Investigation On The Preparation And Properties Of SBS/CNTs Modified Asphalt Sealant

The damage and the poor maintenance of the pavement restrict the development of asphalt pavement,which undertakes an important role in road engineering.Crack,one of the common pavement damage types,causes a decline in the bearing capacity and driving safety.And the more serious damage will occur without suitable maintenance on the crack.The utilization of sealant is an effective method to fill cracks.Accordingly,the sealant performance has a close relationship with the road maintenance life after construction.Hence,it is significant to search for a sealant with excellent performance.The current research is summarized and concluded that the problems such as complex preparation processes and easy thermal aging exist in the current sealant research.Accordingly,the asphalt as the base material,carbon nanotubes(CNTs),and styrene-butadiene-styrene(SBS)as modifiers were used to prepare SBS/CNTs modified asphalt sealant in this paper.First of all,the performance of the sealant was evaluated through orthogonal experiments with the different preparation processes and additives dosages.The softening point,penetration,elastic recovery rate,and flow value of the sealant were selected as criteria to determine the preparation processes and additive dosages of SBS/CNTs modified asphalt sealant.After the preparation of SBS/CNTs modified asphalt sealant,the rheological properties,the anti-fatigue properties,the anti-aging properties,and the self-healing properties were evaluated with the prepared sealants in this paper and two types of commercial sealants.The rheological properties were evaluated with the multi-temperature frequency sweep test and low-temperature shear relaxation test.The multi-stress creep recovery(MSCR)test and molecular dynamic simulation were utilized to evaluate the anti-aging properties of the aged sealants.The linear amplitude sweep(LAS)test and linear amplitude sweep heal(LASH)test were performed to appraise the anti-fatigue properties and self-healing properties.After these experiments,the reference for applying to engineering is proposed eventually.It can be demonstrated from the above experiments that the frequency sensitivity of the SBS/CNTs modified asphalt sealant is lower than that of the commercial 1# sealant,and the addition of carbon nanotubes(CNTs)reduces the temperature-sensitivity of the sealant in the low temperature(high frequency)region.The recommended construction temperature range of the sealant is 170℃～190℃ from the viscosity-temperature curve.The non-recoverable creep compliance decreases and the creep recovery rate R increases,which is due to the hardening effect of sealant after aging,the bulk modulus of the sealant system increases either after aging.And the aggregation degree of the sealant system is improved by the addition of CNTs.CS-0.5 sealant shows a better fatigue resistance and fatigue healing performance at20 ℃,and CS-1 sealant displays a better fatigue healing when the temperature is 60 ℃.In a conclusion,the requirements of the specification can be satisfied with the SBS/CNTs modified sealant prepared in this paper,which possessed excellent anti-aging and anti-fatigue properties compared with the commercial sealants.