新疆岩沥青改性沥青高温性能试验研究

测试了不同新疆岩沥青掺量的改性沥青针入度、软化点、复数模量、相位角等技术指标,分析了新疆岩沥青对基质沥青高温性能的影响。结果表明：随着新疆岩沥青掺量的增加,改性沥青的针入度减小、软化点提高、车辙因子变大,改性沥青的高温性能得到增强：新疆岩沥青可改善沥青结合料的粘弹性质,表现为复数剪切模量的增加和相位角的减小;根据Superpave沥青胶结料高温性能分级标准,研究了新疆岩沥青对高温等级的增强效果。     

脱油沥青和SBS复合改性70号道路沥青的研究

利用脱油沥青(DOA)和SBS调和70号道路沥青生产改性沥青是一条解决DOA应用的有效途径。对DOA和SBS调和商品70号沥青制备改性沥青进行了试验研究,结果表明:在固定SBS,糠醛抽出油均为4%的商品70号沥青中外掺2.5%~1 0.0%的DOA,随着DOA含量的增加得到的改性沥青软化点升高,针入度和5℃延度减小,黏度增大。DOA调和比例为2.5%~5.0%的改性沥青的性质均满足SBS改性沥青1-D级标准。对DOA掺量为5.0%、7.5%的改性沥青和改性沥青原样进行了流变行为表征学测定,结果表明SBS改性沥青中添加DOA后复数模量增大,相位角减小,车辙因子增大,改性沥青的性能显著改善。此外,黏温性能研究表明掺兑DOA后SBS改性沥青的高温性能得到了改善。     

大温差条件下沥青结合料静态、动态室内试验性能研究

为了通过室内试验模拟极端温度条件下沥青结合料在老化前后的蠕变、流变特性,采用BBR(Bending Beam Rheometer)试验、DSR(Dynamic Shear Rheometer)试验和RTF饥(Rolling Thin Film Oven Test)试验分别获取沥青老化前后的蠕变劲度、蠕变速率,以及高温高频旋转下的复合模量和相位角。低温蠕变劲度试验表明,基质沥青与SBS改性沥青和橡胶改性沥青有类似的松驰属性,改性剂降低了低温下的蠕变劲度,提高了蠕变速率;动态剪切流变试验表明,改性剂的添加使基质沥青具备更高的复合模量和更小的相位角;最后,通过使用DSR试验数据和Booji-Thoone近似公式验证了4种沥青结合料类似的线粘弹性力学行为。     

水滑石/废橡胶粉复合改性沥青的制备及其性能研究

以克拉玛依90号沥青作为基质沥青、废橡胶粉和水滑石（LDHs）作为改性剂,制备了LDHs/废橡胶粉复合改性沥青,在废橡胶粉加入量不变的条件下,考察LDHs加入量对复合改性沥青的物理性能、抗紫外老化性能和流变性能的影响。结果表明：当废橡胶粉加入量（w）为15%时,随着LDHs的加入,复合改性沥青的软化点升高,针入度和延度有所下降,两种改性剂相互结合,使复合改性沥青的物理性能得到改善,并且满足国家聚合物改性沥青标准的要求,考虑到改性剂成本,选取LDHs加入量（w）为3%～4%;LDHs的加入使复合改性沥青的软化点增量减小,残留针入度比和延度保留率上升,表明LDHs可明显提高复合改性沥青的抗紫外老化性能;LDHs的加入可使复合改性沥青复数模量和车辙因子增加,相位角下降,说明LDHs可提高复合改性沥青的抗车辙性能。     

SBS改性沥青软化点试验过程研究

采用不同SBS掺量的改性沥青进行软化点试验,通过变化试验条件(加热介质、浇模温度、下坠距离)分析不同SBS掺量改性沥青的软化点试验的变化规律,并分析软化点试样下坠距离与温度的关系。试验结果表明,软化点试验过程分为基质沥青抵抗高温初始形变、SBS三维立体结构抵抗高温变形下坠和SBS三维立体网状结构高温破坏后的下坠过程3个阶段;同时试验结果表明软化点浇模温度应在预估软化点以上90～110℃,旋转黏度小于0.5 Pa·s时的试验结果较为真实。     

改进沥青薄膜加热试验条件的探索研究

为研究沥青薄膜加热试验方法的合理性,选取山东地区常用的70号沥青和SBS I-D聚合物改性沥青,通过粘温曲线分别确定70号沥青和SBS沥青的拌和温度,然后分别进行常规温度下的薄膜加热试验和拌和温度下的薄膜加热试验。试验结果表明,在拌和温度下的老化后针入度、延度均有明显的衰减,黏度随老化温度的升高而增大,软化点没有明显的变化规律。结合老化后的粘温曲线与施工现场的实际情况,得出70号沥青混合料的压实温度宜采用老化沥青黏度为0.28 Pa·s±0.03 Pa·s时的温度作为热拌沥青混合料的压实成型温度~([1]),SBS I-D改性沥青混合料的压实温度宜采用老化沥青黏度为0.45 Pa·s±0.05Pa·s时的温度作为聚合物改性沥青混合料的压实成型温度~([2])。     

寒冷地区SBS改性沥青的制备及性能研究

利用3种中石油昆仑沥青,研究了不同基质沥青、相容剂加量对SBS改性沥青常规性质的影响,并利用沥青剪切流变仪测试了较优条件下样品在不同温度下的c*/sinδ值,利用弯曲梁流变仪测试了样品不同温度下的劲度模量(S)和劲度模量变化率(m)。结果表明:通过工艺的优化,I-C级SBS改性沥青TFOT后的延度(5℃)可达到40cm,软化点大于75℃,PG等级达到PG70-28等级,具有优良的高低温性能。     

干法胶粉沥青大粒径沥青混合料动态模量试验研究

为了探究干法胶粉沥青大粒径沥青混合料LSPM的动态特性,通过干法直投制备胶粉沥青,应用简单性能试验机(SPT)对比了干法胶粉沥青和MAC改性沥青LSPM在不同温度及加载频率下的动态模量和相位角,根据时-温等效原理,得到了参考温度为20℃的动态模量主曲线,结果表明:40 ℃时干法胶粉沥青LSPM中沥青胶结料保持着良好的粘...     

围压对沥青混合料相位角的影响

沥青混合料在路面结构中承受三维应力状态，所以有必要了解其力学性质随围压的变化情况。研究对改性沥青Superpave20和普通沥青Superpave25两种混合料分别在不同温度、不同围压和不同频率条件下进行了三轴复数模量试验，并分析了各种条件下围压对相位角的影响。试验结果表明，无论在有没有围压作用的情况下，在温度较高时，由于矿料骨架的影响增加，相位角随温度的增加或荷载作用频率的减小而减小。在小于15℃时，围压对相位角的影响很小。随着温度的升高和荷载频率的降低，影响变得越来越显著。当围压从0kPa增加到250kPa时，对于Superpave20和Superpave25，相位角分别降低为原来的61％和33％。由此，为了准确的描述路面结构中沥青混合料的行为特性。需要考虑围压对相位角的影响。     

TLA改性沥青流变和老化性能的研究

采用动态剪切流变仪（DSR）对不同掺量的11A改性沥青的流变性能进行了研究,并通过薄膜烘箱老化（TFOT）和紫外老化（uv）试验研究了TLA对沥青老化性能的影响。结果表明：加入TLA后,沥青的复数模量增大,相位角减小,TLA的掺量每增加10％,PG高温区间基本上升1个等级,大大提高了沥青的高温稳定性和降低了其温度敏感性。与未改性沥青相比,TLA改性沥青TFOT和UV老化后的软化点增量和粘度变化指数显著减小,TFOT老化后的残留针入度比明显增大,TLA的加入有效地改善了沥青的热氧老化和紫外老化性能。     

沥青胶结料基本高温性能指标相关性研究

高温稳定性是沥青胶结料重要技术要求之一。针入度、软化点、60℃动力黏度和针入度指数是工程中最为常用的高温性能评价指标。为探究这些高温性能指标的区分度和关联性,对34种源于不同工程的沥青胶结料进行检测,基于聚类分析法和灰色关联分析法对试验数据进行分析。结果表明,60℃动力黏度指标相比针入度和软化点指标能够更有效地区分不同沥青胶结料的高温性能;70号基质沥青和高黏度改性沥青的60℃动力黏度与软化点关联度高,但SBS改性沥青60℃动力黏度与其他高温性能指标的关联度低;考虑到动力黏度能够客观表征流变特性,建议在实际工程中可将60℃动力黏度列为强制性指标。     

Properties of asphalt modified with devulcanized polyethylene terephthalate

The objective of this research is to investigate the effectiveness of the devulcanized polyethylene terephthalate in enhancing the performance characteristics of modified asphalt binders. The physical and rheological behavior of four binder samples were investigated using the penetration, softening point, storage stability, rotational viscometer, and dynamic shear rheometer tests. The polymer tends to decrease penetration and increase softening point, viscosity, and permanent deformation resistance of modified binders in comparison with base asphalt binders. However, this processed polymer could not be considered storage stable blend at high temperatures.     

纳米CaCO3改性沥青与SBS改性沥青综合比较研究

选择纳米CaCO3和SBS为改性剂,研究其对基质沥青的改性作用。针对改性剂的特性确定了相应的制备工艺。通过针入度、软化点、延度、布氏粘度扣动态剪切流变试验及混合料试验评价了改性沥青的路用性能。结果表明纳米CaCO3改性沥青路用性能得到了显著改善。最后对三种典型掺量的改性沥青性价比进行了对比分析,认为纳米CaCO3改性沥青在低等级路面使用中具有较高的性价比。     

An investigation on the effect of SBS+Vacuum bottoms residue modification on rheological characteristics of asphalt binder

In this research, the effect of adding SBS and vacuum bottoms residue on 60/70 neat asphalt binder have been carried out using classic and superpave testing methods. Adding SBS led to increase of softening point, elastic recovery and viscosity of asphalt binder. Besides, SBS reduced the penetration and ductility of specimens. Results of dynamic shear rheometer indicated that G^* and G^*sinδ reduced by adding the SBS content before and after aging while δ and G^*/sinδ parameters increased. Therefore, adding SBS improves the permanent deformation and fatigue resistance of neat asphalt binder.     

Rheological and aging properties of warm mix asphalt binders containing expanded vermiculite

The scope of this study was to investigate the high and intermediate temperature rheological and aging properties of warm mix asphalt binders modified by organo-expanded vermiculites. The rotational viscosity, complex modulus, and rutting parameter (G^*/δ) increased and the penetration and phase angle decreased after modification of 3% organo-expanded vermiculites, indicating that the high temperature rheological properties of the warm mix asphalt binder have been improved. The warm mix asphalt binders containing 3% organo-expanded vermiculites demonstrate the lowest value of phase angle and the highest value of complex modulus compared with the studied binders. In addition, as a result of the rolling thin film oven test, the viscosity aging index of warm mix asphalt binder decreases, while the retained penetration increases obviously with the introduction of organo-expanded vermiculites. The warm mix asphalt binder with 3% organo-expanded vermiculites has more pronounced improvements in aging resistance in comparison with other studied modified warm mix asphalt binders.     

Thermal and rheological properties of nanoparticle modified asphalt binder at low and intermediate temperature range

There is a paucity of knowledge regarding the effect of nanoparticles on the performance of asphalt binder against fatigue and low-temperature cracking. In this research, asphalt binders were modified using SiO₂, TiO₂, and CaCO₃ nanoparticles, and rheological and thermal properties of the modified binders were investigated. Differential scanning calorimetry was used to determine glass transition temperature, and rheological properties at low and intermediate temperatures were determined using bending beam and dynamic shear rheometers, respectively. The results suggested that the addition of these nanoparticles increases glass transition temperature and the low-temperature stiffness of asphalt binder. Furthermore, increase in complex shear modulus and decrease in phase angle values were observed at intermediate temperatures. It can be concluded that inferior performance at low and intermediate temperature is expected by the addition of nanoparticles to asphalt binder.     

CHARACTERIZATION OF POLYMER MODIFIED GULF ASPHALTS

The rheological properties of polymer modified Arab asphalts were characterized using both routine test methods, such as penetration and softening point, and more rigorous methods, which included low temperature stiffness measurements using a bending beam rheometer, and dynamic mechanical analysis using dynamic shear rheometer. HP-GPC method of analysis was used to produce profiles of the molecular size distribution of the modified asphalts. Models were built to predict the rheological and performance-based properties from the HP-GPC profiles. The results indicated that polymer modification is capable and effective in improving the neat Arab asphalt binders rheological properties to meet and satisfy the performance requirements of the Gulf countries.     

The addition effects of macro and nano clay on the performance of asphalt binder

The study was carried out to explore the addition effect of macro and organically modified nanoclay on the physical and mechanical properties of asphalt binders. Both macroclay and modified nanoclay were blended in an asphalt binder in various percentages (starting from 2% to 8%). The blended asphalt binders were characterized using kinematic viscosity (C.st), softening point (°C), and penetration and compared with anunmodified binder. The tensile strength of the asphalt binders was also tested as a function of clay types and content%. The results of the study indicated an increase in softening point; kinematics viscosity and decrease in binder penetration. The tensile strength of modified clay binders was enhanced at all percentages by a comparison with both macroclay and unmodified binders. The best improvements in the modified binders were obtained with 6% nanoclay.     

CHARACTERIZATION OF POLYMER MODIFIED GULF ASPHALTS

Abstract

The rheological properties of polymer modified Arab asphalts were characterized using both routine test methods, such as penetration and softening point, and more rigorous methods, which included low temperature stiffness measurements using a bending beam rheometer, and dynamic mechanical analysis using dynamic shear rheometer. HP-GPC method of analysis was used to produce profiles of the molecular size distribution of the modified asphalts. Models were built to predict the rheological and performance-based properties from the HP-GPC profiles. The results indicated that polymer modification is capable and effective in improving the neat Arab asphalt binders rheological properties to meet and satisfy the performance requirements of the Gulf countries.     

用动态力学方法分析SBS改性沥青的流变性质

从动态力学角度分析了SBS改性沥青的流变性质.改性沥青由实验室制备,采用3个油源4种沥青分别用两种SBS对其改性.研究表明:在高温下SBS能够增加胶结料的弹性,低温下能够改善其柔韧性,流变性质随温度的变化与基质沥青、聚合物的含量和结构有关.