水泥沥青砂浆在室外自然条件下的强度经时损失

Gradual loss of compressive strength of cement asphalt mortar in natural outdoor conditions

为考察室外自然条件对水泥沥青砂浆(CA砂浆)强度发展的影响,将在室内条件下养护28d或56d的CA砂浆试件置于北京地区室外环境中2a,测量了CA砂浆在自然环境中的强度变化。实验结果表明:CA砂浆在室外自然环境中长期放置,其抗压强度降低较小,抗折强度显著降低。水灰质量比一定时,沥青与水泥的比例越大,CA砂浆的强度经时损失越大。沥青与水泥的比例一定时,水灰质量比越大,CA砂浆的强度经时损失越大。通过延长CA砂浆早期养护时间,可以减小强度经时损失;沥青与水泥的比例较大的CA砂浆的改善效果更为明显。

The strength of cement asphalt （CA） mortar cured under standard curing conditions was measured before and after deterioration under natural outdoor conditions to study the influence of the outdoor conditions on the development of the CA mortar strength. The results show that the compressive strength of CA mortar cured under standard curing conditions for 28 days or 56 days declines little after 2 years of exposure under natural conditions, but the bending strength declines significantly. The gradual loss in strength of CA mortar increases with increasing asphalt to cement ratio when the water to cement ratio is constant. The gradual loss in strength of the CA mortar also increases with the water to cement ratio when the asphalt to cement ratio is constant. The gradual strength loss of the cement asphalt mortar especially with higher asphalt content can be reduced by lengthening the curing time under standard curing conditions.