Modification of Bitumen with Desulfurized Crumb Rubber in the Present of Reactive Additives

Bitumen was modified with desulfurized crumb rubber (DCR) in the present of reactive additives . The effect of the kinds and content of the reactive additive on properties of DCR modified bitumen (DCRMB)was investigated. The morphology of DCRMB was characterized by SEM and the changes of the chemical structure of DCRMB without and with the addition of the reactive additive were analyzed by FTIR. The experimented results show that the softening point, the elasticity recoveray and the storage stability of DCRMB were improved significantly by the addition of the reactive additive. This is because that a network structure of rubber in DCRMB was formed and the chemical reaction between C = C double bonds in bitumen and DCR has happened after the reactive additive was added into DCRMB.     

废橡胶粉对SBS改性沥青的老化性能影响研究

在SBS改性沥青中加入糠醛抽出油溶胀后的活化废橡胶粉制备SBS／胶粉复配改性沥青,并对其热老化前后的软化点、针入度、延度等性能进行测试,表明在SBS改性沥青中加入胶粉并不影响改性沥青的热老化性能,而且对改性沥青的耐热老化性能还有一定程度的提高．对几组复合改性沥青的紫外线老化试验也表明加入废橡胶粉能够提高改性沥青的抗紫外老化性能．     

苯乙烯-丁二烯-苯乙烯嵌段共聚物/废胶粉复合改性沥青的制备

为了提高苯乙烯-丁二烯-苯乙烯嵌段共聚物(SBS)/废橡胶粉复合改性沥青的综合性能,同时解决常规胶粉掺量造成的高粘度和相容性问题,利用单因子实验和对废胶粉进行接枝处理,研究不同工艺及其因素对沥青性能的影响.研究得出低掺量接枝胶粉能有效解决高粘度和离析问题,最优配方为:SBS掺量质量分数2.5%,接枝胶粉掺量质量分数1.5%,溶胀剂掺量质量分数4%,稳定剂掺量质量分数16%.     

Investigation of rheological properties of TPS modified bitumen

Rheological properties of the virgin bitumen and TPS modified bitumen binders with several percentages of TPS additives were studied.All TPS modified bituminous binders were prepared on a laboratory scale.Dynamic shear rheometer(DSR) strain sweep test was made to measure the linear viscoelasticity areas of various bitumen binders at -20-70 ℃,then temperature sweep test and frequency sweep test were made in the linear viscoelasticity areas.Complex modulus master curves were drawn to analyze and compare various bitumen binders’ rheological properties.Based on the test results,the ideal percentage of TPS additive was brought forward.The results show that TPS modified bitumen binders have more excellent properties at high,medium and low temperatures compared with original bitumen.The dosages of TPS additive are vital to their properties.     

粉胶比对橡胶沥青胶浆高温性能的影响研究

为了研究不同粉胶比对橡胶沥青胶浆高温性能的影响,选择石灰岩矿粉作为填料,粉胶比掺量为0.2、0.4、0.6、0.8。胶浆高温性能的评价指标选择Fail temperature和ZSV,通过DSR试验对不同胶浆进行研究。试验结果表明:随着粉胶比的增加,橡胶沥青胶浆的Fail temperature和ZSV值均逐渐变大,而且增大幅度较大,橡胶沥青胶浆的高温性能得到明显的改善;利用环境扫描电镜对胶浆进行扫描,发现添加矿粉的橡胶沥青胶浆光滑、细腻,矿粉被橡胶沥青裹覆均匀。     

橡胶沥青相关性能的试验研究

通过室内试验分析研究了不同橡胶粉掺量对基质沥青的改性效果,分析了橡胶沥青的高温性能,水稳定性,耐久性性能指标。结果表明：在试验范围内,轮胎橡胶粉能显著提高沥青混合料的高温性能,轮胎橡胶粉掺量越高,混合料的高温性能越好;橡胶沥青混合料的残留稳定度要比基质沥青混合料有所提高,体现了橡胶沥青较好的抵抗水损害的能力;橡胶粉改性沥青的耐老化性能也有了一定的提高。     

矩形钢管橡胶混凝土短柱强度承载力试验

为了探讨橡胶粉取代率和橡胶粉粒径对矩形钢管橡胶混凝土力学性能的影响,进行了8个矩形钢管橡胶混凝土轴心受压短柱的试验研究,比较了设计规程（如美国ACI（2005）和AISC（2005）、日本AIJ（2008）、英国BS5400（2005）、欧洲EC4（2004）及中国CECS（2004））对矩形钢管橡胶混凝土强度承载力的适用性.结果表明：橡胶粉取代率和橡胶粉粒径均对矩形钢管橡胶混凝土力学性能影响显著,上述各设计规程计算获得的强度承载力与试验结果相比均偏于安全,可为实际工程提供参考.     

改性胶粉对聚苯乙烯结构及力学性能的影响

将微波辐射改性胶粉与聚苯乙烯（PS）共混,通过扫描电镜（SEM）、衰减全反射红外光谱（ATR-FTIR）、X射线衍射（XRD）、拉伸和冲击试验等研究改性胶粉/PS共混材料的结构和力学性能。结果表明,当改性胶粉质量分数为8%时,改性胶粉/PS材料的冲击强度比PS的强度提高了183%,共混材料中改性胶粉以橡胶相分散在PS基体中,二者之间界面粘结良好。     

橡胶颗粒沥青路面除冰效果及影响因素分析

为了深入研究橡胶颗粒沥青路面的除冰雪效果,本文从橡胶颗粒沥青路面的除冰机理入手,分析了在车辆荷载作用下路表冰层破碎的原因。借鉴路面破损状况评价指标的计算方法,提出了冰层破碎率作为评价橡胶颗粒沥青路面除冰能力的定量型指标。以破碎率为基础,通过室内试验分析了路面层厚度、混合料回弹模量和冰层厚度对除冰能力的影响。为橡胶颗粒除冰雪路面的推广奠定了基础。     

橡胶混凝土断裂性能试验研究

开展了橡胶混凝土三点弯曲梁断裂试验,获得了不同试件尺寸和橡胶掺量下的裂缝断裂全过程曲线,对橡胶混凝土断裂能G_F及裂缝扩展K-R阻力曲线进行研究。基于数字图像相关方法,获得了橡胶混凝土试件垂直于裂缝扩展方向的全场位移和应变信息,对裂缝扩展的损伤断裂演化过程进行研究。结果表明：随试件尺寸增加和橡胶掺量提高,断裂能均呈现出上升趋势;K-R阻力曲线随试件尺寸变化表现出明显尺寸效应,橡胶掺量在0%~14%设计范围内时,K-R阻力曲线与橡胶掺量无关。     

Effects of thermal-oxidative aging on rheological properties of montmorillonite modified bitumen

Organic montmorillonite(OMMT) modified bitumen nanocomposites was prepared by melt blending.The effects of thin-film oven test(TFOT) and pressure ageing vessel(PAV) on rheological properties of pristine bitumen and OMMT modified bitumen were investigated by dynamic shear rheometer(DSR).The results show that complex modulus(G*) increases,phase angle(δ) decreases and rutting factor(G*/sin δ) is enhanced for the pristine bitumen after TFOT,whereas G*,δ and G*/sin δ of OMMT modified bitumen have a little change before and after TFOT.Besides,the pristine bitumen exhibits a large increase of G* and a great decrease of δ after PAV aging.However,the changes in G* and δ of OMMT modified bitumen are small before and after PAV.Compared with the pristine bitumen,OMMT modified bitumen presents a lower fatigue factor(G*sin δ) after PAV.As a consequence,resistance to thermal-oxidative aging of bitumen is remarkably improved due to the introduction of OMMT.     

Effect of different montmorillonites on rheological properties of bitumen/clay nanocomposites

Different composites of organomodified montmorillonite(OMMT)/bitumen were prepared by melt blending with hexadecyl dimethyl benzyl ammonium modified montmorillonite(HBM) and double octadecyl dimethyl ammonium modified montmorillonite(DOM).The structures of two kinds of montmorillonite modified bitumen were characterized by X-ray diffraction(XRD).The effects of different montmorillonites on the dynamic rheological properties of the modified bitumens were investigated by dynamic shear rheometer(DSR).The XRD results show that DOM modified bitumen forms an intercalated structure,whereas the HBM modified bitumen forms an exfoliated structure.DSR results indicate that OMMT modified bitumens exhibit higher complex modulus,lower phase angle than pristine bitumen,which means that the resistance to rutting at high temperatures of pristine bitumen is improved due to the introduction of OMMT.Compared with DOM modified bitumen,HBM modified bitumen shows better rutting resistance,which is contributed to the formation of exfoliated structure in HBM modified bitumen.     

聚合物改性沥青微观结构与性能关系的研究

本文用扫描电子显微镜（ＳＥＭ）研究了ＡＰＰ与ＳＢＳ改性沥青的微观形态结构．测定了这两种改性沥青的物理性能（软化点，延伸度）随改性材料用量的变化规律，着重讨论了形态结构与这些性能变化之间的关系。研究结果表明：ＡＰＰ改性沥青形成了均相结构，ＳＢＳ改性沥青形成了非均相结构，ＡＰＰ和ＳＢＳ对沥青物理性能的改善与改性沥青的微观结构密切相关。     

Shear resistance properties of TPS modified bitumen binders and asphalt mixtures

Shear resistance properties of the virgin bitumen and modified bitumen binders with Tafpack Super(TPS) modifier and SBS modified bitumen were discussed.Dynamic shear rheometer(DSR) was used to measure the laboratory creep data for these binders over a wide range of constant shear stresses at 20 ℃ to characterize the shear creep behaviors of all kinds of asphalt binders,and the rutting test system was used to investigate the permanent deformation of porous asphalt mixtures using the above bitumen binders for a fixed compressive stress.The shear strain rate and shear creep modulus were used to characterize the shear creep behavior of the TPS modified bitumen,and the rutting test results were used to show the consistency of porous asphalt mixtures with the bitumen binders.Results indicate that a distinction of shear creep strain can be made among different contents of TPS modified bitumen at the same stress level,where the shear creep strain-time response curve of the SBS modified bitumen binder is between the curves of the 8% TPS and 12% TPS modified bitumen binders.The shear strain rate and the shear creep modulus of the TPS modified bitumen binders are obtained to compare with those of the SBS modified bitumen binder which results in the same trend as the shear creep strain-time response curve.Permanent deformation results of all the porous asphalt mixtures from the rutting test show reasonable agreement with the findings of the shear strain rates and shear creep modulus over the range of shear stress levels.     

废橡胶粉对SBS改性沥青的老化性能影响研究

在SBS改性沥青中加入糠醛抽出油溶胀后的活化废橡胶粉制备SBS/胶粉复配改性沥青,并对其热老化前后的软化点、针入度、延度等性能进行测试,表明在SBS改性沥青中加入胶粉并不影响改性沥青的热老化性能,而且对改性沥青的耐热老化性能还有一定程度的提高.对几组复合改性沥青的紫外线老化试验也表明加入废橡胶粉能够提高改性沥青的抗紫外老化性能.     

Effect of organophilic montmorillonite on thermal-oxidative aging behavior of SBS modified bitumen crack filling material

Styrene-butadiene-styrene (SBS) modified bitumen crack filling material with organophilic montmorillonite (OCFM) was prepared by melt blending. X-ray diffraction analysis shows that the interlayer spacing of organophilic montmorillonite (OMMT) in OCFM is widened and an exfoliated structure may be formed. Thermal-oxidative aging behavior of OCFM and SBS modified bitumen crack filling material (SCFM) was investigated. The experimental results indicate that the rate of thermal-oxidative aging of OCFM is much slower than that of SCFM, which can be attributed to barrier of exfoliated structure of OCFM to oxygen. Funded by the National Natural Science Foundation of China (50773061)     

Microscopic and dynamic rheological characteristics of crumb rubber modified asphalt

A test for crumb rubber modified asphalt containing 20% crumb rubber particles(30 mesh) was performed using a scanning electron microscope(SEM).The experimental results indicate that the crumb rubber particles are evenly distributed in the asphalt.Shear rate sweep and shear-temperature sweep tests on the crumb rubber modified asphalt at-20-80 ℃ using a dynamic shear rheology(DSR) instrument,were carried out.The tests show that the complex modulus decreases with increasing temperature;at equivalent temperature,higher load frequencies lead to a larger complex modulus,and this value increasingly decreases as the temperature increases;the phase angle increases with temperature and decreases as the load frequency increases.It can be concluded that the rutting resistance limiting temperature of crumb rubber modified asphalt is 78 ℃,and the anti-fatigue limiting temperature is 16 ℃,which shows that the asphalt has preferable rutting resistance characteristics at high temperature,as well as anti-fatigue characteristics.In addition,the complex modulus master curve at different temperatures was plotted according to the time temperature equivalence principle,which allows the study of the dynamic state behavior of crumb rubber modified asphalt at a wide range of load frequency.     

Microstructure and properties of fluoroelastomer/butadiene-acrylonitrile rubber interpenetrating polymer networks

Interpenetrating polymer networks （IPNs） based on fluoroelastomer/butadiene-acrylonitrile rubber （FKM/NBR） by molten blending at a high temperature and chemical cross-linking of two components were prepared. The influence of the two networks component on the mechanical properties and thermostabilities was studied. The experimental results show that the mechanical properties of the IPNs are superior to those of the individual FKM and NBR networks due to forming the case of interpenetrating and intercross-linking between the two networks, the mechanical properties and thermal resistance exhibit higher values when 80/20 （w/w） FKM and NBR is blended and respectively cured simultaneously. The co-continuous morphology of the IPNs in the blends of 80/20 （w/w） FKM/NBR is found by transmission electron microscopy （TEM）, the differential scanning calorimetry （DSC） determination shows that the blends of 80/20 （w/w） FKM/NBR have better compatibility, and the glass transition temperature of the elastomer is -21.5 ℃.     

稳定型橡胶改性沥青混合料动态模量研究

为研究稳定型橡胶改性沥青混合料的力学性能,利用基本性能试验系统进行了动态模量试验。文章分析了温度和加载频率对动态模量和相位角的影响规律,基于时间-温度置换原理确定了动态模量主曲线和移位因子,并采用修正的Witczak模型预估稳定型橡胶改性沥青混合料的动态模量。结果表明：稳定型橡胶改性沥青混合料具有更小的低温模量和更大的高温模量;修正的Witczak预估模型可以较好地预测稳定型橡胶改性沥青混合料的动态模量值。     

胶粉改性沥青防水层力学性能有限元分析

为了对采用胶粉改性沥青铺筑的实体依托工程防水层有直观的分析,使用有限元软件对桥面板、防水层和铺装层组成的结构体系进行模拟,比较在不同的防水材料弹性模量E和泊松比μ的情况下,结构体系的最大剪力。