Picture sewage effluent covers mold covers mold Baoding Lunda supply building materials plant dies as a result of the mixing timber species, the nature and content of different concrete cement pipe machine workability and adaptability is not the same with the additive. So easy bleeding, loss of fluidity large admixture with good water retention, loss of fluidity are smaller with the use of mixed materials, can make up for each other, to prevent bleeding, segregation. As well as to improve the workability of concrete admixtures suitable adaptation. Such as slag, steel slag, copper slag and fly ash, coal gangue with use. Can achieve better results, with limestone as admixture, can stimulate early strength cement play. Fly ash, slag do admixture, not only can reduce the heat of hydration of concrete. In terms of ultra-fine powder is added, but also greatly enhance the strength of cement, clinker ratio lower. With covers mold increasingly important for urban construction, covers mold precision has become perfect, began to lightweight and fine direction. Manhole mold will have to increase the use of lightweight plastic and the development of new materials, including new types of plastics, modified plastics, metal and plastics, magnesium alloys, composites, etc., which require a new forming process, which will require the adapt the new mold. To die beautifully, it must nice shape, no internal defects, which requires sophisticated, high precision molds corresponding.