Color-bleeding permeable concrete, with its environmental benefits such as preventing ground settlement, protecting underground water resources, and reducing the heat island effect, is now widely used around the world, making our cities more ecological, environmentally friendly, and sustainable. The technology of permeable concrete is considered advanced and environmentally friendly in China.
Porous concrete must meet strength requirements while maintaining a certain degree of interconnected voids for permeability. Therefore, in addition to selecting suitable raw materials, it is necessary to achieve the desired strength and porosity through mix design, production process, and the use of additives. Porous concrete is composed of aggregates, cement, and water, often using monomial or discontinuous grade coarse aggregates as the framework, with the amount of fine aggregates generally controlled at 20% or less of the total aggregates. Cement options include silicate cement and ordinary 42.5 cement; admixtures can be fly ash, slag micro-fine powder, etc. When batching, first add cement, admixtures, and coarse aggregates, then add half of the water and mix for 30 seconds; next, add additives (additives, pigments, etc.) and mix for 60 seconds; finally, add the remaining water and mix for 120 seconds before discharging.
As the country develops and society progresses, the pace of urban development is also accelerating. In cities, the concept of building sponge cities has gained popularity in recent years. During the construction of sponge cities, there has been extensive renovation of outdoor pavements, transforming impermeable surfaces into permeable concrete. This change enables better urban development while mitigating issues like surface water accumulation and urban flooding.
The challenge in urban areas now is the environmental issue. For cities facing severe water scarcity, relying on the South-to-North Water Diversion Project is overly complicated. Moreover, as cities are constructing sponge cities, they are extensively transforming urban surfaces, replacing them with permeable concrete to enhance the city's environment and the quality of life for its residents. The use and characteristics of concrete binders are increasingly recognized as a new, eco-friendly road material.
Porous concrete and sand-free concrete are made by uniformly mixing aggregates, binders, additives, cement, and water, then spreading them to form road surfaces. They offer higher strength and durability than traditional concrete, meeting the requirements for structural mechanical properties, functionality, and service life. They also blend well with the natural environment, reducing the burden on the Earth and its ecosystems, and enabling the recyclability of non-renewable resources. Furthermore, they provide excellent usability, creating a gentle, comfortable, and convenient living environment for humans.
