改性水稻秸秆对水泥基材料性能影响研究

Study on the Effect of the Modified Rice Straw on the Performance of the Cement-based Materials

为了减少农作物纤维废弃造成的污染,研究了利用植物纤维制备建筑材料的工艺,首先采用碱煮法对植物纤维进行改性,然后将其分别与聚丙烯纤维按照不同的比例加入到水泥净浆中进行比较,结果表明:植物纤维在水泥净浆中的分散比加入聚丙烯纤维均匀,经过改性后的秸秆纤维对水泥凝结硬化时间无明显影响,随掺量增加,水泥净浆的抗折强度呈先增后减趋势,且在掺量为4.5%时最高,与未掺纤维的参照组相比抗折强度提高了11%,抗压强度降低了近24%。并将其掺入砂浆中,砂浆抗干缩性能得到改善,植物纤维掺量为6.0%时砂浆干燥收缩值比基准组下降了37%,在本研究掺量条件下,与加入聚丙烯纤维相比,加入秸秆纤维对水泥净浆的抗折强度和抗压强度影响较小,原因在于其分散性更好。

In order to reduce the pollution caused by plant fiber which is waste,on the technology of the preparation of building materials was studied by using rice straw.First,the rice straw fibers were boiling in alkali solution.Then the modified plant fibers and polypropylene fibers were added to the cement and mortar in the different proportion separately.The results show that：rice straw fibers distributed more evenly than polypropylene fibers in the cement.And the modified rice straw fibers have no obvious effect on cement hydration and hardening time.With the increase of the admixture of cement paste,the flexural strength was increased and then decreased.And the content show the highest at the point where the proportion of fibers were 4.5％,compared with the control sample,the flexural strength increased by 11％,but the compressive strength decreased almost 24％.The content of plant fibers on the flexural and strength of cement mortar also showed a similar trend,the dry shrinkage performance of mortar had been improved.When the proportion of fiber is 6％,dry shrinkage performance of mortar reduced 37％ than the reference group.Compared with the polypropylene fibers,the modified rice straw fibers have less effect on cement under the same condition.The reason is that the dispersion performance of the plant fibers is better.