The cement quality directly affects the quality of construction and the durability. And what’s more, it is the key part of the quality control of concrete batching plant. So, how to identify the cement quality of concrete batch plant?
1. Clinker. As for the standard requirements, calcium metasilicate mineral accounts for no less than 66%, the quality ratio between the calcium oxide and silicon oxide is not smaller than 2.0.
2. Clinker content in the cement. In the standard requirements, the total content of ordinary silicate cement clinker and plaster should be not smaller than 80% and be smaller than 95%. But now, many large cement factories produce cement which contains only 65%-70% clinker, let alone many small cement factories all over our country. Generally, the cement in the small cement factories only contains 50% clinker.
3. Testing methods. Cement supervision and administration are taken by Technical Supervision Bureau and the spot check is done every year, which can not restrain the production of cement factories. The necessary check items of national testing standard are only strength, setting time and safety, along with some chemical index, which is far from enough. What’s worse, some kinds of cement which have been taken some measures can satisfy these requirements easily.