Colored permeable concrete, with its environmental benefits such as preventing ground subsidence, protecting underground water resources, and reducing the heat island effect, is gaining widespread use around the world. This is making our cities more ecological, environmentally friendly, and sustainable. Permeable concrete technology is considered an advanced and eco-friendly technique within our country.
Permeable concrete, while meeting strength requirements, also needs to maintain certain interconnected voids to fulfill permeability needs. Therefore, in its preparation, aside from selecting appropriate raw materials, it is essential to achieve the desired strength and porosity through mix ratio design, manufacturing process, and the use of additives. Permeable concrete is composed of aggregates, cement, water, etc., and usually employs monomial or discontinuous graded coarse aggregates as the framework, with the fine aggregate content generally kept within 20% of the total aggregates. Cement options include silicate cement and ordinary 42.5 cement; admixtures can be chosen from fly ash, slag fines, and other micro-fine powders. During the feeding process, first place the cement, admixtures, and coarse aggregates; then add half the water amount, mix for 30 seconds; next, add the additives (such as admixtures and pigments), mix for 60 seconds; finally, add the remaining water, mix for 120 seconds, and discharge the mixture.
With the development of the country and the progress of society, urban development has also become increasingly rapid. In cities, there has been a surge in the construction of sponge cities in recent years. During the process of building sponge cities, cities are extensively reconstructing outdoor pavements, transforming from impermeable surfaces to permeable concrete. This change allows cities to develop better while also avoiding issues such as surface water accumulation and urban flooding.
The current challenge in urban areas is environmental improvement. For cities severely lacking water, the South-to-North Water Diversion Project is overly complex. 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 well-being of its residents. The use and characteristics of concrete binders are gaining attention as permeable paving becomes 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 harmonize with the natural environment, reducing the burden on the Earth and its ecosystems, and enable the recyclability of non-renewable resources. Additionally, they provide excellent usability, creating a mild, comfortable, and convenient living environment for humans.
