Research On Material Design And Performance Of Porous Cement Concrete Pavement

Tire-pavement interaction noise is one of the significant environment problem in highly populated urban area situated near busy highway. Though the use of sound barriers, they have their own limitations because of the expensive price .The porous cement concrete pavement has a large porosity which does not only reduce the air pressure from the interaction between the tyre and road surface but also absorb the noise by dissipating sound wave energy. In addition, it improves highly traffic safety by draining water swiftly and decreasing water spray. The paper outline systematic research on the design method of porous cement concrete, mold technology and mix technology. The physical and mechanical properties of these mixtures were studied in detail. Compressive and flexural strength were both studied in detail, the influence of silica fume and cinnamene-acrylate was ascertained .Both total porosity and pore size ware determined by using Image Analysis. Accessible porosity is also determined by modified volume method. The relationship between porosity and mechanical properties was also obtained. In addition, the shrinkage of the porous cement concrete was conducted.Freeze-thaw durability was studied by rapid freezing and thawing method.The paper also outline the research on the acoustic property of porous cement concrete , both mechanism of tire-pavement interaction noise and noise propagation were studied. The acoustic absorption coefficients of porous cement concrete were determined using an impedance tube, It was found that the pore volume and pore size have a significant influence on acoustic absorption.The influence of structure factor and the pore connectivity factor on the acoustic absorption were studied in details. In addition, the influence of the specimen thickness on the acoustic absorption was also brought out. A lab test apparatus was developed into evaluating the noise reduction of the porous cement concrete.A constant head permeameter was developed to ascertain the water permeability of porous cement concrete, the influence of the porosity and pore size on the water permeability was studied. Both the pavement design method and the construction technology were studied in detail in order to guide the paving of porous cement concrete pavement.