养护温度对UHPC力学性能的影响

侯庆刚¹，乔大玮¹，胡凤娇¹，蒋雪妮²，张爱勤²，王日升²

1.威海市公路勘察设计院有限公司，山东 威海  264200；2.山东交通学院交通土建工程学院，山东 济南  250357

摘要：为分析标准养护（20 ℃）、高温养护（70 ℃）对超高性能混凝土(ultra-high performance concrete，UHPC)力学性能的影响规律，在不同养护方式与养护龄期（3、7、28 d）下对不同配合比制备的UHPC进行抗压、抗折、抗拉及弹性模量试验，测试UHPC的力学性能。结果表明：高温养护能有效改善UHPC的力学性能，抗压强度增长均匀，抗折强度增幅显著，养护7 d时UHPC的抗压、抗折强度的增幅均最大，养护28 d时UHPC的抗压与抗折强度增大缓慢；UHPC抗拉强度及弹性模量的增大规律基本一致，养护7 d时达到最大抗拉强度与弹性模量，养护28 d时，抗拉强度与弹性模量不再增大或略有下降。选择在（70±2）℃进行高温养护，养护龄期为7 d。

关键词：UHPC；标准养护；高温养护；强度；弹性模量

The influence of maintenance temperature on the mechanical properties of UHPC

HOU Qinggang¹, QIAO Dawei¹, HU Fengjiao¹, JIANG Xueni²，ZHANG Aiqin², WANG Risheng²

1. Weihai Highway Survey and Design Institute Co., Ltd., Weihai 264200, China;

2. School of Civil Engineering, Shandong Jiaotong University, Jinan 250357, China

Abstract: To analyze the influence of standard maintenance (20 ℃) and high-temperature maintenance (70 ℃) on the mechanical properties of ultra-high performance concrete (UHPC), compressive tests, rupture tests, tensile strength tests, and elastic modulus tests are conducted on UHPC samples with different mix proportions under different maintenance methods and maintenance ages (3, 7, 28 days). The results indicate that high-temperature maintenance effectively improves the mechanical properties of UHPC. The increase in compressive strength is uniform, with a significant increase in rupture strength. The greatest increase in compressive and rupture strength of UHPC is observed at 7 days of maintenance, while the increase of that is slower at 28 days. The trends for the increase in tensile strength and elastic modulus of UHPC are consistent, reaching their peak at 7 days of maintenance, and stabilizing or slightly decreasing at 28 days of maintenance. The maintenance temperature is (70±2) ℃, with a maintenance age of 7 days.

Keywords: UHPC; standard maintenance; high temperature maintenance; strength; elastic modulus