UHPC-沥青薄面层环氧界面剂黏结性能试验

Experimental on bonding performances of UHPC-thin asphalt layer with epoxy adhesive agents for ultra-high performance composite bridge deck

为确保超高性能混凝土(UHPC)-沥青薄面层之间黏结牢固,避免产生开裂、拥包、滑移、掀起等早期破坏,并以降低施工成本为重要目标,开展环氧界面黏结剂技术性能研究。超高性能轻型组合桥面体系由钢面板-(35~50 mm)UHPC-沥青薄面层组成。选择进口环氧界面剂202及中国产环氧界面剂2766开展室内试验,对比分析两者的界面力学性能及耐久性。通过常温、高温条件下UHPC-SMA复合试件层间斜剪试验、拉伸试验和界面附着力拉拔试验,探讨环氧界面剂202及2766层间黏结性能;经过多次冻融循环和氯盐高温环境模拟,掌握环氧界面剂在受到水损害和氯盐侵蚀后力学性能的劣化规律。试验结果表明:环氧界面剂2766和202具有很高的黏结强度;常温下,环氧界面剂2766与202抗剪强度相当,拉拔强度前者低于后者18%;高温下,环氧界面剂2766与202黏结性能下降,但仍明显优于沥青类黏结层材料,与环氧界面剂202相比,界面剂2766的抗剪强度和拉拔强度分别提高131%、109%,其高温稳定性更好;在浸水损害和氯盐侵蚀不利自然环境下,环氧界面剂2766和界面剂202劣化规律相似,但劣化程度存在差异;环氧界面剂2766的耐久性能明显优于界面剂202;冻融循环的影响大于氯盐高温循环。中国产环氧界面剂2766的综合单价比进口环氧界面剂202低约40%,且材料来源广泛,施工工艺简单,用量控制准确,可以替代进口产品。

In order to ensure strong bonding between ultra-high performance concrete(UHPC)and thin surface layers,and prevent early damage such as cracking,upheaval,slipping,thin surface layer lifting,etc.,the performances of epoxy interface adhesives were investigated to reduce construction costs.The ultra-high performance lightweight composite bridge deck system consisted of a steel plate(35 to 50 mm)UHPC and thin asphalt surface layer.The epoxy adhesion agents 202 imported and domestic 2766 were selected to carry out laboratory tests,and their interfacial mechanical properties and aging resistance were compared.Under normal temperature and high-temperature conditions,the interlaminar oblique shear test,tensile test,and interfacial adhesion pull test were conducted on UHPC-SMA composite specimens to investigate the bonding performances both 202 and 2766.The deterioration of mechanical properties of epoxy interfacial agents were summarized after repeated freeze-thaw cycles at high temperature with saline water,which simulated water damage and chlorine salt erosion.The results show that adhesion agents 2766 and 202 have high bonding strength.At normal temperature,the shear strengths of 2766 and 202 are almost the same,however,the drawing strength of 2766 is 18%lower than that of 202.At high temperature,the bonding performances of 2766 and 202 decreased,but are still better than those of asphalt adhesive materials.The shear strength and drawing strength of 2766 are 131%and 109%higher than that of 202,respectively,and it also has better high-temperature stability.In the unfavorable natural environments of water immersion damage and chloride erosion,the degradation laws of 2766 and 202 are similar,but the degrees of deterioration are different.The aging resistance of 2766 is better than that of 202.The effect of the freeze-thaw cycle is greater than that of the high-temperature cycle of chloride salt on both 2766 and 202.Therefore,the local epoxy adhesion agent 2766 can replace imported products because its comprehensive unit price is approximately 40%lower than that of 202,it is widely available,the construction/application process is simple,and the dosage control is accurate.10 tabs,8 figs,21 refs.