| 摘要 |
A stress-resistant agent for cement is prepd. by melting one or more of polyethylene, polypropylene, PVC, nylon and styrene-acrylonitrile copolymer, mixing the molten product with one or more of Portland cement, white Portland cement or other hydraulic cement, melt-spinning the mixt., and cutting the resulting fibre into suitable lengths. Nylon 6 is melted at about 250 deg.C., 10 wt.% (based on the nylon) of white cement is dehydrated and added to the molten nylon, and the mixt. is melt-spun at 220-230 deg.C. into a fibre. The fibre is stretched to about 4 times at high humidity and cut into 3 mm. lengths. 3 parts of the stress-resistant agent thus obtd. is mixed with 100 parts Portland cement, 200 parts sand and 65 parts water, the mixt. is cast into a mould, allowed to stand for 1 day, cured at 95 deg. C/3 hr. with steam and for 1 week in air. The product has good resistance to impact and cracking. |
