Study On Cross-linked Modified Asphalt Waterproof Membrane

Asphalt waterproofing membrane is mainly composed of styrene-butadiene-styrene block copolymer(SBS)modified asphalt as the intrusion layer,polyester fiber as the base,eutectic,infiltration,molding,curling,etc.A waterproof material processed in the process.Although the SBS modified asphalt waterproofing membrane has good resistance to high and low temperature,fatigue resistance,puncture resistance and tear resistance,it has the problems of poor heat-resistant oxygen aging performance and salt-alkali corrosion resistance.The more important problem is that the processing temperature of SBS modified asphalt is relatively high,it takes a long time to completely melt,and the production energy of waterproof coiled material is large.In this paper,the following researches have been carried out on the above problems of SBS modified bitumen waterproofing membrane:Firstly,the effects of SBS content on the penetration,softening point,storage stability,ductility,elastic recovery rate and high and low temperature resistance of SBS asphalt waterproofing membrane were systematically studied.The results show that with the increase of SBS content,the high and low temperature resistance of SBS asphalt waterproofing membrane is obviously improved.The SBS content ≥9 parts can meet the requirements of type I modified asphalt waterproofing membrane,and 9 parts are selected from the cost consideration.SBS is used as a modified asphalt base formula for subsequent cross-linking and salt-tolerant modification research.SBS asphalt was cross-linked with sulfur powder,dicumyl peroxide(DCP),di-tert-butylperoxyisopropylbenzene(BIPB)and bis-five vulcanizing agent(BPDH).The experimental results show that:With the increase of the content of cross-linking agent,the softening point of SBS asphalt waterproofing membrane is increasing,the high temperature resistance is obviously improved;the penetration and ductility are reduced,and when the content of cross-linking agent is too much,the whole of the coil becomes hard and low temperature resistant.Sexual deterioration.When the content of sulfur powder is 0.4 parts,the comprehensive performance is excellent;when the content of DCP and BIPB is 0.4 parts,respectively,the comprehensive performance of SBS asphalt waterproofing membrane is better.The effects of sodium dihydrogen phosphate/dipotassium hydrogen phosphate and ultrafine silicon micropowder on the salt and alkali resistance of SBS asphalt waterproofing membrane were studied.The salt-tolerant alkali test shows that the SBS asphalt waterproofing membrane modified by sodium dihydrogen phosphate/dipotassium hydrogen phosphate and ultrafine silicon micropowder can reach the salt and alkali resistance index.In order to solve the problem of long preparation process and high energy consumption of SBS asphalt waterproofing membrane,try to replace SBS with polypropylene(PP),random polypropylene(APP),chlorinated polyethylene(CPE)and ethylene vinyl acetate(EVA).The asphalt is modified.The results show that:PP and APP modified bitumen waterproofing membrane can effectively improve the high temperature resistance of the coil,and the processing temperature is relatively low,but the low temperature resistance is poor;the high temperature resistance of EVA modified asphalt waterproofing membrane Poor,can not effectively replace SBS.Using CPE instead of SBS,the heating temperature is 150℃,the time is 1 h,the prepared coil can meet the requirements of conventional use.