Study On The Basic Properties And Blend Ratio Of Regenerated Vegetation Concret

Regenerated vegetation concrete is a composite multifunctional material that has various advantages such as cost saving,pollution reduction,drainage and water purification,landscape greening,etc.It is widely used in embankment protection,ecological roofs,parking lots,etc.Studying the changes in its basic performance and conducting plant growth experiments can provide theoretical basis and experimental data for exploring the promotion and application of ecological concrete in practical engineering.Therefore,this article adopts a combination of indoor experiments and theoretical analysis to conduct experimental research on the mix ratio and basic performance of recycled vegetation concrete.The main research content and conclusions are as follows:（1）The preparation process of regenerated vegetation concrete was proposed.Firstly,the secondary feeding and stone wrapping method is used for mixing,and then the test block is formed using a combination of manual tamping method and static pressure method.Finally,the standard curing room is used for curing.After forming and curing,the test block has a better appearance and basic performance.（2）The optimization of the mix proportion of regenerated vegetation concrete was studied.Through orthogonal experiments,the fixed design porosity was 0.25.Through range analysis and hierarchical analysis,it was found that the replacement rate of recycled aggregate and fly ash are the most important factors affecting the basic performance of recycled vegetation concrete.Through Z-score comprehensive analysis method,the optimal proportion of recycled vegetation concrete with comprehensive performance was obtained.（3）The methods and effects of reducing alkali content of regenerated vegetation concrete were explored.A 0.5mol/L Fe SO₄ solution was used to perform secondary alkali reduction treatment on the recycled vegetative concrete specimens.After the alkali reduction treatment,the concrete strength was lost to some extent,but the p H value decreased to below 9.5,allowing most plants to survive.（4）The plant adaptability of regenerated vegetation concrete was studied.Based on the statistical results of planting grass and trees in this region,ryegrass suitable for local growth was selected as the grass species for the planting experiment.The NTEP scoring method was used to comprehensively evaluate the plant growth situation,and it was determined that after secondary alkali reduction,some of the mix proportions were suitable for planting ryegrass.（5）The influence of plant growth on the basic properties of regenerated vegetation concrete was analyzed.It is found that the matrix has a agglomeration phenomenon in the pores,blocking some pores,leading to a decrease in water permeability and porosity;Plant growth has little effect on compressive strength;The continuous precipitation of alkaline substances from recycled aggregates is the reason for the increase in the p H value of concrete.（6）The micro mechanism of the basic performance changes of vegetation concrete was proposed was studied.Active substances in fly ash and metakaolin consume some cement hydration products,promote the formation of C-S-H gel in the test block,fill the internal cracks of the test block,make the test block mixed with fly ash and metakaolin have higher compressive strength,but also damage the water permeability and porosity;The acid ions in the ferrous sulfate solution can enter the interior through the pores and cracks of the concrete,and consume alkaline substances to reduce the alkalinity of the concrete.At the same time,the sulfate ions also promote the formation of ettringite,which reduces the compressive strength of the concrete;Short term plant growth experiments have led to changes in the content of Ca CO₃,AFt,and Ca（OH）₂ substances inside the concrete,resulting in a decrease in the performance of RVC.