高温后植筋胶黏结力学性能试验研究

Experimental Study of Bond Strength of Anchorage Adhesive After Heating

摘要:

为了测试工程中植筋胶在高温后的安全性能, 对3种常用植筋胶分别在25,60,100,160和260 °C恒温加载自然冷却后的黏结力学性能开展试验研究.首先，测试了这3种植筋胶的玻璃转化温度.其次，通过拉伸试验，得出了恒温加载、自然冷却后试件受力与滑移曲线关系，极限黏结承载力和其随温度的损失规律.对试验数据拟合，得出受力与滑移三阶段和四阶段数学模型.研究表明，温度会造成植筋试件力学性能的退化，热塑性植筋胶比热固性植筋胶刚性和耐热性均较差.玻璃转化温度是植筋胶高温后承载力的突变点，是植筋胶正常使用的温度上限并影响着它的高温后使用性能.

关键词:植筋胶; 高温后; 黏结强度; 残余承载力

Abstract:

To satisfy the safety properties of the organic anchorage adhesive used in engineering field after heating from elevated temperatures, a series of pullout tests for three anchorage adhesives were conducted after heating at temperatures of 25, 60, 100, 160 and 260 °C. The glass transition temperatures of three adhesives were tested. The heating process was found to follow a fixed curve. Three commonly used anchorage adhesives were adopted. The forceslip relationships of the adhesives after heating, the ultimate strengths and their change regulation with the temperature were obtained. A threestage or fourstage model for the forceslip relationship was obtained by curvefitting. The results show that the bond strength of anchorage adhesive is strongly dependent on temperature, and the rigid and heat tolerance of thermoplastic adhesive is weak than thermosetting adhesive. The results also show that glass transition temperature is the turning point for behaviors of adhesive after heating, which can be used to determine the upper limit temperature for continuous application.

Key words:anchorage adhesive; after heating; bond strength; residual bearing capacity