Preparation, Porous Structure And Camouflage Performance Of Porous Ecological Concrete

The focus of the paper is green-growing porous concrete with broken bricks. Preparation and pH control of it were discussed,and water absorption and water retention of it were researched, and the internal structure of porous concrete and three-dimensional simulation of the construction were studied. Electromagnetic wave absorption properties of porous concrete and influences of absorbing agents on the absorbing properties were analysised. Principles of plant cultivation on green-growing porous concrete were studied. Optical camouflage, infrared camouflage and electromagnetic wave absorption properties of porous concete with plant were researched.It is an important significance from renewable resources, reducing environmental load, and multi-level development application of porous concrete, etc..To use massive waste bricks and improve water absorption of porous concrete, porous concrete was made with the entire broken brick as aggregate. In view of the broken brick aggregate's low hardness and the high water-absorption, preparation process and the physical mechanics performance of porous concrete were studied. Net slurry stone process was used.Mineral admixtures can reduce pH value of ecological planting type concrete Soil pH, and the effect is better than fly ash and slag mix mixed results. Cement paste– aggregate ratio directly determine waterhead and permeability coefficient of ecological planting concrete, with a logarithmic relation coefficient.Cement paste– aggregate ratio creasing,waterhead increases with the positive function relation, but permeability coefficient decreases with inverse function relation. Relation of permeability coefficient and porosity also is the logarithmic relationship,with the same pore ratio, permeability coefficient is taller, shows that the ecological planting concrete has better connectivity. Green-growing porous concrete with broken bricks has better water absorption capacity and water-holding capacity than with gravel. Along with the increase of aggregate-cement ratio, water-holding capacity drops, but water absorption capacity creases.With modern image analysis technique, aggregate size and cement-aggregate ratio on the pore structure parameters were analysised. Used the principles of industrial three-dimensional reconstruction of CT image, adopted digital grapHic process and MATLAB program to achieve three-dimensional reconstruction of the porous concrete.The results showed that the reconstruction view of three-dimensional structure was similar to the real structure of porous concrete, and the inner porous structure and the connectivity of concrete can be analyzed intuitively. It provided an effective model for porous structure, mechanic property and penetrability of porous concrete using finite element method.Porous structures of porous concrete can improve the matching ability of surface impedance and free space impedance, this means that the electromagnetic wave is prone to enter into the internal of it, moreover the reflection loss of electromagnetic wave decreased. Incident wave had undergone multiple reflection and scatter, so the energy loss increased. In 8GHz~18GHz brand, average reflectivity of the sample is less than -20dB. Moreover, influences of iron ore, ferrite and steel fibers on absorbing properties of porous concrete were studied.Green-growing porous concrete can be completely covered with reasonable density grass, the picture with optics cameras can't distinguish between Green-growing porous concrete and soil, tand can escape the optical reconnaissance.With infrared thermograpHy, temperature of grass on green-growing porous concrete is high 0.96℃than that on soil in sunny day, and temperature is same in rainy day. as long as green-growing porous concrete is covered with reasonable thickness out-soil, ensure plant rational planting density, can achieve consistently harmony with environment, can avoid thermal infrared reconnaissance.Ecological planting grass type concrete covered with reasonable density grass can absorpt and scatter electromagnetic wave. And grass density influences electromagnetic wave absorption, when plant grass density of 100%, the minimum, maximum and average reflectivity of the sample is -42.87 dB, -20.16dB and -29.91 dB, respectively. Green-growing porous concrete completely covered with reasonable density grass and can escape the radar reconnaissance.