排水性沥青混合料路用性能分析

对排水性沥青混合料的吸声性能、透水性能、抗滑性能进行了分析,并对其机理进行了阐述,结果表明：排水沥青路面是一种具有透水、防滑、降噪等功能的混合料,其路用性能优良。     

锰渣矿粉沥青混合料抗腐性能研究

利用锰渣矿粉替代沥青混合料中的石灰岩矿粉配制成锰渣沥青胶浆和锰渣矿粉沥青混合料,进行锰渣沥青胶浆直剪试验、吸持性能试验及锰渣矿粉沥青混合料马歇尔试验、浸水马歇尔试验、冻融劈裂强度试验,测试不同替代量锰渣沥青胶浆粘附性能和锰渣矿粉沥青混合料抗腐性能的变化.结果表明,利用锰渣矿粉替代沥青混合料中的石灰岩矿粉能有效地改善和提高沥青胶浆粘附性能和沥青混合料抗腐性能.同时,通过锰渣矿粉改善和提高沥青胶浆粘附性能和沥青混合料抗腐性能的性能机理分析,揭示锰渣矿粉替代量影响沥青胶浆粘附性能和沥青混合料抗腐性能变化的原因.     

基于微观结构的多孔沥青混合料吸声模型

为了在设计阶段实现基于设计参数的多孔沥青混合料吸声性能预估,构建了基于微观结构的多孔沥青混合料吸声模型.依据声-电类比理论,计算了多孔沥青混合料吸声模型的声阻抗和吸声系数;运用图像处理技术及统计分析方法,得到了多孔沥青混合料"特征孔隙直径";依据多孔沥青混合料吸声模型微单元体中毛细管长度随圆球与毛细管截面直径比值的变化规律,得到了微单元体中毛细管的结构参数取值.结果表明:所构建的多孔沥青混合料吸声模型预测的给定声波频率下试件最大吸声系数及其对应频率与驻波管法实测值之间具有良好的相关性,验证了该模型在预测多孔沥青混合料吸声特性方面的准确性.     

Evaluation of pre-coated recycled concrete aggregate for hot mix asphalt

Recycled concrete aggregate (RCA) used for pavement construction can ease aggregate shortage problem and reduce environmental pollution. The mechanical properties of hot mix asphalt (HMA) with RCA are usually inferior to those of HMA with river crushed stone (CS). In this research, slag cement paste used for pre-coated RCA (PCRCA) with coating thickness of 0.25 mm, 0.45 mm and 0.65 mm to reinforce its ability is evaluated. The result shows that the PCRCA with coating thickness of 0.25 mm has the optimum coating paste volume for HMA mixture. The indirect tensile strength (ITS) test, moisture sensitivity test and wheel-track rutting test of HMA with substitution ratios of 25%, 50%, 75% and 100% PCRCA mixture are discussed. The results indicate that the properties of PCRCA have highly pores contents, absorption of water and asphalt contents. However, the physical properties of the PCRCA used as aggregate and test of HMA with PCRCA are within the range of the specification requirements.     

钢渣集料表面改性及其在沥青混凝土中的应用

钢渣用作集料制备沥青混凝土是处理冶炼废弃物和弥补天然集料不足的很好选择,但是钢渣掺量过高会引起沥青混凝土路用性能下降。本研究采用有机硅树脂表面改性技术对钢渣进行处理,研究不同钢渣掺量下沥青混凝土高温、低温及水稳定性变化。通过车辙试验、小梁低温弯曲试验、浸水马歇尔试验和冻融劈裂试验对路用性能进行测试。结果表明,钢渣的掺入对沥青混凝土高温性能有所提高,但钢渣掺量超过60%时开始下降。水稳定性和低温性能随钢渣掺量的增加而下降,但在钢渣集料表面经改性处理后,水稳定性得到显著提高,高温性能也有所改善。根据主要路用性能指标变化情况及规范要求,建议将钢渣掺量控制在60%,对于水稳定要求较高的路面采用有机硅树脂对钢渣进行改性处理。     

Utilization of municipal solid waste incineration ash in stone mastic asphalt mixture: Pavement performance and environmental impact

The objective of this study is to the use of municipal solid waste incinerator (MSWI) fly ash as a partial replacement of fine aggregate or mineral filler in stone matrix asphalt (SMA) mixture. For saving natural rock and reusing solid waste, basic oxygen furnace slag (BOF slag) was used as part of coarse aggregate. And this makes SMA mixtures contain more than 90% solid waste materials by mass. A comparative study of the performance of two mixes designed using superior performance asphalt pavements (SUPERPAVE) and Marshall mix design procedures was carried out in this research. Samples from both mixes were prepared at the design asphalt contents and aggregate gradations and were subjected to a comprehensive mechanical evaluation testing. These tests included Marshall stability, water sensibility, resilient modulus, fatigue life and rutting. In all the performed tests SUPERPAVE mixtures proved their superiority over Marshall mixtures. TCLP test for environmental impact indicated that asphalt is an effective stabilization and solidification agent for heavy metal in MSWI ash. The heavy metal leachates in TCLP tests have great positive correlation with their initial concentration in waste. But Ni is an exception that lower initial concentration leaded to higher cumulative leaching rate.     

排水沥青路面的材料组成及特性

结合排水性沥青路面的特点,分析了排水性沥青路面的各种组成材料在混合料中的作用,得出排水性沥青混合料的各种组成材料应有的品质。最后总结了良好的排水性沥青混合料的组成特性。     

Effect of copper slag and cement by-pass dust addition on mechanical properties of concrete

This research was undertaken to study the effect of copper slag (CS) and cement by-pass dust (CBPD) addition on concrete properties. In addition to the control mixture, two different trial mixtures were prepared using different proportions of CS and CBPD. CBPD was primarily used as an activator. One mixture consisted of 5% copper slag substitution for portland cement. The other mixture consisted of 13.5% CS, 1.5% CBPD and 85% portland cement. Three water-to-binder (w/b) ratios were studied: 0.5, 0.6 and 0.7. Concrete cubes, cylinders and prisms were prepared and tested for strength after 7 and 28 days of curing. The modulus of elasticity of these mixtures was also evaluated. Results showed that 5% copper slag substitution for portland cement gave a similar strength performance as the control mixture, especially at low w/b ratios (0.5 and 0.6). Higher copper slag (13.5%) replacement yielded lower strength values. Results also demonstrated that the use of CS and CBPD as partial replacements of portland cement has no significant effect on the modulus of elasticity of concrete, especially at small quantities substitution.     

钢渣沥青混合料疲劳性能及改善机理

采用钢渣替代部分粗集料,制备了4种钢渣掺量的沥青混合料,并对其进行不同应变水平下的四点弯曲疲劳试验,分析钢渣掺量和应变水平对混合料疲劳性能的影响,以揭示疲劳性能改善机理.结果表明:随着钢渣掺量的增加,沥青混合料疲劳寿命呈先增加后降低的趋势,峰值出现在钢渣掺量为30%(质量分数)时;钢渣沥青混合料初始劲度模量和疲劳寿命均随着应变水平的增大而降低;疲劳损伤演化过程可分为失稳、平衡、失效3个发展阶段,疲劳失效劲度模量衰减比S_r/S_(50)小于50%,并随着应变水平的增大而逐渐减小;疲劳裂纹扩展主要发生在矿料-沥青界面处,且受应变水平影响较大;钢渣的化学性质和表面构造在改善界面相结构方面起到了交互黏附和嵌入锚固作用,用钢渣作为粗集料可显著提升沥青混合料的疲劳性能.     

Utilization of steel slag as aggregates for stone mastic asphalt (SMA) mixtures

Steel slag is a byproduct making up a portion of 15–20% of iron output in an integrated steel mill. Most of them are deposited in slag storing yards and thus results in many serious environment problems in China. This paper aims to explore the feasibility of utilizing steel slag as aggregates in stone mastic asphalt (SMA) mixtures, and properties of such asphalt mixtures are evaluated as well. X-ray diffraction (XRD), scanning electron microscopy (SEM), and mercury intrusion porosimetry (MIP) were employed to study the compositions, structure and morphology of aggregates. Volume properties and pavement performances of SMA mixture with steel slag were also evaluated as compared to that with basalt as aggregates. Results indicated that volume properties of SMA mixture with steel slag satisfied the related specifications and expansion rate was below 1% after 7 days. When compared with basalt, high temperature property and the resistance to low temperature cracking of SMA mixture were improved by using steel slag as aggregate. In-service SMA pavement with steel slag also presented excellent performance on roughness and British Pendulum Number (BPN) coefficient of surface.     

排水性沥青路面在汉十高速公路养护工程中的应用

湖北省汉十高速公路管理处针对雨天路面积水而引发交通事故这一难题,率先在湖北省高速公路养护工程中提出排水性沥青路面技术,并邀请多方专家对此进行技术咨询,研究决定在汉十孝襄段K79+280～K80+500十汉向、K123+000～K122+700汉十向、K125+750～126+150.5十汉向、K151+275～K152+17十汉向四处路面积水严重路段,实施排水性沥青路面加铺方案,并对此排水性沥青路面进行了技术总结,包括路面结构设计方案、排水性沥青混合料组成设计、排水性沥青路面施工、路用性能检验及其关键环节。实际测试表明湖北汉十高速公路排水性沥青路面具有良好的路表服务特性,说明设计方案与施工工艺合理,质量可靠,性能优良,彻底解决了路面积水,确保道路安全畅通。     

高黏沥青改性剂在贵州省干线公路养护工程中的应用

以自主研发的高黏沥青改性剂PEA为研究对象,以日本进口改性剂和某国产品牌改性剂作为平行对比,分别对高黏沥青和高黏沥青混合料的性能进行分析,并铺筑排水沥青路面试验段。结果表明,掺加高黏沥青改性剂PEA制备的混合料路用性能和施工性能优良,具有较好的耐老化性。路面经现场检测,各项技术性能符合《排水沥青路面设计与施工技术细则》(征求意见稿)要求。     

外加材料对乳化沥青再生水泥稳定碎石混合料性能的影响

通过室内试验评价了水泥、消石灰和消石灰矿渣粉3种外加材料对乳化沥青再生水（泥）稳（定）碎石混合料（乳化沥青再生混合料）路用性能的影响,利用扫描电镜观察了水泥乳化沥青胶浆与水稳碎石再生集料界面的微观结构,分析了乳化沥青再生混合料的强度形成机理.结果表明：水泥对乳化沥青再生混合料劈裂强度、水稳性和疲劳寿命提高最大,消石灰矿渣粉次之,消石灰最小.乳化沥青再生混合料中除乳化沥青外,水泥或消石灰矿渣粉也具有明显的胶结材料的作用,但消石灰不具有胶结材料的作用.水泥和乳化沥青水化产生的水化产物,在提高水泥乳化沥青胶浆黏度的同时,能与再生集料上的旧水化产物直接黏结,增大乳化沥青再生混合料中水泥乳化沥青胶浆与再生集料界面的黏结强度.     

锰渣矿粉沥青混合料抗老化性能研究

通过直剪试验和劈裂试验,揭示了老化时间和锰渣代替百分比对沥青混合料抗老化性能的影响,结果表明:用锰渣矿粉代替石灰岩矿粉使沥青混合料粘聚力提高、劈裂强度增大、劲度模量降低,说明了锰渣矿粉的加入能有效的延缓沥青混合料的老化,改善和提高沥青混合料的抗老化性能。     

隧道路面钢渣沥青混合料抗滑性能衰减试验研究

利用室内加速磨耗仪模拟了隧道钢渣沥青路面的抗滑性能衰减过程,研究了钢渣沥青混合料(SSAM)在不同钢渣掺量、不同荷载和不同温度条件下的抗滑性能衰减规律,并且结合扫描电镜(SEM)及压汞(MIP)试验,分析了SSAM抗滑性能衰减过程及机理.结果表明:钢渣的掺入从衰减终值、损失率和衰减速率3个方面提高了沥青混合料的抗滑性能;SSAM抗滑性能随钢渣掺量的增加呈现先升后降趋势,在50%钢渣掺量处出现拐点;荷载对SSAM抗滑性能的影响主要表现在衰减过程的第2阶段至第5阶段,温度对SSAM抗滑性能的影响主要表现在第1阶段;钢渣集料表面纹理丰富,孔结构和孔级配更合理,从而改善了SSAM沥青膜的黏结性,提高了SSAM抗滑性能的稳定性.     

玄武岩纤维沥青胶浆及混合料的低温性能关联性

采用拉伸试验和低温弯曲试验,研究了玄武岩纤维沥青胶浆(BFAM)及混合料的低温性能,并对两者的关联性进行了分析;同时对BFAM相态变化及混合料的微观结构进行了测试与表征,深入分析了玄武岩纤维对沥青胶浆及混合料低温性能的改善机理.结果表明:BFAM与混合料的低温性能有良好的相关性,-20℃下BFAM的拉伸断裂能与混合料的弯拉应变关联性最大;基于低温性能推荐玄武岩纤维的最佳掺量为0.4%;-20℃下最佳玄武岩纤维掺量BFAM的拉伸断裂能是普通沥青胶浆的4.6倍,-10、-20℃下玄武岩纤维沥青混合料弯拉应变比普通沥青混合料分别提高了19.0%、25.0%;BFAM具有良好的低温性能和热稳定性,其玻璃化转变温度比普通沥青胶浆低3.75℃,从高弹态到黏流态转化过程中吸热量增加0.1525J/g;普通沥青混合料内部连接较薄弱,玄武岩纤维增强了沥青混合料的整体性,同时玄武岩纤维能承受和传递应力,约束裂纹的扩展,进而改善混合料的抗裂性.     

考虑集料-胶浆粘附性能的钢渣沥青混凝土体积稳定性改善研究

采用XRD分析了钢渣的矿物相特征以调整沥青胶浆的组成来增强钢渣-沥青胶浆粘附性,利用沥青胶浆包裹的钢渣集料颗粒进行水煮试验以分析钢渣-胶浆粘附作用的强弱,并开展了钢渣沥青混凝土浸水膨胀试验以确定其体积稳定性水平.试验结果表明采用钢渣粉替代传统的石灰石矿粉与沥青制备而成的胶浆与钢渣集料具有优良的粘附性能,可显著提高钢渣沥...     

冷补沥青混合料配合比设计与性能试验

论文结合内蒙地区特有的地质气候环境和交通量特点,开展冷补沥青混合料配合比材料组成设计与性能试验研究,对冷补沥青混合料工作性能、存储性能、初始强度、粘聚性、水稳性和高温性等方面进行了系统的研究。     

胶粉/SBS复合改性高模量沥青混合料性能研究

胶粉/SBS复合改性综合了橡胶沥青和SBS改性沥青的优势,能显著改善混合料的高低温性能。采用残留稳定试验、冻融劈裂试验、低温弯曲试验、车辙试验、四点弯曲疲劳试验和动态模量试验,分析胶粉/SBS复合改性高模量沥青混合料的路用性能及动态力学特性,并与硬质20#高模量沥青混合料及SBS改性沥青混合料进行对比。结果表明,胶粉/SBS复合改性高模量沥青混合料的水稳定性、高低温性能、抗疲劳性能及动态模量值更优,且各项指标满足高模量沥青混合料要求。     

掺钢渣混合料在道路工程中的应用研究

依托项目工程将掺钢渣混合料应用到路面面层与基层中,分别铺设SMA-13和AC-16钢渣沥青混合料面层试验段、水泥稳定钢渣碎石混合料和水泥粉煤灰稳定钢渣碎石混合料基层试验段,并对试验段检测指标进行研究和跟踪评价。结果表明,试验路段相关技术指标满足规范要求,运营过程中路面无明显病害,验证了掺钢渣混合料在路面面层与基层应用中的可靠性与可行性。