聚氨酯改性沥青及其混合料性能研究

通过试验研究了聚氨酯沥青胶结料的制备条件,在此基础上制备沥青混合料,研究了沥青混合料的高温性能、低温性能、水稳定性能及相关的疲劳性能和动态模量。结果表明:聚氨酯对沥青混合料的高温性能、低温性能有极大的改善作用;掺入聚氨酯有助于提高沥青混合料的抗疲劳性能,并且在一定范围内掺量越多效果越明显;但会使沥青混合料的水稳定性降低,需要掺加一定的改性剂才能抵消其负面影响。     

短期老化对桥梁无缝伸缩缝沥青胶结料的影响

通过薄膜烘箱老化试验(TFOT)模拟无缝伸缩缝沥青胶结料的高温短期老化过程,分析老化后沥青胶结料的质量损失、弹性回复率以及流变性能。试验结果表明高温老化导致沥青胶结料中轻组分挥发,低温弹性回复下降,高低温复合模量增加,但相位角变化较小,车辙因子和疲劳因子大体呈增趋势。短期老化后沥青胶结料仍表现出很好的粘弹性,有利于保持其使用性能。     

Sasobit温拌剂对橡胶沥青流变性能的影响

通过试验,从高温流变性能、低温流变性能、抗老化性能三方面,分析了Sasobit温拌剂对橡胶沥青胶结料的影响,结果表明:Sasobit温拌剂的加入对橡胶沥青的高温性能有一定的改善作用,但是会对其低温性能和抗老化性能造成不利的影响,综合考虑各项性能指标,其最优剂量选择在2.5%~3%之间。     

无缝伸缩缝沥青胶结料高温性能指标区分评价

为优选无缝伸缩缝沥青胶结料类型,提高无缝伸缩缝弹塑体高温稳定性,对选用的3种无缝伸缩缝沥青胶结料分别开展沥青基本性能试验、动态剪切温度扫描试验和多应力蠕变恢复试验,采用软化点、车辙因子与相位角,以及蠕变恢复率和不可恢复蠕变柔度等指标来评价3种无缝伸缩缝沥青胶结料的高温性能,并进行一致性和区分度分析,最后结合沥青混合料车...     

桥梁无缝伸缩缝沥青胶结料流变性能研究

利用动态剪切流变仪对桥梁无缝伸缩缝沥青胶结料进行了温度扫描试验、高温蠕变试验和低温应力松弛试验。试验结果表明,无缝伸缩缝沥青胶结料温度敏感性低,车辙因子等于1kPa时对应的温度超过120℃。适用于温带和寒带的无缝伸缩缝沥青胶结料60℃蠕变应变分别为1.68%和6.1%。无缝伸缩缝沥青胶结料低温应力松弛迅速,60s内可以松弛97%的应力,可很好地避免伸缩缝材料及伸缩缝材料与路面界面位置的应力积累,应力松弛能力可以作为评价无缝伸缩缝沥青胶结料的关键指标。     

基于BBR试验的无缝伸缩缝沥青胶结料低温性能分析

为选用适合的性能指标评价无缝伸缩缝沥青胶结料低温性能,选用SHRP计划中的弯曲流变仪(BBR)研究低温工作状态下两种新型无缝伸缩缝沥青胶结料的蠕变性能,并结合材料力学性能通过编程方法获得胶结料的应力松弛性能。试验结果显示,相比于传统低温性能指标,BBR试验指标能够极大程度减少由于高粘弹沥青性能带来的制模等误差,测试结果更准确、合理。     

冻融地区汽车试验场沥青混合料配合比设计技术研究

文章主要通过一汽-大众汽车试验场东北冻融地区的沥青路面沥青混合料配合比设计工作进行研究,重点就寒冷地区的沥青种类确定、沥青混凝土路用性能来进行沥青混合料配合比设计研究。通过实地采集路面内部温度及分布特性,基于PG分级的沥青胶结料的选择,重点研究了沥青胶结料性能及沥青高温和低温性能特点;通过对不同级配分别进行TSRST试验,确定冻断温度和冻断强度等级,作为配合比设计作为判定依据之一,从而实现使设计的沥青混合料配合比更好的适应寒冷地区反复冻融的道路应用环境。     

特立尼达湖改性沥青性能研究

特立尼达湖沥青(TLA沥青)是世界著名的天然沥青,技术性能指标非常稳定.对基质沥青和TLA改性沥青的常规性能和流变性能进行分析.采用动态剪切流变仪(DSR)进行温度扫描和频率扫描试验,以评价沥青胶结料的流变性能;采用蠕变试验评价其抵抗变形的恢复能力.试验结果表明,TLA改性沥青较基质沥青有更好的高温性能,且TLA沥青掺量对沥青胶结料的性能有重要影响.     

废旧橡塑改性沥青及混合料的技术性能研究

利用自主研发的废旧橡胶塑料复合改性剂制备了废旧橡塑改性沥青,通过室内试验评价了废旧橡塑改性沥青的技术性能.在此基础上,以废旧橡塑改性沥青作为胶结料制备了AC-13型沥青混合料,测试了其高温性能、低温性能、水稳定性和疲劳性能,并与山东省常用的SBS改性沥青和橡胶改性沥青技术性能进行了对比.结果表明:废旧橡塑改性沥青及其沥青混合料具有高温稳定性和水稳定性优势,低温性能介于橡胶改性沥青和SBS改性沥青之间,疲劳性能接近SBS改性沥青.利用废旧橡胶和废旧塑料的各自优势对沥青进行复合改性,在提高沥青混合料路用性能方面具有发展潜力.     

橡胶沥青混合料高温性能评价指标的试验研究

以国内道路工程中常用的基质沥青与橡胶粉拌制橡胶沥青混合料,然后通过大量室内车辙试验对橡胶沥青混合料动稳定度与橡胶沥青胶结料177℃旋转黏度、软化点、针入度之间的相关性进行研究.结果表明:橡胶沥青混合料动稳定度与胶结料177℃旋转黏度及软化点之间相关性良好,胶结料177℃旋转黏度及软化点可以作为橡胶沥青混合料高温性能的评价指标.美国评价标准(ASTM D 6144—97)中177℃旋转黏度与软化点值偏低,如按该标准进行胶结料的质量控制,沥青混合料动稳定度可能难以满足国内关于聚合物改性沥青规范(JTJ F40—2004)的要求,故在室内试验的基础上,结合国内实际工程的经验,提出了橡胶沥青混合料高温性能评价指标值.橡胶沥青混合料高温性能受到不同性质橡胶粉的影响很大.     

Effect of different high viscosity modifiers on rheological properties of high viscosity asphalt

High viscosity asphalt (HVA) has been a great success as a drainage pavement material. However, the larger porosity of drainage asphalt mixtures weakens the cohesion and adhesion and leads to premature rutting, water damage, spalling and cracking. The purpose of this study was to investigate the rheological properties of HVA prepared using different high viscosity modifiers through conventional tests, Brookfield viscosity tests, dynamic shear rheometer tests and bending beam rheometer tests. The conventional performance results demonstrated SBS + rubber asphalt (SRA-1/2) exhibited excellent elastic recovery and low-temperature flexibility. The 60°C dynamic viscosity results indicated TPS + rubber asphalt (TRA) had the excellent adhesion. The rotational viscosity results and rheological results indicated that SRA-2 not only exhibited excellent temperature stability and workability, as well as excellent resistance to deformation and rutting resistance, but also exhibited excellent low-temperature cracking resistance and relaxation performance. Based on rheological results, the PG classification of HVA was 16% rubber + asphalt for PG76-22, 20% rubber + asphalt for PG88-22, TRA and SRA-1/2 for PG88-28. From comprehensive evaluation of the viscosity, temperature stability and sensitivity, as well as high/low temperature performance of HVA, SRA-2 was found to be more suited to the requirements of drainage asphalt pavement materials.     

添加不同改性剂的沥青混合料低温性能试验

针对沥青混合料的低温问题,选取约束试件温度应力试验和TPS,湖沥青及Sasobit三种改性剂进行了沥青混合料的低温性能试验,通过试验结果可知,TPS对低温性能的改善最好,其次是Sasobit,湖沥青最差。     

环保型脲醛胶粘剂及其人造板的制备与研究

研究了脲醛树脂胶粘剂的改性及制板工艺对脲醛胶人造板甲醛释放量的影响。脲醛胶的改性方法主要涉及采用脱水工艺和加入聚乙烯醇、三聚氰胺、羟基丙烯酸酯乳液改性剂;人造板的制备工艺主要涉及胶粘剂种类和制板工艺条件。研究表明,加入改性剂及采用脱水工艺不仅能降低脲醛胶的游离甲醛含量,并且粘合强度也得到相应的提高;使用改性脲醛胶粘剂可以明显降低人造板的甲醛释放量;制板工艺中,延长预压时间和热压时间都能够有效地降低人造板的甲醛释放量;提高热压温度时,甲醛释放量呈现先减小后增大的变化趋势。还对脲醛树脂的分子结构进行了分析研究。     

TPS高粘度改性沥青在OGFC路面中的应用研究

介绍了排水性沥青混合料结合料的发展与现状,对TPS改性沥青的性能作了评价,就TPS在降噪排水路面中的应用进行了研究,研究表明,使用TPS高粘度改性沥青可以很好地满足OGFC排水性沥青路面的路用性能要求。     

Duroflex~沥青混合料改性剂路用性能研究

Duroflex是引进德国的沥青混合料添加剂,主要成分为聚合物弹性体和纤维。在沥青中加入这种添加剂,可使基质沥青高温稳定性、低温抗裂性和抗老化性提高,与SBS类改性剂比较,具有节能减排的特点。经对上海浦东航津路工程实践,确定了热料仓各档集料和矿粉比例,最佳沥青用量(5.6%)、木质纤维素用量(0.30%)和Duroflex添加剂用量(0.80%);施工后,体会到动稳定大幅度提高,施工和易性也非常好。     

低温自粘橡胶沥青防水卷材的研制

通过分析沥青、改性剂、增粘剂、助剂等对改性沥青粘结力、剥离力、柔度、耐热度等主要性能的影响，设计了低温下具有自粘性能的改性沥青配方。按此配方制备的改性沥青在低温下具有优良的自粘及综合性能。     

高黏改性沥青高温黏弹特性指标区分度分析

为得到能准确区分高黏改性沥青高温性能的评价指标,分别对3种高黏改性沥青(高黏改性剂掺量均为12%)及基质沥青进行滞后环、动态剪切流变(DSR)和软化点等试验,并采用沥青混合料车辙试验进行了验证,基于沥青混合料试验结果对3种高黏改性沥青的高温性能评价指标作了一致性和区分度分析.结果表明:3种高黏改性剂的掺入均可提高基质沥青的黏弹特性和高温性能,但改性效果不同;不同高温评价指标基本能对3种高黏改性沥青的高温性能做出一致性评价,但区分能力不同,其中滞后环试验技术指标和Carreau模型拟合的零剪切黏度(ZSV)值区分度和评价效果最好,而车辙因子和软化点较差.     

轻烧白云石轻质墙体材料的研究

将白云石在合理的温度和时间下煅烧 ,以煅烧后的白云粉为主要原材料 ,配以调和剂以及各种外加剂、活性改性材料 ,在常温常压条件下自然养护 ,制成轻质内墙砌块、陶粒空心砌块及玉米秸轻质隔墙板。具有生产工艺简单、投资小、成本低廉、轻质高强等优点     

Using transient plane source sensor for determination of thermal properties of vacuum insulation panels

The energy use in buildings has to be decreased to reach the targets and regulations in the European Union. One way of reducing the energy demand is to use vacuum insulation panels (VIP) in the building envelope. To make sure the declared thermal properties of the VIP are valid for the mounted panels, in situ measurements are needed. The transient plane source (TPS) method allows fast measurement of the thermal properties of a variety of materials. However, the large anisotropy of the VIP makes it hard to interpret the temperature increase in the TPS sensor. This paper presents a comparison between an analytical solution, numerical simulations and TPS measurements of polystyrene and polystyrene with aluminum film. Polystyrene and aluminum were used instead of VIP to increase the number of setups. The numerical simulation model was validated by comparing the simulated temperature increase with an analytical solution for the polystyrene sample. The simulated temperature increase in the polystyrene sample after 40 s was 7.8% higher than the TPS measurements. For the case with polystyrene with aluminum film, the deviation was 5.7%. Losses in the wires of the TPS sensor, uncertainties regarding the material parameters and surface resistances could explain the deviations.     

Characterization of carbon dioxide leakage process along faults in the laboratory

It is important to understand the process of multiphase carbon dioxide (CO₂) leakage in faults for the risk assessment of carbon capture and storage (CCS). To quantitatively characterize the CO₂ leakage process in the fault, pressure sensors, fiber Bragg grating (FBG) temperature and strain sensors were simultaneously used to monitor CO₂ leakage in the fault. Ten experiments were carried out, including five groups of gaseous CO₂ leakage tests with initial pressures of 1–5 MPa and five groups of liquid CO₂ leakage tests with initial pressures of 6–10 MPa. The results indicate that when liquid CO₂ leaked with an initial pressure of 7–10 MPa, the pressure and temperature of CO₂ dropped rapidly in the first few seconds and then remained unchanged. The behavior that CO₂ continues to leak while maintaining temperature and pressure unchanged is defined as “temporary pseudo-sealing (TPS)” behavior, which continues for the first 1/3 of the leakage period. However, this TPS behavior did not occur in gaseous CO₂ leakage. If only the pressure and temperature data were used to evaluate whether CO₂ leakage occurred, we would misjudge the risk of leakage in CCS projects during the TPS period. The causes and conditions of TPS behavior were further studied experimentally. The results show that: (1) TPS behavior is caused by the phase transition energy generated when liquid CO₂ leaks. (2) The condition for TPS behavior is a small leak aperture (0.2 mm). Only a small leakage rate can make the phase transition energy and pressure change from a dynamic equilibrium, and (3) The compression zone caused by the Bernoulli effect and fault “barrier” could reduce the CO₂ leakage rate and further promote the occurrence of TPS behavior. This study provides technical and theoretical support for the quantitative characterization of the CO₂ leakage process in faults of CCS projects.