Study On Porous Vegetation-Growing Concrete

The side slope defence has been a continuous career for human beings. However, a perfect junction has never been found between the side slope defence and virescence. Compared with the traditional defence materials, the porous vegetation-growing concrete can not only attain a higher strength to effectively defend the side slope and reinforce its stability in a longer defense period, but also get a higher void ratio to make it possible for plants to grow better in it. It really functions in improving the environment and has been commonly considered as an ecological concrete. Therefore, to do researches on the porous vegetation-growing concrete is a significant task.In allusion to the fact that there is not any uniform and reasonable mix proportion design method for the porous concrete, this thesis put forward a design method which consider void ratio as the main design parameter and strength the subordinating one. And the calculating method about kinds of materials in porous concrete is ascertained. It has been verified by the experiments that in the prerequisite for ensuring concrete's void ratio it is feasible to increase the concrete strength by some methods including increasing the strength of cementation materials, decreasing the diameter of aggregate and so on. This method is concise and all design parameters have the definite physical meaning, which avoids the use of experiential formulary and curve.According to the structural speciality of the porous concrete, the thesis brings forward the preparing technics of the porous concrete after masses of experiments. Firstly, the mixing craftworks are as follows:â‘ mix the aggregate and 70 percent of adding water for 1 minute;â‘¡mix 50 percent of binding materials for 1minutes;â‘¢mix the remnant 50 percent binding materials and 30 percent water for 2 minutes. Secondly, the moulding technics differs from the usual concrete's: the fresh concrete is cast three times per mould and each of the layers is required to be pestled with a 16mm diametric pontil for twenty times,after which a 20 seconds'mechanical vibration is given and then the compressive stress about 0.1~0.15MPa is followed. Finally, there is particularity on porous concrete curing method, in the laboratory concrete can be cured under standard conditions and the moist curing with film cover is used on site.One of the salient problems in Portland cement prepared porous green-growing concrete lies in the alkaline environment of water in voids, which is not suitable for plants to grow. After an analysis of the source and existing configuration of alkaline...