Permeable concrete is a new type of road pavement material, it is a comprehensive innovation to the traditional concrete road pavement, it by adding green, environmentally friendly inorganic reinforcer agent (water, powder), and cement, water, paint in a certain mixing ratio, made from porous lightweight concrete material, pavement can meet all kinds of load roads, parking lots, walkways and other facilities. It has the characteristics of high strength, strong permeability and good wear resistance.
Function
The pervious concrete is developed and used in Europe, America, Japan and other countries for the original urban road surface defects, which can allow rainwater to flow into the ground, effectively replenish the groundwater, alleviate some urban environmental problems such as the rapid decline of the city's groundwater level. And can effectively eliminate the oil compounds on the ground to the harm of environmental pollution; At the same time, it is an excellent paving material to protect groundwater, maintain ecological balance and alleviate urban heat island effect. It is of special significance to the benign development of human living environment, urban rainwater management and water pollution prevention and control.
Permeable concrete system has a series of color formula, with the creative design, according to the different environment and personality requirements of the decorative style for laying construction. This is the traditional paving and general permeable brick can not achieve the special paving material.
Permeable concrete has been studied and applied in the United States since the 1970s and 1980s, and has been widely promoted in many countries. For example, Germany is expected to transform 90% of the roads into permeable concrete in a short period of time, so as to change the ground laying that damaged the urban ecology in the past, so that the permeable concrete pavement depends on extensive social benefits.
The Main Technical
Preparation of pervious concrete
Permeable concrete not only meets the strength requirements, but also needs to maintain a certain amount of through-through pores to meet the permeability requirements, so in addition to selecting the appropriate raw materials, but also through mix design and preparation process and additives to ensure the strength and porosity. Permeable concrete is composed of aggregate, cement, water, etc., and single or intermittent coarse aggregate is mostly used as the skeleton. The amount of fine aggregate is generally controlled within 20% of the total aggregate. Cement can choose Portland cement, ordinary Portland cement and slag Portland cement; The admixture can choose silica fume, fly ash, slag fine powder, etc. When feeding, first put in cement, admixture, coarse aggregate, then add half of the amount of water, stirring 30s; Then additives (enhancer, pigment, etc.) were added and stirred for 60s. Finally, add the remaining water and stir for 120s.
Pervious Concrete Construction
The construction of permeable concrete mainly includes paving, forming, surface treatment, joint treatment and other procedures. Paving by mechanical or manual means; The forming can be carried out by plate vibrator, vibration leveling roller, manual push-pull roller, vibration leveling beam, etc. The main purpose of surface treatment is to improve the appearance of the surface, and to trim or clean the surface of the formed permeable concrete. The joints of permeable concrete pavement are basically the same as those of ordinary concrete, with equal spacing of shrinkage joints, and the spacing shall not exceed 6m.
Maintenance Of Pervious Concrete
After the construction of permeable concrete, adopt cover curing, water spraying and moisturizing curing for at least 7 days. During the curing, prevent the pores on the concrete surface from being polluted by sand. The daily maintenance of concrete includes daily cleaning and pore sealing. Air blower, high pressure flushing or vacuum cleaning can be used to clean and seal the pores.
The Characteristics Of
High Permeability
Permeable floors have 15 to 25 per cent porosity, enabling permeable speeds of 31-52 litres/m/h, well above the drainage rate of the most efficient rainfall in the best drainage configurations.
High Bearing Capacity
The bearing capacity of pervious floor can reach the bearing capacity of c20-c25 concrete, higher than that of permeable brick.
Adornment Effect
Permeable floor has color optimization matching scheme, can cooperate with the designer's unique creativity, to achieve different environment and personality requirements of the decorative style. This is generally permeable brick is difficult to achieve.
Easy Maintainability
The pore clogging problem that people worry about is not necessary, the special permeable pavement system makes it can be easily solved by high-pressure water washing.
Freezing-Thawing Resisting Sexual
Permeable pavement is more freeze-thaw resistant than ordinary concrete pavement, and will not be affected by freeze-thaw surface fracture, because its structure itself has larger pores.
Durability
The durability and wear resistance of permeable floor is better than that of asphalt, and it is close to that of ordinary floor.
High Heat Dissipation
The low density of the material itself (15-25% voids) reduces the heat storage capacity, and the unique pore structure allows lower underground temperatures to be introduced into the surface, thereby lowering the temperature of the entire pavement surface. These characteristics make the permeable pavement system close to the surface covered by natural vegetation in terms of heat absorption and heat storage.
Fatigue Strength
Due to the use of open - grade mixture, the fatigue resistance is low.
Using Range
Sidewalks and bike paths.
Ground decoration in the community.
Landscape roads and city squares.
Swimming pool and stadium.
Community fire access and lightweight roads.
Golf course tram.
Outdoor car park.