Study On Key Technologies And Performances Of New Antifreeze Vegetation Concrete

In application of vegetation concrete there existing the problems of strength and frost resistance, plant effect, construction process complex in the northern region at present. In the basis of referring to lots of relevant literature and previous studies, the new antifreeze vegetation concrete was developed successfully, which can be widely used in northern cold area roads, rivers, reservoirs and slopes, repairing and sponging damaged mountains, urban constructions and other fields.At first, optimization of mix proportion of common vegetation concrete was carried out. Incorporation of appropriate amount 801 glue powder can greatly reduce the sensitivity of water cement ratio and solve the easy sinking pulp engineering problems; broaden the gravel particle size range properly under the premise of ensuring the permeability can optimize the distribution, increase the intensity, reduce the difficulty of screening and raise the utilization rate; adding silica fume can obviously enhance early strength and achieve the purpose of waste utilization; the optimal ratio of new vegetation concrete was determined through orthogonal test identified which improved the performances of vegetation concrete.Secondly, in order to improve the frost resistance of vegetation concrete, the method was adopted which using the crude fiber(steel fiber), fine fiber(polypropylene fiber),building glue and sand, moreover, an appropriate amount of air entraining agent and other materials were also adopted under the premise of ensuring the permeability. The best ratio of new antifreeze vegetation concrete was identified initially through orthogonal test. When using the ratio of forming, the vegetation concrete frost resistance grade greatly increased from F20 to F150, the mechanical properties and permeability have also been greatly improved, all above have laid the foundation for vegetation concrete application in the northern cold area.Thirdly, different concentration of fertilizer solutions soaking or spraying vegetation concrete to reduce pore fluid pH value alkalinity reducing technology was proposed. the alkali reduction material and reducing alkali solution concentration was optimized. Through study the influence on the performance of alkali reduction on vegetation concrete, it can be noted that the technique can rapidly reduce the alkalinity of pore solution with maintain in the range for plant growth in a long time. This technique also can increase concrete strength and promote plant growth with little effect on the permeability properties of vegetation growing concrete. According to the climate and soil characteristics of the northern region, the optimal selection of selected vegetation such as tall fescue, velvet grass and stolons cut glume was carried out, to achieve the effect of cold resistance, drought resistance and trampling resistance. This technique is suitable for popularization and application in practical engineering.