Material life cycle

High-performance ceramic materials may be difficult to decompose after being discarded. Building polymer materials are often difficult to degrade. The complex composition of composite building materials also makes it difficult to recycle. Clay concrete blocks are lightweight, high-strength, thermal insulation and fireproof performance Good, but its production requires higher energy consumption; plastic steel doors and windows are stronger and more durable than steel windows and aluminum alloy windows, and have better thermal insulation performance, but they involve high energy costs and will cause a serious burden on the environment when discarded; Shaft kiln cement may also be considered to be more environmentally compatible than rotary kiln cement because of its low energy consumption. Even the cement industry, which is "notorious" for releasing the greenhouse gas CO2, should be made into It is the absorption of CO2 in the natural carbonization process of cement concrete during use. In the production of 1 ton of cement clinker, approximately 1 ton of CO2 is released due to the decomposition of coal and limestone. In addition to the CO2 released from coal combustion (about 40%), the amount of CO2 released by the decomposition of calcium carbonate during cement burning can be slowly carbonized It is completely absorbed by cement concrete in the process. In order to comprehensively evaluate the environmental coordination performance of building materials, it is necessary to adopt the Life Cycle Assessment (LCA). The life cycle assessment method is a method for the impact of environmental pollution, energy and resource consumption and resources in the entire life cycle of materials. Although some monographs have been introduced and have entered the ISO international standard, for building materials, LCA is still a method under research and development.