【摘要】：伴隨著交通量及車輛荷載的增加,瀝青路面的病害問題日益凸顯,在荷載和環(huán)境的綜合作用下路面容易出現(xiàn)各種形式的損壞(如車轍、擁包、松散、推移、開裂等)。從瀝青混合料入手,改善其路用性能也成為當(dāng)下的研究熱點(diǎn)。本文提出了硫酸鈣晶須和秸稈纖維復(fù)合改性瀝青。將硫酸鈣晶須(calcium sulfate whisker,CSW)和秸稈纖維作為復(fù)合改性劑加入基質(zhì)瀝青中,研究復(fù)合改性后瀝青的技術(shù)性質(zhì)及瀝青混合料的路用性能。首先采用XRD、SEM及實(shí)驗(yàn)室常規(guī)分析手段,對(duì)CSW的物相、形貌等基本技術(shù)性質(zhì)進(jìn)行測(cè)試,并對(duì)秸稈纖維的吸油性、吸水性、熱穩(wěn)定性等進(jìn)行測(cè)試,結(jié)果表明所選CSW及秸稈纖維均滿足瀝青改性劑的基本要求。用機(jī)械攪拌法制備CSW改性瀝青,測(cè)試改性瀝青技術(shù)指標(biāo),結(jié)果表明:在CSW摻量0-8wt%范圍內(nèi),70#瀝青和90#瀝青針入度、延度均有所下降,軟化點(diǎn)均升高,70#瀝青針入度指數(shù)PI從-1.3793增加至-0.7834,│VTS│從1.4311一直降低到0.4139,90#瀝青PI從-1.4773增加至-0.8397,│VTS│從2.1341一直降低到0.4434,CSW可以改善瀝青的粘滯性、溫度穩(wěn)定性、溫度敏感性,降低了塑性。用機(jī)械攪拌法制備CSW和秸稈纖維復(fù)合改性瀝青,測(cè)試改性瀝青技術(shù)指標(biāo),結(jié)果表明:在CSW0-6wt%,秸稈纖維0-0.5wt%范圍內(nèi),隨改性劑摻量的增加,瀝青錐入度降低、抗剪強(qiáng)度增加,10℃、15℃延度最大降幅分別為61%、40.5%,軟化點(diǎn)從49.1℃增加到62.3℃,溫度敏感性系數(shù)從0.0337一直降到0.0279,│VTS│從2.1339一直降到0.3536,復(fù)合改性可以改善瀝青的粘滯性、溫度穩(wěn)定性、溫度敏感性。通過RTFOT和PAV實(shí)驗(yàn)發(fā)現(xiàn)復(fù)合改性劑對(duì)瀝青耐老化性有一定的改善作用。選取SAC-16瀝青混合料,用VCADRF法對(duì)擬用礦料進(jìn)行級(jí)配檢驗(yàn),通過馬歇爾法對(duì)瀝青混合料進(jìn)行配合比設(shè)計(jì)。進(jìn)一步分析硫酸鈣晶須和秸稈纖維復(fù)合改性瀝青混合料的性能,通過車轍實(shí)驗(yàn),發(fā)現(xiàn)復(fù)合改性瀝青混合料動(dòng)穩(wěn)定度DS最高增幅為34%,抗車轍性有較為顯著的提升;通過間接拉伸實(shí)驗(yàn),發(fā)現(xiàn)在一定摻量范圍(CSW0-4%,秸稈纖維0-0.5%),復(fù)合改性瀝青混合料劈裂強(qiáng)度、勁度模量最大增幅分別為29%、40%,低溫抗裂性有所改善;通過凍融劈裂實(shí)驗(yàn),發(fā)現(xiàn)凍融劈裂強(qiáng)度比TSR由83.2%增加到93.2%,水穩(wěn)定性亦得到改善;用灰關(guān)聯(lián)分析法,綜合評(píng)價(jià)了復(fù)合改性劑摻量對(duì)混合料路用性能的影響程度,選取了最優(yōu)摻配比例為CSW摻量4wt%,秸稈纖維摻量0.5wt%。
[Abstract]:With the increase of traffic volume and vehicle load, the disease problem of asphalt pavement is becoming more and more prominent. Under the combined action of load and environment, pavement is prone to various forms of damage (such as rut, wrapping, loose, moving, cracking, etc.). Starting with asphalt mixture, improving its road performance has become a hot research topic at present. In this paper, the composite modified asphalt of calcium sulfate whisker and straw fiber was proposed. Calcium sulfate whisker (calcium sulfate whisker,CSW and straw fiber were added as composite modifiers to the matrix asphalt. The technical properties of the modified asphalt and the road performance of the asphalt mixture were studied. Firstly, the phase and morphology of CSW were tested by XRD,SEM and conventional laboratory analysis, and the oil absorption, water absorption and thermal stability of straw fiber were tested. The results show that the selected CSW and straw fiber meet the basic requirements of asphalt modifier. CSW modified asphalt was prepared by mechanical mixing method, and the technical index of modified asphalt was tested. the results showed that the penetration and ductility of 70 # asphalt and 90 # asphalt decreased and the softening point increased in the range of 0 脳 8wt% of CSW. 70 # asphalt penetration index PI increased from-1.3793 to-0.7834, 鈮，

本文編號(hào)：2476222