Development Of Tunnel Smoke Suppression Asphalt And Research On Road Performance Of Smoke Suppression Asphalt Mixture

Based on the current widespread concern of the whole society on the atmosphericpollution and human health，and the majority of experts and scholars in the highwaysystem are also be eyeing the remediation of highway and highway tunnel constructionenvironment，and especially concerning on the remediation and prevention of theasphalt smoke release during the construction of highway tunnel asphalt pavement.Therefore, this study summarized research status at home and abroad, and developed anasphalt smoke suppression modifier which is efficient, economy and shows no sideeffects on asphalt mixture road performance，and provided a technical support oncreating a low-carbon, environmental friendly construction environment and protectingthe health of employees. This study followed social hot spots, and launched the study ondevelopment of tunnel smoke suppression asphalt and research on road performance ofsmoke suppression asphalt mixture. This study has some theoretical significance andpractical values, and its research and development has made great progress. This studyyielded the following main results:1. This study solved the problem of poor compatibility which shows in asphaltand smoke suppression modifier. This study proposed a method of SurfaceModification Treatment (SMT) as preparing modified asphalt which shows smokesuppression effect. We used KH550silane coupling agents as the bridge which canconnect non-polar molecules with polar molecules. After using infrared spectrometer,Electron microscopy scanner and Fluorescence microscope, we found that the smokesuppression modifier after SMT can effectively overcome the stratification andsegregation in the asphalt. SMT effectively solved the problem of poor compatibilitywhich shows in asphalt and smoke suppression modifier. This method provided atechnical support for showing effect of smoke suppressant and guaranteeing asphaltmixture road performance.2. We improved the evaluation on smoke suppression performance. Referring tothe detection method of asphalt smoke concentration,which shows in <occupationalexposure limit for petroleum asphalt (fume) in the air of workplace>（GB18553-2001）,we noted the limitations of existing UV spectrophotometry, which includes the data issingle and the accuracy is not high. This study Introduced the turbidity method (TM)and the laser particle size distribution method (LPSD) based on UV spectrophotometry，and determined three indicators that can evaluate smoke suppression performance： Asphalt smoke (pyridine) concentration in the air、Asphalt smoke (particulate matter)concentrations in the air、Cumulative percentage of fine particles PM2.5。Smokesuppression performance can be achieved on a more comprehensive evaluation bycomparing the three indicators. And these indicators can provide the technical supportfor screening smoke suppressant modifier.3. This study completed the development of new asphalt smokesuppression modifier.This study summarized the technology of asphalt smokesuppression at home and abroad and referred to related fields about the smokesuppression technology. Based on the warm mix smoke suppression technology，wedetermined130℃as the best testing temperature，referring to the analysis about therelationship between asphalt smoke concentration with temperature. By analysisingasphalt technology index and smoke suppression performance between Sasobit warmmix agent and EvothermTM3G agent, we found EvothermTM3G warm mix agentshowed excellent smoke suppression performance, and had no side effects on thetechnical performance of asphalt, and its best dosage is3‰; We also used asphalt flameand smoke suppression technology and smoke suppression technology of high polymermaterials. Through comparing the smoke suppression performance of14alternative smoke suppression modifier，we used4%Al(OH)3and3%MOO3as theobjects to be re-allocated EvothermTM3G; Through the evaluation on smoke suppressionperformance of the complex-type smoke suppression modifier、technical performance ofthe complex-type smoke suppression modified asphalt and economic analysis, wedetermined the3‰EvothermTM3G+4%Al(OH)3as the new asphalt smoke suppressionmodifier.4. We completed road performance detection of SMA-13which doped with3‰EvothermTM3G+4%Al(OH)3. Firstly, we completed the design of mix proportion,and it met the regulatory requirements. Secondly, smoke suppression mixture SMA-13and conventional mixture SMA-13are used to comparative experimental researcheswhich includes high temperature stability、low temperature crack resistance and waterstability. We found smoke suppression mixture SMA-13improved its high temperaturestability, and its low temperature crack resistance and water stability showed smallmagnitude lower than conventional mixture SMA-13, but all the indicators can meet thespecification requirements.`5. Lastly, we completed the evaluation on the new smokesuppression technology through practical engineering. Relying on Chongqing Jiu Long tunnel emergency rescue renovation project, we used smoke suppression modifier[3‰EvothermTM3G+4%Al (OH)3] in the preparation process of SMA-13that is used astop layer, and compared the asphalt smoke concentration which is released during thesmoke suppression mixture SMA-13and following layer conventional asphalt mixtureAC-20are paved. We found that the asphalt smoke concentration of smoke suppressionasphalt mixture SMA-13was significantly lower than the conventional asphalt mixtureAC-20. Through smoke suppression effect analysis, we use the new smoke suppressionmodifier [3‰EvothermTM3G+4%Al(OH)3]under the specified temperature range ofconstruction. It can play an important role in the smoke suppression performance, so thesmoke suppression modifier [3‰EvothermTM3G+4%Al(OH)3] has some practicalvalues.