Study On Frost Resistance Performance Of Semi-rigid Base Material And Construction Control

In the low temperature and humid environment of seasonal frozen region of northern China,freezing-thawing damage is the most common disease of semi-rigid base. Especially withincreasing of traffic in recent years and frequent extreme climatic changes, semi-rigid basechallenges freezing-thawing damage，which need be resolved urgently. This paper carries outresearch on frost resistance performance and construction control of semi-rigid base, to reducethe damage of asphalt pavement in seasonal frozen area,to improve service performance anddurability of the asphalt pavement, and to reduce the maintenance costs of maintenance.In view of freezing-thawing damage, indoor test methods and control methods arestudied to establish unified evaluation methods of freezing-thawing of semi-rigid base.Combined with construction, through control of mixture ratio, segregation and interlayerbinding mode, the thesis summarized the key construction techniques of freezing-thawingresistance of semi-rigid base to strengthen the construction quality control.Based on plenty of tests and comparative analysis, the paper presents semi-rigid baseindoor freezing-thawing cycle test methods and test conditions to evaluate the stability offreezing-thawing resistance performance of semi-rigid base material. The paper proposedreasonable strength standard, which is for semi-rigid base in intermediate and severe-frozenarea, residual compressive strength of the five freezing-thawing cycles by28-day age shouldnot be less than50%and ten freezing-thawing cycles by180-day age should not be less than70%, but for semi-rigid base in light frozen area, residual compressive strength of the fivefreezing-thawing cycles by28-day age should not be less than40%and ten freezing-thawingcycles by180-day age should not be less than65%. Semi-rigid base should be as early aspossible formed which would be best to be completed in45days before the arrival of theautumn of the first frost, the anti-frozen compressive strength should be3.5~4.0MPa at least.The paper presents the anti-frozen construction measures of semi-rigid base as well.