低温压实对沥青混合料路用性能的影响

Influence of Compaction in Low Temperature on Asphalt Mixture Performance

利用现场实测结果,确定了低温成型的温度范围。通过对AC-13改性沥青混合料在不同压实温度下的密实性、强度特性、水稳定性、高温稳定性及低温抗裂性等指标的室内试验,研究了低温压实对沥青混合料路用性能的影响。结果表明:(1)随着压实温度的降低,沥青混合料的各种性能指标不断变差,其空隙率、压实度、稳定度、常温劈裂强度、动稳定度、低温劈裂强度、低温弯拉强度以及线收缩系数等指标与压实温度具有非线性相关性,而残留稳定度、冻融劈裂残留强度比及低温弯拉应变等指标具有线性相关性;(2)存在一个低温压实临界温度,当压实温度低于此值后,沥青混合料的路用性能显著下降。而当路面施工受条件限制处于冬季低温环境时,可采用此低温临界温度来控制现场压实。

Based on in-site survey, the scope of low temperature in construction was investigated.According to indoor experiments of modified AC-13 under different compaction temperatures, the influences of compaction in different low temperatures on asphalt mixture performance were analyzed, including compaction property, intensity property, water stability, high temperature stability, and low temperature anti-crack ability. It is concluded that： （1） All kinds of asphalt mixture performances deteriorate with the falling of compaction temperature, and the correlation of parameters about W, K, MS, RT at normal or low temperature, DS, RB at low temperature, and C with compaction temperature are nonlinear. However, the indexes about MS0, TSR and εB at low temperature show linear relation. （2） There is a critical low-temperature which can ensure the compaction quality, and when the compaction temperature is lower than this value, the asphalt mixture performances will be descended remarkably. Therefore, if the asphalt pavement is constructed in low temperature, this critical temperature could be applied to control the quality of compaction.