防裂剂对混凝土综合抗裂性能的影响  

Influence of anti-cracking agents on concrete complex crack resistance

作　　者：张丰[1,2] 白银 陈波[1,2] 宁逢伟 吕乐乐[1,2] 胡海明 ZHANG Feng;BAI Yin;CHEN Bo;NING Fengwei;LYU Lele;HU Haiming(Nanjing Hydraulic Research Institute,Nanjing 210029,Jiangsu,China;State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering,Nanjing 210024,Jiangsu,China)

机构地区：[1]南京水利科学研究院,江苏南京210029 [2]水文水资源与水利工程科学国家重点实验室,江苏南京210024

出　　处：《水利水电技术（中英文）》2022年第2期154-162,共9页Water Resources and Hydropower Engineering

基　　金：国家重点研发计划项目(2018YFC0406702);国家自然科学基金项目(51739008);中央级公益性科研院所基本科研业务费专项(Y419004)。

摘　　要：为探究防裂剂对混凝土综合性能的影响,研究掺不等量防裂剂条件下混凝土的工作性、力学性能,并且采用平板开裂、温度-应力试验方法分析防裂剂对混凝土抗裂性能的影响。结果表明:防裂剂对新拌混凝土工作性影响不大,但可改善混凝土力学性能和抗冻性能,掺8%防裂剂,混凝土7 d、28 d、60 d抗压强度较基准混凝土分别提高16.0%、17.3%和9.2%。防裂剂的掺入可增大混凝土极限拉伸值4.4%~15.6%,降低混凝土干缩20%~30%,同时可使平板混凝土裂缝数量明显减少,单位面积总开裂面积减小72.4%~83.3%。与基准混凝土相比,掺防裂剂混凝土压应力增大,第二零应力出现时间延后,开裂温降提高5~15℃,抗裂性得到显著改善。In order to explore the influence of anti-cracking agents on the comprehensive performance of concrete, we make the study on the workability and mechanical properties of concrete with unequal amount of anti-cracking agent, and analyze its influence on the anti-crack performance of concrete by plate cracking and thermal stress test methods. The results show that the anti-cracking agent has little effect on the workability of fresh concrete, but can improve the mechanical properties and frost resistance of hardened concrete. The 7 d, 28 d and 60 d compressive strengths of the concretes mixed with 8% anti-cracking agent can be increased by 16.0%, 17.3% and 9.2% respectively. The addition of anti-cracking agents can increase the ultimate tensile value of concrete by 4.4%~15.6%, and reduce the dry shrinkage of concrete by 20%~30%. At the same time, it can reduce the number of cracks in slab concrete obviously, and decrease the total cracking area per unit area by 72.4%~83.3%. Compared with the reference concrete, the concrete mixed with anti-cracking agents has greater compressive stress, the occurrence time of the second zero-stress is delayed, and the cracking temperature drop increases by 5~15 ℃, so the crack resistance of concrete has been improved significantly.

关 键 词：防裂剂 混凝土 综合抗裂性 温度-应力试验 收缩 

分 类 号：TV42[水利工程—水工结构工程]