3)With regard to the drought resistance of roof greening substrates,under the rare sustained drought,this study repeatedly observed the morphology and coverage of bergamot grass on roof greening planting blocks,construction waste,ordinary soil,and pumped light substrates,and altitude changes.Compared with ordinary soil and green roof planting blocks,construction waste and pumped bergamot on light substrates have smaller wilting area,greener leaves,and less leaf curling.The coverage and height of the bergamot grass on the construction waste substrate has the smallest change,the light soil substrate and the roof greening planting block have the same change,and the ordinary soil has the largest change.Studies have shown that under rare droughts,construction waste base materials have the best drought resistance,followed by pumping light base materials,roof greening planting blocks,and ordinary soil having the worst.(4)The adaptability of different plants and substrates in planting trough wall greening,this study uses a 1.5×1.2×2 m~3building model was used to simulate the real building,and the greening tests were performed on the 3 walls of the east,south,and west of the building model.Growing state,coverage and height of plants in different planting troughs were compared and observed at 6 months.The results showed that:compared with(L.f.)Ker-Gawl and Zephyranthes candida,the application effect of Sedum lineare Thunb was better in planting trough wall greening;the coverage of the three kinds of plants in the planting trough wall greening order:Sedum lineare Thunb>(L.f.)Ker-Gawl>Zephyranthes candida.Sedum lineare Thunb grew best on construction waste substrates,(L.f.)Ker-Gawl grew best on pumped light substrates,and Zephyranthes candida grew best on planting block substrates;Sedum lineare Thunb best in the south wall planting trough,(L.f.)Ker-Gawl and Zephyranthes candida grew best in the west wall planting trough.This study proved that different plants and substrates have different greening effects in planting trough wall greening.