Experimental Study And Engineering Application Of Cast-in-place Frost-resistant Vegetation Concrete

The report of the 19th National Congress of the Communist Party of China regards"adhering to the harmonious coexistence of man and nature"as the basic strategy for the development of the new era,which promotes the construction of ecological civilization to a new height.Ecological water conservancy construction,as an important part of the construction of ecological civilization,plays a vital role in protecting the ecological environment and harmony between human and nature.Ecological slope protection of rivers is an important part of ecological water conservancy construction.Traditional concrete and stone masonry slope protection is difficult to meet the green ecological needs of slope protection.Although hole-type concrete slope protection technology has certain greening effects,problems such as soil and water loss in the holes will occur due to the continuous erosion of rainwater.Vegetated concrete,as a new slope protection material that takes into account both ecological construction and slope protection,has broad prospects in the next application of ecological slope protection.The research team developed frost-resistant vegetation concrete and applied prefabricated blocks to the construction of ecological slope protection projects,which showed good ecological slope protection effect.In order to further optimize the construction procedures,shorten the construction period and reduce transportation costs,the research team conducted preliminary research on the cast-in-place frost-resistant vegetation concrete.Based on the preliminary test,this article conducts in-depth research on the construction technology and performance of cast-in-place antifreeze-thaw vegetation concrete.Three-factor four-level orthogonal test considering construction process factors such as forming thickness?8cm,10cm,12cm,15cm?,vibration time?4s,6s,8s,10s?,forming slope?1:1.0,1:1.5,1:2.0,1:2.5?was carried out.The test data of the mechanical properties?28d compressive and flexural strength?and water permeability?porosity,water permeability coefficient?were analyzed through the range analysis and variance analysis.This helps to find out the influence order and influence rule of forming thickness,vibration time,forming slope and other factors on the performance of cast-in-place frost-resistant vegetation concrete,and propose the optimal construction process influencing factor level.In combination with the demonstration project,the construction process and quality control standards have been initially established,providing theoretical support for the application of ecological slope protection engineering.The main conclusions are as follows:?1?By analyzing the effects of the forming thickness,vibration time and forming slope of on the mechanical properties and water permeability of cast-in-place frost-resistant vegetationconcrete,it can be known that:When the vibration time and the molding slope are constant,and the molding thickness is less than 15cm,as the molding thickness increases,the mechanical properties?28d compression and flexural strength?of cast-in-place frost-resistant vegetation concrete show a trend of first increase and then decrease.The mechanical properties are the best when the molding thickness is 10 cm;the water permeability?porosity,permeability coefficient?gradually increases with the increase of the molding thickness.When the forming thickness and forming slope are constant,as the vibration time increases,the mechanical properties?28d compression and flexural strength?of cast-in-place frost-resistant vegetation concrete show a trend of first increase and then decrease.The vegetation concrete has the best mechanical properties when the vibration time is 8s;the water permeability?porosity,permeability coefficient?gradually decreases with increasing vibration time.When the forming thickness and vibration time are constant,as the forming slope decreases,the mechanical properties?28d compression and flexural strength?of cast-in-place frost-resistant vegetation concrete show a trend of first increase and then decrease.The mechanical properties of vegetation concrete reached the best when the forming slope is 1:1.5;the water permeability?porosity,permeability coefficient?gradually increases with the decrease of the slope.?2?The influencing order of the mechanical properties?28d compressive and flexural strength?of cast-in-place frost-resistant vegetation concrete is forming thickness>forming slope>vibration time,the best combination is A₂B₃C₂;the influencing order of water permeability?porosity,permeability coefficient?is forming slope>Forming thickness>Vibration time,the best combination is A₄B₁C₄.Comprehensively considering the four performance indexes of 28d compressive strength,flexural strength,porosity and water permeability coefficient of cast-in-place frost-resistant vegetation concrete,the optimal influencing factor level of construction process is A2B3C2,that is,the molding thickness of10cm,the vibration time of 8s,and the molding slope of 1:1.5.The frost resistance of the optimized block of the best level of cast-in-place frost-resistant vegetation concrete is 205 times,which meets the requirements for the application the material in northern regions.?3?Through the construction of the ecological slope demonstration project in the Shuhe River Basin,the construction technology of cast-in-place frost-resistant vegetation concrete was initially established,and the application technology system of cast-in-place frost-resistant vegetation ecological river channel was initially formed.This research explores the influence of construction influencing factors on the performance of cast-in-place frost-resistant vegetation concrete.The level of influencing factors of the optimal construction process has been proposed.A cast-in-place construction teconology of the material has been established.This research helps to form a technical system for the application of frost-resistant vegetationconcrete in ecological slope protection.providing theoretical support and engineering application reference for the popularization and application of cast-in-place frost-resistant vegetation concrete in north region.