基于MTS的桥面铺装防水粘结层抗剪性能研究

Study on the Shear Performance of Waterproof-bonding Layer Based on the Material Testing System

针对桥面铺装防水粘结层容易出现推移、开裂、脱离等病害的情况,选择武汉四环线工程项目为依托,设计了基于MTS(material testing system)试验系统的直剪试验夹具,制备ES-2稀浆封层和AC-5沥青砂复合试件,对其抗剪切性能进行评价.结果表明,温度对于桥面防水粘结层材料的抗剪强度影响很大,材料的抗剪性能会随着温度升高而急剧降低;AC-5沥青砂较ES-2稀浆封层抗剪强度较大,粘结效果更好;在实际工程中,水泥混凝土桥面板的失养层必须清洁干净,露出质地坚硬且洁净的界面,以避免失养层处发生剪切破坏.

For the fact that the bridge waterproof-bonding layer usually displays certain damages, such as traction and crack, this research designs a direct shear test fixture that is suitable for MTS. Com- posite specimens with ES-2 slurry or AC-5 asphalt mixture are fabricated. Shear strength is measured by direct shear test to evaluate the shear property of waterproof bonding layer. The test results indi- cate that 1） the temperature for bridge water-bonding layer has great influence on the shear strength of materials, as the temperature rises, the shear performance of materials will he reduced sharply; 2） the shear strength of AC-5 is higher than that of ES-2; 3） the laitance on bridge deck must be clear and hard, and the clean interface must be exposed to avoid shear failure from laitance.