| 摘要 |
A process for manufacturing eco-friendly less toxic precast closed conduit is provided to prevent contamination of water flowing through the conduit and to improve water environment by adding mineral materials such as illite, plagioclase, dolomite, etc. to raw material of the conduit to counteract cement toxicity of the conduit. The process comprises the steps of: screening and processing mineral materials containing illite, plagioclase and dolomite into microfine powders having less than 150 mesh; homogeneously admixing 19-21wt.% of cement, 19-21wt.% of sand, 29-31wt.% of aggregate, 9-11wt.% of illite, 6-8wt.% of plagioclase and 3-5wt.% of dolomite and 1.5-2.5wt.% of admixing agent, then, adding 6-8wt.% of water to the admixture; introducing the pasted concrete admixture into a mold after placing reinforced structure inside the mold, pressing the mold to form a precast closed conduit(10); and positioning the conduit in a curing room at 25-65deg.C and curing the conduit for 12 hours during intermittent steam injection. |
