沥青阻燃剂的应用研究进展

沥青作为一种优质路用材料广泛应用于公路工程中,但沥青的易燃性使其需要经过阻燃处理才可实现在隧道等特殊路面铺装工程中的安全应用。基于此,沥青阻燃剂的开发与应用对于沥青阻燃性能的改善具有重要意义。综述了国内外沥青阻燃剂的研究进展,介绍了各类沥青阻燃剂的性质特点、阻燃机理和阻燃效果,简述了沥青阻燃荆的最新研究动态,展望了沥青阻燃剂的发展趋势。     

阻燃改性沥青疲劳与自愈合性能研究

将氢氧化镁、红磷和十溴二苯乙烷分别均匀混入SBS改性沥青中制备阻燃沥青,利用红外光谱分析仪探究阻燃剂与沥青的化学反应情况,然后通过室内试验分析阻燃剂掺量对沥青基本性能和阻燃性能的影响,最后通过基于动态剪切流变仪(DSR)的疲劳-愈合-疲劳试验研究了阻燃剂和愈合温度对沥青疲劳与自愈合性能的影响规律。结果表明:红外光谱分析结果表明阻燃剂与沥青之间没有发生明显的化学反应;阻燃剂虽然提高了沥青材料的阻燃性能,但是降低了沥青的施工和易性和存储稳定性;随阻燃剂掺量增加,沥青的疲劳与自愈合性能先升高后降低,存在最佳阻燃剂掺量;在不同愈合温度下,适量阻燃剂均能提高SBS改性沥青的疲劳与自愈合性能。     

阻燃沥青的制备及性能研究

利用氢氧化铝、氢氧化镁制备了阻燃沥青，通过沥青三大指标评价了阻燃剂对沥青物理性能的影响，并利用SHRP试验及热分析方法对阻燃沥青高温、低温性能及阻燃机理进行了研究。结果表明：阻燃剂的加入可以提高沥青的粘性，提高其抗高温性能；在掺量为15％左右时可以提高沥青抗低温开裂的能力；无机阻燃剂能有效减少沥青的热解数量，有利于减少有毒气体的生成，起到良好的阻燃效果。     

水热反应法制备Mg(OH)_2阻燃剂及其对沥青阻燃性能的影响

以自制的聚氨酯乳液为分散剂,以氢氧化钠(NaOH)和氯化镁(MgCl_2·6H_2O)为原料,采用水热法制备了纳米片状氢氧化镁,研究了不同反应温度、浓度以及分散剂对材料形貌和晶体结构的影响,结果表明在氢氧化钠(NaOH)和氯化镁(MgCl_2·6H_20)物质的量比为3.6:1.0,聚氨酯乳液添加量为5%,反应温度为110℃条件下,能制备出片层厚度为30.5 nm的二维纳米氢氧化镁材料。进一步以所制备的氢氧化镁进行填充改性沥青,测试了不同阻燃剂掺量下阻燃沥青的物理性能和阻燃性能,研究了Mg(OH)_2阻燃剂对沥青阻燃性能的影响。结果表明,Mg(OH)_2阻燃剂掺量低于10%时,阻燃沥青性能满足聚合物改性沥青I-D技术要求,且随着Mg(OH)_2阻燃剂掺量的增加,阻燃沥青软化点增加,针入度和延度减小,同时Mg(OH)_2阻燃剂掺量为10%时,氧指数为24.5%,具有一定的阻燃效果,但并不显著;在Mg(OH)_2阻燃剂8%掺量下,加入5%十溴二苯乙烷后阻燃沥青氧指数达到27.8%,加入8%十溴二苯乙烷后氧指数达到29.5%,均可获得自行熄灭的阻燃效果,同时采用DSC、红外—热重联用对掺加Mg(OH)_2和十溴二苯乙烷的阻燃沥青的结构和性能进行分析,发现加入Mg(OH)_2可以显著提高沥青的热性能,研究表明,加入少量溴系阻燃剂可显著提高沥青的热稳定性,并改善Mg(OH)_2与沥青的相容性,从而获得较好溴系协效的效果。     

环保型SBS改性阻燃沥青性能研究

采用氧指数测定法、动态剪切流变实验、弯曲梁流变实验和DSC-TG实验、扫描电镜(SEM)手段研究了环保型SBS改性阻燃沥青的性能;通过研究环保型阻燃剂对SBS改性沥青阻燃性能、物理性能、135 ℃运动黏度和高低温流变性能的影响确定了环保型阻燃剂的加入量;检测了环保型SBS改性阻燃沥青的环保性能。结果表明,环保型SBS改性阻燃沥青具有良好的阻燃性能、物理性能、热储存稳定性及环保性能,环保型阻燃剂可以提高SBS改性沥青的高温性能,但会影响低温性能;环保型阻燃剂的加入可以提高SBS改性沥青的热分解温度和开始燃烧温度,并且在沥青燃烧时可以减少烟密度及有毒烟气的释放。     

阻燃沥青混合料的配合比研究

隧道沥青路面在使用过程中,一旦发生交通事故引起路面着火,后果不堪设想。故在长隧道沥青路面表面层铺装过程中,有必要应用阻燃剂来提高基质沥青的阻燃性能,从而达到隧道路面阻燃的效果。应用AC-16密集配以及两种阻燃剂（海川和路安特）对阻燃沥青混合料的配合比试验以及路用性能进行探讨。提出了在进行隧道阻燃沥青混合料的配合比设计过程中,必须参照沥青路面的路用性能以及阻燃剂的阻燃性能综合比选。     

阻燃沥青的研究进展与建议

介绍了对沥青进行阻燃处理的必要性、沥青的阻燃机理、常用阻燃剂的特性及其作用模式;参照塑料材料阻燃性能的测试手段介绍了常用的沥青材料阻燃性能的测试方法;最后分析了我国沥青阻燃的研究现状,指出了该领域存在的主要问题,并给出了相应的建议。     

军用聚氨酯硬质泡沫迷彩伪装材料阻燃剂的研究

为提高军用聚氨酯硬质泡沫迷彩伪装材料的阻燃性能．对各种阻燃剂进行了筛选并进行正交复配试验，确定了复配阻燃剂的最佳配方。考察了复配阻燃剂对材料阻燃性能和伪装性能的影响。在不影响材料伪装性能的基础上，制得了氧指数在34以上的高阻燃性聚氨酯硬质泡沫。     

SQA阻燃剂的合成及应用研究

本课题通过对双氰胺甲醛树脂(简称SQA)的合成研究，制得了阻燃性能良好的阻燃剂。通过测试氧指数，研究了阻燃剂浓度对阻燃性能的影响。实验结果表明，该阻燃剂是一种阻燃性能良好的聚合物。     

氢氧化铝阻燃剂的表面改性及其在软质聚氯乙烯中的应用

采用不同的表面改性剂对氢氧化铝进行湿法表面改性处理,研究了氢氧化铝阻燃剂对软质聚氯乙烯(PVC)体系的阻燃性能和机械力学性能的影响,同时考察了阻燃协效剂对软质PVC体系的阻燃性能和机械力学性能的影响。结果表明:最佳的表面改性剂为硬脂酸钠,氢氧化铝阻燃剂的添加量为60g/g时体系的综合性能较好。加入阻燃协效剂后,体系的阻燃性能有大幅度的提高。     

Study on Properties of Flame Retardant Asphalt for Tunnel

Abstract

The flame flame-retardant asphalt for a tunnel containing various kinds of flame retardants including decabromodiphenyl oxide (DBDPO), decabromodiphenyl ethane (DBDPE), Sb₂O₃, ZnBO₃, Mg(OH)₂, and Al(OH)₃ under different additive concentrations was studied. To improve the properties of asphalt changed by adding the flame retardants, a smoking inhibitor and blender were used and the effect on the properties was investigated. Finally, the styrene butadiene rubber (SBR) modifier was added to the asphalt in order to increase the ductility. Asphalt with both good flame retardancy retardance and paving properties was prepared successfully to meet two demands as flame-retardant materials and road materials at the same time.     

CHANGES IN ASPHALT CHEMISTRY AND DURABILITY DURING OXIDATION AND POLYMER MODIFICATION

The Gulf Countries' environmental conditions are very severe. The temperature zoning study indicate that more than half of Gulf areas experience a maximum seven consecutive days pavement temperature of 76°C (Al-Abdul Wahhab et al., 1997). This has resulted in damage to the road networks in the form of cracking, rutting and deformation. Polymer modification of asphalt is required to increase the resistance to permanent deformation at relatively high temperatures without adversely affecting the properties of the asphalts at low temperature. In this work chemical and performance-related properties of fresh, oxidized, and polymer modified asphalts were evaluated. The physical properties and performance characteristics of asphalts were found to depend on the chemical composition of asphalt. The interactions of polar functionalities actually present or formed during oxidative aging or due to polymer modification, influence the viscosity and related flow properties. The changes in composition of fresh, oxidized and polymer-modified asphalts can be clearly identified from Infrared spectroscopy. NMR spectroscopy enables detailed information about the Carbon-and-hydrogen-types and average molecular/structural parameters of asphalt without separating it into different components.     

CHANGES IN ASPHALT CHEMISTRY AND DURABILITY DURING OXIDATION AND POLYMER MODIFICATION

The Gulf Countries' environmental conditions are very severe. The temperature zoning study indicate that more than half of Gulf areas experience a maximum seven consecutive days pavement temperature of 76°C (Al-Abdul Wahhab et al., 1997). This has resulted in damage to the road networks in the form of cracking, rutting and deformation. Polymer modification of asphalt is required to increase the resistance to permanent deformation at relatively high temperatures without adversely affecting the properties of the asphalts at low temperature. In this work chemical and performance-related properties of fresh, oxidized, and polymer modified asphalts were evaluated. The physical properties and performance characteristics of asphalts were found to depend on the chemical composition of asphalt. The interactions of polar functionalities actually present or formed during oxidative aging or due to polymer modification, influence the viscosity and related flow properties. The changes in composition of fresh, oxidized and polymer-modified asphalts can be clearly identified from Infrared spectroscopy. NMR spectroscopy enables detailed information about the Carbon-and-hydrogen-types and average molecular/structural parameters of asphalt without separating it into different components.     

STUDY ON THE PREPARATION OF ASPHALT WITH SPECIAL USES FROM CHINESE TAR SANDS

Tar sand heavy oil ( TSHO ) was extracted from Xinjiang Xiaoxigou and Fengcheng tar sands. The basic properties of the TSHO were investigated. It is found that the TSHOs are not suitable to produce paving asphalt. However, some asphalt products with special uses were prepared from the TSHOs. The results show that Xiaoxigou TSHO can be used to produce anticorrosion asphalt for pipeline. Fengcheng TSHO, blended with kramai vacuum residuum and Gudao vacuum residuum, can be used to produce painting and polishing asphalt. The influence of the blending asphalt's SARA compositions on their qualities was also investigated.     

道路石油沥青中蜡对沥青性质的影响

测定了大庆和辽河１００号道路石油沥青中蜡的分布,并将其中的饱和蜡,芳香蜡,总蜡分离出来,用其与脱蜡沥青调制成蜡含量不同的系列样品,考察了饱和蜡,芳香蜡对沥青物理性质的影响,总蜡对沥青路用性能的影响,对沥青质量指标中否应设置蜡含量指标进行了讨论．     

阻燃沥青主要性能研究

采用石油沥青及阻燃添加剂等为基础原料，研制出用于公路火灾易发路段及隧道路面的阻燃沥青铺筑材料。其常规性能符合GB／T15180规定的技术要求，阻燃性能极限氧指数满足GB2406规定的技术要求。采用不同温度下三点针入度回归计算，考察了阻燃沥青的使用性能，并与国内外几种典型道路沥青的使用性能进行了比较。结果表明，该沥青不仅具有良好的阻燃性能而且还具有良好的感温性能、高温稳定性、低温抗裂性以及较大的粘弹区间，能够满足铺装隧道路面的性能要求。     

化学法改性克拉玛依沥青研究

针对克拉玛依沥青难以改性，产品稳定性差等问题，本研究采用化学改性法，对比分析了4种基质沥青在改性前后的元素组成、红外光谱、族组成、分子量的变化以及SBS改性沥青的常规性质的差异。结果表明：相对于物理改性，化学改性不仅显著降低了SBS改性沥青的反应温度，而且还提高了SBS改性沥青的高温性能。     

Preparation and evaluation of 30# hard grade asphalt

The preparation and evaluation of 30# hard grade asphalt by blending softening point hard deoil asphalt with several soft components were investigated. The results showed that the properties and proportions of blending soft components had a great influence on the properties of 30# asphalt. Chunfeng 70# asphalt and Maoming deoil asphalt were more suitable as blending soft components and their blended asphalt met the technical requirements of GB/T 15180-2010 when the proportion of hard deoil asphalt were 6–12% and 8–16%, respectively. PG grade results indicated that dynamic modulus of 30# asphalts at high temperature increased significantly, and antirutting ability was also improved notably, while the bending resistant ability at low temperature was slightly inferior to the high-grade asphalt. The results of mix performance tests showed that 30# hard grade asphalt had excellent anti–high-temperature deformation ability and preferable water stability compared with high-grade asphalts.     

USE OF THE ENVIRONMENTAL SCANNING ELECTRON MICROSCOPE TO INVESTIGATE THREE POLYMER MODIFIED ASPHALTS

ABSTRACT

Polymer modified asphalts present an opportunity to enhance the properties of asphalt concrete for road building where conventional asphalts are not appropriate. In this field, researchers have proposed different kinds of chemical and physical techniques to define the properties of these materials. At the same time, microscopic techniques were being developed to visualize the microstructure of the asphalt. In this paper another microscopic technique using Environmental Scanning Electron Microscopy (ESEM) to investigate the morphological structures of neat polymers and commercial polymer modified asphalts is presented. Samples examined present different kinds of morphology easily observable by ESEM. The two commercial polymer modified asphalts show numerous differences, but after heat treatment they lost their macrostructure.     

A STUDY OF LOW TEMPERATURE HARDENING ON THIN FILM ASPHALT BINDER IN CONTACT WITH AGGREGATE SURFACE

The interaction between asphalt and aggregate surfaces before and after low temperature storage (reversible and/or irreversible) at various film thickness was investigated by means of the sliding plate geometry with standard Pyrex glass plates and machined aggregate plates. Significant differences in behavior of asphalts in contact with aggregate plates have been observed, especially at low shear rates. One asphalt shows substantial aggregate surface-induced structuring while another shows essentially none. Moreover, the study of the film thickness effect on the rheological properties of asphalt binders and asphalt aggregate mixtures show that thin films of asphalts on an aggregate surfaces have substantially changed rheological properties from bulk asphalt properties and further, physical properties in thin films are not easily predicted from bulk properties. In addition, the study of storage and setting in thin films of asphalts on aggregate surfaces indicates that oxidative aging occurred after long-term storage (5 months) at room temperature of 25°C. Infrared spectroscopic analytical results on asphalt binders show that sulfoxide and ketone form during storage. It is interesting to note that the molecular structuring effect in asphalt-aggregate mixtures could be partially eliminated by heating to a temperature above 100°C for a short period of time (20 seconds). The results also show that the aggregate surface-induced structuring as well as the asphalt composition contribute to the long-term storage hardening of asphalt-aggregate mixtures at low temperature.