玉米秸秆纤维素的提取及其对沥青性能影响的研究

Study on the extraction of corn straw cellulose andits effect on asphalt performance

纤维素作为秸秆的重要组成部分,是决定其力学强度的关键。若将其应用于沥青路面中,有望改善路面的性能并解决秸秆在路面中易产生降解、老化等问题。研究首先利用星点设计-效应面法,探究了秸秆中纤维素的提取工艺对沥青性能的影响,并确定了纤维素的最佳提取工艺;然后,通过流变性能试验、离析试验以及红外光谱试验分析,研究了纤维素对沥青高温稳定性、低温抗裂性及储存稳定性的影响。结果表明,在NaOH浓度为2.5%,HNO_(3)浓度为4.3%的条件下所提取的纤维素对沥青物理性能的改善效果最佳,同时,玉米秸秆纤维素的掺入提高了沥青的高温稳定性、低温抗裂性以及在高速车辆荷载剪切作用下的抗变形能力。当玉米秸秆纤维素的掺量为7%时,沥青的综合性能最佳,未产生严重的离析现象。与基质沥青相比,纤维素掺量在7%时的高温连续分级温度(T_(LH))提升了13℃,低温性能提升了49.3%。此外,纤维素仅以物理增强作用互相粘结改善沥青的性能,并未发生化学反应。

As an important part of straw,cellulose is the key to determine its mechanical strength.If applied to asphalt pavement,it is expected to improve the performance of the pavement and solve the problems of straw degradation and aging in the pavement.Firstly,the central composite design-response surface method was used to explore the influence of the extraction process of cellulose in straw on the performance of asphalt,and the optimum extraction process of cellulose was determined.Secondly,the effects of cellulose on high temperature stability,low temperature crack resistance and storage stability of asphalt were studied by rheological property test,segregation test and infrared spectrum test.The results show that the cellulose extracted under the condition of NaOH concentration of 2.5%and HNO_(3) concentration of 4.3%has the best effect on improving the physical properties of asphalt.At the same time,the incorporation of corn straw cellulose improves the high temperature stability,low temperature crack resistance and deformation resistance of asphalt under high-speed vehicle load shear.When the content of corn straw cellulose is 7%,the comprehensive performance of asphalt is the best,and there is no serious segregation phenomenon.Compared with matrix asphalt,the high temperature continuous grading temperature(T_(LH))of cellulose content at 7%is increased by 13°C,and the low temperature performance is increased by 49.3%.In addition,cellulose only bonded with each other by physical enhancement to improve the performance of asphalt,and no chemical reaction occurred.