The Construction Technology Of High-Modulus Asphalt Concrete Base

Combined with conditions of Africa, in Ethiopia’s national AA highway pavement structure design, adopted high modulus asphalt concrete base, through the following four steps:The first step:the choice of high modulus additives. Based on 10 kinds of different high modulus agents at home and abroad were reviewed and the optimum proportion of Marshall experiment results and the standard of rutting test and freeze-thaw splitting test, splitting test, uniaxial compressive modulus of resilience test and construction performance evaluation and so on carries on the analysis comparison, determine the thick venerable Beijing NZ agent of high modulus modulus agent, the ministry of communications, France PR MOUDLE high modulus, high modulus poly, qingchuan rock asphalt agent in jiangsu all the indicators meet the objective. Reach according to the dynamic modulus of SPT test again to add high modulus dose of RA, the PRM after asphalt mixture in 45℃ and 55℃ dynamic modulus, high temperature resistance of the asphalt and the rutting resistance are far higher than that of ordinary asphalt mixture, the final project selected the French also agent of high modulus as the additive of high modulus asphalt concrete base.Step 2:research on mixture ratio design of high modulus asphalt mixture. Mixture ratio of raw materials produced by AA highway K7+800 yard of basalt, limestone ore powder and Iran from 40～50# as Ethiopia AA highway asphalt mixture ratio design, on the base of the high modulus asphalt macadam mixture ratio design of HMAC -25 c target results:mineral aggregate ratio for:1# material (16～31.5 mm):2# material (3～316 mm):mechanism sand (0～3 mm), kuangfen=22:46:0:2, and the optimum proportion of 4.5%.Step 3:agent mixed with high modulus method and content of research. Based on the principle of ball mill method is highly efficient dry process in situ dispersion technology of high modulus dose of mixed mixing method, can promote efficient high modulus agent evenly dispersed in the asphalt, so as to greatly improve the performance of modified. Dry process modification process mechanism research of basic test evaluation technology can be used to evaluate high modulus agent under the different dry mixing time of mixing conditions, thereby can pass this kind of evaluation techniques to determine the mixing time of high modulus agent, through the study confirmed that it is advisable to dry mixing time is more than more than 8 seconds. AA highway project, it is concluded that meet the design index of the PRM modulus agent dosage is 0.4 to 0.5%.Step 4:high modulus asphalt concrete engineering application. Combined with Ethiopia AA highway high modulus at the grass-roots level relying on engineering construction process, with higher modulus of agent, the strength of the asphalt mixture, dynamic stability and resistance to water damage indicators are greatly increased, that high modulus rutting resistance and water stability of asphalt mixture, verified the large indoor research conclusion; With higher modulus dose of dry construction technology is simple, easy to operate, can direct artificial added already, also can be mechanical, can fully use the existing equipment construction; Temperature control of high modulus asphalt mixture and common asphalt mixture are obviously different; High modulus asphalt mixture of mixing temperature higher than the ordinary road asphalt 10～20℃, the specific need according to matrix asphalt type, high modulus agent content, mixing equipment status, and so on and so forth comprehensive determine; High modulus asphalt mixture paving, rolling temperature according to the mixing temperature and appropriate control limit increases. High modulus of asphalt mixture transportation, paving and compaction technology compared with ordinary asphalt mixture has no special requirements.