低剂量水泥稳定碎石基层干缩温缩性能研究

针对目前半刚性基层易出现温缩与干缩裂缝这一难题,试图从降低水泥剂量的角度来减少裂缝的产生。将低剂量水稳碎石做成梁式试件,并在两侧粘以电阻应变片,通过温度变化和含水量变化试验,测得了水泥剂量为2%、3%和4%的梁式试件的温度收缩系数和干缩系数。结果表明,不同龄期的干缩试验均呈现明显规律性,即随着水泥剂量的增大,干缩系数增大。在水泥剂量低于3%的情况下,28 d干缩系数对水泥剂量的变化较为敏感。7 d与28 d龄期随着水泥剂量增大平均温缩系数增大,高温下的平均温缩系数要明显大于常温和低温的。

Analysis on Shrinkage and Temperature Contraction Character for Low Dosage Cement Stabilized Aggregate

Aiming at the involved crack problem of semi-rigid base,decreasing the crack by reducing the content of cement in aggregate is tried.Beam samples are produced by low dosage cement stabilized aggregate and electric resistance strain gage is glued at its both sides.Shrinkage coefficient and temperature contraction coefficient of 2%,3% and 4% cement content stabilized aggregate are got by changing temperature and water content.The evident rule is shown in shrinkage test of different curing age that shrinkage coefficient raise with the increasing of cement content.When the cement content is under 3%,the shrinkage coefficient of twenty-eight days is sensitive to cement content.Temperature contraction coefficient of both seven and twenty-eight curing ages raise with the increasing of cement content and temperature contraction coefficient of 7 d and 28 d ages in high temperature is remarkably bigger than that in common and low temperature.